Rfidenabled Sensor Design And Applications Amin Rida Li Yang

Rfidenabled Sensor Design And Applications Amin
Rida Li Yang download
https://ebookbell.com/product/rfidenabled-sensor-design-and-
applications-amin-rida-li-yang-1566022
Explore and download more ebooks at ebookbell.com

Here are some recommended products that we believe you will be
interested in. You can click the link to download.
Design And Development Of Rfid And Rfidenabled Sensors On Flexible Low
Cost Substrates Amin Rida
https://ebookbell.com/product/design-and-development-of-rfid-and-
rfidenabled-sensors-on-flexible-low-cost-substrates-amin-rida-2121408
Design And Construction Of An Rfidenabled Infrastructure The Next
Avatar Of The Internet 1st Edition Nagabhushana Prabhu
https://ebookbell.com/product/design-and-construction-of-an-
rfidenabled-infrastructure-the-next-avatar-of-the-internet-1st-
edition-nagabhushana-prabhu-4747672
Rfid Protocol Design Optimization And Security For The Internet Of
Things 1st Alex X Liu Muhammad Shahzad Keqiu Li
https://ebookbell.com/product/rfid-protocol-design-optimization-and-
security-for-the-internet-of-things-1st-alex-x-liu-muhammad-shahzad-
keqiu-li-47515524
Rfid In Manufacturing 2008th Edition Oliver P Gnther Wolfhard Kletti
https://ebookbell.com/product/rfid-in-manufacturing-2008th-edition-
oliver-p-gnther-wolfhard-kletti-57592942

Rfid In Logistics A Practical Introduction Erick C Jones Christopher A
Chung
https://ebookbell.com/product/rfid-in-logistics-a-practical-
introduction-erick-c-jones-christopher-a-chung-2001808
Rfid Technology And Applications 1st Edition Stephen B Miles
https://ebookbell.com/product/rfid-technology-and-applications-1st-
edition-stephen-b-miles-2013766
Rfid Security And Privacy Concepts Protocols And Architectures Lecture
Notes Electrical Engineering 1st Edition Dirk Henrici
https://ebookbell.com/product/rfid-security-and-privacy-concepts-
protocols-and-architectures-lecture-notes-electrical-engineering-1st-
edition-dirk-henrici-2169334
Rfid Applications Security And Privacy Rosenberg Beth Garfinkel
https://ebookbell.com/product/rfid-applications-security-and-privacy-
rosenberg-beth-garfinkel-22041746
Rfid Design Fundamentals And Applications 1st Edition Albert
Lozanonieto
https://ebookbell.com/product/rfid-design-fundamentals-and-
applications-1st-edition-albert-lozanonieto-2326352

Library of Congress Cataloging-in-Publication Data
A catalog record for this book is available from the U.S. Library of Congress.
British Library Cataloguing in Publication Data
A catalogue record for this book is available from the British Library.
Cover design by Vicki Kane
ISBN 13: 978-1-60783-981-1
© 2010 ARTECH HOUSE
685 Canton Street
Norwood, MA 02062
All rights reserved. Printed and bound in the United States of America. No part of this book
may be reproduced or utilized in any form or by any means, electronic or mechanical, in-
cluding photocopying, recording, or by any information storage and retrieval system, with-
out permission in writing from the publisher.
All terms mentioned in this book that are known to be trademarks or service marks have
been appropriately capitalized. Artech House cannot attest to the accuracy of this informa-
tion. Use of a term in this book should not be regarded as affecting the validity of any trade-
mark or service mark.
10 9 8 7 6 5 4 3 2 1

Contents
Preface xi
1 Automatic Identification Systems 13
1.1 Barcode Systems 15
1.2 Magnetic Stripe Card 16
1.3 Smart Cards 17
1.4 RFID Systems 18
1.4.1 Definition 18
1.4.2 History of RFID 19
1.4.3 Beyond RFID: RFID-Enabled Sensors 23
References 24
2 Fundamentals and Operating Principles for RFID 27
2.1 RFID Tag Components 27
2.1.1 Tag Antenna 28
2.1.2 Integrated Circuits 30
2.1.3 Substrate 30
2.2 RFID Tag Types 31
2.2.1 Passive Tags 31
2.2.2 Active Tags 33
vii

2.2.3 The 1-Bit Transponder and Chipless Tags 34
2.3 RFID Readers and Middleware Component 34
2.3.1 RFID Readers 34
2.3.2 RFID Middleware 35
2.4 Communication Fundamentals in RFID Systems 36
2.4.1 Coupling Mechanisms 36
2.4.2 Data Encoding 37
2.4.3 Multipath Effect 39
2.5 Tag, Reader, and Sensor Communication 41
2.5.1 Passive Systems 43
2.5.2 Active Systems, UWB, Zigbee, and Wi-Fi Tags 44
2.6 Licenses and Standards for Global Operation 45
References 47
3 Fundamentals and Operating Principles of Sensors 49
3.1 Types of Sensors 49
3.1.1 Use of Sensors 49
3.1.2 Types of Sensors 51
3.2 Basic Considerations of Sensor Design 53
3.2.1 What to Measure 53
3.2.2 Requirements for Accuracy 53
3.2.3 Requirements for Resolution 54
3.2.4 Environment of the Sensor 54
3.2.5 Calibration 54
3.3 Wireless Sensors and Wireless Sensor Networks 55
References 58
4 Design of RFID-Enabled Sensors 59
4.1 RFID Antenna Design Challenges 59
4.1.1 Antenna Basics and the Dipole 60
4.1.2 Passive RFID Antennas Using Serial Stubs 64
4.1.3 Bowtie T-Match RFID Antenna 75
4.1.4 Passive RFID Antenna Using Inductively Coupled
Feed Structure 81
4.1.5 Active RFID Monopole Antenna Design 85
4.2 Integrated Circuit Design 95
4.2.1 Voltage Multiplier for RFID Integrated Circuits 95
viii RFID-Enabled Sensor Design and Applications

4.2.2 Microcontroller for Active RFID-Enabled Sensor 98
4.3 Characterization and Development of Printed
Circuit Boards or Substrates 105
4.4 Integration and Packaging: Integration of Sensors and
RFID: Design Examples 119
4.4.1 Single-Layer, Dipole-Based Sensor Wireless Module 120
4.4.2 Double-Layer Monopole-Based Sensor Wireless
Module 122
4.4.3 Fabrication/Assembly of the Dipole- and
Monopole-Based Wireless Sensor Modules 125
4.5 Power Consumption and Link Budget 137
References 141
5 State-of-the-Art Technology for RFID/Sensors 145
5.1 Inkjet-Printed Technology 145
5.2 Flexible Low-Cost Substrate 149
5.2.1 Paper as the Ultimate Solution for a Low-Cost
Environmentally Friendly RF Substrate 150
5.2.2 Liquid Crystal Polymer: Properties and Benefits for
RF Applications 152
5.2.3 Dielectric Characterization of the Paper Substrate 153
5.2.4 Cavity Resonator Method 157
5.3 Maintenance-Free RFID-Enabled Sensors 160
5.4 Power Scavenging: Wearable Battery-Free Active
RFID Tag with Energy Scavenger 169
5.4.1 Energy-Harvesting Unit 171
5.4.2 Shoe-Mounted Antenna Design 173
5.4.3 Circuit Implementation 178
References 184
6 Worldwide Applications 189
6.1 Logistics/Supply Chain 190
6.2 Automotive 194
6.3 Healthcare Monitoring 194
6.4 Space and Navigation Systems 199
References 200
Contents ix

About the Authors 201
Index 203
x RFID-Enabled Sensor Design and Applications

Preface
Radio frequency identification (RFID) is gaining in popularity, especially
as we find ourselves in this communications age and headed towards a
ubiquitous computing world. Automatic identification systems become
an important aspect not just in today’s technology but also as part of our
daily life. We need RFID in our cars, transportation systems, access
points, and even simple transactions; we also acknowledge the need for
RFID in our logistics systems, healthcare, and tracking and locating
applications.
RFID has witnessed many technological improvements since it was
first discovered in the 1970s and 1980s and that is due to advancements
in integrated circuits and radios. Up-to-date automatic identification has
been included in many new applications and is improving the way many
processes run.
This book introduces the underlying principles of RFID systems
and goes way beyond a world of omnipresence intelligence. RFID-
Enabled Sensor Design and Applications is intended for a wide range of
readers starting from students, engineers, and researchers who would like
to learn not just about RFID systems but also about RFID potentials.
Several novel concepts are introduced and implemented throughout
the book, presenting directions toward the realization of low-cost and
environmentally friendly mass production of RFID and RFID-enalbed
sensors. Several design examples are given, backed up by detailed results
and explanations.
xi

Chapter 1 introduces various automatic identification systems and
focuses on RFID, introducing RFID’s potential in the wireless identifica-
tion world. Chapter 2 details the fundamentals and operating principles
of RFID systems, covering the different types of RFID tags and readers,
communications among the systems components, and standards used.
Chapter 3 introduces fundamentals and operating principles of sensors
and wireless sensor networks. Chapter 4 provides the design principles for
RFID tags and RFID-enabled sensors; it provides guidelines backed up
by examples on designing RFID tags for passive and active systems, inte-
grating with sensors, and other tag components while addressing the
issues of packaging and power links. Chapter 5 talks about the state of the
art fabrication techniques for low cost environmentally friendly
RFID/sensors. Novel fabrication techniques such as conductive inkjet
printing are introduced and tested on paper-based and other organic high
frequency substrates. Chapter 5 also gives guidelines for designing a
“maintenance free” wearable RFID tag by using a mechanical energy
scavenger. Chapter 6 concludes with a discussion on worldwide
applications to the RFID-enabled sensors.
The authors wish to acknowledge the help and support of the mem-
bers of the Georgia Electronic Design Center at the Georgia Institute of
Technology; especially present and past members of the ATHENA
Research Group.
xii RFID-Enabled Sensor Design and Applications

1
Automatic Identification Systems
Identification plays a major function in our lives, the operations that we
run, and even businesses. Identification and/or authentication is essential
in most, if not all, of the objects, people, or procedures that we deal with
on a daily basis. Examples include: barcode technology for identifying
groceries, vehicle identification numbers (VIN) for recognizing vehicles,
magnetic stripe cards used for payment methods (like credit cards),
biometrics procedures for identifying humans, and holography tech-
niques used for the authentication of stamps and/or money. There are
several other techniques that are used for identification/authentication
such as: access cards, proximity cards, contactless smart cards, and radio
frequency identification (RFID), which takes on several forms and may
be used in any other identification or authentication wireless methods
mentioned [1].
Moreover, automatic identification known as Auto-ID has seen
tremendous demand, especially in our current communication age as we
have witnessed a large transition in technological fields towards wireless.
Immediate identification of people, animals, goods, and products
becomes essential. Several huge industries are requiring an increased uti-
lization of Auto-ID systems. A listing of such industries is but not
restricted to: logistics, supply chain, transportation, manufacturing,
warehousing systems, health care, security, space, and navigation [2].
Figure 1.1 shows various scenarios that incorporate the use of automatic
identification.
13

This chapter introduces the major identification/authentication
techniques and briefly describes their method of operation. These
include: barcodes, magnetic stripe cards, holography, biometrics, and
more complex electric systems like the smart card or contactless smart
card, memory card, proximity card, access badge, and finally RFID tech-
nology. RFID is first introduced, then its principles of operation are
defined, and capabilities such as added functionalities are mentioned.
Figure 1.2 compares the most employed Auto-ID methods in terms of
technological gaps and capabilities. Certain methods such as biometrics
were omitted since they only apply to identifying personnel and do not fit
under the general low cost identification techniques.
14 RFID-Enabled Sensor Design and Applications
Figure 1.1 Identification—various scenarios.

1.1 Barcode Systems
Barcodes found their first successful commercial application in auto-
mated supermarket checkout systems in 1974 and since then have
become widespread, simple, and cost effective, but have limited identifi-
cation capabilities. Nowadays it is common for certain smart phones to
have barcode reading software, a feature that can link the barcode
scanned to the Web for product verification and/or shopping
comparisons.
A barcode is an optical representation of data that uses a sequence of
a predetermined pattern of parallel bars and gaps varying in widths and
gap size. Upon reading the barcode by an optical scanner or the barcode
reader, the sequence can be interpreted numerically and alpha-
numerically. Several different types of one-dimensional (1-D) and
two-dimensional (2-D) barcodes exist. While 1-D barcodes or linear
barcodes use bars and gaps to represent data, 2-D barcodes use geometri-
cal patterns within images such as patterns of dots or squares and are also
used frequently. The dotted region of Figure 1.3 shows a barcode exam-
ple that uses the EAN-13 barcode symbol; one of the most commonly
Automatic Identification Systems 15
Figure 1.2 Comparison of Auto-ID systems.

used barcodes today is known as European Article Number (EAN) code,
which was designed specifically to fulfill the requirements of the grocery
industry in 1976 [3]. It represents a development of the UPC (Universal
Product Code) from the United States, which was introduced as early as
1973. As shown in Figure 1.3, the EAN code is made up of 13 digits,
which can be broken down into four sections: the country identifier (first
2 digits), the company identifier (5 digits), the manufacturer’s item num-
ber (5 digits), and a single check digit. Figure 1.4 shows a photograph of a
2-D barcode (public domain barcode known as PDF417), used for iden-
tifying driver licenses. Since 2-D barcodes or 2-D codes have more data
representation capability, they require special readers and are limited in
use compared with linear barcodes.
1.2 Magnetic Stripe Card
The magnetic stripe card is another method used in identification. It
stores data by altering the magnetism of the iron-based magnetic particles
on a plastic-like film band of magnetic material on the card. The
Figure 1.4 Example of a 2-D barcode.
Figure 1.3 EAN-13 barcode symbol.

magnetic stripe card (also known as magstripe), as shown on the back a
card in Figure 1.5, is in theory very similar to a piece of cassette tape
fastened to a card that can have data written to or read by it. Its operation
requires physical contact by swiping the card past a reading head. In
most cards, the magnetic stripe contains three tracks which are typically
recorded at 210 bits per inch (8.27 bits per mm) or 75 bits per inch (2.95
bits per mm), which may contain diverse data such as personal informa-
tion, an identification number, an expiration date, and other information
depending on the nature of the application [4]. This technique is com-
monly used in credit cards, identity cards, transportation tickets, elec-
tronic benefit transfer cards (such as food stamps), gift cards, and so
fourth. Certain magnetic stripe cards like credit cards may contain an
RFID tag as well for electronic payments.
1.3 Smart Cards
There are two types of smart cards: contact smart cards and contactless
smart cards. Defined as an electronic data storage system, the smart card
embeds an integrated circuit, which has the capability of processing data.
The contact smart card is battery-less and is powered by the reader, which
requires mechanical contact with the smart card for its transaction. The
smart card became widely used through mobile phone usage in 1990s.
The dimensions of contact smart cards are usually credit card size
(85.60 mm × 53.98 mm). Ones used in SIM cards (25 mm × 15 mm)
have a thickness of 0.76 mm [5]. A photograph of a SIM card is shown in
Figure 1.5 An example of a magnetic stripe card found on the back of a college identity
card.

Figure 1.6. The several pads shown on the SIM card are used for func-
tions like: clocking, ground, power supply, I/O, and reset. Two types of
contact smart cards exist: memory cards and microprocessor cards. Mem-
ory cards are characterized by nonvolatile memory electronically erasable
programmable read only memory (EEPROM), which is accessed through
sequential logic states. Microprocessor cards are characterized by volatile
memory ROM, RAM, and EEPROM segments and contain micropro-
cessor components.
In contactless smart cards, the chip communicates with the reader
using a built in inductor that captures the incident radio frequency inter-
rogator signal from the reader. These readers are normally installed in
places where a fast or hands-free transaction is desired, such as convenient
stores and public transport networks. A universal contactless smart card
reader symbol has been established and is shown in Figure 1.7. Examples
of commonly used contactless smart cards are: South Korea’s T-money
(transportation fares, convenient stores), Mumbai bus transportation ser-
vice, Japan Rail’s Suica Card, and London’s Oyster Card. RFID is a
related technology to that of the contactless smart card. Ampleness of
information on RFID is given in the next section.
1.4 RFID Systems
1.4.1 Definition
Radio frequency identification (RFID) is an emerging compact wireless
technology for the identification of objects, and is considered an eminent
Figure 1.6 Photograph of one of the many SIM card pad layouts found on a contact
smart card.

candidate for the realization of completely ubiquitous ad hoc wireless net-
works. RFID utilizes electromagnetic waves for transmitting and receiv-
ing information stored in a tag or transponder to/from a reader. This
technology has several benefits over the conventional ways of identifica-
tion, such as higher read range, faster data transfer, the ability of RFID
tags to be embedded within objects, no requirement of line of sight, and
the ability to read a massive amount of tags simultaneously. A listing of
applications that currently use RFID are: transportation and logistics,
product tracking and inventory systems, access control, library book
tracking and management, passports, parcel and document tracking,
automatic payment solutions, asset tracking, real time location systems
(RTLS), automatic vehicle identification, and livestock or pet tracking.
RFID’s underlying technical procedure has been adopted from radar
engineering.
1.4.2 History of RFID
RFID is a rapidly developing automatic wireless data-collection technol-
ogy with a long history [6]. The first multibit functional passive RFID
systems, with a range of several meters, appeared in the early 1970s [7]
and continued to evolve through the 1980s [8]. Recently, RFID has expe-
rienced a tremendous growth due to developments in integrated circuits,
radios, and an increased interest from the retail industry and government
Figure 1.7 Universal contactless smart card symbol.

was then discovered that by flying the airplanes in a certain known (to the
ground radar crew) pattern when returning to base can change the radio
signal reflected back, and thus alert the ground radar crew of an
approaching friendly airplane. Such a crude method made it possible to
identify one’s own planes. During that time, the first active iden-
tify-friend-or-foe (IFF) system was developed by placing a transmitter on
each airplane. This allowed the transmission of signals from the aircraft to
be identified as being from a “friend” [12].
An early exploration of RFID technology occurred in October 1948
by Harry Stockman. He stated that [12], “considerable research and
development work has to be done before the remaining basic problems in
reflected-power communication are solved, and before the field of useful
applications is explored.” However, his vision stalled until other develop-
ments in transistors, integrated circuits, microprocessors, and communi-
cation networks took place [13].
Advances in radar and RF communication systems continued after
World War II through the 1950s and 1960s, as described in Table 1.1. In
the 1960s, application field trials were initiated, followed by the first
commercial product. Companies were investigating solutions for
antitheft, which revolutionized the RFID industry. Antitheft systems
Table 1.1
RFID over the Years
Decade Event
1940s Radar refined and used—major World War II development effort.
RFID invented in 1948.
1950s Early explorations of RFID technology—laboratory experiments.
1960s Development of the theory of RFID.
Start of applications field trials.
1970s Explosion of RFID development.
Tests of RFID accelerate.
Very early adopter implementations of RFID.
1980s Commercial applications of RFID enter mainstream.
1990s Emergence of standards.
RFID widely deployed.
RFID becomes a part of everyday life.

were investigated that utilized RF waves to monitor whether an item was
paid for or not. This was the start of the 1-bit electronic article surveil-
lance (EAS) tags by Sensormatic, Checkpoint, and Knogo. This is by far
the most commonly used RFID application.
The electronic identification of items caught the interest of large
companies as well. In the 1970s, large corporations like Raytheon (which
created RayTag in 1973), RCA, and Fairchild (which created an elec-
tronic identification system in 1975 and electronic license plates for
motor vehicles in 1977) built their own RFID modules. Thomas Meyers
and Ashley Leigh of Fairchild also developed a passive encoding micro-
wave transponder in 1978.
By the 1980s there were mainstream applications all around the
world for RFID. In the United States, RFID technology found its place
in transportation (highway tolls) and personnel access (smart ID cards).
In Europe, RFID was attractive to industrial and business systems; they
used RFID for applications such as short-range animal tracking and stock
keeping. The world’s first commercial application of RFID was collecting
tolls in Norway in 1987 and afterwards on the United States Dallas
North Turnpike in 1989.
In the 1990s, IBM engineers developed and patented an ultra
high frequency (UHF) RFID system. IBM conducted early research with
Wal-Mart, but this technology was never commercialized. UHF offered a
longer read range and faster data transfer compared to the high frequen-
cies (HF) 125 kHz and 13.56 MHz applications. These accomplishments
led the way to the world’s first open highway electronic tolling system in
Oklahoma in 1991. This was followed by the world’s first combined toll
collection and traffic management system in Houston by the Harris
County Toll Road Authority in 1992. In addition to this, GA 400 and
Kansas Turnpike Highways were the first to implement multiprotocol
tags, which allowed two different standards to be read.
After IBM’s early pilot studies in the 1990s with Wal-Mart, UHF
RFID got a boost in 1999 when the Uniform Code Council, European
Article Number International, Procter & Gamble, and Gillette teamed
up to establish the Auto-ID Center at the Massachusetts Institute of
Technology (MIT). This research focused on putting a serial number on
the tag to keep the price down using a microchip and an antenna. By stor-
ing this information in a database, tag tracking was finally realized. This
was a crucial point in terms of business since a stronger communication
link between the manufacturers and the business partners was established.

A business partner would now know when a shipment was leaving the
dock at a manufacturing facility or warehouse, and a retailer could auto-
matically let the manufacturer know when the goods arrived.
The Auto-ID Center also initiated the two air interface protocols
(Class 1 and Class 0), the EPC numbering scheme, and the network
architecture used to look for the RFID tag data between 1999 and 2003.
The Uniform Code Council licensed this technology in 2003 and
EPCglobal was born as a joint venture with European Article Number
International to commercialize EPC technology.
Today some of the biggest retailers in the world such as Albertsons,
Metro, Target, Tesco, Wal-Mart, and the U.S. Department of Defense
stated that they plan to use EPC technology to track their goods.
Healthcare/pharmaceutical, automotive, and other industries are also
pushing toward adaptation of this new technology. EPCglobal adopted a
second-generation (Gen-2 ISO18000-6-C) standard in January 2005.
This standard is widely used in the RFID world today.
For a successful RFID implementation, one has to possess a keen
knowledge of its standards, technology, and how it meets the different
needs of various applications. FedEx CIO Rob Carter quoted Bill Gates’
definition of a “2-10 technology” in an interview when he was asked
about RFID. The 2-10 technology means that for the first two years,
hype reigns, followed by disappointment, until the day 10 years later
when people realize the technology has flourished and become part of
daily life. Carter, who is in charge of tracking and shipping parcels all over
the world, accepts after noticing the challenges and problems FedEx was
experiencing with RFID tags, that “RFID might be a 3-15 technology”
[14]. Apart from higher-level problems in RFID applications, tag
design imposes different lower level challenges to be discussed in later
chapters.
1.4.3 Beyond RFID: RFID-Enabled Sensors
One of the several positive characteristics of RFID technology that makes
it so attractive for identification, “cognitive intelligence,” and wireless
applications is its ability to support additional functionalities. One such
addition to the identifying ability or process is sensing applications. Using
existing protocols defined for RFID technologies, (shown in Chapters 4
and 5) integration of a sensor can be made possible.
Moreover, as the demand for low cost, flexible, and power efficient
broadband wireless electronics increases, materials and integration

techniques become critical and face more challenges. This is witnessed as
a result of the growing demand for “cognitive intelligence” married with
RFID technologies. This results in inexpensive and reliable RFID-
enabled sensors, which are the focus of Chapters 4 and 5, preceded by the
fundamentals and operating principles of RFID and sensors as separate
entities (Chapters 2 and 3).
In order to create a completely ubiquitous network, the cost of the
RFID tags would need to be extremely inexpensive. This is also a crucial
factor for the mass production of RFID tags and/or sensor-enabled RFID
tags. While current fabrication processes use the conventional metal etch-
ing techniques, the theme of this book will be about environmentally
friendly fabrication techniques and materials, namely inkjet printing and
paper-based substrates. This will also allow for the easy disposal of a mas-
sive number (in the billions) of RFID tags.
References
[1] Finkenzeller, K., RFID Handbook, 2nd ed., New York: John Wiley & Sons, 2003.
[2] Banks, J., et al., RFID Applied, New York: John Wiley & Sons, 2007.
[3] Wikipedia, “Barcode,” http://en.wikipedia.org/wiki/Barcode.
[4] Wikipedia, “Magnetic Stripe Cards,” http://en.wikipedia.org/wiki/Mag-
netic_stripe_card.
[5] Wikipedia, “Smart Cards,” http://en.wikipedia.org/wiki/Smart_card.
[6] Landt, J., “The History of RFID,” IEEE Potentials, November 2005, pp. 8–11.
[7] Koelle, A. R., S. W. Depp, and R. W. Freyman, “Short-Range Radio-Telemetry
for Electronic Identification, Using Modulated RF Backscatter,” Proceedings of the
IEEE, August 1975, pp. 1260–1261.
[8] Koelee, A. R., “Short Range UHF Telemetry System Using Passive Transponders
for Vehicle ID and Status Information,” IEEE Workshop on Automotive Applica-
tions of Electronics, October 1988, pp. 34–38.
[9] Want, R., “An Introduction to RFID Technology,” IEEE Pervasive Computing,
January–March 2006, pp. 25–33.
[10] Gartner, Inc. “Worldwide RFID Revenue to Surpass $1.2 Billion in 2008,”
http://www.mb.com.ph/issues/2008/03/05/TECH20080305118642.html.
[11] “The History of RFID Technology,” RFID Journal, 2005,
http://www.rfidjournal.com/article/articleview/1338/1/129.
[12] Stockman, H., “Communication by Means of Reflected Power,” Proceedings of the
IEEE, October 1948, pp. 1196–1204.

[13] Landt, J., “Shrouds of Time—The History of RFID,” AIM Inc., ver. 1.0. Octo-
ber 2001.
[14] Baldwin, H., “How to Handle RFID’s Real-World Challenges,” Microsoft Cor-
poration, 2006, http://www.microsoft.com/midsizebusiness/businessvalue/
rfidchallenges.mspx.

2
Fundamentals and Operating Principles
for RFID
An RFID system consists of RFID tags, an RFID reader, and middleware.
The identification of the RFID tag takes place by the reader over the
wireless medium or air. This chapter introduces RFID tags, their compo-
nents, the different RFID tags used, RFID readers, and middleware,
as well as communication fundamentals for tags, readers, and sensors.
Finally, an introduction to licenses will be given for global operation of
RFID systems.
2.1 RFID Tag Components
While RFID tags come in different shapes, dimensions, and have differ-
ent capabilities, all RFID tags have the following essential components:
• Tag antenna;
• Integrated circuit;
• Substrate.
It is to be noted that active tags, as will be described in Section
2.2.2, contain more than the three essential components listed above.
However, this section adheres to the components of the passive RFID
tags. To illustrate this, Figure 2.1 shows a passive printed RFID tag [1].
27

of the tag. In simpler terms, the real part of the antenna input impedance
must be equal to the real part of the load’s impedance and the imaginary
part of the antenna input impedance must be equal to the opposite of the
imaginary part of the load’s impedance.
2.1.2 Integrated Circuits
The integrated circuit (IC) is the heart of the RFID tag. It is a silicon chip
with dimensions usually less than 1 × 1 mm. The IC chip in an RFID tag
works like a microprocessor, but in a much less sophisticated way. The IC
has a single main purpose—to transmit the tag’s unique identifier. The
unique identifier is stored in the IC’s memory. When the IC is powered
up by the energy flowing from the tag antenna, its logic circuit will
retrieve the identifier number stored in the memory, and will then modu-
late the backscatter signal to broadcast this information out. Depending
on the type and purpose of the tag, the IC tag can have extra memory to
which the user can write extra information onto by using the reader.
2.1.3 Substrate
The substrate is the material that holds the tag together. The substrate
can be rigid or flexible depending on the application, and may be manu-
factured though several different types of materials. For example, certain
automotive applications use RFID-enabled sensor tags embedded inside
the tire of the vehicle in order to monitor the car tire condition. When
the car is running, the interior of the tire heats up to a very high tempera-
ture while already being at high pressure. This harsh environment places
several restrictions on the tag substrate, and the tag has to be placed inside
a protective capsulate to protect the antenna trace and IC chip. In
another example, RFID tags used as a document tracking solution need a
flexible substrate so that RFID tags can bend just as the paper it is
attached to. If possible, an organic substrate such as a paper-based sub-
strate would be an ideal candidate due to its environmental friendliness
and capability of being printed together with the document. In some spe-
cial cases, the space to place RFID tags is very strict, and tag dimensions
become the major concern. Special developed substrates, such as a flexible
magnetic composite substrate, can help with reducing the antenna form
factors around two to three times, while trading off with the total cost of
the tag. Several design examples will be given in Chapters 4 and 5, on

several types of substrates while focusing on the sensing applicability and
state of the art fabrication technologies of these sensor tags.
2.2 RFID Tag Types
There are two general classifications for RFID tags: active and passive.
Passive tags are mostly deployed primarily for their low cost and ease of
implementation due to established standards, which will be described in
Section 2.6. Passive tags find several applications in the fields of:
• Logistics such as in manufacturing, warehousing, and distribu-
tion systems;
• Security in libraries and bookstores, passports, and airports;
• Transportation in automatic vehicle identification, electronic toll
collection, and electronic vehicle registration.
Active tags prove to be extremely flexible in terms of the functional-
ity they can offer. This is due to their onboard battery, which extends
their reading range. There also exist other classifications of RFID tags:
1-bit transponders, chipless RFID tags, and RFID sensor tags as
explained in Section 1.5. However, there is no one clear definition of
these “other” tags category in the literature; instead they are still under
development and are in general nonstandardized. Though this is true,
research finds a plethora of useful scenarios for RFID tags and especially
sensor tags. Imagine for example a low cost passive RFID tag with addi-
tional sensing capability, or a passive RFID tag but with much longer life-
time, or an active tag that can function well beyond identification such
as sensing as described in Section 1.5. In addition to the sensor tags
explained in Section 1.5, the next three sections will define the two main
categories of RFID tags (active and passive) while also introducing an
alternative to the IC-based tags (the 1-bit transponder and chipless
RFID) and giving examples of their applications.
2.2.1 Passive Tags
Passive RFID tags are by far the most deployed due to their low cost,
miniaturized size, low profile, and simple architecture. They do not
include any on-board battery, hence the name passive tags, which leads to
Fundamentals and Operating Principles for RFID 31

a very thin and low-profile RFID tag that can be manufactured by simple
and fast techniques as will be explained in Chapter 5.
Passive tags utilize the backscattering (Section 2.4.1) to power up
their IC (Section 2.1.2). This means that the energy radiated out of the
reader’s antenna (Section 2.3) becomes one of the most important factors
determining their operating range. Unfortunately, due to the complexity
of electromagnetic wave propagation, simple formulas like Friis transmis-
sion is not sufficient to explain the operating range of an RFID commu-
nication link (reader-tag-reader). It is far beyond the scope of this book to
explain the detailed RF propagation of an RFID system, which is a classic
short range communication system, but Friis transmission will be given in
this section as a benchmark:
( )
P
P
G G
d
r
t
t r t r
= − ⋅ ⎛
⎝
⎜ ⎞
⎠
⎟
1
4
2 2
2
ρ ρ ρ
λ
π
$ $ (2.1)
where:
Pr: the received power from the receiver antenna;
Pt: the radiated power from the transmitter antenna;
Gr: the reader antenna gain;
Gt: the tag antenna gain;
ρ: the complex reflection coefficient at the input of the transmit an-
tenna;
$
ρt : polarization unit vector of the transmitter antenna;
$
ρr : polarization unit vector of the receiver antenna;
λ: free space wavelength at the transmission frequency;
d: read range of RFID system (reader-tag distance).
The Friis formula can also be written in a decibel form, as shown in
the equation below:
P P G G L L d
r t t r m p
= + + − − − ⎛
⎝
⎜ ⎞
⎠
⎟ −
20
4
20
10 10
log log ( )
π
λ
(2.2)
The polarization mismatch is given by $ $
ρ ρ
t p
⋅
2
and equals the mis-
match loss Lp in decibels between the polarization of the reader and the
tag. (1 − |ρ|
2
) or Lm represents the mismatch loss between the impedance
of the IC and the antenna of any RFID tag. These terms represent the

propagation or the path loss, which depends on the wavelength (and
hence frequency) of operation and the distance traveled. From (2.2) it can
also be noted that the read range is inversely proportional to the square
root of the received power at the tag coming from the reader.
It is both important and useful to deal with decibels (dB) when talk-
ing about communication systems including RFID. At this point it is also
useful to introduce the term sensitivity of the system, as it is a crucial
parameter of RFID tags and readers. The sensitivity of a communication
electronic device, in our case an RFID tag, defines the minimum magni-
tude of input signal that is required to produce a specific output signal
with a given signal-to-noise ratio. This number is given in dBm (dBm is
dB milliwatt where 0 dBm is equivalent to 1 milliwatt) by the manufac-
turers. In one scenario, consider a signal being emitted by an RFID reader
at a power of 1W, which corresponds to 30 dBm. After a distance d, the
Pr has to exceed a certain threshold to activate the RFID tag; this is com-
monly known as the tag’s sensitivity and is given in dBm as well. Sensitiv-
ity for passive RFID tags (or sensitivity of their ICs) are typically around
negative tens of dBm depending on their design, while sensitivity of
RFID readers could go below negative hundreds of dBm. This is due to
the low profile of the tag’s IC and the complexity of the RFID readers.
This also makes sense since the signal going back to the reader after it had
activated the tag is at much lower power according to (2.2). An additional
note on the passive systems is that the power emitted by the reader’s
antenna has to abide by the regulatory situation (as will be described in
Section 2.6), but it does define the bottleneck of the read range of the
whole system.
2.2.2 Active Tags
An active tag contains an onboard battery or power source, which pro-
vides flexibility towards the read range primarily since the tag’s sensitivity
is no longer restricted and could be much lower since it is powered by a
source. This lifts the constraints on the IC designers that are normally
found in passive systems, and overcomes any objects found in between
the tag reader that tend to impede the read range.
Active tags also are not known to have specific standards as passive
RFID systems; however, this also brings out certain limitations such as
being more application specific due to the absence of standards. These
tags also cost much more that passive tags (factors of 10+) and are

physically larger due to their design complexity and on-board battery and
are normally packaged which in turn adds to the cost of the system.
2.2.3 The 1-Bit Transponder and Chipless Tags
There are additionally other class of RFIDs such as 1-bit transponders
and chipless RFID tags. These are tags that do not include an IC. The
data carriers in these RFID tag types depend on physical effects and not
on any IC memory. In a 1-bit transponder, only two states can be embed-
ded, so it can only have active and nonactive states. This type of tran-
sponder is typically used in retail stores for antitheft.
Surface acoustic wave (SAW) technology can also be used in RFID
tags [3]. The main idea is to convert the RF wave from the reader into a
nanoscale surface acoustic wave performed by an interdigital transducer
(IDT) placed on a piezoelectric substrate such as lithium niobate or lith-
ium tantalate. The IDT is connected to the antenna for direct receiv-
ing/transmitting to and from the antenna. Once the wave is transformed
into an acoustic wave, it travels past a set of SAW reflectors (or a series of
electrodes with a unique pattern, i.e., placed in a unique manner on the
substrate) that are placed on the surface with a unique configuration, thus
defining its ID number. This also means that each tag has its own unique
ID due to the physical placement of the reflectors.
The 1-bit transponder and chipless tags are characterized by insuffi-
cient memory for higher level applications; however they may be ideal for
certain applications as antitheft.
2.3 RFID Readers and Middleware Component
2.3.1 RFID Readers
The RFID reader is the soul of the RFID system. It is in charge of com-
municating with the tags by transmitting and receiving RF waves. The
RFID reader also provides an interface for RFID-application software to
access the tag data. A reader consists of an antenna and a microprocessor.
RFID readers have at least one antenna for transmitting and receiv-
ing RF signals. The antenna comes in different forms and is tuned for the
environment it will be deployed in. The key performance of a reader
antenna is its gain, polarization, and bandwidth. Gain directly determines
the effective reading rage to detect a tag. Typically the higher the gain of
the reader’s antenna the longer the read range. The polarization helps to

improve system robustness in multipath environments. It is typical of
reader antennas to be circularly polarized for that reason. The bandwidth
is another important indication of the RFID reader, and determines
whether a reader can be used globally due to the different frequency allo-
cations for the different regions. Since different countries and regions use
different UHF bands for RFID application, a wideband antenna allows
the reader to detect the tag designed for another RFID band.
The reader’s microprocessor processes the information to be com-
municated with the tag. It also uses the embedded algorithm to handle
the anticollision communication when there is more than one tag present
in the reading zone. The anticollision has to be done on reader’s side, and
is one of the major functions of a microprocessor.
2.3.2 RFID Middleware
Middleware is the software component between the RFID reader hard-
ware and RFID application software. RFID middleware filters, formats,
and converts low-level RFID hardware communication with the tags into
usable event information, so that the data can be processed by a software
application.
The function of the RFID middleware is similar to the compiler
inside a computer system. In a computer system, the CPU can only
understand “1” and “0.” In the early years, an executable program used to
be written in the fashion of binary codes. However, even writing the sim-
plest arithmetic operations becomes a tedious job, not to mention having
to develop a more sophisticated function, such as a graphic interface. It is
hence the appearing of compiler that frees the programmers from dealing
directly with abstract binary codes. The complier translates the CPU code
into an easily understandable language and vise versa. As a result, the pro-
grammers can write with the alphabet instead of “1s” and “0s,” a language
they are more familiar with, which the application software can use to
focus on how to deal with the application rather than how to talk with
the CPU.
In an RFID system, middleware translates machine information
into tag event information. There are different types of tag event informa-
tion. The most common one is “reader reads a tag.” This information can
include some other useful parts depending on the specific reader model
used, such as tag ID, zone ID, and time stamp. The reader generates huge
amounts of such event information. For example, let us assume an RFID
reader is used in smart shelf management as illustrated in Figure 2.4.

reader. Very high currents are generated in the antenna coil of the reader
by resonance in the parallel resonant circuit, which can be used to gener-
ate the required field strengths for the operation of the remote tran-
sponder. The inductively coupled system is based upon the coil coupling
between the primary coil in the reader and the secondary coil in the tag.
Since the tag is located in the near field of the transmitter antenna, induc-
tive coupling is a short range coupling mechanism and is used primarily
for LF and HF systems.
Outside the radius of the near-field, the interrogation pulse from the
reader propagates outwards. This RF signal travels outwards and encoun-
ters the antenna element in the tag. This is very similar to a RADAR sys-
tem in which electromagnetic waves will be reflected by objects with
dimensions greater than around half the wavelength of the wave. An elec-
tromagnetic field propagates outwards from the reader antenna and
reaches the tag antenna. The power is supplied to the antenna connec-
tions in the form of sinusoidal continuous wave. It needs to be converted
from AC power to DC. After rectification by diodes, this can be used as
turn on voltage for the tag IC chip. A proportion of the incoming RF
energy is reflected by the antenna and reradiated outwards. The amount
of reflected energy can be influenced by altering the load connected to the
antenna. In order to transmit data from the tag to the reader, a load
impedance inside the IC chip connected in parallel with the antenna is
switched on and off in time with the data stream to be transmitted. The
strength of the signal reflected from the tag can thus be modulated (a
technique referred to as modulated backscatter). Once the data in the
microchip is modulated and encoded, it is transmitted back to the reader.
The reader then decodes and demodulates the modulated data and
retrieves the required information. Modulated backscatter coupling is
widely used for long range UHF RFID systems.
2.4.2 Data Encoding
Most of commercial available RFID tags come with memory on the chip.
Data is stored, accessed, transmitted, and changed in the tag. Data encod-
ing refers to the processing of the data from the time the signal transmit-
ted from the RFID reader arrival at the RFID tag and back to the reader.
Several data encoding algorithms have been defined for RFID, the choice
of which affects the implementation cost, data error recovery, and data
synchronization capability.

There have been several types of data encoding and access methods
developed. Encoding methods and access points are set by RFID stan-
dards, such as: ISO 14443, ISO 15693, ISO 18000-6, EM4102 from
EM Microelectronics, and others depending on frequency of operation
and application. For example, ISO 15693 systems operate at 13.56 MHz,
and hence utilizes the magnetic field, and uses amplitude shift keying
(ASK) with 10% or 100% modulation index for the downlink communi-
cation from the reader to the card. ASK is a form of digital modulation,
which expresses digital information as variations in the amplitude of a
carrier wave. As for the uplink communication to the reader, the data is
sent either using amplitude shift keying with 100% modulation index or
frequency shift keying (FSK), both of which use Manchester encoding.
Manchester encoding is a simple type of data extraction that does not
require any additional information about the transmit clock—in other
words, self-clocking where bits are transmitted over a predefined period
of time.
The major encoding methods used inductive and/or capacitive cou-
pling RFID systems are:
• Nonreturn to zero (NRZ) direct: In this method a binary “1” is
represented by one significant condition (logic high level) and a
binary “0” is represented by another (logic low level) [4].
• Manchester encoding: Also called split phase encoding, this encod-
ing mechanism does not require any additional information
about the transmit clock (self-clocking). A level change always
occurs at the middle of a clock cycle. A “1” is translated into a low
to high transition (0 to 1) and a “0” is translated into a high to
low transition (1 to 0) [5].
• Miller encoding: Also referred to as Miller subcarrier encoding. In
this encoding mechanism a binary “1” is represented by a transi-
tion (low-to-high or high-to-low) in the middle of the clock
cycle. A binary “0” is represented by a continuation of the logic
state of the “1” over the next clock cycle. If a sequence of binary
zeros occurs, then a transition takes place at the start of the clock
cycle. Moreover, a Miller sequence might consist of 2, 4, or 8
subcarrier cycles/bit.
• Modified Miller encoding: In this encoding mechanism, each tran-
sition (in Miller) is replaced by a short negative pulse.

• FM0 encoding: This is also known as biphase space encoding. A
transition occurs at the beginning of each clock cycle. A binary
“0” is represented by an additional transition at the middle of the
clock cycle and a binary “1” is represented by no transition at the
middle of the clock cycle.
• Unipolar RZ encoding: In this encoding method a binary “1” is
represented by a high logic level during the first half of the clock
cycle and a binary “0” is represented by a low logic level for the
duration of the clock cycle.
• Differential encoding: In differential encoding a binary “1”
changes the logic level and a binary “0” causes no change in the
logic level.
• Differential biphase: In this encoding mechanism, a level change
occurs at the middle of a clock cycle. A “1” is represented by a
change in level at the start of the clock and a “0” is represented by
no change in level at the start of the clock.
• Pulse-interval encoding: In pulse interval encoding (PIE) or
pulse-pause encoding a binary “1” is represented by a pause of
duration 2T prior to the following pulse and a binary “0” is rep-
resented by a pause of duration T prior to the following pulse.
[Other sources such as Finkenletzer have the binary 1(T) and
0(2T).]
The UHF RFID system that uses the capacitive coupling mecha-
nism uses the PIE for downlink from reader to tag, Miller subcarrier, and
the FM0 for uplink from tag to reader. These are set by the Gen 2 APC
standards and approved by the International Standard Organization ISO
18000-6C. As for magnetic fields that use inductive coupling, Manches-
ter encoding, modified Miller, differential biphase, NRZ, and PIE are
being used in such systems. Figures 2.5 through 2.7 illustrate example
data encodings of the digital signal 11010010 for all of the aforemen-
tioned data encoding schemes.
2.4.3 Multipath Effect
Compared to the traditional barcode system, which relies on the line of
sight contact, one significant advantage of RFID is that it can operate in
an environment in the absence of line of sight. The RF signal transmitted

from millimeters to a few hundreds of meters. It is a good practice to
introduce the open system interconnection (OSI) model at this point in
order to explain how an RFID system’s components communicate. The
OSI model is a conceptual illustration for data communication. The
module is hierarchical in structure and is constructed of layers that define
the requirements of communication between two end users such as the
RFID tag and RFID reader.
The OSI is a logical description of the environment and network
protocol design. The OSI consists of seven layers:
• Layer 1: physical layer;
• Layer 2: data link layer;
• Layer 3: network layer;
• Layer 4: transport layer;
• Layer 5: session layer;
• Layer 6: presentation layer;
• Layer 7: application layer.
This section focuses on the OSI model and short range communica-
tion towards RFID operations. The OSI model allows for the integration
of all of the seven layers as shown in Table 2.1; however, in RFID short
range communications only layers 1, 2, 6, and 7 are used for most con-
temporary systems, which include passive systems.
Each of the layers shown in Table 2.1 depends on its precedent
layer. For instance, a data link establishing the transmission of data blocks
cannot be created without a physical interface such as RFID antennas (tag
and reader). The network layer is not used, since communication in
RFID is point to point and does not require an intermediate user. The
transport layer is not used in RFID, since no complex links between the
end users are involved (an example of such complex links is keeping track
of packets transmitted). The session layer is responsible for procedures
such as restart and termination of operation; hence, there is no need for
this layer in RFID. The presentation layer encrypts data to certain stan-
dards to be used by the application layer (the function of this layer may
also be embedded onboard integrated circuits). Finally, the application
layer, which is the main interface for the user, is responsible for carrying

the application completed onboard the IC in the tag to and from the
reader.
While the OSI model represents a general overview of the commu-
nication that takes place in RFID systems among its different compo-
nents, a more detailed description is also provided in the following three
sections for RFID passive systems, active systems, and systems using
ultrawideband, Zigbee, and Wi-Fi tags.
2.5.1 Passive Systems
Upon the powering of a tag through its transponder antenna by a reader
in a passive RFID scenario as described in Section 2.2.1, the physical
layer of the OSI model becomes active and establishes a link between the
RFID reader and tag. This is the most important factor of the communi-
cation in a passive RFID system and it generates a bottleneck in this short
range communication. Without the activation of this layer, as explained
before, no communication takes place. As a result of the establishment of
the physical layer, a communication protocol must be followed. This sec-
tion will group together the different layers used in RFID communica-
tion: data link, presentation, and application layers as described in
Generation 2 (EPC Gen2), a standard that defines the physical and logic
requirements for passive-backscatter RFID systems operating at 860–960
Table 2.1
Description of Each of the Seven OSI Layers
Type Layer Description
Data Application Sends/receives applications to/from tags.
Data Presentation Data encryption and representation.
Data Session Manages and terminates connection between transmitting
and receiving ends.
Segments Transport Controls the reliability of data transfer among end users.
Packets Network Flow control and network routing.
Frames Data link Transmission of data blocks while addressing management,
error detection, and correction. Collision detection and
recovery.
Bits Physical Manages physical interface (air) between reader and tags.
This layer also details rates of transmission, modulation, and
encoding schemes.

MHz, and which are regarded as the most practical and cost effective
RFID systems. Standards will be further discussed in Section 2.6. These
protocols define the commands used between the reader and tag within
the read range, how the memory is organized, and anticollision algo-
rithms. For instance a passive tag memory layout is composed of four
main sections as defined in Gen2 protocols, these are: reserved, electronic
product code, tag identification, and user memory banks. Tag commands
are also defined by these protocols, and in our example (Gen2), the reader
issues commands to tags within the read range to access data found in the
tags. These commands can be:
• Select command: used to effectively select the tag to be communi-
cated with;
• Inventory commands: include the query command followed by
ACK (acknowledge) and NACK commands. The inventory com-
mand represents the handshake of the RFID passive
communication.
• Access commands: include the write, read, and kill commands
responsible for accessing a tag in order to read from, write to, or
make inaccessible.
It is also worth mentioning that although RFID systems might
include some 1-bit transponders or SAW components, as introduced in
Chapter 1, this section only explains the communication for the vast
majority of deployed RFID systems, which use integrated circuits (IC) for
memory functionality. There are two general types of ICs as shown in
Figure 2.8.
2.5.2 Active Systems, UWB, Zigbee, and Wi-Fi Tags
RFID systems that include an onboard battery as a power source for the
tag are classified as active systems. These systems typically differ from the
reader-tag communication explained above in two major ways:
1. The 433-MHz RFID systems, typically referred to as the active
systems, are nonstandardized systems.
2. Other systems such as UWB, Zigbee, and Wi-Fi RFID tags use
their own established protocols and so depending on the

• China: Ministry of Information Industry;
• Japan: Ministry of Internal Affairs and Communications (MIC);
• South Korea: Ministry of Commerce, Industry, and Energy;
• Malaysia: Malaysian Communications and Multimedia Commis-
sion (MCMC);
• Taiwan (China): National Communications Commission
(NCC);
• South Africa: Independent Communications Authority of South
Africa (ICASA);
• Australia: Australian Communications and Media Authority;
• New Zealand: Ministry of Economic Development;
• Singapore: Infocomm Development Authority of Singapore;
• Brazil: Agência Nacional de Telecomunicações (Anatel).
There are several frequency allocations that can potentially be used
in RFID systems, four of which are major for global operations. These
are: low- frequency (LF): 125–134.2 kHz; high-frequency (HF): 13.56
MHz; ultra-high-frequency (UHF), which depends on the region of
operation and ranges: 433 MHz (for active tags) and 840–954 MHz; and
microwave frequency operating at 2.45 GHz. These frequencies are
known as the industrial scientific and medical (ISM) bands. Character-
ized by a short range and limited data transfer, RFID systems operating at
LF and HF bands that use the inductive coupling technique (as explained
in Section 2.2.7) do not require any licenses for global operation. This
facilitates the import/export of tagged objects at LF and HF bands. How-
ever, the UHF band has been the most popular on a worldwide basis in
recent years due to long read ranges and high data transfers. Proof of this
band’s popularity, besides the investments in the designs of RFID systems
and RFID tags at the UHF band, would be the ambitious standards fol-
lowed globally by the International Organization for Standardization
(ISO) and the electronic product code (EPC). Furthermore, the ISO has
set several standards regarding RFID technology such as ISO 18000,
which describes passive backscatter RFID systems and is titled “Informa-
tion Technology—Radio Frequency Identification for Item Manage-
ment.” ISO 18000 consists of seven parts and is regarded as the most
significant standard for RFID. ISO 18000-1 includes reference architec-
ture and definition of parameters to be standardized; ISO 18000-2, 3, 4,

5, and 6 include the parameters for air interface communications at below
135 kHz, 13.56 MHz, 2.45 GHz, and 860–960 MHz, respectively. ISO
18000-7 includes parameters for active air interface communications at
433 MHz. EPCglobal is also considered a standard approved by large dis-
tributors and government customers. At this point it would be useful to
introduce EPCglobal UHF Class 1 Generation 2 (EPC Gen2), a standard
that defines the physical and logic requirements for passive-backscatter
RFID systems operating at 860–960 MHz, which are regarded as the
most practical and cost-effective RFID systems. EPC Gen2 specifies the
frequency of operation and bandwidth, power, technique, number of
channels, spurious limits, as well as regulator of RFID systems for each
country. For instance in North America, a center frequency of 915 MHz
can be used with a bandwidth of 26 MHz (~ 2.48% bandwidth) with a
4-W emitted isotropic radiated power (EIRP) by the reader’s antenna,
with 50 channels that allow channel hopping and spurious limits of −50
dBc.
References
[1] Rida, A., et al., “Conductive Inkjet-Printed Antennas on Flexible Low-Cost
Paper-Based Substrates for RFID and WSN Applications,” IEEE Antennas and
Propagation Magazine, Vol. 51, No. 3, June 2009, pp. 13–23.
[2] Balanis, C., Antenna Theory, Analysis and Design, 3rd ed., New York: John Wiley
& Sons, 2005.
[3] Banks, J., et al., RFID Applied, New York: John Wiley & Sons, 2007.
[4] “Interface Bus, NRZ Encoding,” http://www.interfacebus.com/NRZ_Defini-
tion.html.
[5] “Manchester Encoding,” Wikipedia, http://en.wikipedia.org/wiki/Manches-
ter_code.
[6] “UHF Gen-2 System Overview,” Texas Instruments, September 2005,
http://rfidusa.com/superstore/pdf/UHF_System_Overview.pdf.
[7] Finkenzeller, K., RFID Handbook, 2nd ed., New York: John Wiley & Sons, 2003.

3
Fundamentals and Operating Principles
of Sensors
3.1 Types of Sensors
3.1.1 Use of Sensors
A sensor is a device that measures a physical quantity and converts it into
a signal, which can be observed by an instrument. Therefore, sensors
function as part of the interface between the physical world and electrical
devices. The counterpart, which converts electrical signals into physical
phenomena, is called an actuator. To have a better understanding of
sensors, an appropriate example is a thermocouple, which converts the
temperature to an output voltage which can be read by a voltmeter, as
shown in Figure 3.1.
A thermocouple is a junction between two different metals that pro-
duces a voltage related to a temperature difference. In 1821, the German-
Estonian physicist Thomas Johann Seebeck discovered that when any
conductor is subjected to a thermal gradient, it will generate a voltage.
This is now known as the thermoelectric effect or Seebeck effect. Any
attempt to measure this voltage necessarily involves connecting another
conductor to the “hot” end. This additional conductor will then also
experience the temperature gradient, and develop a voltage of its own,
which will oppose the original. Fortunately, the magnitude of the effect
depends on the metal in use. Using a dissimilar metal to complete the cir-
cuit creates a circuit in which the two legs generate different voltages,
49

leaving a small difference in voltage available for measurement. This cou-
pling of two metals gives the thermocouple its name. Thermocouples
measure the temperature difference between two points, not absolute
temperature. In traditional applications, one of the junctions—the cold
junction—was maintained at a reference temperature, while the other
end was attached to a probe.
Sensors are used in everyday objects. Applications include cars,
machines, aerospace, manufacturing and robotics. There are also innu-
merable applications for sensors of which most people are not aware such
as touch-sensitive elevator buttons and lamps, which dim or brighten by
touching the base.
Among sensors’ parameters, sensitivity is the most critical one. Sen-
sitivity indicates how much the sensor’s output changes when the mea-
sured quantity changes. For instance, if the mercury in a thermometer
moves 1 cm when the temperature changes by 1°C, the sensitivity is 1
cm/°C. Sensors that measure very small changes need to have very high
sensitivities. Unavoidably, sensors also have an impact on what they mea-
sure; for instance, a room temperature thermometer inserted into a hot
Figure 3.1 A thermocouple is plugged into a voltmeter to display the room temperature
in Celsius.

cup of liquid cools the liquid while the liquid heats the thermometer.
Sensors need to be designed to have a small effect on what is measured;
making the sensor smaller often improves this and may introduce other
advantages. Technological progress allows sensors to be manufactured on
a microscopic scale as microsensors using MEMS technology. In most
cases, a microsensor reaches a significantly higher speed and sensitivity
compared with macroscopic approaches. For accuracy, all sensors need to
be calibrated against known standards [1].
3.1.2 Types of Sensors
There are numerous sensors available for different applications and vari-
ous physical quantities. It is necessary to classify sensors in order to study
them. Based on different criterion, sensors can be divided into different
categories.
In considering the application, sensors can be classified as, but not
limited to:
• Acoustic: geophone, hydrophone, seismometer;
• Automotive: crank sensor, defect detector, MAP sensor,
speedometer;
• Chemical: breathalyzer, carbon dioxide sensor, hydrogen sensor,
Pellistor;
• Electric current, magnetic, radio: ammeter, current sensor, magne-
tometer, metal detector, voltmeter;
• Flow: air flow meter, gas meter, mass flow meter;
• Ionizing radiation, subatomic particles: cloud chamber, Geiger
counter, neutron detection, particle detector;
• Navigation instruments: air speed indictor, altimeter, gyroscope,
variometer;
• Position, angle, acceleration: accelerometer, inclinometer, rotary
encoder;
• Optical, light, imaging: colorimeter, Nichols radiometer,
photodiode;
• Pressure, force, density: anemometer, barograph, hydrometer,
oscillating u-tube;
Fundamentals and Operating Principles of Sensors 51

• Thermal, temperature: bolometer, calorimeter, thermocouple,
thermometer;
• Proximity, presence: motion detector, occupancy sensor, Reed
switch.
3.1.2.1 Types of Power Supplies
In considering the sensor structure, sensors can be classified as being
either active or passive. In passive sensors, output power comes from the
input, so it is a type of self-generating sensor. Conversely, active sensors
have an auxiliary power source to supply the output signal power. The
input power only controls the output. Active sensors have the advantage
of overall higher sensitivity, with the cost of the auxiliary power source
and the increasing danger of explosion in explosive atmospheres.
3.1.2.2 Type of Output Signals
Analog sensors generate continuous outputs, such as amplitude. Digital
sensors generate discrete steps or states of outputs. Digital output is easier
to transmit than the one form analog sensor, and more reliable and accu-
rate. However, analog sensors can measure much more physical quantities
than digital sensors.
3.1.2.3 Type of Input-Output Relationships
The order (zero, first, second, and higher) is related to the number of
independent energy-storing elements in the sensor. The existence of these
elements will affect the sensor accuracy and speed. Such classification is
important when the sensor is part of a closed-loop control system due to
the oscillation caused by excessive delay.
3.1.2.4 Type of Operating Modes
In deflection sensors, the measured quantity produces a physical effect
that generates in some part of the instrument a similar but opposing effect
that is related to some useful variable. In null-type sensors, a known effect
is applied that opposes that produced by the quantity being measured in
order to attempt to prevent deflection from the null point. For example,
in a weighing scale, the placement of a mass produces an imbalance indi-
cated by a pointer. Calibrated weights have to be added on the other arm
until a balance is reached. Null measurement are usually more accurate
because the opposite known effect can be calibrated against a high-preci-
sion standard or a reference quantity.

3.2 Basic Considerations of Sensor Design
Most of the sensors are used to make quantifiable measurements. There-
fore, it is obvious that the requirements of the measurement are the basic
considerations that determine sensor selection and design [2]. The major
considerations will be discussed in the following subsections.
3.2.1 What to Measure
Sensors are available to measure almost every physical parameter. Tem-
perature, pressure, and gas detection are probably the most common
measurements related with our daily life, as well as in many industrial
processes and material supply chains. There are also many other not so
well known applications in which sensors play important roles. For exam-
ple, in the Large Hadron Collider (LHC), which is the world’s largest and
highest energy particle accelerator built by the European Organization for
Nuclear Research, there are two sensors called compact muon solenoid
(CMS), which sense the generation of hadrons produced in the collision
events. Each sensor is 13 meters long and 6 meters in diameter. Sensors’
shapes and built-up materials will vary dramatically in different
applications.
3.2.2 Requirements for Accuracy
This relates with the uncertainty of the measurement. A good sensor
obeys the following rules:
• It is sensitive to the measured property.
• It is insensitive to any other property.
• It does not influence the measured property.
Linearity is an important consideration in this category. Ideal sen-
sors are designed to be linear. The output signal of such a sensor is lin-
early proportional to the value of the measured property. The sensitivity
is then defined as the ratio between output signal and measured property.
For example, a temperature sensor measures temperature and has a volt-
age output, and the sensitivity is a constant with the unit [V/°C]; this sen-
sor is linear because the ratio is constant at all points of measurement.
However, in more of the cases, the direct output of the sensor is
Fundamentals and Operating Principles of Sensors 53

nonlinear. Further using the temperature sensor as an example, for a
real-world handheld temperature sensor using temperature sensitive resis-
tor, the resistance variation is nonlinear at a different temperature range.
The resistance variation at a high temperature (for example, from 100°C
to 120°C) would be more obvious than the one at a low temperature (for
example, from 10°C to 30°C). Looking at the chart of resistance value
versus temperature would result in a curvature line instead of a straight
line. For a successful sensor, an extra step of design work is needed to
compensate this, usually a projection on mathematics conducted by the
microcontroller before the temperature is shown on the sensor display.
3.2.3 Requirements for Resolution
The resolution directly relates with the sensor accuracy. The resolution of
a sensor is the smallest change it can detect in the quantity that it is mea-
suring. Often in a digital display, the least significant digit will fluctuate,
indicating that changes of that magnitude are only just resolved. The res-
olution is related to the precision with which the measurement is made. It
is also a trade off between achieving the lowest possible uncertainty and
economical feasibility.
3.2.4 Environment of the Sensor
Environment is perhaps the biggest contributor to measurement errors in
most measurement systems. One of the greatest challenges for a sensor
designer is to minimize the response to the environment and maximize
the response to the desired measurand. The environment includes not
only parameters such as temperature, pressure, and flow, but also the
mounting or attachment of the sensor, electrostatic effects, and the rate of
change of the various environment parameters. For example, a sensor may
be quite accurate and little affected by extreme high temperature, but may
produce huge errors under a rapidly changing temperature condition.
Accessing the environment and estimating its effect on the sensing mea-
surement system play a very important role in the sensor selection and
design process.
3.2.5 Calibration
To maintain the sensor accuracy, the user must ensure that the whole sys-
tem is calibrated. There are national standards organizations that instruct

Random documents with unrelated
content Scribd suggests to you:

Art in Holland
SIX
any people consider Dutch art the most interesting in the world. The
artists of Holland did not portray classic gods and prayerful
madonnas. They were too practical and matter-of-fact for that.
Their minds were serious, and scenes of everyday life attracted them
more than they did the artists of Italy or Spain. Portrait painting began
very early among the Dutch. This was because the Dutch spirit was
essentially commercial. The prosperous burghers liked to have great
artists paint them, and they were usually willing to pay pretty well for the
privilege. Also the nobility, due to their love of splendor, gave abundant
employment to the artists.
Some of the earlier Dutch artists who achieved fame are the brothers Van
Eyck, Hugo van der Goes, Roger van der Weyden, and Quentin Massys.
But greater than any of these is Frans Hals, who was born in 1580. He
was a great portrait painter. His marvelous capacity for catching an
impression on the instant brought him many patrons. He loved to paint
people as they were, and jolly topers and rich burghers were his favorite
subjects; but, great artist though he was, he died almost in poverty.
Rembrandt Harmanzoon van Rijn, who was born in 1607, the son of a
miller of Leyden, has been called the greatest painter of northern Europe.
Today his pictures are beyond price. His influence on the Dutch artists
that followed him was very great. But he died at the age of sixty-two,
alone and neglected.
Paul Potter, called the “Raphael of animal painters,” was born in 1625,
and died from overwork at the age of twenty-nine. It is said that he
painted portraits of animals, and tried to know the character of every
beast that he drew.
Jan Steen painted all sorts of subjects,—chemists in their laboratories,
card parties, marriage feasts, religious subjects, and especially children.
Besides being a successful artist, he was a brewer at Delft. He failed in
this business and opened a tavern. Hence he has often been called “the
jolly landlord of Leyden.”

Pieter de Hooch was the most neglected of all Dutch painters; yet in 1876
the Berlin Museum paid $26,000 for one of his paintings. He was born in
Rotterdam about 1630, and became one of the most charming painters of
homely subjects that Holland has produced. He died at Haarlem about
1681.
Meyndert Hobbema was born in Amsterdam about 1638, and was buried
there in a pauper’s grave in 1709. Although today he is considered one of
the great landscape painters of Holland, his work was not appreciated
during his lifetime. Hobbema liked to paint only landscapes. It is said that
when it was necessary for him to get a figure in a picture he had another
artist do it.
All these men were great artists of Holland. And it is a peculiar thing that
most of them lived in the sixteenth and seventeenth centuries. Since then
Holland has done comparatively little in art.
PREPARED BY THE EDITORIAL STAFF OF THE MENTOR ASSOCIATION
ILLUSTRATION FOR THE MENTOR, VOL. 2. No 6. SERIAL No. 58
COPYRIGHT, 1914, BY THE MENTOR ASSOCIATION, INC.
The Mint Tower, Amsterdam

H
HOLLAND
By DWIGHT L. ELMENDORF
Lecturer and Traveler
THE MENTOR · DEPARTMENT OF TRAVEL · MAY 1, 1914
MENTOR GRAVURES
THE RYKS MUSEUM, AMSTERDAM
VEEN KADE, THE HAGUE
STREET SCENE, ROTTERDAM
STREET SCENE, AMSTERDAM
MONTALBANS TOWER, AMSTERDAM
SCENE IN HAARLEM
olland has been described as a “country of unpainted pictures.” That
is the artist’s point of view; for his eye takes in the picturesque
possibilities of the subject. To us it seems as if Holland is of all
countries the one most often seen in pictures. While, no doubt, there are
many “untouched pictures” in the miles of level Dutch landscape, art has
surely shown a generous recognition of Holland’s attractive scenery, and
has celebrated its picturesqueness to all the rest of the world. Holland is a
country of dikes and level meadow lands, of windmills and canals. From
the point of view of an aëronaut the Dutch cities look like a map of Mars.
This is especially true of Amsterdam, which, viewed from above, appears
to be a network of canals. These canals are an attractive feature of the
cities. In some cases the whole street is canal; in other cases the street is
both “wet and dry”—a canal flanked by a street.

Copyright, American Press Association
“THE HOUSE IN THE WOOD,” THE HAGUE
This is Queen Wilhelmina’s favorite place of
residence. It is located in the forest park about one
and a half miles from The Hague, and was the
meeting place of the first International Peace
Conference, held in 1899
Imagine a country, in some spots lower than the sea, maintaining its
existence only by constant vigilance and industry, fighting for its very life
through the changing seasons against the one great enemy, water. The
dunes or sand hills which line the coast serve as a barrier against the sea.
These are reinforced by coarse grass, which holds the sand together. In
some places the dikes are made of earth, sand, and clay, held together by
willows, which are carefully planted so as to form a binder. In other

places dikes are built of stone. The dikes are the fortifications against the
inroads of the ocean, and also the floods in the rivers that flow through
Holland to the sea.
HOUSES OF PARLIAMENT, THE HAGUE
With the Queen’s Fish Pond in the foreground
When there are heavy rains in Germany the Rhine brings down a great
additional volume of water, which has to be checked by the dikes and led
away by the canals. Holland’s fight against water has been a warfare of
varying fortunes. At times in the past dikes have been broken, great
tracts of land have been inundated, and thousands of people drowned.
The Dutch are a careful, plodding, and industrious people, and they have
profited by experience. As a result they are now not only holding their

water enemy in check, but they have actually advanced upon the sea,
and have taken from it sufficient territory to add materially to their
cultivated lands. But the contest with the rivers and the sea has to be
constant. A special body of engineers is appointed to look after the work,
and the Dutch government spends annually several million dollars to keep
the dikes in order and hold the ground. Water is confined in canals and in
large basins; and the ever-faithful windmill, when not otherwise engaged,
is employed to pump the water from the lowlands.
DIKES A ND W INDMILLS
The dikes and the windmills are the two great factors of physical and
commercial life in Holland. The dike safeguards the land; the windmill
fans the currents of trade. Whether corn is to be ground, timber sawed,
tobacco cut, paper manufactured, or water pumped, the long arms of the
mill perform a willing and efficient service while the wind blows. The
importance of the dike is reflected in the names of many Dutch towns.
The word dam or dike is to be found almost everywhere. Amsterdam is
the “dike” of the River Amstel (ahm´-stel); Rotterdam, the “dike” of the
River Rotte; Zaandam (zahn-dahm´), the “dike” of the River Zaan—and
so on. The thought of the protecting dike was generally in mind when a
town was founded. The windmill is not only an untiring servant of
industry, but is a sign of Dutch prosperity as well. You may hear it said of
a Hollander, “He is worth ten millions.” You are quite as likely to hear it
said, “He is worth ten windmills.”

THE ROYAL PALACE, AMSTERDAM
The palace, formerly the town hall, was begun in
1648, finished in 1655, and cost 8,000,000 florins. It
rests on a foundation of 13,659 piles, and its tower is
167 feet high. The weather vane on the tower
represents a merchant vessel, formerly the crest of
the city
It required dogged determination and persevering energy to make the
history of Holland. The Dutch people successfully resisted Spanish
domination at a time when Spain was a supreme world power, and then
they built up a government of their own in a country where they had to
fight for the very existence of the land. In government administration, in
thrift and commercial enterprise, in exploration and colonization, in
literature, and in arts, Holland has proved herself to be a wonderful little
country. She has had much to say in the Congress of Nations. One of her
chief cities, The Hague, is identified in everyone’s mind with one of the
most important world movements of modern times,—the International
Peace Conference.
The population of Holland does not exceed 6,000,000, and there are only
four towns having a population exceeding 100,000,—Amsterdam, The
Hague, Rotterdam (rot´-er-dam; Dutch, rot-ter-dahm´), and Utrecht (u´-
trekt; Dutch, oo´-trekt).

A MSTERDA M
This most interesting city is situated where the River Amstel enters the
Zuyder Zee (zy´-der zee; Danish, zoi´-der zay). Just where the city lies
there is an arm of the sea which goes by the odd name of Y or Ij
(pronounced eye). Amsterdam is the chief commercial city of Holland;
though in some branches of business Rotterdam disputes its supremacy.
The city is of odd, semicircular shape, and is intersected by canals, which
run in curves like the rows of seats in an amphitheater. Each of these
semicircular canals marks the line of the city walls and moat at different
times. Other canals cross these in such a manner as to cut the city up
into a number of islands. The old part of the city lies in the very center,
inclosed by the inner semicircular canal. At one end of this canal is the
“Weepers’ Tower,” which takes its name from the fact that it stands at the
head of what was the old harbor, and was the scene, therefore, in ancient
times, of many sad leavetakings. There wives and sweethearts said
goodby to the men who went “down to the sea in ships.”
THE GATE OF THE STADTHOLDER,
THE HAGUE

THE NEW THEATER, AMSTERDAM
Amsterdam is supposed to have originated about 1204, when Gysbrecht
II, Lord of Amstel, built a castle there. It came to be really important
about the end of the sixteenth century, when the wars with Spain had
ruined Antwerp, and many merchants, manufacturers, and artists left
there and settled in Amsterdam. The population of the city today is close
to 600,000, and it is one of the busiest markets in Europe, doing a large
business in imports, especially in the products of the Dutch colonies.

PALACE OF PEACE, THE HAGUE
The city, moreover, is very beautiful. The main canals are lined with
avenues of elms, and they offer a picturesque appearance and a pleasant
shade. The streets are full of life, and their interest is enhanced by the
varied activities of those who walk and ride on the paved roads and
others who ply oddly constructed boats through the waterways.
A CI TY BU ILT O N P ILES
The costumes, while not so picturesque as those to be found in the
country districts, are interesting to the traveler from other lands. The
houses are built on piles driven into the soft soil—a fact that the witty old
Erasmus of Rotterdam turned to jest by saying that he knew a city whose
inhabitants dwelt in the tops of trees like rooks.
There are so many things in Amsterdam of historic, literary, and art
interest that no one can expect to “do the city” and do it thoroughly in
the brief time usually allotted by the ordinary tourist. For the student of
art there is enough to fill a month’s time. The home city of Rembrandt

naturally holds the interest of an artist, and the Ryks Museum contains a
wonderful collection of Dutch art and Historic relics.
THE RIDDERZAAL, THE HAGUE
The old Ridderzaal on the Brennenhof is
the ancient castle of the counts of
Holland. The most modern
improvements, such as electricity and
telephones, have been installed in this
ancient structure. The grand assembly
hall seats two hundred and eighty, and is
lighted by eight immense chandeliers of
antique style, containing fifty-four lights
each
RYKS MU SEU M
This museum is an impressive stone and brick building, constructed in
1877-1885, and filling nearly three acres of ground. It holds a place

among the greatest museums of the world, and in its devotion to its own
particular subject—Dutch art and history—it is unique. It is not the lover
of art alone who will find the place fascinating: the historian will be held
by the military, naval, and colonial collection; the antiquarian will linger
over the old works in gold and silver, the models of ships of different
periods, antique books and furniture, textiles and stained glass; while the
artist will regard the picture galleries as a treasure house.
For the artist, if interested in the Dutch masters of art, the museum is the
one particular place in Europe. There about him he will find some of the
most celebrated works of Rembrandt, Franz Hals, Paul Potter, Jan Steen
(stane), Hobbema (hob´-be-mah), and other Dutch painters.
The picturesque old buildings of Amsterdam, especially those in the inner
city, will delight the visitor. Many of these have great historic interest—
notable among them Admiral de Ruyter’s (ry´-ter; Dutch, roi´-ter) house,
bearing his portrait in relief on its front, and a little beyond that the old
Montalbans Tower.

Copyright, Underwood & Underwood
A STREET IN AMSTERDAM
The Royal Palace is a solid building which was begun in 1648, just after
the Peace of Westphalia, and was finished in the course of seven years at
a cost of 8,000,000 florins ($3,216,000). It is not a beautiful building; but
in its structure and its inner equipments it is interesting as showing the
character of Dutch life and government. You bring from a visit to the
palace an impression of the solidity, power, and the enduring virtues that
are the ancestral inheritance of the Hollander.
No visit to Amsterdam is complete without a sight of the Zoölogical
Garden, which is one of the best in Europe, and a trip out to the unique
little Island of Marken. There in that odd spot you will find all the
picturesqueness of Holland in solid deposit. Gaily colored costumes are

everywhere; houses are queer in structure and in furnishing; and
manners and habits of life are peculiar and interesting. But let the visitor
be cautious in Marken. It has of recent years come to be a show place,
stocked with all sorts of Dutch articles of no special value, most of which
are manufactured solely to catch the fancy of the unwary tourist.
HA A RLEM
On returning from Marken the traveler will find it worth his while to run
west to the quaint old town of Haarlem (hahr´-lem). This is the city of
the governor of the province of North Holland, and is one of the cleanest
and neatest towns in the Netherlands. Its population is something over
70,000, and it has the appearance of prosperity and welfare. During the
Middle Ages, Haarlem was the residence of the counts of Holland, and
was the scene of several important military engagements between the
Dutch and the Spaniards. It is famous for its horticulture, and furnishes
bulbs to every country in Europe and North America. Along about the
middle of spring a wonderful sight may be seen in the lands surrounding
Haarlem. Whole fields of hyacinths, crocuses, anemones, tulips, lilies,
etc., offer a brilliant variety of color and fill the air with delicious perfume.
It is a feast for the senses indeed!

SAINT NICHOLAS CHURCH, AMSTERDAM
RO TTERDA M
Situated about thirty miles south of Amsterdam and Haarlem is
Rotterdam, the second largest town in the Netherlands, which has a
population of about 370,000. To some it is known chiefly as the home of
the illustrious Erasmus, who was born there in 1465. In the great
marketplace of Rotterdam there stands a fine bronze statue of Erasmus.
To merchants Rotterdam is known as one of the busiest import cities on
the Continent; as in its import trade it is exceeded only by Hamburg and
Antwerp, while its cattle market is the most important in Holland. There is
much life in Rotterdam, and plenty of entertainment to enliven the visitor
who goes there for other purposes than those of trade.

THE POSTOFFICE, ROTTERDAM
Boyman’s Museum contains a most valuable collection of Dutch art, and
the churches, parks, and public ways are attractive and interesting. Down
at the large docks you will find busy scenes; at the Wilhelmina Kade
especially, where the great passenger steamers lie. You will meet that
name Kade wherever you go in the towns of Holland. It means quay, and
the different thoroughfares distinguished by the name are either quays or
else have been quays in times past, and in the course of the city’s growth
have become streets with waterways in them.
You will be impressed with the vast multitude of bridges in Rotterdam. I
do not know that they actually exceed in number the bridges of
Amsterdam; but they appear to, for many can be seen from almost every
point of view. The service of the canal to Holland is manifold, and this is
true in winter as well as in summer. Over the frozen surface of the canal
children skate to school, women skate to their shopping, and those who
have time for recreation skim the icy surfaces from town to town in
skating trips.
THE HA G U E
There are many towns in Holland to invite the traveler, and most of them
will delight him as well. This is especially true of Utrecht, Dordrecht, and

Delft, the last famous the world over for its pottery. It is well, however,
when making a visit to Holland, to save The Hague until the last.
The Hague is the political capital of Holland, and in some ways the most
beautiful and interesting of all Dutch cities. It is a most cosmopolitan
town, and its population includes many distinguished people. Among the
cities of Holland, The Hague leads in culture and refinement, as
Amsterdam and Rotterdam do in commerce. It is, moreover, the most
attractive city. In neatness and in cleanliness it is claimed that The Hague
cannot be excelled by any city in the world. You are willing to believe that
when you are there.
THE HO U S E IN THE W O O D
The full Dutch name of this city of royalty is ’s Graven Hage (’s grah´-fen
hah´-ge), which means “the count’s inclosure.” The name was given to it
originally when it was a richly wooded plain and a hunting resort of the
counts of Holland. It is now the residence of the queen of Holland and
the seat of government, where most of the important national
transactions of the last three hundred years have taken place. There is no
great amount of business at The Hague. It is a place of important political
affairs and of social life and enjoyment. The life there is distinguished for
its gaiety, and the society for its distinction. Great interest naturally
centers in “The House in the Wood,” a most picturesque château erected
in 1645 for Princess Amalia, consort of Prince Frederick Henry, son of
Henry the Silent. This is the favorite home of royalty. The most interesting
apartment in the palace is the Orange Room, which was prepared by the
princess as a memorial to her husband, and has been the scene of many
important diplomatic and social events. The first International Peace
Conference, at which twenty-six powers were represented, met in this
room in the summer of 1899. The House in the Wood is beautifully
furnished and decorated, and, more than the usual royal residence, it
realizes the meaning of the word “home.”

GROOTE KERK, DORDRECHT
This church dates from the fourteenth century. Its tower is two
hundred and thirty feet high
A TTRA CT IO NS O F THE HA G U E
The population of The Hague is more than 240,000, and it has, besides
The House in the Wood, a number of notable features. There is the
celebrated picture gallery called the Mauritshuis, the Municipal Museum
which, next to the Ryks, is the finest in Holland, the Mesdag Museum,
which contains among other art treasures a fine collection of pictures by
the Barbizon painters, and the Steengracht Gallery, which is rich in
modern French and Dutch paintings. The quaint old Hall of the Knights
will attract attention for its historic interest, and so will the beautiful and
imposing national monument, which was set up in 1869 to commemorate
the restoration of Dutch independence and to honor Prince William
Frederick of Orange.

Altogether The Hague is a delight to the traveler. Thackeray exclaimed
over it, “The brightest little brick city, with the pleasantest park to ride in,
the neatest, comfortable people walking about, the canals not unsweet,
and busy and picturesque with life!”
THE CATHEDRAL, UTRECHT
The cathedral was erected in 1254-67. At the time it
was one of the finest and largest churches in Holland
SCHEVENING EN

ON THE BEACH, SCHEVENINGEN
It might be Brighton or Margate, and, except for the swarm of hooded
beach chairs, it might be Coney Island, this popular seaside resort of
Holland. Most of the features familiar to those who frequent the sea coast
resorts of other lands are to be found at Scheveningen. There is the wide,
gradually shelving beach, ceaselessly washed by the rolling surf, crowded
with people of all ages and stations, bobbing in the water, frolicking on
the beach, or sedately seated in the shaded chairs. Back on the beach
runs the long line of hotels and cottages that we find at all great ocean
resorts. The pleasure of playing on the seashore is much the same
wherever humanity is found, and no matter what the locality may be the
pleasure in all places finds pretty much the same forms of expression.
Scheveningen (shay´-ven-ing-en) began its life as a fishing village away
back in 1400. It is situated about three miles from The Hague, and has
been a bathing resort since 1815, growing in popularity and population
until now the annual number of visitors is about 40,000, chiefly Dutch
and German, but including also many Britons and Americans. The season
runs from the first of June to the end of September, and, just as in the
case of other summer resorts, its activities are at their height about the
first of August.
Aside from its many attractions as a summer resort, Scheveningen has
some historic interest. It was from there that Charles II set sail when he

Welcome to our website – the perfect destination for book lovers and
knowledge seekers. We believe that every book holds a new world,
offering opportunities for learning, discovery, and personal growth.
That’s why we are dedicated to bringing you a diverse collection of
books, ranging from classic literature and specialized publications to
self-development guides and children's books.
More than just a book-buying platform, we strive to be a bridge
connecting you with timeless cultural and intellectual values. With an
elegant, user-friendly interface and a smart search system, you can
quickly find the books that best suit your interests. Additionally,
our special promotions and home delivery services help you save time
and fully enjoy the joy of reading.
Join us on a journey of knowledge exploration, passion nurturing, and
personal growth every day!
ebookbell.com

Rfidenabled Sensor Design And Applications Amin Rida Li Yang

More Related Content

Similar to Rfidenabled Sensor Design And Applications Amin Rida Li Yang (20)

Recently uploaded (20)

Rfidenabled Sensor Design And Applications Amin Rida Li Yang