Skip to Main Content
Advanced Chipless RFID
book

Advanced Chipless RFID

by Nemai Chandra Karmakar, Mohammad Zomorrodi, Chamath Divarathne
August 2016
Intermediate to advanced content levelIntermediate to advanced
304 pages
8h 54m
English
Wiley
Content preview from Advanced Chipless RFID

CHAPTER 3TINY POLARIZERS, SECRET OF THE NEW TECHNIQUE

3.1 INTRODUCTION

The idea of electromagnetic (EM) imaging for data encoding in chipless radiofrequency identification (RFID) systems was briefly introduced in Chapter 2. It was shown that imaging technique differs from other conventional methods as it provides extra spatial diversity. In imaging approach, each small section of the tag is separately scanned while it independently carries data. Providing fine scanning resolution governs the frequency band of operation and mandates the synthetic aperture radar (SAR) technique. However, the next issue that shall be answered is how to encode data in a small area of millimeter order.

Earth imaging system, the first and most important application of EM imaging, may suggest an approach for data encoding. In earth imaging, the earth's surface is interrogated by a radar system that is normally mounted on an air-/spacecraft. Based on the reflected signal, the radar system forms the related EM image of the earth. The strength of the reflected signal from each section of the earth's surface is linked to the image and shows the terrain of the earth. Rough surfaces result in higher reflection and therefore a brighter part in the EM image, for example, a building or mountain. An impinged signal on a flat surface is reflected in the opposite direction, by Snell's law; hence, radar receives no energy and a dark section in the image is formed. Figure 3.1 shows the principle of image brightness ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Getting Started with RFID

Getting Started with RFID

Tom Igoe
RFID For Dummies®

RFID For Dummies®

Patrick J. Sweeney II
RFID Sourcebook

RFID Sourcebook

Sandip Lahiri
How to Cheat at Deploying and Securing RFID

How to Cheat at Deploying and Securing RFID

Frank Thornton, Paul Sanghera

Publisher Resources

ISBN: 9781119227311Purchase book