BLOCKING READER: DESIGN AND IMPLEMENTATION OF A ...
BLOCKING READER: DESIGN AND IMPLEMENTATION OF A ...
BLOCKING READER: DESIGN AND IMPLEMENTATION OF A ...
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2.1 Introduction<br />
CHAPTER 2<br />
ELECTROMAGNETIC’S <strong>OF</strong> RFID<br />
It is important to know the Electromagnetic’s of Radio Frequency Identifi-<br />
cation(RFID), the physics concerning the communication between reader and tag.<br />
Knowledge of the fields and different laws governing the entire RFID System commu-<br />
nication will help us to give more insight to analysis. The thesis consist of analysis<br />
of RF Radiation patterns of the Blocking reader. The RF front end of the blocking<br />
reader design consists of proper selection of the type of modulation, frequency and<br />
power. This chapter gives a small introduction to all the theories involved in the<br />
communication like Electric field, Magnetic field theory, equations governing them,<br />
modulation, antenna theory, multi-path and polarization.<br />
2.2 Basic RFID System<br />
A typical RFID system is as shown in the Figure 2.1. It consists of a Reader<br />
which readers the Tag information and transmits to the back-end information system<br />
for further processing. Unlike barcodes the Tags communicate wirelessly transmitting<br />
the identifier to the Reader. There are different types of RFID systems.<br />
RFID systems can be classified based on frequency and based on communica-<br />
tions. In this thesis we will only talk about passive UHF RFID system. UHF systems<br />
are far field operated systems where data is communicated through electromagnetic<br />
waves. UHF band allowable in US for RFID communication is 902-928 MHz. Passive<br />
RFID systems consists of Passive UHF Tags. Passive Tags are battery-less that de-<br />
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