Design of a Smart RFID Tags Antenna Using an Inductively Coupled Loop

Abstract

The objective of this chapter is to study the performance of the RFID (radio frequency identification) technology and especially the passive UHF RFID (ultra high frequency RFID) tags by means of simulation. In this chapter, the authors discuss the design of a smart RFID tags antenna using an inductively coupled loop at 915 MHz in order to achieve complex impedance matching between the antenna impedance and the chip selected with high performance. The antenna is printed on a Rogers RT/duroid 5880 substrate with a relative permittivity of 2.2 and thickness of 1.575 mm. Studies demonstrate that the inductively coupled loop matching technique is a good candidate to adapt the antenna impedance to chip impedance. They have achieved an adaptation of 99.90%, a very wide bandwidth of 409.6 MHz, a broadside and asymmetrical radiation pattern in the E-plane, a read range of 21.19 m, and an antenna gain of 4.17 dB with the inductively coupled loop matching technique.