Simulating Performance of a Low Cost, Chipless RFID System

An RFID tag system is examined using XFdtd EM Simulation Software to validate its performance for use in situations where high volume usage requires very low-cost components. This example is derived from a system described in a published journal paper. The RFID tag is constructed as a microstrip device with spiral resonators tuned to specific frequencies that represent separate bits of the tag code.

The resonators are connected to two cross-polarized ultrawide band (UWB) monopole disk antennas which receive and transmit the signal from the scanning system. The system is demonstrated with a design capable of encoding six bits that are formed by resonances 100 MHz apart between 2.0 and 2.5 GHz. The testing is done using two cross-polarized log period dipole array (LPDA) antennas which transmit and receive the signal from the RFID tag.