Analysis of a Compact Electrically Small Antenna with SRR for RFID Applications

This paper contains the design and analysis of a compact, bidirectional Electrically Small Antenna (ESA) at 0.9 GHz for Radio Frequency Identification (RFID) and a global system for mobile communication applications. The proposed design consists of a microstrip patch antenna enclosed inside the split ring resonators, in which a split ring resonator was subtracted from the ground plane in order to obtain the results at lower frequencies by maintaining a compact size. This ESA was designed on FR4 substrate having a dimension of 30 mm × 30 mm × 1.6 mm. This antenna was created and simulated with the Ansys HFSS. The ESA was fabricated by chemical etching and it was measured with the MS2037C Anritsu Combinational Analyzer. The simulated results show that the ESA attains a bandwidth of 100 MHz (with S11 < -10 dB) at 0.9 GHz. The bidirectional radiation pattern in both H and E planes with a radiation efficiency of 80% at the resonant frequency was obtained. A close agreement of 90% between the simulated and the measured results was observed.