A modified square patch antenna with improved bandwidth performance for WiFi applications

A modified square patch antenna, for WiFi applications, operating at 5.5 GHz, is proposed in this article. A complementary square open loop resonator, having the resonance frequency at the upper 3 dB frequency of the patch resonance, is introduced on the patch to enhance the bandwidth more than twice that of the conventional square patch antenna operating at the same frequency. The concept of introducing a resonant slot at 3 dB frequency helps to eliminate the cross-polarized component seen in most of the classical designs due to the presence of resonance slots. Simulation results show that 2:1 VSWR bandwidth of the antenna is 7% whereas the conventional square patch antenna offers only 3% bandwidth. The proposed antenna has a compact size of 1.9 cm × 2 cm. It offers a uniform gain of 4.25 dB and a directivity of 6.1 dB at the frequency of operation.