Characteristic Mode Analysis and Optimization of Meandering Probe Fed Patch Antenna for Wide-Bandwidth in UHF Band

Patch antennas operating in ultra-high frequency band (especially between 500 MHz and 1.5 GHz center frequency) have been seldom used in practical applications due to its narrow bandwidth limitations. The goal of this work is to enhance the bandwidth of a conventional patch antenna in the ultra-high frequency band by varying the location of meandering shaped probe. The -10 dB return loss (or S11) impedance bandwidth has been improved from 23.5% (before optimization) to 35.86% (after optimization). Characteristic mode analysis has been used to identify and understand the differences in impedance bandwidth before and after optimization. In addition, a rectangular shaped slot has been introduced to create a low-frequency resonance which expands our future scope for bandwidth improvement.