Characteristic mode analysis of ground plane size in microstrip patch antennas

The Theory of Characteristic Modes is proposed as a systematic approach to antenna design to achieve the goal of finding the antenna structure with optimum broadband behavior. This theory provides a physical insight to the radiating nature of microstrip patch antennas and reduces the design optimization time. In this paper, the resonant behavior of different ground plane sizes are analyzed using this theory. The modal analysis concludes that the larger the ground plane the more resonant the antenna structure is. Hence, microstrip patch antennas with larger ground plane are a good candidate to achieve the highest impedance bandwidth.