Design of Rectangular Microstrip Antenna on Finite Ground Plane for Circular Polarized Response

摘要

Rectangular microstrip antenna with proximity feed is proposed for circular polarized response. An offset placement of proximity feed excites TM_(01) and TM_(10) modes in rectangular patch which gives impedance bandwidth of higher than 760 MHz (>65%) with axial ratio bandwidth of 48 MHz (5.28%) on an infinite ground plane. The antenna exhibits broadside pattern with maximum gain of 8 dBi. In practical application of proposed antenna finite ground plane will be used. Further in the proposed paper, detailed study to outline the effects of finite dimensions of ground plane below the rectangular patch and its effect on axial ratio bandwidth is presented. With smaller ground plane, dimensions of rectangular patch have to be altered against larger and infinite ground plane design, for to cover same frequency range of axial ratio bandwidth. Thus proposed study will be helpful in understanding the effects of ground plane dimensions on circular polarized bandwidth while designing antenna for given circular polarized application.