Techniques for bandwidth optimization of probe-fed microstrip antennas on small, finite ground planes

Finite ground planes limit the performance analysis of microstrip antennas which are traditionally designed assuming an infinite ground plane. In this paper a technique based on a cavity model and full-wave (MoM) analysis is proposed for bandwidth optimization and results are included for probe-fed microstrip antennas on finite ground planes. Results for optimized probe locations, for 2:1 VSWR bandwidths, are compared that are obtained using both cavity model and IE3D code-which employs a moment method (MoM) technique and genetic algorithms to determine the optimized probe locations. The results suggest that the cavity model can be used to determine the probe location for the best 2:1 VSWR bandwidth on an infinite ground plane, which can be further refined by subsequently using the 1E3D code when considering finite ground planes.