Rectangular microstrip patch antennas with infinite and finite ground plane dimensions

The rectangular microstrip patch antenna is analyzed as to radiation conductance and resonant frequency. Improved formulas for the GO-conductance are presented. The formula for the input impedance based on the coax-excited transmission line model is shown to agree with computer-generated and measurement results. Solutions for the radiation conductance and resonant frequency of a finite ground plane are obtained which take the contribution of the ground plane edge diffraction into account and which are valid under the condition that only one of the ground plane dimensions is finite at a given time. Comparison with experimental results shows that the formulas are sufficiently accurate, except when both ground plan dimensions are small, in which case other methods must be used to calculate the radiation conductance.