- Volume 1 Issue 2
In this paper, the input impedance of coaxial fed rectangular microstrip patch antenna located inside rectangular waveguide is calculated by using the cavity model and the mode excited in the waveguide by the patch antenna. The return loss and efficiency of the patch antennas as a function of feed position in. free space and in waveguide are calculated and compared. The maximum efficiency of the antennas in waveguide and in free space are obtained at different feed position.