Extended analysis of rectangular microstrip resonator antennas

An extended theory on rectangular microstrip resonator antennas is presented using the cavity model. Radiation from all four edges of the open cavity is taken into account as well as dielectric and ohmic losses. For a rectangular microstrip antenna excited in its lowest resonance mode, losses, input conductance, and bandwidth are calculated and plotted versus frequency for some different parameters, showing that bandwidths of up to 15 percent (for a voltage standing-wave ratio (VSWR) of less than two) are possible to achieve in the band.