Modelling of dielectric losses in microstrip patch antennas: application of FDTD method

A frequency dependent complex permittivity is used to describe the dielectric losses of a microstrip patch antenna. The theoretical and experimental results for the usual parameters (input impedance, reflection coefficient and radiation pattern) of a rectangular microstrip patch are compared for a lossy and a nonlossy dielectric. Good agreement is obtained between the experimental measurements and theoretical results when the dielectric losses are considered.