Analysis of circular microstrip antennas on low- and high-relative-permittivity substrates

A simple and accurate cavity model called the modified Wolff model (MWM) is presented to compute the resonance frequency and input impedance of the circular microstrip antenna oil the PTFE, alumina, and GaAs substrates. Results of the MWM show better agreement with the experimental results as compared to results of the commercial software; namely, the standard cavity model adopted in the PCAAD, the multiport cavity, model (MCM), and the method-of-moinents- (MOM) based Ensemble. The MWM works with high accuracy on both the thin and thick substrates and from microwave to millimeter-wave range. (C) 2002 Wiley Periodicals, Inc.