A CAD-ORIENTED APPROACH FOR APERTURE-COUPLED PATCH ANTENNAS

A simplified model is suggested for describing aperture-coupled patch antennas in CAD applications. The scattering parameters of the antenna are calculated by assuming a single mode distribution for the current s on the slot and on the microstrip-line. The coupling between the slo t and the patch is represented by superimposing a contribution from a fundamental mode and that from higher order modes. The former is descr ibed by a complex eigenvalue of a cavity model with impedance walls. T he latter is described by a parallel plate waveguide model, which prop erly accounts for the storage of reactive energy close to the slot. Nu merical results are presented and compared with experiments. In partic ular, S-band patches have been fabricated and tested to demonstrate th e accuracy of the model. (C) 1993 John Wiley & Sons, Inc.