Equivalent circuit model for a waveguide probe exciting a dielectric resonator antenna

A simple equivalent circuit model for arbitrarily loaded waveguide probes is constructed and employed to analyze the problem of a probe-fed dielectric resonator antenna (DRA). Expressions for the circuit parameters in terms of the probe length and position in the waveguide are obtained and can thus be easily optimized in the circuit simulator environment. The circuit parameters are determined by equating the reflection coefficient obtained through the method of moments (MoM) solution to that obtained using circuit analysis. The circuit model naturally allows the extension to the array problem, where the DRA array can be modeled using the multiport Z-matrix.