Complete network characterisation of stratified planar circuits using the method of moments technique: an integrated approach to lumped and wave ports

This study gives a full treatment of the network characterisation of multi-port planar circuits embedded in shielded stratified media with an integrated approach to lumped ports and wave ports. The details of the mathematical formulation for the retrieval of scattering parameters are given in three cases: networks possessing only lumped ports, networks possessing only wave ports and networks with a combination of both types. A detailed description of the computer algorithm is presented to help the reader easily reproduce our results. The implementation of combined ports in the framework of planar multi-layered structures is particularly useful in analysing systems that have waveguide connections and planar circuitries in their structure, such as cavity-backed antennas and their associated feeding systems, dielectric resonator antennas or compound microwave filters. In such structures one can divide the system into the waveguide structure and the planar circuitries and analyse each part separately with an appropriate and efficient numerical technique. Network characterisations will be consequently communicated at the port interfaces. This strategy enhances the total performance of the computational scheme to a great extent, while not affecting the accuracy of the full-wave analysis.