Using N-port models for the analysis of radiating structures

Radiating structures with distributed parameters, such as PCBs, are considered as linear N-port networks and correlations between port currents and field strength values at arbitrary observation points are calculated. Knowing the S-parameters for all accessible ports the port currents can be re-calculated for other source and load scenarios. Field strength values are then obtained as a linear combination of contributions due to the individual port currents. The effect of changing load and source parameters, e.g. varying de-coupling impedances on a PCB, or changing the internal impedance of sources, on radiated fields can then be investigated in a very efficient way without repeating full wavefield simulations.