Extended foster approach for equivalent circuit synthesis of lossy microwave circuits

In this paper, a circuit synthesis approach based on an extended Foster canonical expansion for representation of distributed passive lossy electromagnetic structures is described. Compact lumped element model is extracted from data provided by numerical TLM method in the time-domain and then embedded into a conventional circuit simulator. The equivalent circuit synthesis procedure is applied to the two-port low-pass and band-pass microstrip filters. The resultant circuits with elements are analyzed and the obtained S parameters results are in a good agreement with numerical results.