Evaluation of time domain Green’s functions for layered medium using FAM and NMSP methods

Recently, there is increasing interest in transient analyses of electromagnetic problems using the time-domain integral equations (TDIE) method. In order to use the TDIE for the micro-strip problems, several methods have been made previously to evaluate the time-domain Greenpsilas functions for layered medium. The Cagniard-de Hooppsilas method [2] is restricted to non-dispersive media and also becomes less useful for multilayered media. Another method, based on the full-wave discrete complex images (FWDI) theory [3], only involves the quasidynamic terms of the Greenpsilas function and renders inaccurate results as the bandwidth of the transient signal increases. The half-space extraction method with fast Hankel transform (FHT) has the difficulty to maintain the accuracy at the large source-to-field distance [4].