Short-Pulse Microwave Coupling to Apertures in a Conducting Plane

Computational studies are made of the diffraction of microwaves by circular apertures in a conducting plane. The fields in and behind the apertures are calculated by linking high and low frequency numerical approximations through the resonance region, using a solution of the electric field integral equation (EFIE). The transient responses of the apertures to short microwave pulses with varied rise and decay times are obtained by Fourier inversion of the frequency domain responses. Transfer functions are calculated in and behind the apertures. Agreement is found with exact theory and experimental results.