Application of FDTD method to NRD-guide bandpass filter design using half-wave step-impedance prototype

The application of the FDTD method to filter synthesis based on a half-wave step impedance prototype is investigated in the context of a coupled cavity NRD-guide band pass filter. The advantage of this method is that it gives the reflection coefficients of each discontinuity inside the structure. These parameters can readily be found using a full wave FDTD simulator. The accuracy of the approach is verified by a series of numerical simulations, using FDTD code, and experiments. This approach has been found to give a better agreement between theory and experiment than techniques used previously.