FD-TD analysis of bandwidth characteristics in the asymmetrical ridge rectangular waveguide

The finite-difference time-domain (FDTD) method is applied to analyzing the influence of the ridge position on the cutoff wavelength and bandwidth of the dominant mode in the ridge waveguide. The cutoff wavelength and bandwidth of the dominant mode of the asymmetrical single- and double-ridge rectangular waveguide have been analyzed. Numerical results demonstrate that FD-TD method is precise and efficient, and the cutoff wavelength and bandwidth can be adjusted by changing the ridge dimensions as well as by adjusting its position.