Rotationally symmetric FDTD for wideband performance prediction of TM₀₁ DR filters

The generalized perfectly matched layer (GPML) coupled with rotationally symmetric (RS)-FDTD method has been utilized to extract the S-parameters for several probe-coupled TM₀₁ dielectric resonator (DR) filters to directly obtain the theoretical wideband spurious performance. The computationally efficient (RS)-FDTD method has also been used to obtain accurate filter parameters for TE₀₁ and TM₀₁ dielectric resonators loaded in cylindrical cavities. The RS-FDTD method combined with digital filtering and the Matrix Pencil technique are used to analyze the resonant frequencies, inter-resonator coupling, and external Q values. When perturbation theory is used with RS-FDTD, accurate values of unloaded Q are obtained.