Accurate Parameter Extraction of Substrate Integrated Waveguide with Equivalent Resonator Model

The searching for characteristics of arbitrary guided-wave structures can be transformed to the analysis for the harmonica-wave oscillation performance of a resonant cavity by means an equivalent resonator model as presented in this paper. In the analysis of substrate integrated waveguide (SIW), its propagation constant should be determined, which includes attenuation constant and phase constant because an SIW is a semi-unbounded structure. With the equivalent resonator model, the calculation of attenuation constant can be removed and only the phase constant is concerned. Therefore, the periodic boundary condition is greatly simplified and the simulation of SIW guided-wave properties can be significantly speeded up. Moreover, some numerical methods, for example, finite difference time domain method (FDTD), which cannot be adopted in the case of modeling a complex propagation constant, can be used conveniently since the simulation has been transformed to a lossless guided-wave problem in this case. So far, the equivalent resonator model has greatly enabled accurate modeling for SIW components and antennas.