Dispersion and attenuation analysis of substrate integrated waveguides by driven eigenproblem computation

The leakage attenuation makes the modelling of substrate integrated waveguides (SIWs) a complicated complex eigenproblem. The analogy to resonators opens up a new way to solve the eigenproblem from a physical point of view. A novel driven eigenproblem computation is presented in this paper to solve the eigenproblem in periodic structure like SIW by treating the structure in a unit cell with periodic boundary and applying the model with an excitation. The dispersion and attenuation behaviour of a classical rectangular waveguide are analysed first to verify the method. Then, the method is employed to two SIW structures. Good agreement can be observed among the results from the driven eigenproblem computation, the software simulations, and the measurements.