Extraction of Lumped Circuit Parameters of Coupled-Cavity Structures by using 3D Finite Element Method

Coupled-cavities are employed in the traveling-wave amplification of microwaves as slow wave structures. The general behavior of coupled-cavity structures can be suitably described by using a lumped circuit model. In this work, the parameters of the equivalent lumped circuits of the Hughes and the Chodorow-Nalos structures can be extracted by fitting the dispersion relations based on 3D HFSS simulations. The characteristics of the 3D structures can be simply described by the equivalent lumped circuits