The analysis of distributed two-layers components in three-layer planar structure

Distributed two-layer components (also known as defective ground structures) are widely used to create filters with a wide stop-band, including matching networks for high-efficiency amplifiers. They are usually calculated either by equivalent circuit methods or by numerical methods. For a better understanding of physical processes in a distributed two-layer discontinuity in three-layer structures, it is desirable to develop semi-analytical methods that allow us to obtain dependences of constant propagation on parameters of structure. The transverse resonance technique (TRT) is close to such methods, which calculates the scattering characteristics of discontinuity in planar-type transmission lines in the microwave range. It is based on the solution of boundary value problems for three-dimensional resonators containing, in the general case, multiplane discontinuity. Such name of this method is due to introduction of boundary conditions in the transverse with respect to the discontinuity of the direction in terms of the coefficients of reflection from the ideal boundaries (electric or magnetic). The key to effectively solving a boundary-value problem (for example, by the Galerkin method) is its algebraization method that is, the choosing a basis on which the unknown field or current components are decomposed.