Application of FDFD Algorithm Combined with Shift-and-Invert Arnoldi Technique in Bilateral Interdigital Coplanar Waveguide Slow Wave Structure

摘要

In this paper, the bilateral interdigital coplanar waveguide (CPW) slow wave line is studied. The slow wave effect is obtained by the capacitively loaded structure with a symmetrical interdigital line loaded on the both sides of the central line. This kind of the slow wave line can be regarded as a periodic guided wave structure. As a result, in order to accurately analyze this periodic structure, the finite difference frequency domain (FDFD) algorithm for periodic guided wave structures can be adopted to extract its complex propagation constant and characteristic impedance. The FDFD method for the analysis of periodic guided-wave structures will lead to a nonsymmetrical generalized eigenvalue problem. The shift-and-invert (SI) Arnoldi technique is used to directly resolve this nonsymmetrical generalized eigenvalue problem to improve the accuracy of original FDFD algorithm. Especially for the large scale eigenvalue problem, SI technique can have a very fast speed of calculation.