Compact microstrip diplexers based on a dual-passband filter
Novel microstrip diplexer structures composed of a dual-passband filter together with two matching circuits are proposed. By using only a single dual-passband filter, the proposed diplexer may be made compact when compared with the conventional diplexer configuration which has two single- passband filters. In this study, the dual-passband filter is realized using the parallel-coupled microstrip structures, and the matching circuits are developed based on the stepped- impedance transmission-line sections along with suitable open stubs. By suitably incorporating the open stubs into the matching circuits, a 3 rd-order Chebyshev microstrip diplexer with dual center frequencies at 2.36 GHz and 5.17 GHz and an acceptable isolation is implemented.
Abstract A new formulation for the C 0 quadrilateral and Serendipity plate elements is presented. It is an extension of the mode-decomposition approach that has been successfully applied in evaluating the C 0 triangular linear plate element. In contrast to the triangular element, the concept of an equivalent discrete Kirchhoff configuration is utilized. The elements are applied to several examples and the performance of these elements is shown to be quite good.