A Compact and Wideband Coupled-Line Coupler with High Coupling Level Using Shunt Periodic Stubs

A wideband microstrip forward-wave coupled-line coupler with high coupling value is presented. Compared with the conventional edge-coupled microstrip forward-wave coupler, this symmetrical structure, consisting periodic shunt stubs between the two coupled-lines, achieves wider operating bandwidth and larger coupling level. To characterize this structure, the equivalent circuit model is established and verified by measurement and full-wave results. The designed and fabricated prototype is a 0-dB forward-wave coupler with 0.6 mm stub length. This coupler exhibits a coupled amplitude balance of ±2 dB, good matching (15dB) and at least 15dB isolation between adjacent ports over a wide bandwidth of 66% from 2 GHz to 4 GHz centered at 3 GHz. The coupled-line length and width of the proposed structure are approximately λg/2 and λg/13, respectively, which makes it more compact than the conventional forward coupled-line couplers

A New Basis Function for Fast Computation of Electromagnetic Fields in Meshless Frames

Abstract—In this study, we try to develop the application of meshless method, particularly conventional radial point interpolation method (CRPIM), in computational electromagnetics. Indeed, this development focuses on the two important factors of every numerical algorithm, i.e., the computational time and the accuracy. Comparing the identity of shape and basis functions in RPIM, a new algorithm is proposed by which the shape and basis functions coincide. As a result, the computational time of existing RPIM in electromagnetics reduces, approximately to half. Also, the accuracy improves even in comparison with some developed methods as finite element method (FEM) and CRPIM. All improvements are shown in analysis of a parallel plate waveguide with internal discontinuity. Index Terms—Meshless Method, functional analysis, basis function, shape function, parallel waveguide. I