Mathematical Model of a Square Waveguide Polarizer with Diaphragms

Abstract

The development of new mathematical model for guide polarization converter with diaphragms was carried out in the research by the method of wave matrices. In addition, numerical modeling of the performance of a polarizer with diaphragms is made by simulating the propagation of the fundamental modes with perpendicular linear polarizations. The wave matrix model was obtained by splitting the polarizer into separate structural elements. Each element was described by its own wave transmission matrices. As a result, a general wave scattering matrix was formed. Based on the elements this matrix the electromagnetic characteristics of the considered polarizer were obtained theoretically. In particular, complex reflection and transmission coefficients were calculated. Their modules and phases were analyzed in the frequency interval 10.7-12.8 GHz. To check the correctness of the obtained results an independent numerical simulation was carried out applying the finite element methodology in the frequency interval. The results of both approaches are in good agreement. The engineered converter of polarization with four diaphragms provides a reflection coefficient modulus of less than 0.14 and a transfer coefficient modulus of more than 0.99 for two orthogonal types of polarizations. As a result, a rigorous mathematical method was developed to analyze the elements of the scattering matrix of a waveguide polarizer with diaphragms. It can be used for the development of new broadband waveguide polarizers and waveguide filters based on diaphragm elements.

Accuracy and Agreement of FDTD, FEM and Wave Matrix Methods for the Electromagnetic Simulation of Waveguide Polarizers

“…For the obtained dimensions of the developed polarization device, the basic electromagnetic characteristics in the operating frequency range of 13.0-14.4 GHz were calculated and optimized using the proposed method [82][83][84][85], the finite integration method [86] and the finite element method [87,88], respectively, which are presented in Tables II-IV. For the obtained dimensions of the developed polarization device, the basic electromagnetic characteristics in the operating frequency range of 13.0-14.4 GHz were calculated and optimized using the proposed method [82][83][84][85], the finite integration method [86] and the finite element method [87][88][89], respectively, which are presented in Tables II-IV. Tables 2-4 show that the developed device for polarization conversion with three diaphragms provides satisfactory matching in telecommunication systems.…”

Computer‐aided development and experimental investigation of a double‐ridged orthomode transducer for modern satellite and space communication systems

“…[11][12][13][14] The advantages include the reduction of amplitude and polarization distortions caused by Faraday effect in the ionosphere and by the multipath propagation in urban environments and mobile systems. [15][16][17][18][19][20][21] Wideband antenna systems with the possibility of simultaneous operation at two orthogonal circular or linear polarizations require application of specific kinds of waveguides (with irises, [22][23][24][25][26][27][28][29][30] ridges, [31][32][33][34][35][36][37][38][39] corrugations, [40][41][42][43][44] posts, [45][46][47][48][49][50] or a longitudinal septum 51,52 ) and microwave devices in the antenna system's structure. [53][54][55][56][57]…”

“…Wideband antenna systems with the possibility of simultaneous operation at two orthogonal circular or linear polarizations require application of specific kinds of waveguides (with irises, 22–30 ridges, 31–39 corrugations, 40–44 posts, 45–50 or a longitudinal septum 51,52 ) and microwave devices in the antenna system's structure 53–60 . One of frequently used and compact solutions for the operation at two orthogonal circular polarizations are the integration of a septum‐based polarization converter into a waveguide antenna feed system 61–65 .…”