Synthesis of Waveguide Diaphragm Polarizers Using Wave Matrix Approach

Abstract

Waveguide polarization converters perform the transformation of circularly polarized signals to linearly polarized signals in receiving antennas. In transmitting antennas they perform the inverse conversion of linearly polarized signals to circularly polarized signals. This paper presents a new synthesis method and its application for the development of optimal waveguide polarization converters with diaphragms. The chosen diaphragms-based design allows to improve the performance compared to designs with other types of discontinuities. The results of the performed synthesis method were presented for the polarizer operating in the satellite frequency range 10.7-12.8 GHz. The synthesized waveguide diaphragm polarization converter provides an output phase difference of 90° ± 2.8° in the whole operating satellite frequency range of 10.7-12.8 GHz. Its peak value of the standing wave factor by voltage is 1.67 for both linear polarizations. In addition, the minimum level of discrimination of the linear polarizations is 31 dB. The maximum level of calculated ellipticity parameter equals to 0.47 dB.