High performance waveguide polarizer for satellite information systems

Signals with circular polarizations are widely used in modern satellite information systems and wireless data transmission systems. Signals of this type require the application of specific antenna systems with polarization processing. This approach allows to save twice the frequency resources, which are limited. As a result, the information capacity of information transmission channels of satellite and another information systems increases. A polarizer is the essential element of antenna systems with circular polarizations. Such device carries out the transformation of circularly polarized electromagnetic waves into linearly polarized waves or vice versa. The application of a polarizer and of an orthomode transducer in antenna systems provides the transformation of the signals polarization and their simultaneous transmission to the isolated waveguide channels. The article contains the results of the analysis and optimization of a new high performance waveguide polarizer for satellite information systems. The design of the developed polarizer consists of a square waveguide with four diaphragms. The polarizer has been optimized for its application within the frequency band from 10.7 GHz to 12.8 GHz. The phase, polarization and matching characteristics have been analyzed and optimized using the numerical finite integration technique. The developed waveguide polarizer with four diaphragms provides the differential phase shift of 90 ° ± 3.5 °, voltage standing wave ratio less than 1.24, axial ratio less than 0.53 dB, crosspolar discrimination higher than 30.3 dB. Therefore, the created new polarizer based on a square waveguide with four diaphragms provides highly efficient performance in the whole operating Ku-band 10.7–12.8 GHz. The device can be widely applied in modern antenna systems with the processing of signal’s polarization in telecommunication, radar and satellite information systems