Comparative Analysis of Compact Satellite Polarizers Based on a Guide with Diaphragms

In this article we carry out the comparative analysis of new compact satellite polarisers based on a square guide with diaphragms. The main electromagnetic parameters of the developed microwave guide devices with various amount of diaphragms were obtained within the satellite frequency interval from 10.7 GHz to 12.75 GHz. Waveguide polarization converters with different amount of diaphragms from 3 to 5 have been designed and optimized. The main parameters of the presented polarizer were calculated applying the numerical method of finite integration in the frequency domain. Optimization of the electromagnetic parameters of the developed waveguide devices was carried out using the finite elements method in the frequency domain. As a result, sizes of the guide polarizer designs have been optimized for the provision of improved polarization and phase parameters. The performed analysis showed that a waveguide polarizer with five diaphragms has the best electromagnetic parameters. The developed compact polarizer with five diaphragms based on a square guide provides a minimum deviation of the output phase difference from 90 degrees and high level of isolation between linear polarization over the entire operating frequency range. Presented in the article compact waveguide polarization converters can be applied in modern satellite systems, which require efficient polarization transformation and separation of signals.

Comparative Analysis of Compact Satellite Polarizers Based on a Guide with Diaphragms

In this article we carry out the comparative analysis of new compact satellite polarisers based on a square guide with diaphragms. The main electromagnetic parameters of the developed microwave guide devices with various amount of diaphragms were obtained within the satellite frequency interval from 10.7 GHz to 12.75 GHz. Waveguide polarization converters with different amount of diaphragms from 2 to 5 have been designed and optimized. The main parameters of the presented polarizer were calculated applying the numerical method of finite integration in the frequency domain. Optimization of the electromagnetic parameters of the developed waveguide devices was carried out using the software CST Microwave Studio. As a result, sizes of the device designs have been optimized for the provision of improved polarization and phase parameters. The performed analysis showed that a waveguide polarizer with five diaphragms has the best electromagnetic parameters. The developed compact polarizer with five diaphragms based on a square guide provides a minimum deviation of the output phase difference from 90 degrees and high level of isolation between linear polarization over the entire operating frequency range. Presented in the article compact waveguide polarization converters can be applied in satellite systems, which require efficient polarization separation of signals.

A Miniaturized Compact Wideband Partial Ground Antenna Used in RFID Systems

In this paper, a new compact waveguide-fed flexible antenna is presented for RFID applications. This antenna is operated at the resonant frequency of 2.45 GHz. The proposed antenna is designed with small size on (43 × 30) mm2 epoxy substrate material type (FR4) used in the proposed antenna that has a dielectric thickness of 1.6 mm, the relative permittivity of 4.3 and tangent loss of 0.025 where the FR4 dielectric combines good electrical features, price, and availability. The return loss is less than −10 dB in the frequency interval (2.1 − 2.98) GHz. The maximum gain of the proposed antenna is 2.47 dB. The proposed antenna has a wide impedance bandwidth, and an omnidirectional radiation pattern with a small size has been achieved. The overall size of the compact antenna are (43 × 30 × 1.67) mm3. The Computer Simulation Technology (CST) microwave studio software is used for simulation.