Design, Simulation, and Fabrication of Optimal Feeding Structure for High Power Radial Line Slot Array (RLSA) Antennas

Radial Line Slot Array Antenna (RLSA) is a high-efficiency plane array antenna used to generate circular polarization. Its reflection coefficient and bandwidth have a great impact on antenna performance. Two very important factors in determining the amount and bandwidth of the reflection coefficient are the converter of the coaxial cable to a radial waveguide and the180 degrees of electric bend. In this paper, first, a mathematical analysis of these two sections is performed. An optimal structure is then designed and simulated for these two sections. The proposed structure was used to design an radial line slot array antenna at 10.2 GHz frequency. The simulation results showed that the minimum reflection coefficient is -19.367 dB and its bandwidth is more than 1 GHz . Finally, a prototype of the simulated antenna was constructed using the proposed structure. Antenna power analysis showed that the minimum tolerable power of the antenna is more than 120 Mw and the antenna test results for the reflection coefficient also confirmed the simulation results.