Design of a Dielectric-loaded Wide Beam Quad-ridged Horn Antenna

摘要

A quad-ridged horn antenna with dielectric loading covering the 0.6 GHz to 4 GHz band is proposed. Through the comprehensive design of differential feeding, a quad-ridged flare and loaded dielectrics, the feed antenna can be used to match a reflector with a large illumination angle of approximately 150 degrees. In the working band, the reflection coefficient is less than -8 dB, the isolation is larger than 40 dB, and its cross-polarization discrimination is larger than 31 dB for both polarizations. To verify the simulations, a prototype is fabricated and measured, and the measurements are in good agreement with the simulations. A reflector with a diameter of 33 meters and a focal diameter ratio of 0.33 is adopted to analyze the in-dish performance of the feed. The simulated results show that an average efficiency of 55.16% is realized and that the problem of the efficiency decrease caused by beamwidth narrowing at high frequencies is solved.