The Analysis of Balanced Feed Low Cross-Polarization Quad-Ridged Horn Antenna for OTA Testing

This paper presents the analysis of a balanced feed low cross-polarization quad-ridged horn antenna. The S-parameters of the equivalent circuit is proposed which help the quad ridged transmission line design. The electric field amplitude of the fusiform-shaped cross filler conductor is further analyzed to verify the effectiveness of the fusiform-shaped cross filler in reducing the level of cross-polarization. The comparison of the electric field distribution of the quad-ridge waveguide loaded with fusiform-shaped cross filler conductor and the modes supported by the traditional quad-ridge waveguide is also shown to explained the principle of reducing cross polarization.