Ultra-wideband Antenna Design and Optimization for Constant 10-dB Beamwidth in E-plane

The quad ridged horn antenna (QRHA) is designed with constant 10 dB beamwidth in the E-plane over 1 - 19 GHz band. The antenna is occurring from 2 parts which are coaxial to a waveguide adapter and a flare section. Higher order modes are suppressed by minimum of 16 dB using pyramidal back cavity in the adapter section. The VSWR of the antenna is below 2 in range of 2 - 20 GHz. The average of 10 dB beamwidth of the antenna is about 125 degrees with maximum deviation of 9% in the desired band. Also, the phase center variation is below lambda/4 for the entire band.