Computational design of a gain-stabilized 2.5∶1 bandwidth ridged horn antenna

The design of a ridge waveguide horn antenna covering the 18-45 GHz band and having a gain of 15.5 dBi plus or minus approximately 0.5 dB throughout the band is discussed. This gain stability enables the antenna to achieve a total beamwidth variation of only 13 degrees (10 degrees average) across the entire band, while achieving a return loss greater than 18 dB throughout the band.