Design of Circular Cross-Section Smooth Profile Spline Horn Antenna for Ku-Band Applications

A novel design of smooth profile spline horn antenna having circular cross section for Ku-band application is presented in this paper. Conventionally, low cross-polarization and high Gaussian coupling efficiency is achieved by corrugated conical horn. However, due to multiple corrugation the production cost of such horn increases significantly. Smooth profile horn offers symmetric beam, low crosspol and low sidelobe are preferred choice as their manufacturing is simpler than that of corrugated conical horns. The proposed horn is designed for a wide frequency range 10-15 GHz Ku-band operation with rectangular waveguide WR-75 as its input. The measured result shows reflection coefficient value below -17dB over a wide band frequency 10-15 GHz for Kuband application. The measurement of fabricated horn demonstrate strong correlation between simulations and measurements in terms of input matching. The simulated results suggests that this horn has very high Gaussian Coupling efficiency comparable to classical corrugated horns and the constant beam waist of $2.7\pm 0.2$ cm over full waveguide band.