Design and implementation of THz ultra Gaussian corrugated feed horn

A novel THz Ultra Gaussian corrugated feed horn is proposed in this paper, which combines a sine-squared and a straight parallel profile to excite and couple the HE₁₁ and HE₁₂ modes at the optimum range of inputs. The center frequency is 0.34THz and the bandwidth is larger than 10%. The maximum fundamental mode Gaussian power coupling efficiency increases to approximately 99.8% in this design. Typically, this corrugated feed horn achieves sidelobe and cross-polar levels around -37 dB and -50 dB. Both the simulation and measurement results are given to illustrate the performance of the proposed horn. The measured results meet the simulated results very well.