Development of a 6-18GHz Quad-Ridged Flared Horn

In this paper, the cutoff frequency of the quad-ridge flared horn (QRFH) with respect to its ridge is studied. Based on the studies, we developed a QRFH to operate from 6 GHz to18 GHz with high efficiency. The test results show that the return loss is less than -10 dB across the whole band. When the QRFH is used to illuminate a reflector antenna, the aperture efficiency is above 55.8%.