X/Ku-Band Highly-Isolated Circularly Polarized Horn Antennas for Full Duplex Applications

A simultaneous transmitting and receiving antenna system, consisting of two horn antennas operating at X/Ku band, is proposed for wideband full-duplex applications. Each horn antenna has circular aperture. Four ridges are inserted to decrease the working frequency and increase the bandwidth. The two horn antennas are embedded in parallel in a cylinder cavity. Corrugation slots are etched around the circumference of the cylinder cavity to increase the port isolation. The VSWR in the 8–18 GHz band is less than 2, and the peak gain is above 15 dBiC in the whole band. What's more, the port isolation between the transmitting and receiving horns is higher than 70 dB, with element spacing of 350 mm.