Demountable K/Q Band Coaxial Feed for Cassegrain Antenna

Lemberg, K.V., Boev, N.M., Kantyshev, A.V., Grican, O.B., Shabanov, D.A.// IEEE International Multi-Conference on Engineering, Computer and Information Sciences//

DOI: 10.1109/SIBIRCON56155.2022.10016929

In this paper demountable K/Q bands feed for satellite communication Cassegrain antenna is reported. The feed is based on the combined coaxial-circular waveguide, in which outer wall of a circular waveguide is used as an inner conductor of a coaxial waveguide. This design allows to simultaneously transmit and receive signals in two widely separated frequency bands. A coaxial joint, which is the key part of the feed, is proposed and described in details. The joint performs several functions. First is to transmit the microwave energy through both waveguides. Second is ensuring the waveguides sealing. And third is ensuring the circular and coaxial waveguides alignment. The joint simulation results demonstrated return loss below –20 dB and insertion loss less than 0.06 dB in 20-21 GHz frequency range (K-band) as well as return loss below –30 dB and insertion loss less than 0.15 dB in 43-45.5 GHz frequency range (Q-band). Mechanical prototype of the joint was manufactured and tested.