A Tri-Band Nested Coaxial Quad-Ridged Horn Feed for Satellite Communication

A novel C/X/Ka tri-band nested coaxial quad-ridged horn (NCQRH) feed for satellite communication is presented. The tri-band feed consists of the central spline-profile conical horn (SPCH) feed for Ka-band and the external coaxial quadridged horn (CQRH) feed for C/X dual-band over a 2.47:1 bandwidth. The 2.47:1 wideband characteristics of the NCQRH are achieved by introducing quad-ridged structure into the common coaxial horn. An efficient three-step optimization design method is proposed to achieve rapid optimization design of the feed and enable excellent performance in tri-band. A feed prototype is manufactured and tested. Simulated and measured results are in good agreement to validate the design method. The measured reflection coefficients are better than -10dB in the C/X dual-band and -23dB in the Ka-band, respectively. The aperture efficiency is better than 55% over the C/X/Ka tri-band by feeding a f/D=0.54 parabolic reflector antenna.