Designing Cassegrainian reflector and feed system for a cloud radar: The Minimum Blockage Condition

Dual-reflector antennas are considered as pencil beam antennas that can produce radiation identical to searchlight beams. As compared with front-fed configuration, design of dual - reflector geometry is complicated since the parameters like feed location, subreflector size, required taper on subreflector, selection of focal length to diameter ratio of the main reflector, amplitude distribution provided by feed etc. are to be adjusted as per the given specifications. Also the sidelobe suppression effort requires the antenna to be designed for minimum subreflector blockage. In this paper, design of such a Cassegrainian reflector is considered for the Minimum Blockage Condition. Along with the parameters like high gain and low cross-polarization; low VSWR is also one of the prenominal parameter that can be achieved by designing the conical corrugated horn antenna with throat section. The design of Scalar Feed is also discussed. This type of design is easier than the former. For obtaining the radiation diagram, `Induced Current Analysis of Reflector Antenna´ software is used.