dual-reflector
3.Cassegrain antenna is a kind of dual-reflector antenna, with characteristics of high-gain, narrow-beam, suppressed side lobes and agility in designing.
4.For a dual-reflector,such as Cassegrain antenna,the total scattered field should be the phase summation of the diffracted and reflected fieldsfrom the mainreflector and subreflector.
6.According to field correlation theorem,the efficiency of microwave dual-reflector antenna is computed and analyzed by means of GTD in this paper,which the mainre flector is paraboloidal and subreflcctor is arbtrary spun and symmetric by axle.

