Ka-Band Shaped Reflector Hybrid Antenna Illuminated by Microstrip-Fed Horn Array

The numerical simulation and experimental results of a shaped reflector hybrid antenna (SRHA) structure are presented. The SRHA design was optimized for a scan range of plusmn3deg for a broadside of 45deg in elevation to maintain a gain of more than 38 dBi and low side-lobes. The designed SRHA has an aperture size of less than 60 times 70 m² and an offset structure for a low profile to meet the need for a mobile satellite platform. The antenna geometry and reflector surface was determined by a geometrical optic (GO) method and the radiation pattern was obtained by physical optic (PO) analysis. A microstrip horn array was used as a feeder and was composed of eight elements. The number of array elements was chosen so as to maximize antenna performances, such as gain and efficiency, without overdesign. The SRHA breadboard, including a shaped reflector and a feed horn array, was fabricated and measured. The measured results showed good agreement with the simulation and met the performance required of SRHA.