Design And Experimental Research Of Multi-band Shared-aperture Reflector Antenna

Reflector antenna is widely used in radar system,including weather detection and satellite communication,due to the characteristics of high gain,low side lobe and high efficiency.At present,operating bands at Ka and W-band are both applied in weather detection and satellite communication.In order to meet the increasing demand of multi-band applications,and minimize the structural complexity and volume of the antenna system,more and more multi-band reflector antennas are being researched and developed.This work mainly studies and designs the structure of multi-band feed horns.The main research contents of this article includes:(1)The main design methods of multi-frequency reflector antenna are compared,and a variety of implementation approaches are introduced,including: multiple feed horns,loading FSS as a secondary reflector and single multi-band feed horn.The design methods of multi-band feed horns are compared and studied,in addition,the advantages and disadvantages of single-cavity feed horns and multi-cavity feed horns are also expounded.(2)The propagation mode theory of waveguide is introduced,and common waveguide transmission modes with application scenarios are introduced.This article introduces the design of waveguide mode coupler and multi-band single-cavity feed horn.(3)Based on the designed multi-band feeding network,a multi-band feed horn with simple structure and single cavity is designed,which can work at the wide-distributed operating bands of Ku/Ka/W.The operating frequency points are 14.5ghz,35 GHz and 94 GHz respectively,and the ratio of highest and lowest frequency is about 6.5:1.At last,the multi-band shared-aperture reflector antenna system with wide-distributed operating bands is realized by means of multi-band feed horn.(4)In order to prove its universality and expansibility,the setting of the operating frequency and coupling port of the feed is further analyzed.Base on the original tri-band structure,it realizes the X/Ku/Ka/W quad-band reflector antenna system.The ratio of the feed's operating frequency reaches 10:1,which provides the key design for the wide-distributed quad-band reflector antenna.