Research On K/Ka-Band Coplanar Beam Scanning Antenna Array For LEO Satellite Communication

With the reduction of rocket launch costs,the improvement of satellite manufacturing capabilities,and the advancement of integrated circuit technology,satellite communications have developed rapidly.Compared with medium and high orbit satellite communications,low-orbit satellite communications have the advantage of wide coverage,short transmission delay.In order to ensure the information transmission with the Ka-band high-throughput satellites during the movement of the platform carrier,it is of great significance to develop miniature satellite communication terminal equipment with the ability to “communicate in motion”.The beam scanning antenna is one of the best solutions for this application,and the beam scanning antenna integrated with the transceiver has a more compact structure.In this paper,for Ka-band low-orbit satellite communication application,two circularly polarized beam scanning antenna arrays with coplanar transceivers are studied:(1)Developed a K/Ka band dual circularly polarized coplanar beam scanning antenna array with high transmit and receive isolation.The aperture of the receiving and transmitting antennas are separated and placed on the same plane,and the two frequency band antennas work in the form of orthogonal linear polarization to improve the isolation between the two antennas.In order to verify the scanning characteristics,the 0°,20°,40°beam scanning of K and Ka-band antenna arrays were realized by designing a microstrip phase-shifting power divider network.A linear to circular polarizer was further designed and loaded on the designed linear polarization antenna array to achieve dual circular polarization.The measured results show that the inter-band isolation greater than 32 dB between the receiving and transmitting antenna arrays,and both K,Ka-band antenna array beam can scan to 40°.(2)Developed a K/Ka band shared-aperture dual circularly polarized coplanar beam scanning antenna array.The receiving and transmitting antennas are placed in the shared-aperture form and coplanar.The transmitting antenna works in the Ka-band with left-hand circular polarization,and the receiving antenna works in the K-band with righthanded circular polarization.In order to improve the purity of circular polarization,the K,Ka-band antennas adopt four element sequential rotation technique.The K,Ka-band antenna arrays 0°,20°,40° beam scanning are realized by designed a microstrip phaseshifting power divider network that satisfies a specific angle phase shift.The measured results show that both K,Ka-band antenna array beam can scan to 40°.