Studies On The Techniques For Integration And Miniaturization Of Multi-band Luneberg Lens Antenna Feeds

Multi-band feed antenna is a technical trend in modern satellite communicationbase station antennas, and has widespread applicational prospect in large reflectorantenna or Luneberg lens antenna. The advantages of multi-band feed antenna includegreater communication capacity, smaller system volume, low system cost andone-station with multi-propose usages, etc. Thus, the multi-band feed antenna design isan important issue for the satellite communication systems.In this thesis, some relevant studies on the design of multi-band feed antenna forlarge size Luneberg lens antennas are presented. including the following contents:Firstly, the applicational requirements of the Luneberg lens feed antenna areintroduced, including domestic and foreign development status. The designrequirements and applications of a multi-band feed for Luneberg lens antenna in thispaper are also presented.Secondly, the design approach of the Ku/Ka multi-band feed antenna is carefullystudied, and then different options are analyzed theoretically. Various parts of theantenna feed are considered by taking appropriate technical solutions based on differenttechnical requirements. And the design scheme of the antenna feed is finally determinedaccording to the aforementioned principles.Thirdly, a Ku/Ka multi-band feed antenna based on a nested coaxial waveguide isdesigned. In this design, the quadrature couplers are adopted to achieve the transceiverisolation. The adjustment of Ku-band and Ka-band antenna performance is achievedthrough horizontal corrugated flanges and a dielectric rod load respectively. Metal stepsbetween the coaxial waveguide structure are used for the matching adjustment atKu-band. Consequently, this feed antenna has a good transceiver isolation performance,a better VSWR, a rotationally pattern symmetry and a wide beamwidth characteristics,simultaneously.Finally, focused on a relatively large aperture sized Luneberg lens antenna, a jointsimulation of the designed feed antenna with Luneberg lens antenna is performed.Numerical results show that the designed Ku/Ka multi-band feed antenna basically meets the design requirements of the Luneberg lens antenna.