On The Vehicle-borne And Satellite-borne Circular Polarization Antennas

The research works are made with scientific projects, the design method of the vehicle-borne dual-band circular polarization antenna and dual-band high phase center stability circular polarization antenna used in satellite is presented. It includes two parts in this thesis:1. The engineering prototypes of vehicle-borne antennas have properties with dual-band, common-caliber, wide beam-width and circular polarization for the vehicle-borne communication systems; 2. Another engineering prototypes of antennas used in satellite have properties with dual-band, high phase center stability and circular polarization for the satellite-borne communication systems.Firstly, the requirements of the parameter for the dual-band, common-caliber, wide beam-width and circular polarization antennas are presented. Two piece of microstrip antennas are combined so as to the index of the antenna to be satisfied. The circular polarization antennas are simulated and optimized by commercial EDA software Ansoft HFSS. Then the antenna with dual-band, common-caliber, wide beam-width and circular polarization is made, which includes L band and S band antenna. On this condition, the prototype of the antenna is constructed and measured. The proposed antenna has characters that VSWR is less than 2, beam width is more than 100°and axial ratio is less than 3dB. The measured results agree well with simulated ones, and the design is valid.Secondly, the design method of the satellite-borne high phase center stability dual-band circular polarization antenna is presented. It includes two piece of microstrip antenna and fed by four points. The antenna fed with two type forms are simulated and optimized by commercial EDA software Ansoft HFSS. The simulated results show that the characters of this antenna are enough to content application. On this condition, the prototype of the antenna is constructed and measured. The designed antenna operate at L1 band and L2 band has the characters that VSWR is less than 2, axial ratio is less than 3dB and high phase center stability. The measured results agree well with simulated ones. The measured results show that the antenna has high phase center stability property with four feeding. In addition, the measured results show that this design method is valid and it can be applied.