On The Airborne Arrays And Circularly-Polarized Antennas

The research works are made with scientific projects in this thesis. The content of the research works are included of three parts: 1st, the engineering prototype of the airborne array antenna with special radiation pattern. 2nd, the engineering prototype of the high gain circularly polarized airborne microstrip array antenna and the model of the dual-band, common-caliber, wide beam-width and circularly polarized airborne antenna. 3rd, the engineering prototype of the microstrip array antenna conformal to conical surface.Firstly, airborne array antenna with special radiation pattern is discussed in this paper, the design methods of element antennas and feed network constituted by multilevel unequal Wilkinson power divider are presented and simulated by software HFSS. According to the simulation results, engineering prototypes of the airborne antenna with special radiation pattern are made. The measurement results are agreed well with the simulation results, which indicate that the design method is available and valid.Secondly, according to the requirements of projects and the theory of microstrip antenna, a single-point-fed circularly polarization microstrip antenna element is designed and simulated by HFSS. On this basis, high-gain circularly polarization microstrip antenna array is designed and engineering prototypes of this antenna array are fabricated. The measured results of the antenna prototypes are consistent with the simulated results, which indicate these antenna design methods are effective and universal. Further more, one double-point-feed circularly polarization microstrip antenna element is designed, on this basis, the model of the dual-band, common-caliber, wide beam-width and circularly polarized airborne antenna is presented and simulated by HFSS.Finally, a method for designing the compact conical conformal array antenna for GPS is proposed in this thesis. The way to achieve compact antenna size has been discussed. And the antenna is designed by software HFSS. A prototype has been fabricated and tested. The measured results shows that the array antenna proposed in this paper has compact size and well conformal effect; the omnidirection of the H plane pattern has also been realized. So it is valuable for the practice.