On The Terminal Antennas For Satellite Navigation System And The Microstrip Arrays Conformal To Bomb Shell

The research works are made with scientific projects. The design methods of the terminal antennas for satellite navigation system and the microstrip arrays conformal to bomb shell are discussed in this dissertation. The major works done can be divided into three parts: the engineering samples of the terminal antennas for BeiDou-I satellite navigation system are made in the first part, and the simulated analysis of the terminal antennas for BeiDou-II and GPS dual-mode satellite navigation system are proposed in the second part, then the engineering samples of S-band telemetry conformal array and GPS conformal array on bomb shell are made in the last part. The main contents can be summarized as follows:Firstly, the project requirements of the terminal antennas for BeiDou-I satellite navigation system are illustrated. In order to satisfy the requirements, the design method with theories of quadrifilar helix antenna(QFHA) is given, which employs combined printed quadrifilar helix antenna(PQFHA). On this basis, the prototype of this antenna is fabricated and measured. The measured results show that for the designed antenna the VSWR is less than 1.5, the port isolation is greater than 30dB, and the AR is less than 3dB in operation bands. In addition, the antenna creates more than 120°beamwidth, and maintains a higher gain in low elevations. The measured results are agreed well with the simulated ones, which indicate that the design method is available and valid.Secondly, the design method of the terminal antennas for BeiDou-II and GPS dual-mode satellite navigation system is proposed, which employs cross-aperture coupled fed to achieve wideband circularly polarization properties. To improve multipath rejection effectively, the choke ring on which the presented antenna is mounted is introduced. Using the software Ansoft HFSS, the analytic model is simulated. According to the simulated results, the antenna can operate in BeiDou B1, B2, B3 and GPS L1, L2 bands with VSWR<1.5 and AR<3dB. Besides, the stability of phase center is less than 2mm in±50°beamwidth. Such that, the designed antenna meets the project requirements , and can be applied in engineering.Thirdly, the design method with theories of microstrip conformal array is discussed. Two engineering prototypes, S-band telemetry conformal array and GPS conformal array are fabricated and measured. The measured results show that the two designed antennas can obtain omnidirectional radiation characteristics in H plane. Therefore, it is available for this design method to be applied in engineering.Finally, the design method of ultra-wideband(UWB) antenna is devoted, two UWB planar monopole antenna are design, fabricated, and measured. The measured results show that the two antennas can meet the requirements of indoor UWB wireless communication systems.