Multi-band Circular-polarization Antenna Research And Design

Antenna, as the necessary elements of communication and navigation devices, has been developing rapidly recent years. More and more complex factors should be taken into considerations when designing antennas to meet various application needs. The developments of mobile communication and multi-mode navigation technology, require antennas be featured with a series of characteristics, such as multi-band operation, circular polarization, compact size.etc. An introduction of current development status of modern satellite navigation technology was given, and the characteristics and advantages of multimode satellite navigation system were listed. Multimode navigation is. the inevitable trend for the future navigation development, which leads to the wide application needs for multi-frequency circular-polarization antennas. And then the main techniques to achieve circular-polarization and miniaturization goals for four-arm helix antenna and micro-strip antennas were summarized.Based on the theoretical study, a tri-band circular-polarization stacked patch antenna was proposed, and a prototype was fabricated and measured. The antenna was featured with simplified structure, compact size, low cost and so on. Both the-10dB impedance bandwidth and3dB axial ratio bandwidth is covering GPS L1band (1.575GHz) and two S-band2.2GHz-2.4GHz,2.025GHz-2.11GHz. The main polarization gain of the antenna at1.575GHz,2.05GHz,2.30GHz is5.42dBi,6.3dBi,6.09dBi respectively. Test results show that all the performances of the antenna meet the needs of all aspects of the GPS navigation applications. The antenna design and simulation process were carried out in CST which is a full-wave electromagnetic simulation software and a complete design and analysis process was given. The proposed antenna was developed from a basic single-band circular-polarization micro-strip antenna, optimized gradually and ultimately achieved ideal performance. To better understand the working principle of the antenna, the main parameters were scanned in CST and simulation results are analyzed and summarized.Two novel multi-band circularly polarized antennas, which are suitable for handheld terminal devices, were proposed too. The structures of the two antennas were similar and both of them adopted three-dimensional design structures, which effectively reduced the space occupied by the antenna. The simulation and parameter optimization were completed in HFSS and two prototypes were fabricated and measured. both the theoretical and experimental results covered L1-band of GPS and Galileo, L1C/A band of GLONASS, B1band of Beidou system and L2C band of GPS. All the performances were good to meet the navigation application needs. The detailed process of antenna design was given and how the antenna can achieve circular-polarization and dual-band operation was analyzed. The main parameters of the antenna structure were scanned in HFSS, and a comparative analysis of a series of simulation results were given, The basic rules how the various parameters affect the performance of the antenna were summarized lastly...