The Research Of A Kind Of Active Anti-Interference Multi-mode System Of Antenna

Global Navigation Satellite System who has irreplaceable not only in the economic field but also in the defense is symbol of a big country with soft power.However, because of the long distance between the Earth and satellites, the signal from satellites is very weak and easy to interference caused by space or man-made. Therefore, it is very important to study the anti-interference technology in theoretical field and practical applications. At the same time the study for compatible multi-mode satellite navigation and positioning antenna has a realistic significance because of the coexist of GPS, GLONASS of Russia, Galileo of European and China’s Beidou satellite navigation.This paper which is supported by the fund of the central college fund project" High accuracy shipboard multi-mode satellite navigation and positioning antenna" deals mainly a kind of active anti-interference multi-mode system of antenna, especially on wide-band power-split phase shifter based on composite right/left hand transmission wire, wide-band circular polarization microstrip antenna, array design, and integrated LNA and digital phase shifter. The main contribution is follows:Firstly, a four-feed wide-band antenna unit-cell is designed for anti-interference antenna array. The measured results show that the antenna has good circular polarization radiation characteristics over the GNSS working band. The measured results are in good agreement with the simulated ones. The gain of the antenna with LNA is24.9dB.Secondly, a study on how to choose the number of the elements, the space between them and the arrangement in the anti-interference antenna array is showed. Considering a4anti-interference antenna for example, the nulling process is described, which is validated with the High Frequency Structure Simulation Software (HFSS).Thirdly, considering the weak signal from satellite, a double-stage Low Noise Amplifier which can provide gain of25dB and whose noise factor fluctuates in0.7dB-1.1dB is designed, processed with engraving machines and tested.Finally, The nulling process need different phase from every antenna element,22.5°,45°,90°and180°digital phase shifters are designed to provide16kinds of phase shift status, which meet the need of anti-interference antenna array.