Gnss Anti-jamming Receiver Technology Research

Global Navigation Satellite Systems (GNSS) anti-jamming receivers and RF channels'designing technology are illustrated in detail in this paper. The weakness of navigation systems gains much attention to the anti-jamming technology researches. Today the multi-array antenna adaptive anti-jamming technology equips the best anti-jamming ability and is widely researched. Although algorithms are of most important in daptive anti-jamming technology, a good quality, minimum distortion multi channels are the preconditions to farthest behave the anti-jamming processes. Some simple analysis and research of adaptive anti-jamming technology are made firstly, then are described detailedly with how to use them in the navigation systems.Low noise, high linearity, and high uniformity radio frequency multi channels are the premises of all the multi-array anti-jamming technology either in the adaptive nulling antennas or in the adaptive beamforming antennas. And this is the major research theis of this paper. This paper not only enphasis on the single RF channel design but also on the multi-channel uniformity correction and realization. With single RF channel, the performance estimation and assignments are researched in order to fit navigation systems which is using spread spectrum and suitable for anti-jamming process. Electronic Design Automatic (EDA) softwares are used to simulate and optimise receiver systems, and calculate performace parameters such as noise figure and 3rd intercept point. For multi-channel, new methods using phase shifting networks to perform corretion are researched in the RF analog region. Under the precondition of gain consistent among each channel, a new method of RF Automatic Gain Control (AGC) system is designed to enhance dynamic range of the multi-channel receiver. The design methods of multi channels introduced in this paper when used in adaptive anti-jamming navigation systems can enhance nulling depth and beamforming directivity gain.