Research On The Decoupling Technologies Of The Beidou Anti-jamming Antenna Array

In recent years, The Beidou Satellite Navigation System developed by China independently is widely used in mapping, water resources, fisheries, transportation, military and other fields. It means that the System has significant political, economic, technological and military significance. However, as a global satellite navigation system, the satellites of The Beidou System are thousands of kilometers away from the Earth. This makes the signal very weak and susceptible to the complex environment and human factors, so it’s very important to carry out researches about the anti-jamming of The Beidou System. Due to the antenna array is an important part of The Beidou anti-jamming system, it’s of great theoretical and practical significance to carry out some researches about the antenna design and decoupling technologies of the Beidou anti-jamming antenna array system.Under the premise of the adaptive array of anti-jamming technology, this paper focuses on the key technologies of Beidou anti-jamming antenna array and has carried out the following tasks in the aspects of antenna design and array decoupling:1. According to the requirements of the Beidou anti-jamming array for the single element, this paper has designed a small circularly polarized microstrip antenna by dual-fed method. Simulated and experimental results satisfy the index requirements and verify the reasonableness of design ideas. Then we use the single element to form a 2×2 array in the ideal condition and we get the nulling generation process in the simulation.2. In recent years,the trend of miniaturizd array platform allows the array element spacing becomes smaller, so the mutual coupling brought by small element spacing can’t be ignored. This paper has analyzed and discussed the effects of mutual coupling on the anti-jamming performance. As the mutual coupling correction algorithm can’t improve the signal to noise ratio of the system, this paper has a detailed qualitative analysis of the generation process about the mutual coupling of a two element microstrip antenna array. Then the paper has adopted the decoupling and matching network(DMN) to decouple the coupling of the two element single-fed array whose element spacing is 0.3?. Simulated and experimental results of the single-fed array have shown that the DMN has not only improve the ports isolation,but also made the maximum pattern direction close to the axial direction.Simulated results of the two elelent dual-fed array have shown that the DMN has improved the isolation of the feeding ports. The results above have shown that the DMN has some significance in the engineering applications.3. For the 2×2 single-fed circularly polarized microstrip antenna array of 0.3? element spacing,this paper has a mutual coupling mechanism analysis according to the antenna mode analysis theory. This paper has also adopted the DMN based on the eigenmode theory to decouple the four element array. Using lumped elements in the ADS simulation has achieved a good feeding ports isolation in the center frequency band.