Research Of The Planar Microstrip Antenna Array Based On Space Mapping Algorithm

Antennas are the important front-end devices of modern wireless communication system. Because of a series of advantages, microstrip antennas attract more and more attention. With the increasingly high performance requirements, the microstrip antenna array show more advantages than a single microstrip antenna in some areas. While the performance of microstrip antenna array is not a simple superposition of the single antenna, because the mutual coupling effects between its elements have a great impact on the performance of the overall array. And the complexity of the mutual coupling effects requires a lot of effort and time-consuming in some design optimization methods of the antenna array, so the fast and accurate analysis and optimization for the microstrip antenna array has become the domestic and foreign scholars’research priorities. The space mapping algorithm proposed by John. W. Bandler. The basic idea of the space mapping algorithm is first establishing a mapping between the two parameter space of the coarse model and the fine model, then using the iterative calculation and updating the coarse model instead of the fine model which has a high cost of calculation. With the accumulation of data, the coarse model response will gradually close to the fine model response,and ultimately achieve consistent within the error range. The advantages of this algorithm are high-efficiency and high-precision.This paper first introduces the basic concepts and the development of the microstrip antenna, and the basic concepts of the space mapping algorithm. Then the mutual coupling effect in far-field radiation pattern of planar antenna array is studied by using space mapping algorithm idea. In the paper, the far-field radiation pattern of planar antenna array is analysed by the basic theory of planar antenna array and the port network theory, and has derived the corresponding formulas. First we establish the coarse model without considering the mutual coupling effects between the elements, which has high computational efficiency but low accuracy, and the fine model, the whole array element model considering the mutual coupling effect, which has high accuracy but low computational efficiency. Then we study the mutual coupling effect in depth by matlab programming and parameter extraction using HFSS with the aid of the principle of space mapping first based on a3*3planar array of rectangular microstrip antenna and then a5*5planar array. Through these two examples, the reliability of this method and the effectiveness of combining of the efficient in the coarse model and the accurate in fine model are verified, which have a good reference value for the optimization analysis of the large antenna array.