The Analysis Of Microstrip Antenna Considering The Mutual Coupling And Compensation

Due to the unique advantages, such as low-profile, lightweight, easy integration, micorstrip antennas and arrays are widely applied in various wireless communication and radar systems. However, mutual coupling inevitablely exists among microstrip elements, especially when the element spacing is very small, the impact of mutual coupling on the input impedance and the array's directivity pattern is very complicated. Therefore, an accurate and efficient method to study the characteristics of mutual coupling array antenna is very essential.This paper introduces a method of RWG basis function to study the mutual coupling characteristics of the antenna. Firstly, it introduces the RWG basis function and its applications of calculating the array antenna's surface current and directivity pattern, and calculating the dipole element's input impedance and the array's radiated power against the element space varying. Secondly, it introduces the method of transmission-line to analyze rectangular microstrip antenna and investigates all kinds of factors that affect the antenna's characteristics. Thirdly, it introsuces general method of moment to calculate the rectangular microstrip patch arrary's surface current and analyze the method of solving generalized impedance matrix and voltage-fed. For the reason that it is very difficult to deal with the integral singular points of impedance matrix and to use the electric field integral equation when calculating the directivity pattern, thus we analyze microstrip patch array's mutual coupling characteristics based on the RWG basis function, Finally, we verify the conclusions by comparing the difference between the results from ideal directivity patterns and coupled directivity patterns;also from RWG based and generated from HFSS.By using equivalent network method, we analyze the array's output signal with considering the mutual coupling, and also simulate an adaptive linear array against varied the element spacing and the singal direction. A compensation method of mutual coupling is proposed with coupling matrix and the respective applicable conditions which can be used as an algorithm to calculate the coupling matrix. This method is not only good for analyzing microstrip array antenna but also suitable for any arbitrary types and arranges of array antennas.