Research On Mutual Coupling Of Array Antenna Based On Method Of Moment

Mutual coupling seriously affect the performance of the array antenna, causing the radiation pattern distortion and active impedance variation.We must consider mutual coupling effects in order to design an excellent performance of antenna array. Moment of method is an efficient numerical tool that can accurately analyze mutual coupling effects.In this paper, method of moment is employed to analysis the effect of mutual coupling of the dipole antenna and the microstrip antenna array, and we are based on the idea of sub-array to study how to calculate the large array radiation field and compensate a large array of pattern. The main work and research results can be summarized as follows:1. Research on mutual couping of the dipole array antenna using method of moments. According to the boundary conditions of electromagnetic fields, we apply Pocklington equation to the antenna array, and then solving the equations using the method of moments. Since the mutual coupling influence the feed port, and to study the relationship between the mutual coupling and array element mutual impedance, input impedance, current distribution; since the mutual coupling influence the radiation field of array, and to study a uniform array, low sidelobe Taylor array and beam scanning array.2. Research on mutual coupling of the microstrip array antenna.First, according to the equivalence principle and boundary conditions, the integral equations for metallic structures, dielectric structures and composite metallic and dielectric structures was deduced; the divergence-free basis functions was used to discrete dielectric structures what could effectively reduce the number of unknowns; the gap voltage source model was used as a feed model. Then related examples are used to verify the calculation results. For two kinds of microstrip array, it analyzes the mutual coupling on the array unit reflection coefficient, efficiency resonant frequency and array directivity and gain.3. Due to the large array radiation field is difficult to calculate for limited computer resources, we calculate the radiation field based on the current distribution and mutual impedence matrix of the small array.Current distribution of large antenna arrays is calculated using the small array, and it can accurately calculate the radiation patterns of large linear array and planar array. Traditional impedance matrix extrapolation is modified to make radiation field more accurate.4. In this paper, mutual coupling compensation matrix of large array is calculated with mutual coupling compensation matrix of small array, so the pattern of large arrays can be effectively compensated.