Analysis of Mutual Coupling Effect for 16 Elements Microstrip Antenna Array

Phased Array Feed receiver is a signal receiving technology that places array antenna at the focal plane field of radio telescope to achieve higher gain and more flexible beam regulation. It is the same as the array antenna, which is composed of multiple antenna elements arranged in a certain way. The electromagnetic coupling between the array elements during operation will cause impedance mismatch between the array elements and lead to the distortion of the array pattern. Therefore, the study array of mutual coupling effect is crucial. This paper designs $4\times 4$ rectangular array with 16 elements microstrip antenna. Through the simulation, the actual input impedance of each element port under the equal amplitude and phase excitation of the whole array is obtained, and the array performance is simulated again under this actual input impedance. Finally, it is seen that the return loss of elements NO. 1, 2, and 6 at 1.25 GHz is significantly reduced, and the impedance bandwidth of -10 dB is also expanded doubled compared with the original. The above work has deepened the understanding of the bandwidth characteristics of the array antenna, and also made it possible for the phased array feed receiver applied to the radio telescope system to achieve a wider working bandwidth.