Research And Application Of Array Antenna Decoupling Structure

Array antenna is widely used in modern communication equipment because of its high gain and high directionality.With the continuous improvement of performance requirements,array antennas are also developing in the direction of high efficiency and miniaturization.The mutual coupling between the elements causes the radiation characteristics of the antenna to deteriorate,which in turn affects the performance of the entire antenna array.Therefore,it is necessary to analyze the mutual coupling effect of the antenna elements,study the design of the decoupling structure between the antenna ports,and reduce the mutual coupling between the antennas,which is of great value for the further development of the array antennas.Based on the existing decoupling technology,in this paper,multiple decoupling structures between antenna elements are designed and a decoupling method applied to microstrip antenna arrays in combination with related decoupling theory is proposed.Firstly,the effect of mutual coupling on the performance of array antenna is analyzed and two methods for analyzing mutual coupling effects are introduced in detail based on the impedance effect of mutual coupling between antenna elements.Secondly,taking the two-element printed monopole antenna as an example,three decoupling structures are designed,namely the radiating surface decoupling network,the ground plane decoupling network and the metal baffle decoupling structure.The effects of three structures on reducing the coupling between antenna ports are proved by software simulation or experiment in microwave chamber.Finally,combined with the basic principle of the microstrip antenna and the understanding of the coupling mechanism between the elements,the ground plane gap structure is introduced into the decoupling process of the microstrip antenna array.A three-port transceiver antenna consisting of series-fed microstrip array is designed and the decoupling effect of ground plane gap structure is verified by observing the radiation performance before and after adding the gap structure.