Based On The Double-balanced Feed Structure Of The Strong Mutual Coupling Wideband Phased Array Research

Broadband phased arrays are widely used in radar, electronic countermeasures and communication systems, due to their attractive features such as the electronic beam scanning and the broad bandwidth. The design of broadband phased arrays usually subjects to the rules of designing an antenna element with wider bandwidth first and then making up the arrays. The mutual coupling effects among the array elements are usually considered as adverse factors and should be compensated. This thesis presents some studies on a kind of broadband phased arrays based on enhanced mutual coupling, and the desgin was verified through experiments. The thesis mainly contains the following several parts:Firstly, the background, importance and the research status of broadband phased arrays are introduced.Secondly,by using the concept of Smith chart and the equivalent circuit model, the basic theory of the broadband phased array based on mutual coupling is presented.Thirdly, based on the theoretical analysis, optimal design of the periodic radiating element for the broadband phased array and a broadband linear phased array based on mutual coupling effect have been given in great detail, which show a large scanning angle and a broad bandwidth over 4:1. Besides, this thesis proposed a metal balun feeding structure. Simulation results show that this type of metal balun feeding structure greatly improves the impedence match between transmission lines and SMA connectors.Finally, a feeding box is constructed in order to arrage all the passive components used in the experimentations. Preliminary experiments are presented for theoretical verifications in the SATIMO Starlab. Measured results show that the designed 1x8 linear phased array can be used to obtain broadband properties.