Circular-array Interfermeter Direction Finder

Direction finding is one of most important task for the surveillance system. Moreover, the requirements for the size, weight, performance-price ratio of the direction finding device are becoming more and more rigorous with the increasing development of modern electronic techniques. The success of circular-array interfermeter direction finding technique resolves the contradiction between the direction finding device of omnidiretional coverage, wideband and high precise and its size. The direction finding system characterized by wideband and broad azimuth coverage is most suitable for small surveillance direction-finding platform.This paper mainly analyzes and investigates the circular-array direction-finding technique. On the basis of analyzing the theory of antenna array, the theory of phase mode in the circular-array direction-finding technique is analyzed in detail, and the characteristic of the circular array is analyzed in terms of the number of antenna elements, the spacing between antenna elements, the pattern of each order, and the ripple of array pattern. On the basis of theoretical analysis, this paper presents a practical design method for an eight-element circular-array interfermeter direction finding system, and provides the test results of this system. The novelty of this paper is the research and implementation of wideband monopolar antenna and highly integrated wideband beamforming network. Moreover, this paper proposes a new wideband phase regularization technique. After breakthrough of this key technique, the antenna-front component is reduced to the size of 220mm diameter and 160 mm high, and the precise for direction finding achieves 1.28°。...