Analysis of the dipole circular array in interferometric direction-finding system

The interferometric method is one of the important techniques for direction-finding when the high accuracy of DOA is required, since the angle of the incident wave can be determined from its phase information. An Adcock antenna system of which the short baseline is less than 0.5/spl lambda//sub min/, is often used in the interferometric direction-finding technique. This kind of system has many advantages such as small size, light weight, convenient assembly, and flexible mobility. Moreover, such a system can achieve unique DOA results, because no ambiguity occurred in the direction-finding procedure. In this paper, the model error of the interferometric method is analyzed. A technique which can minimize the effect caused by the coupling between the DF antennas is presented. The technique is that of loading the antennas with matching networks. Some numerical results which reveals the validity of the technique proposed in this paper are also given.