Omnidirectional broadband direction-finding method based on time-modulated array

To solve problems of the front-to-back ambiguity and the limited bandwidth respectively induced by the symmetric linear array and the fixed baseline in the direction-finding method with time-modulated array(TMA), an omnidirectional broadband direction-finding method with five element TMA is proposed in this paper. By extending the linear array to a planar array, a new spatial degree of freedom can be provided to distinguish the front-to-back of the incident wave in this paper. Further incorporating the technology of the virtual baseline, the virtual phase difference can be introduced by the differences of baselines to solve the phase difference ambiguity caused by the frequency variation and achieve the goal of omnidirectional broadband direction finding. Numerical simulations are performed to effectively realize direction finding within 360° under the condition of a three octave working bandwidth and demonstrate the feasibility of the proposed method.