基于时间调制阵列的全向宽带测向方法

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

为解决时间调制测向技术中由线型阵列对称性和固定基线长度引入的目标前后向模糊问题和测向带宽受限问题,提出了一种基于五单元时间调制阵列的全向宽带测向方法.通过将一维线型阵列扩展为二维平面阵列,提高空间自由度以区分来波前后向;进一步结合虚拟基线技术,利用相邻单元排布间距的差异性引入虚拟相位差,解决工作频率变化引起的相位差模糊问题,从而实现全向宽带测向的目标.通过数值仿真在3倍频程工作带宽条件下有效实现了360°全向测向,验证了所提出方法的可行性.

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.