Range-angle pencil-beamforming for non-uniformly distributed array radar.

Digital beamforming with non-uniformly distributed array radar can make full use of resources and enhance the target detection capability. However, it encounters severe grating lobes and high false alarm probability. In this paper, a novel range-angle pencil-beamforming with the non-uniformly distributed frequency diverse array (FDA) is proposed. FDA is referred to as an array transmitting linearly increased carrier frequencies with the array elements. The FDA is capable of providing controllable degrees-of-freedom in range domain, which is superior to the conventional phased array. In our approach, the frequency increments and element positions are optimally determined via particle swarm optimization algorithm to focus the transmit power within a particular range and angle region. With the proposed method, the range-angle pencil-beampattern is obtained and its side-lobes in range-angle domains can be further lowered down. Numerical simulation examples are provided to verify the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]