Robust Frequency Diverse Array Beamformer via Random Frequency Offset

In this paper, we consider the issues of mainlobe interference and periodic mainlobes in frequency diverse array (FDA) radar. In existing methods for FDA radar with uniform inter-element frequency offset, the beampattern presents multiple peaks in range dimension, which leads to lower energy at target position. Instead of using fixed frequency offset, a random frequency offset with uniform distribution for FDA radar is proposed to form a nonperiodic beampattern in range, i.e., the mainlobe only steers the target location. The signal model and bempattern of transmitter are formulated firstly. Then a robust FDA beamformer with flexible magnitude response constaints is designed to suppress mainlobe interference. Numerical examples are presented to demonstrate that the periodic mainlobe and mainlobe interference in FDA are addressed simultaneously.