Range-angle Decoupled Transmit Beamforming with Frequency Diverse Array

It has been shown that Frequency Diverse Arrays (FDA) exhibit a range-angle dependent beam steering feature by employing a uniform frequency increment across the array elements. However, this beam pattern generates maxima at multiple range values, possibly leading to loss of signal-to-interference-plus-noise ratio when the interferences are located at any of the maxima. Herein, we prove that the beam pattern of FDA is range-periodic and propose the basic criteria for the FDA configuration to decouple the range and angle. In an illuminated space, a single-maximum beam pattern can be obtained by configuring the frequency increment between the elements. Specific examples have been discussed herein, and the simulation results verify the proposed theory.