Decoupled frequency diverse array range–angle-dependent beampattern synthesis using non-linearly increasing frequency offsets

The frequency diverse array (FDA) using linearly increasing frequency offsets has received much attention, but it has a range and angle coupled beampattern. This study proposes a new uniform linear FDA with non-linearly increasing frequency offsets to decouple the range–angle-dependent beampattern. Square increasing and cubic increasing frequency offsets are suggested for the FDA. In doing so, the range and angle of targets are solely estimated without ambiguities by the multiple signal classification algorithm. Numerical results show that the proposed approach outperforms the existing approach using logarithmically increasing frequency offsets in both focusing transmit energy and target localisation performance, especially in the range dimension.