Reducing clutter in airborne radars equipped with active electronically steered array antennas by using a novel receive aperture weighting

It is commonplace to use an unweighted transmit aperture and a weighted receive aperture in radars utilising active electronically steered array (AESA) antennas. The preferred receive weightings are usually Gaussian or Taylor as these are perceived to give the best compromise between loss of main-beam directivity, minimised main-beam dilation and excellent sidelobe control. However, this is only part of the story. This paper addresses the total systems analysis from the clutter point of view and proposes an alternate receive aperture weighting to reduce the overall clutter in the system for an airborne radar application. The paper compares the antenna patterns of a simple 31 times 31 AESA element array and then extends the analysis to compare the installed systems clutter performance for a surveillance-type radar operating in medium pulse-repetition frequency (MPRF) mode.