Cross modulation cancellation for airborne phased array radar

The control of spurious signals, caused by cross modulation of two or more strong signals, is a demanding driver on the linearity of transmit/receive modules and subarray channel receivers in active electronically scanned array (AESA) antennas used with airborne radars. This paper proposes a method for the suppression of the spurious signals caused by cross modulation and presents simulation results to quantify its performance. The effects of potential errors on the suppression achieved are considered and a method is proposed for reducing these effects. With adaptive equalisation filtering, suppression of up to 30 dB can be achieved in the presence of realistic errors.