Null placement in a circular antenna array for Passive Coherent Location systems

Passive Coherent Radar (PCL) is heavily constrained by the level of direct signal illumination. This paper investigates null steering techniques for a circular array antenna. An 8-element circular array has been designed and a method is proposed to steer multiple nulls in different directions. We present computed performance for two nulls achieved simultaneously. An 8 element dipole array has been constructed and the VSWR results are presented. This antenna will form the basis of practical null formation measurements.