IMPROVEMENT OF PHASE NOISE PERFORMANCE IN TRACKING ARRAY OF UAV SIGNAL BASED ON MIXED PHASED/RETRODIRECTIVE ARRAY

An improved mixed phased/retrodirective array is presented. The phase conjugation technique will be achieved in base band instead of intermediate frequency (IF) band. Canceling the need to the intermediate frequency stage in the receiver will reduce the complexity and cost of the system. The ability to entire processing of the tracking array function to be applied using software defined radio (SDR) system is added. The effect of the phase errors at each channel is compensated, and the noise performance of the tracking array is improved. Also an expanded analytical study of the noise performance of the array to include the impact of the phase errors on the array performance is presented. The proposed equivalent one-channel model of the N-channel array model provides a clear and efficient way to characterize the noise performance of array receiver systems with any amplitude tapering and also considering the phase errors. The improvement provided by the mixed phased/retrodirective array compared to the traditional phased array is evaluated. The effect of array size on the tracking array performance in the presence of phase error is discussed. A monopulse tracking array is taken as an example.