Analog direct path interference suppression for FM based passive radars

摘要

In passive radar systems the direct path interference strongly limits the detection performance, and demands the application of high resolution ADCs (Analog to Digital Converter). In this paper a direct path interference suppression technique is presented which operates in the analog domain prior to the digitalization. Using the introduced interference mitigation procedure the dynamic range required to the received signal can be effectively decreased, allowing the use of low resolution ADCs and low cost general purpose SDR devices. Laboratory measurement results taken with an FM based demonstrator system shows 20dB suppression. While in real environment 15dB detection performance enhancement could be evinced with field trials.