FMCW Proximity sensor that minimizes the influence of leakage signals

Abstract

The proximity fuze is a fuze developed to inflict damage by detecting a target and detonating the warhead when it approaches the target. The latest proximity fuze adopts Frequency Modulated Continuous Wave (FMCW) sensors to improve separation distance accuracy and selfdestruction time precision. However, the FMCW radar has a chronic problem in that leakage signals are generated by various causes, such as antenna mismatch of the transmission signal, crosstalk between antennas, and leakage on the substrate. Leakage signals lower the target signal to noise (SNR) by raising the noise floor over the frequency. This paper presents an improvement of SNR through attenuation of leakage signal by tracking the leakage signal. We mathematically prove that the target SNR can be increased by leakage signal attenuation. By solving the undetectable problem, it was verified that the proposed signal processing technique is effective in reducing the malfunction probability of the proximity fuze sensor.