Proximity fuse sensor system with voltage tracking of FMCW leakage signal followed by leakage voltage reduction

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) radio wave sensor to improve separation distance accuracy and self-destruction time precision. However, the FMCW radar has a chronic problem in that leak signals are generated by various paths, such as antenna mismatch of the transmission signal, crosstalk between antennas, and leakage on the substrate. Leakage signals cause a phenomenon in which the signal to noise ratio (SNR) of target signals is lowered by raising the noise floor over the frequency domain in the obtained power spectrum result. In the frequency domain, since the leakage noise signal corresponding to the short distance is generally larger than the target reflected signal, there is a problem in that the target distance cannot be measured within the short distance area due to the occurrence of a blind zone within the short range. This paper deals with the improvement of SNR through attenuation of leakage signal according to leakage signal tracking, which is a signal processing method proposed to solve the problem. It is mathematically proved that the target SNR can be increased through leakage signal attenuation, and the demodulated leaky in-phase and quadrature-phase (I/Q) signal obtained in the anechoic chamber without a target and the demodulated 1/Q signal obtained in the anechoic chamber with the target By showing the result of 1-Dimension Fast Fourier Transform(lD FFT) signal processing with a difference of In addition, as a result of applying the proposed signal processing technique with the result when the target is fixed in an environment where ground clutter exists, the SNR of the target is increased in all situations to increase the recognition probability of the target. 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.