Acoustic-pulse compression is obtained in systems with different timebandwidth products by applying the digital matched-filter technique to ultrasonic non-destructive testing. The signal is linearly frequency -modulat...Acoustic-pulse compression is obtained in systems with different timebandwidth products by applying the digital matched-filter technique to ultrasonic non-destructive testing. The signal is linearly frequency -modulated (LFM) pulse and the digitized electrical-excitation signal itself is used as a digital matched filter. Experimental results are in good agreement with theory. Suppressions of side lobes achieve -41.9 dB and -41.5 dB for the Hamming and Gaussian weighted signals respectively. It shows that the application of the digital matched-filter technique improves the performances of a ultrasonic testing system explicitly.展开更多
文摘Acoustic-pulse compression is obtained in systems with different timebandwidth products by applying the digital matched-filter technique to ultrasonic non-destructive testing. The signal is linearly frequency -modulated (LFM) pulse and the digitized electrical-excitation signal itself is used as a digital matched filter. Experimental results are in good agreement with theory. Suppressions of side lobes achieve -41.9 dB and -41.5 dB for the Hamming and Gaussian weighted signals respectively. It shows that the application of the digital matched-filter technique improves the performances of a ultrasonic testing system explicitly.
