Frequency modulated continuous wave ultrasonic radar

Pulse compression techniques relying on chirp excitation are largely adopted in both diagnostic and Non-Destructive Testing applications for ultrasound. In the present work, the adoption of the Frequency Modulated Continuous Wave Radar technique to ultrasonic Non-Destructive Testing is considered. Numerical simulations on both synthetic and experimental data are performed and the results are compared with those obtained by means of the standard matched-filter approach. Moreover, in order to improve the resolution of the technique, the Chirp-Z-Transform is exploited instead of the Fourier Transform. By proper design of the excitation signal, the Frequency Modulated Continuous Wave Radar approach retrieves the envelope of the pulse-compression output signal without the need of any correlation step at the heart of the matched filter approach. This feature allows for an integrated hardware elaboration, relaxing both the computational and the ADC resources.