Signals of Ultrasonic Systems

The signal path in ultrasonic system was analyzed for the quality of the ultrasonic signal acquisition:excitation, reception and digitization. Transmitted signal properties and influence on time-of-flight (ToF) random errors is presented. The excitation hardware issues are discussed: electrical matching and operation performance were analyzed. Several evaluation criteria considered: power delivery efficiency, power delivered at operation frequency, bandwidth, effective bandwidth, power factor and total efficiency. Results obtained for particular transducer are presented. Reception performance analysis was based on the preamplifier-transducer noise model. Investigation of few amplifier topologies in combination with specific transducer is given. The acquisition parameters selection is suggested to be based on achievable accuracy of ToF estimation. Numerical simulation investigated the influence of noise power spectral density, signal bandwidth, carrier frequency, the sampling frequency and resolution of the analog-to-digit converter. Interpolation techniques influences are discussed.