Golay Code Excitation of Ultrasonic Transducers with Different Backing

Two 3.7 MHz focused ultrasonic transducers were built. One without backing and the
second loaded on back. The primary application of the first transducer is Doppler blood flow
measuring ultrasonic devices, the second is most useful for the B-mode imaging devices. The
electrical and acoustical properties were tested and finally the results of the different Golay
code excitations were compared. Efficiency of the not backed transducer was 4.1 dB higher.
The not backed transducer performed maximum sensitivity for 8 bit two periods per bit code
excitation. The backed transducer achieved maximum axial resolution for 16 bit one period
per bit excitation.