A bidirectional front-end for ultrasonic pulse-echo measurements

In this work, we present a compact bidirectional front-end for pulse-echo ultrasound applications. This electronic system is realized by using a pseudo floating gate amplifier, which directionality can be reversed by swapping the power supply rails. The proposed electronic circuit is characterized by small dimensions and low power consumption, which are the main requirements to realize a modern and portable ultrasonic device. A prototype has been realized using discrete components such as the integrated circuit CD4007UB and a wide-bandwidth piezoelectric transducer (KB-AEROTECH). These components have been mounted on a printed circuit board (PCB) and tested with a power supply of 10V. The ultrasonic transducer is realized to work in “underwater” applications with a resonance frequency at 3.5 MHz. Experimental results prove that the proposed Front-End activates the transducer creating energetic sound-waves, which echo can be read-out once the directionality of the system is reversed. Nevertheless, significant improvements such as higher gain and wider bandwidth, could be obtained by realizing this analog interface in Application Specific Integrated Circuit (ASIC).