Low-amplitude high-precision ultrasonic pulser

A method of generating and receiving ultrasonic pulses in the form of chirps, for use by an ultrasonic transducer that receives a transmit signal from the pulser in transmit mode and delivers a receive signal to the pulser in receive mode, comprising:

• generating the transmit signal using a pulser system with a transmit path having at least:
• a direct digital synthesizer operable to generate a chirp signal;
• a converter operable to convert the chirp signal to a transmit signal having a single ended voltage;
• voltage amplifier operable to increase the voltage of the transmit signal;
• a power amplifier operable to boost the current of the transmit signal;
• first switch between the converter and the voltage amplifier;
• second switch downstream of the power amplifier operable to deliver the transmit signal to the transducer;
• wherein the first switch and the second switch are operable to shut off the transmit path during receive mode;
• the pulser system further having a receive path with at least a third switch operable to receive both the transmit signal and receive signal, and an attenuator, wherein the transmit signal is delivered to the attenuator when the pulser is in transmit mode, and the third switch is used to bypass the attenuator when the pulser is in receive mode;
• and
• using a matched filter to receive both the transmit signal from the attenuator and the receive signal from the third switch, and to correlate the receive signal against a copy of the transmitted signal.