On: Why Are Ultrasound Machines So Expensive?

[highd]

Wouldn't you normally mix down on the receive side for better SNR? Doppler should be pretty negligible, so if your LO tracks the output the receive side could probably be an audio ADC.

Power on the output side is the big one for sure, however. Also I'm not sure the transducers cited are anywhere near big enough.

[hwillis → highd]

Mixing is only useful when the change in the signal is slow. In ultrasound you're operating around single wavelengths so you can't mix down.

[highd → hwillis]

FMCW systems would be slowly changing around the central wavelength. It wouldn't work for pulsed systems, though - I'm not sure what's more common.