It would need a digital or analog filter with a brick-wall high-pass characteristic, pass the ping waveform through it,
then amplify the signal linearly (perhaps with step-up transformer). A lot more complicated than a digital waveform
into a LC resonator. However a pre-calculated sampled waveform could be used eliminating the filtering.
There might still be issues with non-linearities in the transducer - rectification or intermodulation can generate
low frequencies.