Hi Mr. Choi, I want to do an experiment on ultrasound that has to be completed, and I would like to ask you a question about a circuit related to the drive of an ultrasonic transducer.

This is a beautiful oscilloscope, but it doesn't show 1 wave, does it? It's a lot of 200KHz square waves stacked on top of each other, isn't it? But I can't see the smaller square waves, so I hope that's the case.

The circuit above can drive a 200KHz transducer, but why is it designed this way, it's a bit strange, is it a reference to foreign circuits?

For the selection of L2, adjust its inductance so that the waveform at point C is close to a sine wave.

For impedance matching, R9 should be equal to 120R, or replace it with an inductor;

I'm afraid that 100nF is not enough for C13, and it's better to add another 100uF;

A resistor should be connected in series with Vout, otherwise this transmitter circuit will cause a lot of interference with Vcc, which affects the overall stability;

The parameters of Q1 are not available. I didn't look it up, so let's assume it's good for now.

In addition, from the oscilloscope, the static voltages of C and D are not correct, the transducer is not connected, right?

Also from the oscilloscope, the static voltages of C and D are not correct.