Re: Why is Vth negative?
Hi,
Thank you for letting me know about depletion MOS. I've only dealt with enhancement MOS before.
At low frequency we're taught that with high impedance probe we are able to observe voltage waveform without loading the circuit.
I'm speculating that high impedance probe will cause reflection at high frequency hence it cannot be used?
Suppose we use 50 Ohm terminated probes at high frequency, but such would load the circuit heavily. But wouldnt we be able to correct for the loading effect hence get an accurate measurement anyways? Is it because it is very difficult to properly manufacture purely resistive probes?
If my understanding is correct, many amplifier classes are defined by their voltage and current waveforms and respective harmonic termination.
It seems puzzling to me that we're not able to measure voltage and current waveform at high frequency(hence verify that, say, a class F is actually behaving as class F)
Are there more fundamental reasons why people havent been pushing to measure V/I at high freq, and simply rely on power measurements ?
Thanks