Consider the [Piezoelectric transformer], which is [in close-loop
|The power is
controlled by a frequency shift.
|So, in close
loop, we measure the output voltage.
signal] is shifting the frequency.
Piezoelectric Transformer is, basically, resonant network,†††††††† †††††† the [frequency shift] will be
translated into an [Amplitude Modulation].
designing the feedback loop] there is a need to get a transfer function
between the [frequency shift] and the [envelope change].