how this FM modulator works?

[sapphire]

how fm modulator works

I am not sure whether this circuit can work as a FM modulator, because the modulation point and the output are the same.

Anyone has seen this before? Thanks for your help

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[toonafishy]

how an fm modulator works

Vin (the modulating signal) will vary the reversed-biased diode's junction capacitance. As the capacitance changes, the resonant frequency of the diode capacitance/inductor will change. The diode capacitance/inductor are a resonator in an oscillator.