I have a 2 stage amplifier setup for high gain. Where the input is 200uV and the output is 1V. However this signal comes with distortion i.e. harmonics.
Now passing this signal into a difference amplifier with a gain of 1, with the inverting input being a pure sine wave with the same frequency, amplitude and phase and the red signal, the resultant green signal is twice the frequency of both the 10Hz inputs.
Is this due to the sine waves adding even though its a difference amplifier or is it that the first harmonic of 10Hz is 20Hz and the amplitude of the green signal is the magnitude of the 1st harmonic (20Hz) in the distorted amplified red signal (10Hz). Im really curious if this is a circuit that 'computes' a fourier transform of a signal or if its something else, any assistance is appreciated!
