Why do I get only odd harmonics appearing? This not only happens at saturation of the transfer curve, but also in the linear portion of the curve.
I make a input signal that has too high power that it will saturate the transfer curve. The transfer curve below is for Amplitude modulation, I also have a transfer curve of the output phase change for each input signal level.
This is basically how I do it
My input signal, x(t), is the sum of two sine waves
For each point on the transfer curve above I apply Amplitude and Phase modulation by using this array
modulating_phasor = (power_out / power_in) * exp(i*phase_deviation)
Then I look at my input signal and lookup where its value matches the input power of the transfer curve and use that location in the modulating_phasor array
output_signal = x[t] * modulating_phasor[location]
This makes the output signal complex array so I take the absolute value and for parts that should be negative, I multiply that location on by -1 by finding the correct location on input signal.
I cant upload my code... but you get the idea of what I am doing right?
Now this is my output and no matter what my input level on my signal is i.e. whether I am in the non-linear part or linear part, I always get odd harmonics. I've also tried a different transfer curve. Only get odd again.