I'm a little confused about your plots. You say it is a time series plot, yet there are several places where your rises and falls "bend backward" so they aren't functions at all. I assume time is not going backward at those moments, so are these complex plane plots?
Disregarding that for a moment. You have a characteristic shape, so I think your best ...
To be honest, I don't think CNNs, RNNs and LSTM are useful for this kind of problem – a bandpass filter followed by a threshold would be.
Now, that would have three parameters:
Lower cutoff frequency
Upper cutoff frequency
and what is usually called "Machine Learning" is nothing but finding local minima over some (loss) function with real ...
The product $x(t)y(t)$ of two periodic signals with fundamental periods $T_x$ and $T_y$ is not a periodic signal unless $T_x$ and $T_y$ are rational multiples of one another; that is, $T_x = aT_y$ where $a$ is a rational number. Thus, except when such a relationship holds, $x(t)y(t)$ does not have a Fourier series.
When $T_x$ is a rational multiple of $T_y$,...