In the traditional rife world, the most common technique used is the amplitude modulated carrier wave. A high frequency carrier wave is amplitude modulated by a lower frequency modulating wave. When the modulating wave is at high voltage, then the carrier wave amplitude is maximum in the modulated signal, but when the modulating wave is at low voltage, the carrier wave amplitude is zero in the modulated signal. Here is a graphic of a carrier, modulating wave, and modulated wave.
Most Rife systems using a fixed carrier wave, that is, the carrier is only one frequency. With Spooky, you can have a carrier wave that changes every time there is a new frequency, based on a multiple of the original frequency. The benefit of this is you can avoid frequency fatigue of having a fix frequency.
There is a picture of a damped square wave and damped sinusoid on page 229. For lower frequency, a damped sinusoid is better because it allows for harmonics, and most of the low frequencies are subharmonics of the true mortal frequency. When you have a high frequency, it is most likely the true mortal frequency, in which case you have a sinusoid, because you don't need the harmonics, or energy going into creating harmonics.
For more details, please check the link: