Guilin Sun
Ansys Employee

A1: it is the percentage of the energy inside the simulation volume at any moment relative to the original injected energy.

A2: it is due to resonance. You can use a time monitor and then check the spectrum after the simulation terminates.

A3: somewhat: since the time domain monitor uses Fourier transform from the time signal to the CW result, we need to simulate long enough to let the signal decay completely for accuracy.

A4: It depends on each individual device: each time the parameter changes it will have different performance (or they are different devices), such as resonance. It is normal.