FDTD analysis of unwanted emissions from a variable capacitor with sinusoidal motion

In this paper, we investigate the unwanted emission from a variable capacitor with sinusoidal motion. Then, a finite-difference time-domain method with an adaptive local subcell implementation is applied. First, our computational implementation is verified by computing the time course of the charge accumulated on the electrode of the capacitance with those for the electrode with a fixed separation. The primary finding of our numerical result shows that unwanted emission is radiated with its amplitude modulated at the frequency of the motion of the metal.