Electromagnetic Feedthrough is one of the key sources of electrical noise in signal transmission. It is especially a problem in Si/ZnO Surface Acoustic Wave (SAW) devices. The feedthrough is because input and output connectors effectively form a capacitor so that electromagnetic energy can be coupled directly between them. The induced Feedthrough creates unwanted amplitude and phase ripples in the transmitted signal.
Using feedthrough components (filters and capacitors) is an important solution to attenuate the undesired EM/RF noise. Feedthrough components can safely carry high frequency electrical signals through PCBs or enclosures. They act like a bypass and can carry either high current or high voltage signals.