Abstimmdiode

The capacitance diode, or varicap, also known as varactor or tuning diode, is an electronic semiconductor component. By changing the applied voltage, a variation in capacitance of 10:1 can be achieved. This provides an electrically controllable capacitance that has largely replaced the significantly larger variable capacitors that were commonly used before. The p-n junction of a diode has a capacitance that depends on the width of the depletion zone. When a diode is operated in reverse bias, a carrier depletion zone forms at the p-n junction, where an electric field also develops due to the absence of charge carriers.