What is a Varactor Diode?Varactor Diode A varactor diode is defined as a reverse-biased p-n junction diode whose capacitance can be varied electrically. These diodes are also known as varicaps, tuning diodes, voltage variable capacitor diodes, parametric diodes, and variable capacitor diodes.The operation of the p-n junction depends on the type of bias applied, either forward or reverse. In forward bias, the width of the depletion region decreases as the voltage increases.On the other hand, the