Question

Write a note on Varactor diode.

Answer 1

Varactor diode is a p-n junction diode whose capacitance is varied by varying the reverse voltage. Before going to varactor diode, let’s first take a look at the capacitor.

The term varactor or varicap is originated from variable capacitor. The varactor diode acts like a variable capacitor under reverse bias.The varactor diode is manufactured in such as way that it shows better transition capacitance property than the ordinary diodes.

Answer 2

A varactor diode is designed to store electric charge not to conduct electric current. So varactor diode should always be operated in reverse bias. When a reverse bias voltage is applied, the electrons from n-region and holes from p-region moves away from the junction.