Worksheet 25-Varactor Diodes

Question 1

What uses are there for a varactor diode?

Answer 1

A varactor is a device used for filters, oscillators, and amplifiers where high-frequency operation is required.

Question 2

What part of the varactor creates variable capacitance?

Answer 2

The variable capacitance of this device is created by the width of the depletion zones in the diode that causes changes in electrical potential the same way a capacitor does.

Question 3

In what class of operation is the diode in when operating as a varactor?

Answer 3

A varactor is designed to operate in reverse bias.

Question 4

As the reverse bias voltage decreases, what happens to the capacitance value of the varactor?

Answer 4

When the reverse bias voltage decreases the capacitor value in the variation increases.

Question 5

What can happen to a varactor when the reverse bias voltage is increased above its rated level?

Answer 5

If the reverse bias voltage is increased too high, the breakdown voltage is reached which will stop the varactor from functioning.