What is the normal operating range of a varactor diode and its working principle 1

Variable capacitance diode, also known as variable capacitance diode or capacitive diode, is a diode that can change its capacitance value by changing voltage or current. It usually consists of two electrodes and a variable medium. The working principle of varactor diodes involves the characteristics of their structure and materials.

The structure of the variable capacitance diode LM258ADR typically consists of two electrodes and a variable dielectric. One of the electrodes is a metal plate called a fixed plate, and the other electrode is a movable metal plate called a movable plate. The space between two electrodes is filled with a variable dielectric, typically a high dielectric constant material such as aluminum oxide or aluminum nitride.

When the varactor diode is in its normal working area, the distance between the movable plate and the fixed plate is fixed, and the capacitance value remains unchanged. When the applied voltage or current changes, the movable plate will be affected by the electric field force, thereby changing its position and distance from the fixed plate. This will cause a change in the capacitance value.

The working principle of a varactor diode can be explained through the following steps:

1. Unbiased state: In the absence of external voltage or current, the varactor diode is in an unbiased state. At this point, the movable board is located in the middle of the fixed board, and the capacitance value is in the middle.