Basically, it’s piece of rock and it’s an insulator. Its schematic symbol is shown in Figure SB1. Varactor (varicap) circuit symbol How does a varactor diode work? To form the PN junction that makes a ...

LC-tank circuit portion Varactor (or “varicap”) diodes are used primarily in radio-frequency (RF) circuits to provide a capacitance that can be varied by changing the applied voltage. These ...

It is possible to fine-tune the frequency by varying the voltage to the varicap. Not much is demanded of the inductor, a type with a relatively low Q factor (35 to 40) is sufficient according to Maxim ...