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 types of diodes often are ...

Superconductivity is an advantageous property observed in some materials, which entails an electrical resistance of zero at ...

There was a time when all radio receivers contained at least one, now with the advent of the varicap diode and the frequency ... the inductive part of a tuned circuit, but this coil is shorted ...

How does a varactor diode work? To form the PN junction that makes a diode, half the piece is doped with a trace amount of “donor atoms” that have one more electron than the intrinsic stuff to make ...

Use C4 for fine frequency adjustments. For a great frequency stability, this crystal oscillator circuit must use a good varicap diode (you can use BB139) and a good crystal too.