Editing Varicap (section)

== Applications ==
Varactors are used as voltage-controlled [[capacitor]]s. They are commonly used in [[voltage-controlled oscillator]]s, [[parametric amplifier]]s, and [[frequency multiplier]]s.<ref>{{cite web|last1=Calvert|first1=James|title=Varactors|url=http://mysite.du.edu/~etuttle/electron/elect40.htm|website=Dr Tuttle's Home Page|access-date=23 January 2017|language=en|date=15 February 2002}}</ref>  Voltage-controlled oscillators have many applications such as [[frequency modulation]] for FM transmitters and [[phase-locked loop]]s. Phase-locked loops are used for the [[frequency synthesizer]]s that tune many radios, [[television set]]s, and [[cellular telephone]]s.

The varicap was developed by the Pacific Semiconductor subsidiary of the Ramo Wooldridge Corporation who received a patent for the device in June 1961.<ref>{{cite patent |inventor1-last=Barnes |inventor1-first=Sanford H. |inventor2-last=Mann |assign=Pacific Semiconductors, Inc. |inventor2-first=John E. |title=Voltage sensitive semiconductor capacitor |country-code=US |patent-number=2989671 |publication-date=23 May 1958 |issue-date=20 June 1961}}</ref> The device name was also trademarked as the "Varicap" by [[TRW Inc.|TRW Semiconductors]], the successor to Pacific Semiconductors, in October 1967. This helps explain the different names for the device as it came into use.{{Clarify|date=May 2013}}