Patent ID: 6407412
Filing Date: 2002-06-18
Classification: H01L

Abstract:
A compound varactor comprising a varactor element pair having:a p gate varactor element and an n gate varactor element coupled in parallel between an output and ground; each varactor element having: a body constructed out of a first conductivity type substrate; a well of opposite conductivity type implanted in the body; a gate contact; a gate insulator coupled between the gate contact and the body and electronically isolating the body from the gate contact; and two regions of the body doped with said opposite conductivity type impurities, said two regions being positioned on opposite sides of the gate insulator; the p gate varactor element has a p type gate contact constructed to have p type properties; the n gate varactor element has an n type gate contact constructed to have n type properties; said two regions of both p gate and n gate varactor elements are connected to a voltage source; the gate contacts of both n gate and p gate varactor elements are connected to an output; and the voltage source is connected to ground.