Variable reactor (varactor) with engineered capacitance-voltage characteristics

摘要

In one embodiment, a varactor includes a first node and a second node. The varactor includes: at least one first varactor element including a source, a drain, and a p-type doped gate; at least one second varactor element including a source, a drain, and an n-type doped gate; and at least one third varactor element including a source, a drain, and an intermediately doped gate, the intermediately doped gate having doping characteristics intermediate to doping characteristics of the p-type and n-type gates. The varactor includes one or more wells in a substrate region underlying the first, second, and third varactor elements. The first, second, and third varactor elements are coupled in parallel between the first and second nodes.