Tuning limits of shunt varactor diodes for maintaining high OIP3 in arbitrary circuits

Abstract

For the first time, an analytical formula is presented for calculating the OIP3 of any arbitrary circuit with a single shunt varactor diode. Additionally, numerical calculation of the limits on varactor tuning range when a specific OIP3 is desired is discussed, and a commercial varactor is found to maintain 44% of its tuning range with a OIP3 > 37 dBm.