Fabrication and characteristics of varactor diode for UHF TV tuner operated within ultra-low tuning voltage

Abstract

A varactor diode for a ultra-high-frequency (UHF) TV tuner that can be operated within 5V of tuning voltage (VT) is presented. The fabricated diode has a shallow junction with a heavily doped p++ region on a steep hyperabrupt n+ region. Depletion capacitance was from 18.2pF at VT=0.5V to 2.8pF at VT=5V. This enables the diode to tune the UHF full band without a DC-DC converter. The quality factor of the diode was 20 at VT=0.5V and 470MHz of tuning frequency (f T).