System and method for a voltage controlled oscillator

摘要

In accordance with an embodiment, a voltage controlled oscillator (VCO) includes a VCO core having a plurality of transistors and a varactor circuit that has a first end coupled to emitter terminals of the VCO core and a second end coupled to a tuning terminal. The varactor circuit includes a capacitance that increases with increasing voltage applied to the tuning terminal with respect to the emitter terminals of the VCO core.

主权项

1. A voltage controlled oscillator (VCO) comprising:
a VCO core comprising a plurality of transistors; a varactor circuit having a first end coupled to emitter terminals of the VCO core and a second end coupled to a tuning terminal, wherein the varactor circuit has a capacitance that increases with increasing voltage applied to the tuning terminal with respect to the emitter terminals of the VCO core, the varactor circuit comprising
a first capacitor having a first terminal coupled to a first of the emitter terminals of the VCO core,a first varactor diode having a cathode coupled to a second terminal of the first capacitor and an anode coupled to the tuning terminal, andan RF choke circuit coupled between a second terminal of the first capacitor and a varactor reference terminal; and a voltage reference circuit coupled to the varactor reference terminal.