Voltage-controlled oscillator with reduced single-ended capacitance

摘要

Embodiments provide a voltage controlled oscillator (VCO) having reduced single-ended capacitance. In one embodiment, the VCO may include a transformer, a capacitor bank, and a gain stage. The transformer may include a primary inductor and a secondary inductor, and the secondary inductor may be inductively coupled to the primary inductor. The capacitor bank may be coupled to the secondary inductor and may provide a majority of a total capacitance of the VCO. The gain stage may be coupled to the primary inductor and configured to receive a supply signal and to drive a differential current in the primary inductor, thereby inducing an output signal across the secondary inductor having a frequency equal to a resonant frequency of the VCO.

主权项

1. A circuit comprising:
a radio transceiver to transmit or receive a wireless communication signal with a carrier frequency via a wireless communication network; and a voltage controlled oscillator (VCO) coupled to the radio transceiver, the VCO including:
a transformer including a primary inductor and a secondary inductor having a same number of turns, wherein the secondary inductor is configured to be inductively coupled to the primary inductor;a capacitor bank coupled to the secondary inductor, the capacitor bank to provide a majority of a total capacitance of the VCO; anda gain stage coupled to the primary inductor, the gain stage to receive a supply signal and to drive a current in the primary inductor to generate an output signal across the secondary inductor having a frequency substantially equal to a resonant frequency of the VCO.