Patent ID: 9019021
Filing Date: 2015-04-28
Classification: H03B,H03K

Abstract:
1. A voltage controlled oscillator (VCO) comprising: a passive conductive structure having a first ring and a plurality of taps spaced around the first ring; a capacitive load coupled to the passive conductive structure; a plurality of feedback structures, wherein one or more feedback structures of the plurality of feedback structures are coupled between a pair of opposing taps of the plurality of taps, the one or more feedback structures configured to provide positive feedback between the pair of opposing taps with gain so that output signals at the pair of opposing taps oscillate with a predetermined phase-relationship with respect to one another; and a plurality of current injection devices coupled together in a second ring, a first current injection device of the plurality of current injection devices coupled between a pair of adjacent taps of the plurality of taps and configured to provide output signals at the pair of adjacent taps with a common frequency; wherein the plurality of current injection devices include a plurality of inverters arranged in the second ring, an output terminal of a first inverter of the plurality of inverters coupled to an input terminal of a second inverter of the plurality of inverters in the second ring, the first and second inverters being coupled in series with one another.