Multi-ring coupled ring oscillator with improved phase noise
US10396807B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 2017 |
| Grant date | Aug 27, 2019 |
| Priority date | — |
| Expiry date | Jan 23, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/24
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The disclosure of the present application presents a multiple-ring coupled ring oscillator design that employs multiple-ring coupling to achieve improved phase noise by minimizing noise injection from tail current and adjacent rings, while providing additional output phases for multiphase signal generation. In one non-limiting exemplary prototype embodiment, a 1.5 GHz triple-ring coupled ring oscillator achieved measured phase noise of −110.5 dBc/Hz at 1 MHz offset, demonstrating phase noise reduction of 7 dB compared with its single-ring oscillator counterpart. The MROs couple multiple rings with proper phase shifting to achieve improved phase noise. Common source coupling benefits from tail current noise reduction, and introducing phase delays in the coupling paths minimizes noise coupling from the adjacent cores. The overall effect leads to improved phase noise performance as demonstrated in quadrature voltage controlled VCO designs. The concept is applied to ring oscillator designs and, as stated previously, demonstrates a triple-ring coupled ring oscillator with phase noise improvement. The design of the present application also triples the number of output phases compared to …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.