Highly Efficient Class-C CMOS VCOs, Including a Comparison With Class-B VCOs
Författare
Summary, in English
This paper presents two class-C CMOS VCOs with a dynamic bias of the core transistors, which maximizes the oscillation amplitude without compromising the robustness of the oscillation start-up, thereby breaking the most severe trade-off in the original class-C topology. An analysis of several different oscillators, starting with the common class-B architecture and arriving to the proposed class-C design, shows that the latter exhibits a figure-of-merit (FoM) that is closest to the ideal FoM allowed by the integration technology. The class-C VCOs have been implemented in a 90 nm CMOS process with a thick top metal layer. They are tunable between 3.4 GHz and 4.5 GHz, covering a tuning range of 28%. Drawing 5.5 mA from 1.2 V, the phase noise is lower than -152 dBc/Hz at a 20 MHz offset from a 4 GHz carrier. The resulting FoM is 191 dBc/Hz, and varies less than 1 dB across the tuning range.
Avdelning/ar
Publiceringsår
2013
Språk
Engelska
Sidor
1730-1740
Publikation/Tidskrift/Serie
IEEE Journal of Solid-State Circuits
Volym
48
Issue
7
Dokumenttyp
Artikel i tidskrift
Förlag
IEEE - Institute of Electrical and Electronics Engineers Inc.
Ämne
- Electrical Engineering, Electronic Engineering, Information Engineering
Nyckelord
- Class-C
- CMOS
- dynamic-bias
- low phase noise
- start-up
- VCO
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0018-9200