Improved switched tuning of differential CMOS VCOs
Publikation/Tidskrift/Serie: IEEE Transactions on Circuits and Systems - 2, Analog and Digital Signal Processing
Dokumenttyp: Artikel i tidskrift
Förlag: IEEE--Institute of Electrical and Electronics Engineers Inc.
Varactors for continuous frequency tuning are typically used in LC-oscillators. However, they have some drawbacks for large tuning-ranges, such as high tuning sensitivity causing high sensitivity to noise and disturbances on the control voltage. Furthermore, large metal-oxide-semiconductor (MOS) varactors have high conversion of harmless amplitude noise into harmful phase noise. To reduce these problems a small varactor can be used in combination with MOS-transistors that switch fixed capacitors in and out of the oscillator. The limitations due to the imperfect complementary metal-oxide-semiconductor (CMOS) switches are investigated, and an improved structure for use with the popular differential CMOS LC-oscillator is presented.
- Electrical Engineering, Electronic Engineering, Information Engineering
- complementary metal-oxide-semiconductor
- frequency tuning
- switched tuning
- RF CMOS
- voltage-controlled oscillator (VCO)
- Analog RF-lup-obsolete
- ISSN: 1057-7130