A Differentially-Tuned Voltage ControlledOscillator Using Symmetric Transformer

This letter proposes a new voltage controlled oscillator (VCO) topology that cancels common-mode noise by adoption of differential tuning varactor. To suppress common mode noise effectively, a symmetric three-coil transformer is proposed as a differential tuning resonator. The measured phase noise s...

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Bibliographic Details
Published inIEEE microwave and wireless components letters Vol. 18; no. 7; pp. 464 - 466
Main Authors Seok-Ju Yun, Yen, N.D.B., InYoung Lee, Jin-Taek Lee, Sang-Gug Lee
Format Journal Article
LanguageEnglish
Published IEEE 01.07.2008
Subjects
Differentially-tuned
Frequency measurement
Frequency ranges
Microwaves
Noise
Noise cancellation
Noise levels
Noise measurement
Oscillations
Phase measurement
Phase noise
Topology
Transformers
Tuning
Varactors
Voltage
Voltage control
voltage controlled oscillator (VCO)
Voltage-controlled oscillators
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Summary:This letter proposes a new voltage controlled oscillator (VCO) topology that cancels common-mode noise by adoption of differential tuning varactor. To suppress common mode noise effectively, a symmetric three-coil transformer is proposed as a differential tuning resonator. The measured phase noise shows -128.7 dBc/Hz at 1 MHz offset frequency from the 1.2 GHz oscillation frequency. Over the whole frequency range, common-mode noise rejection is larger than 36 dB. Measured tuning range of the proposed VCO is about 204 MHz from the 1.18 GHz to 1.38 GHz while dissipating 1.2 mA at 1.8 V power supply.
Bibliography:ObjectType-Article-2
SourceType-Scholarly Journals-1
ObjectType-Feature-1
content type line 23
ISSN:1531-1309
1558-1764
DOI:10.1109/LMWC.2008.925108