Quadrature VCO Via Transformer-coupled Transmission Line

Lai, Wen‐Cheng; Jang, Sheng‐Lyang; Syu, Jia-Wun

doi:10.1109/emccompo.2019.8919938

Cited by 7 publications

(1 citation statement)

References 20 publications

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“…One of essential circuit blocks in the high-frequency wireless systems is a voltage-controlled oscillator (VCO). Various VCOs are investigated [5][6][7][8][9] for quadrature signal processing [10][11][12][13][14][15][16][17] in the high-performance wireless systems, however, a highfrequency VCO usually needs an exceptionally fine CMOS technology and/or a special high-Q inductor process [18][19][20][21][22][23] for suppressing the phase noise. Thus, their process cost could be considerably high.…”

Section: Introductionmentioning

confidence: 99%

A Study of Phase-Adjusting Architectures for Low-Phase-Noise Quadrature Voltage-Controlled Oscillators

Ugajin

Kakei²

2023

IEICE Trans. Electron.

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Quadrature voltage-controlled oscillators (VCOs) with current-weight-average and voltage-weight-average phase-adjusting architectures are studied. The phase adjusting equalizes the oscillation frequency to the LC-resonant frequency. The merits of the equalization are explained by using Leeson's phase noise equation and the impulse sensitivity function (ISF). Quadrature VCOs with the phase-adjusting architectures are fabricated using 180-nm TSMC CMOS and show low-phase-noise performances compared to a conventional differential VCO. The ISF analysis and small-signal analysis also show that the drawbacks of the current-weightaverage phase-adjusting and voltage-weight-average phase-adjusting architectures are current-source noise effect and large additional capacitance, respectively. A voltage-average-adjusting circuit with a source follower at its input alleviates the capacitance increase.

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