A Constant-Current-Controlled Class-C Voltage-Controlled Oscillator using Self-Adjusting Replica Bias Circuit

2015 ◽  
Vol E98.C (6) ◽  
pp. 471-479
Author(s):  
Teerachot SIRIBURANON ◽  
Wei DENG ◽  
Kenichi OKADA ◽  
Akira MATSUZAWA
Keyword(s):  
Constant Current ◽  
Voltage Controlled Oscillator ◽  
Class C

A VERY LOW NOISE WIDEBAND CLASS-C CMOS LC VCO

2012 ◽  
Vol 21 (04) ◽  
pp. 1250033 ◽  
Author(s):  
FATEMEH ATAEI ◽  
MOHAMMAD YAVARI
Keyword(s):  
Phase Noise ◽  
Tuning Range ◽  
Capacitor Bank ◽  
Cmos Technology ◽  
Low Noise ◽  
Voltage Controlled Oscillator ◽  
Switching Scheme ◽  
Wide Tuning Range ◽  
New Class ◽  
Class C

In this paper, a new class-C voltage-controlled oscillator (VCO) is presented. In the proposed VCO, the tail capacitor of the conventional class-C oscillator is dislocated from the source of the cross-coupled transistors to their gate to achieve a rail-to-rail output swing. This improves the phase noise by 2.9 dB compared to the conventional class-C one. Besides, a new switching scheme is presented in the switched capacitor bank used for coarse tuning of the proposed VCO to lower the on resistance of the switches as well as to reduce the parasitic capacitors. This wide tuning range class-C VCO is designed in a 0.18 μm CMOS technology. It achieves a -125.3 dBc/Hz phase noise at 1 MHz offset from a 2.2 GHz carrier frequency while covering a wide tuning range from 1.82 to 2.65 GHz and consuming 3.5 mW power from a single 0.9 V power supply.

A 400 μW Near-Threshold Feedback Class-C VCO with Auto Amplitude Control

2018 ◽  
Vol 27 (05) ◽  
pp. 1850072
Author(s):  
Chenggang Yan ◽  
Chen Hu
Keyword(s):  
Low Power ◽  
Phase Noise ◽  
Feedback Loop ◽  
Cmos Process ◽  
Voltage Controlled Oscillator ◽  
Amplitude Control ◽  
Ultra Low Power ◽  
Class C ◽  
Low Phase Noise ◽  
Near Threshold

A 400[Formula: see text][Formula: see text]W near-threshold supply class-C voltage controlled oscillator (VCO) with amplitude feedback loop and auto amplitude control (AAC) is proposed in this paper. The amplitude feedback loop and AAC ensure the robust startup of the proposed VCO and automatically adapts it to the class-C mode in steady state. Consequently, ultra-low power can be achieved in AAC mode and low phase noise, high swing can be achieved in AAC off mode. The proposed VCO with AAC gets ultra-low power consumption by limiting the oscillating amplitude and driving the proposed VCO into the deep Class-C mode. Additionally, the peak value detector is employed in this work to boost the controlling voltage of capacitors bank. Thus, a low on resistance of switch transistors is obtained, which increases the Q value of capacitors bank. The simulated phase noise is [Formula: see text]124.5[Formula: see text]dBc/Hz at 1[Formula: see text]MHz offset with the 1.16[Formula: see text]GHz oscillation frequency. In this case, the figure-of-merit including tuning range (FOMT) of proposed VCO is [Formula: see text]195[Formula: see text]dBc/Hz. The proposed VCO is fabricated in SMIC 40[Formula: see text]nm CMOS process and consumes 0.62[Formula: see text]mA from 0.65[Formula: see text]V supply. The measured phase noise is [Formula: see text]109[Formula: see text]dBc/Hz and FOMT is [Formula: see text]179[Formula: see text]dBc/Hz.

scholarly journals Low Phase Noise and Wide-Range Class-C VCO Using Auto-Adaptive Bias Technique

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1290
Author(s):  
Jeong-Yun Lee ◽  
Gwang Sub Kim ◽  
Goo-Han Ko ◽  
Kwang-Il Oh ◽  
Jae Gyeong Park ◽  
...  
Keyword(s):  
Phase Noise ◽  
Tuning Range ◽  
Frequency Tuning ◽  
Wide Frequency Range ◽  
Cmos Process ◽  
Voltage Controlled Oscillator ◽  
Frequency Range ◽  
Wide Range ◽  
Class C ◽  
Low Phase Noise

This paper proposes a new structure of 24-GHz class-C voltage-controlled oscillator (VCO) using an auto-adaptive bias technique. The VCO in this paper uses a digitally controlled circuit to eliminate the possibility of start-up failure that a class-C structure can have and has low phase noise and a wide frequency range. To expand the frequency tuning range, a 3-bit cap-bank is used and a triple-coupled transformer is used as the core inductor. The proposed class-C VCO implements a 65-nm RF CMOS process. It has a phase noise performance of −105 dBc/Hz or less at 1-MHz offset frequency and the output frequency range is from 22.8 GHz to 27.3 GHz, which consumes 8.3–10.6 mW of power. The figure-of-merit with tuning range (FoMT) of this design reached 191.1 dBc/Hz.

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