Browsing by Author "Chen, Kuan-Han"

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A Dual-Resonant Mode 10/22-GHz VCO With a Novel Inductive Switching Approach
(2012-07-01)
Liu, Szu-Ling
;
Chen, Kuan-Han
;
Chin, Albert
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This paper presents a novel dual-band voltage-controlled oscillator (VCO) in a standard 0.18-mu m CMOS technology. With special design in the LC tank, the circuit exhibits two oscillation modes in different frequency bands. The frequency band selection is achieved by a switched coupled inductor with the tunable inductance and quality factor. This VCO can operate in a 10-GHz band with 7.6% tuning range and a 22-GHz band with 8% tuning range, while the core circuit draws a dc current of 8.44 mA from a 1.8-V supply voltage. The figures-of-merit at 10- and 22-GHz bands are -184.63 and -181.81 dBc/Hz, respectively. These performances are comparable with state-of-the-art dual-band LC-VCOs.
A Low-Power K-Band CMOS VCO With Four-Coil Transformer Feedback
(2010-08-01)
Liu, Szu-Ling
;
Chen, Kuan-Han
;
Chang, Tsu
;
Chin, Albert
;
電子工程學系及電子研究所
A K-band low-power and low-phase-noise voltagec-ontrolled oscillator (VCO) is presented in this letter. By utilizing four-coil transformer feedback and forward body bias topology, good performances are obtained under a low-power supply with a 5.1% tuning range and a phase noise of -109.8 dBc/Hz at 1 MHz offset from the 21.37-GHz carrier frequency. The core circuit of this VCO only consumes 3.5 mW with a 0.6-V supply voltage and a 0.55-V body bias.
Investigation and Optimization of Low-Power Techniques in X-Band CMOS LC-VCO Design
(2011)
Tian, Xin-Cheng
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Liu, Szu-Ling
;
Chen, Kuan-Han
;
Hao, Yue
;
電子工程學系及電子研究所
This paper investigates the optimization method for two low-power circuit techniques in low-power LC-VCO designs: Transformer feedback and forward body-bias. In addition to theoretical analysis, a low-power, low-voltage X-band VCO using these two techniques has also been implemented in a standard 0.18 mu m CMOS technology. This VCO exhibits good FOM and of -191.4dBc/Hz while the core circuit draws a DC current of 2.73mA from 0.55V low supply voltage. The excellent performance can be compared with the best reported X-band CMOS VCOs.