Browsing by Author "Wu, Chuan-Yi"

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A 2.4 GHz Low Phase Noise In-Phase Coupled Class-C Quadrature VCO in 0.18 mu m CMOS
(2015-10-01)
Wu, Chuan-Yi
;
Liao, Yu-Te
;
電機資訊學士班
;
Undergraduate Honors Program of Electrical Engineering and Computer Science
This letter presents a 2.4 GHz Class-C QVCO using an in-phase coupling topology. The phase noise of the proposed QVCO is effectively reduced by using a lower gate biasing voltage at the cross-coupled pairs and an in-phase coupling technique. A complementary Class-C oscillator is employed to enhance the startup robustness over a temperature range from -25 degrees C to 100 degrees C. A quadrature oscillator, implemented in a 0.18 mu m CMOS process, achieves a phase noise lower than -130.7 dBc/Hz at 1 MHz offsets and a frequency tuning range from 2.23 to 2.57 GHz while only consuming 3 mW. The design attains a remarkable figure-of-merit of 193.7 dBc/Hz.
A 2.6mW,-192dB/Hz FOM Class-C QVCO Using Capacitive Source Degeneration Coupling
(2014-01-01)
Hong, Zhi-Hao
;
Wu, Chuan-Yi
;
Liao, Yu-Te
;
電機資訊學士班
;
Undergraduate Honors Program of Electrical Engineering and Computer Science
The paper presents a novel Class-C type QVCO using a capacitive source coupling mechanism to enhance the startup robustness over process-temperature-voltage variations. Class-C type oscillator has superior phase noise performance with low power consumption at the cost of weak startup. In this design, complementary architecture and capacitive source degeneration coupling are employed to increase the loop gain of Class-C quadrature oscillator. The capacitive coupling mechanism also provides extra phase shifts that eliminate the quality factor degradation of the LC tank in QVCO design. An optimal coupling factor is derived to compromise power-phase noise trade-offs. The proposed 2.4GHz QVCO, fabricated in 0.18 mu m CMOS technology, achieves -128dBc/Hz at 1MHz offsets while only consuming 2.6mW. The design attains a remarkable figure-of-merit (FOM) of -192dB/Hz.
Robustness Enhancement of a Class-C Quadrature Oscillator Using Capacitive Source Degeneration Coupling
(2015-01-01)
Hong, Chi-Hao
;
Wu, Chuan-Yi
;
Liao, Yu-Te
;
資訊工程學系
;
Department of Computer Science
This brief presents a low-phase-noise Class-C-type quadrature voltage-controlled oscillator (QVCO) with a robust start-up. The chip was implemented using the 0.18-mu m CMOS technology. A source degeneration coupling technique is used to generate quadrature signals and enables the elimination of bimodal oscillation. Capacitive degeneration coupling also provides negative impedance to compensate for losses in the LC tank, resulting in less power consumption in the core circuit to sustain oscillation. The proposed 2.4-GHz QVCO design achieves a 13.46% tuning range and a phase noise of -128.65 dBc/Hz at a 1-MHz offset while only consuming 2.67 mW from a 1.8-V supply. The oscillator demonstrated robust operation from -25 degrees C to 85 degrees C with phase noise lower than -122 dBc/Hz at a 1-MHz offset. The proposed QVCO achieves a remarkable figure of merit of -192 dBc/Hz.