Browsing by Author "Yu, CY"

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A 0.8V 5.9GHz wide tuning range cmos VCO using inversion-mode bandswitching varactors
(2005)
Wu, CY
;
Yu, CY
;
電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
This paper presents a completely integrated 0.8V 5.9GRz CMOS voltage-controlled oscillator (VCO) with inversion-mode MOS (IMOS) bandswitching varactors. IMOS varactors are used to maintain a large tuning range when the supply voltage is lower than 1V. Moreover, a large resistance connects to the bulk of each IMOS varactor to further improve the VCO tuning capability. Through this large resistance, the tuning range increases by 500MHz. A bandswitching topology is used to ameliorate the adverse effects of highly sensitive IMOS varactors. The VCO was simulated with a 0.8V supply with a tuning range of 29.12% from 4.4 to 5.9 GRz when tuned from 0 to 0.8V. The simulated phase noise is -109.65dBc/Hz at 1MHz offset from the carrier frequency of 5.52GHz. The VCO-core power dissipation is 1.2mW. When the supply is reduced to 0.6V, the tuning range becomes 22.64% from 4.7 to 5.9GHz. The VCO-core dissipates 0.9mW, and the phase noise is -105.24dBc/Hz at 1MHz offset from the carrier frequency of 5.65GHz. The VCO circuit has been designed using TSMC 0.18-mu m CMOS technology with deep n-well processing.
Chaos synchronization and chaos anticontrol of a rotationally supported simple pendulum
(2004-03-01)
Ge, ZM
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Yu, CY
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Chen, YS
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機械工程學系
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Department of Mechanical Engineering
Chaos synchronization and anticontrol of a rotationally supported simple pendulum was studied in this paper. Different kinds of coupling terms are used to synchronize the two identical chaotic systems with different initial conditions. An observed-based scheme is also used to achieve synchronization. The results are demonstrated by phase portrait, Lyapunov exponent, Poincare maps and synchronization time. Next, in order to analyze the transient behavior of the synchronized systems, Euclidean distance is used to plot a figure with coupling strength versus the distance. The chaotic signals are used to mask the message function in the secure communication system. Finally, anticontrol of chaos is achieved by adding constant term, periodic term, impulse term, time-delay term and adaptive control.
Synthesis and second-order nonlinearities of chiral prolinol-substituted chromophores
(2004-06-01)
Chou, SSP
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Yu, CY
;
Lin, HC
;
Yang, PK
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光電工程學系
A new series of thiophene- and furan-containing chromophores with a chiral prolinol donor and a sulfone acceptor has been synthesized. The UV-vis absorptions, second-order nonlinear optical properties, and X-ray crystal structures are described.