Shao-Hua Lee

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A 4.8GHz low-noise quadrature Colpitts VCO is presented. Use of the current switching differential Colpitts configuration together with super harmonic coupling scheme for quadrature signal generation ensures low phase noise operation. The advantage of proposed differential VCO is analyzed in terms of power consumption, phase noise, and figure of merit. The(More)
This paper presents a new voltage controlled oscillator (VCO) topology for radio frequency operation. The low phase noise differential CMOS VCO uses capacitive degeneration and transformer coupling between the gate and source of the negative conductance transistor. An on chip transformer in positive feedback is used to increase the voltage swing in(More)
The design of a low phase noise 4 GHz voltage controlled oscillator (VCO) based on tapped inductor with 10% frequency tuning range fabricated in 0.18-um 1P6M CMOS technology is reported. The LC resonator consists of two tapped inductors and varactors. The varactors have one control terminal to vary the effective resonator capacitance, which is used to fine(More)
This paper presents a LC-tank injection locked frequency divider with Complementary structure. The frequency divider is implemented using a standard UMC 0.18-mum CMOS process. The proposed circuit adds an injection nMOS transistor between the differential outputs of the frequency divider with the structure of complementary VCO that contains a tapped LC(More)
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