Chi-Chen Chen

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A wideband low-noise amplifier (LNA) based on the current-reused cascade configuration is proposed. The wideband input-impedance matching was achieved by taking advantage of the resistive shunt-shunt feedback in conjunction with a parallel LC load to make the input network equivalent to two parallel RLC-branches, i.e., a second-order wideband bandpass(More)
A low-power low-phase-noise 48-GHz CMOS LC voltage-control oscillator (VCO) and a low-power 60-GHz CMOS low-noise amplifier (LNA) for 60-GHz dual-conversion receiver are reported. The VCO dissipated 5.556 mW power, and achieved state-of-the-art phase noise of −105 dBc/Hz at 1-MHz offset from 47.84 GHz. The corresponding figure-of-merit (FOM) was(More)
Abscisic acid (ABA), an important chemical signal from roots, causes physiological changes in leaves, including stomata closure and photoprotection. Furthermore, endogenous ABA concentration in leaves and stomatal behavior vary with the species adapted to different water regimes. In this study, Ficus microcarpa, a hemiepiphyte, Salix warburgii, a(More)
One broad-leaved pioneer tree, Alnus formosana, two broad-leaved understory shrubs, Ardisia crenata and Ardisia cornudentata, and four ferns with different light adaptation capabilities (ranked from high to low, Pyrrosia lingus, Asplenium antiquum, Diplazium donianum, Archangiopteris somai) were used to elucidate the light responses of photosynthetic rate(More)
A 3.1-10.6-GHz ultra-wideband low-noise amplifier (UWB LNA) with excellent phase linearity property (group-delay-variation is only plusmn16.7 ps across the whole band) using standard 0.13 mum CMOS technology is reported. To achieve high and flat gain and small group-delay-variation at the same time, the inductive peaking technique is adopted in the output(More)
In this paper, a polysilicon PGS (pattern ground shield) pattern, which located exactly inside and outside the spiral metal wires of the RF transformers/ inductors in standard RF BiCMOS technology, was demonstrated. The proposed PGS pattern can effectively improve the drawback, i.e. large parasitics between the transformers/inductors and the PGS pattern,(More)
A 60-GHz receiver front-end with an integrated 180° out-of-phase Wilkinson power divider using standard 0.13 µm CMOS technology is reported. The receiver front-end comprises a wideband low-noise amplifier (LNA) with 12.4-dB gain, a current-reused bleeding mixer, a baseband amplifier, and a 180° out-of-phase Wilkinson power divider. The(More)
A 57-GHz CMOS Voltage-Controlled Oscillator (VCO) using tunable LC source-degeneration for operation frequency and tuning-range enhancement is demonstrated. The tunable LC source-degeneration is made by adding two tunable LC tanks, where varactors are used as the needed capacitors, to the source terminals of the cross-coupled transistor pair of the VCO.(More)
Selective removal of the silicon underneath a set of single-turn multilayer interlaced stacked (SMIS) radio-frequency (RF) transformers with nearly perfect magnetic-coupling factor (k<sub>IM</sub>~1) and high resistive-coupling factor (k<sub>Re</sub>) is demonstrated. This process is based on the inductively coupled-plasma (ICP) deep trench technology.(More)