Browsing by Author "Hsu, MC"

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A systematic approach for low phase noise CMOS VCO design
(2003-08-01)
Kao, YH
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Hsu, MT
;
Hsu, MC
;
Wu, PA
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傳播研究所
The fully integrated LC voltage controlled oscillator by 0.35 mum CMOS technology is demonstrated. It has 2 GHz oscillation frequency, 23.58 mW power consumption under 3 V biased and 9.1% frequency tuning. The layout optimization method of inductor to increase quality factor and also to reduce phase noise is used. A general method is proposed which is capable of making an effective prediction of F, device excess noise number, and acquiring the phase noise of oscillators accurately. From this proposed method, the low phase noise by calculation is. attained. The phase noise of measured value which shows good match with calculating data is about -115.5dBc/Hz at off set frequency 600 kHz.
Multicolor infrared detection using two stacks of superlattice structures in a back-to-back configuration
(2000-10-02)
Hsu, MC
;
Kuan, CH
;
Wang, SY
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
Voltage-controlled multicolor detection with a two-stack GaAs/AlGaAs superlattice structure is reported. Each stack contains a superlattice and current blocking layers. The responsivity of each stack has a voltage-tunable spectral range and can be turned on or off by controlling the bias polarity. In a back-to-back configuration of the two stacks, a variable detection range with peak wavelength at 5.5, 6.8, 8.5, and 10.8 mu m is achieved by changing the applied voltage at 45 K. (C) 2000 American Institute of Physics. [S0003- 6951(00)05037-3].
Performance and application of a superlattice infrared photodetector with a blocking barrier
(2002-02-01)
Chen, CC
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Chen, HC
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Hsu, MC
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Hsieh, WH
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Kuan, CH
An infrared photodetector that contains a superlattice structure and a blocking barrier was investigated. The photodetector shows advantages including a low operating voltage (<0.7 V), wide detection bandwidth, flexible miniband engineering, and in particular, voltage-tunable spectral responsivity. The blocking barrier not only prohibits the dark current but also acts as a high-pass energy filter to tune the spectral responsivity. The zero background peak detectivity of our detector is 3.7x10(9) cm Hz(0.5)/W (9.7 mum) at -0.5 V and 2.2x10(10) cm Hz(0.5)/W (6.7 mum) at -0.1 V. Since the spectral responsivity at different biases is independent, temperature sensing is feasible by taking the ratio of the measured photocurrent at different biases. A demonstration of temperature sensing by using our superlattice infrared photodetector with a blocking barrier is also shown in this article. Those results show the superlattice is a simple and efficient structure for the design of a multicolor infrared photodetector. (C) 2002 American Institute of Physics.
Relaxation mechanisms of the photoelectrons in the second miniband of a superlattice structure
(2003-02-01)
Chen, CC
;
Chen, HC
;
Hsu, MC
;
Hsieh, WH
;
Kuan, CH
Photoelectron relaxation in the second miniband of a superlattice was studied with a high-pass energy filter at one end of the superlattice. By analyzing the spectral responses with different biases across the energy filter, the photoelectron distribution and relaxation in the second miniband of the superlattice can be resolved. In this paper, a model based on the rate equation is proposed to extract the related parameters of the photoelectron transport. The photoelectrons suffer from both intraminiband and interminiband relaxation. The extracted interminiband relaxation time is 11 ps, while the intraminiband one is in the sulipicosecond range. In addition, this structure can also be utilized as an infrared photodetector. Our analysis shows that the fast intraminiband relaxation is the dominant mechanism of the maximum achievable responsivity of the detector and the theoretical model not only provides the insight of the photoelectron transport in the superlattice miniband but also is useful for designing a superlattice infrared photodetector.