Browsing by Author "Lai, Chih-Wei"

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A 147 GHz Fully Differential D-Band Amplifier Design in 65 nm CMOS
(2013)
Li, Chun-Hsing
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Lai, Chih-Wei
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Kuo, Chien-Nan
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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
This work presents a 147 GHz D-band fully differential amplifier design in 65 nm CMOS. By using a T-network, composed of three inductors, to replace an on-chip transformer, the proposed impedance transformation network can provide an impedance transformation ratio larger than one. So the passive gain can be acquired to increase the amplifier gain. The measured results show that the amplifier can provide power gain of 7.1 dB at 147 GHz. The power consumption is 104 mW from a 2 V supply voltage.
A 37.5-mW 8-dBm-EIRP 15.5 degrees-HPBW 338-GHz Terahertz Transmitter Using SoP Heterogeneous System Integration
(2015-02-01)
Li, Chun-Hsing
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Chao, Tzu-Yuan
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Lai, Chih-Wei
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Chen, Wei-Cheng
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Ko, Chun-Lin
A low-cost terahertz transmitter is proposed by using system-on-package (SoP) heterogeneous system integration. A signal source in 40-nm CMOS is integrated with an antenna array on a Benzocyclobutene carrier through a broadband low-loss terahertz interconnect. The signal source adopting triple-push oscillator topology is able to produce a differential output without any additional balun circuit. Hence, the power consumption and the chip area can be reduced. The antenna array containing 50 patch antennas is differentially excited to give simulated directivity, efficiency, and antenna gain as high as 22.6 dB, 88%, and 22 dBi, respectively, at 335 GHz. The terahertz interconnect employs a resonator coupling technique to provide low-loss and broadband performance while occupying a small area. Measured results show that the proposed terahertz transmitter can work at 338.4 GHz with equivalent isotropically radiated power (EIRP) of 8.0 dBm while consuming only 37.5 mW from a 1-V supply. The measured half-power beam-width can be as narrow as 15.5 degrees. The EIRP can be further raised to 9.5 dBm as the supply V-DD is increased to 1.3 V. The CMOS chip only occupies an area as small as 0.028 mm(2). All of the design efforts enable the proposed terahertz transmitter to feature in small form factor, low power dissipation, low cost, and high performance. To the best of the authors\' knowledge, this is the most compact, lowest power, lowest cost, and high-performance SoP-based terahertz transmitter reported thus far.
A DEA window analysis on the product family mix selection for a semiconductor fabricator
(2008-07-01)
Chung, Shu-Hsing
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Lee, Amy Hsin-I
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Kang, He-Yau
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Lai, Chih-Wei
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工業工程與管理學系
In a competitive market, semiconductor fabricator must face an environment with multi-product types, multi-priority orders and demand changes in time. Since semiconductor fabrication has a very complicated production process, the above-stated characteristics make the production planning even more difficult. This paper applies data envelopment analysis (DEA) to find a set of product family mix that is efficient for the company to produce. To ensure long-term effectiveness in productivity and in profit gaining, window analysis is adopted to seek the most recommended set of product family mixes for manufacturing by measuring the performance changes over time. With this method, the performance of a mix in one period is compared not only with the performance of other mixes but also with its own performance in other periods. The proposed mechanism can provide guidance to the fabricator regarding strategies for aggregate planning so as to improve manufacturing efficiency. (c) 2007 Elsevier Ltd. All rights reserved.
A Low-Cost Broadband Bondwire Interconnect for THz Heterogeneous System Integration
(2015)
Li, Chun-Hsing
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Lai, Chih-Wei
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Yan, Tzu-Chao
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Kuo, Chien-Nan
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電機工程學系
A low-cost broadband bondwire interconnect is proposed for THz heterogeneous system integration. A transversal path composed of two transmission lines and a bondwire is introduced to effectively reduce the bondwire effect of an original signal path consisted of a single bondwire only. Simulation results indicate that the return loss and insertion loss can be better than 15 dB and 2.3 dB from dc to 456 GHz, respectively. Measured interconnect loss is around 0 dB to 1.5 dB from 320 to 340 GHz.
A Spin-controlled Microcavity Laser
(2015)
Hsu, Feng-Kuo
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Xie, Wei
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Lee, Yi-Shan
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Lin, Sheng-Di
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Lai, Chih-Wei
We demonstrate highly circularly polarized lasing under non-resonant elliptically polarized optical pumping in a semiconductor microcavity at room temperature. (C) 2014 Optical Society of America
CMOS THz Transmissive Imaging System
(2014)
Yan, Tzu-Chao
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Li, Chun-Hsing
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Lai, Chih-Wei
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Chen, Wei-Cheng
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Chao, Tzu-Yuan
This paper presents a THz imaging system composed of a signal source and a signal sensor in CMOS technology The signal source integrates a 338 GHz oscillator in 40-nm CMOS and an antenna array on a Benzocyclobutene (BCB) carrier using the SoP (System-on-Package) technique. The measured EIRP achieves +8 dBm. The signal sensor is implemented in 0.18 mu m CMOS. The measured maximum responsivity is 632 kV/W at 332 GHz. The signal source and signal sensor consume dc power of 37.5 mW and 7.92 mW, respectively. The resolution of the proposed THz imaging system is 4 mm.
Electronic THz Transmissive Imaging System
(2015)
Chen, Wei-Cheng
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Lai, Chih-Wei
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Yan, Tzu-Chao
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Li, Chun-Hsing
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Chao, Tzu-Yuan
An electronic THz transmissive imaging system is presented in this work. This system is composed of a CMOS signal source, a CMOS signal sensor, lenses, and commercial electronic chopping components. The output frequency of the signal source is 339 GHz, and the responsivity of the signal sensor is 200 kV/W. The total dc power consumption of those CMOS circuits is 91.02 mW. Using electronic chopping at the frequency up to 100 kHz helps improve the system dynamic range and makes imaging feasible. The resolution of the realized imaging system achieves 2 mm.
Resonance-enhanced dipolar interaction between terahertz photons and confined acoustic phonons in nanocrystals
(2008-03-03)
Liu, Tzu-Ming
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Lu, Ja-Yu
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Chen, Hung-Ping
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Kuo, Chung-Chiu
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Yang, Meng-Ju
Taking advantage of the specific core-shell charge separation structure in the CdSe/CdTe core-shell type-II nanocrystals, we experimentally observed and verified the existence of the resonance-enhanced dipolar interaction between terahertz photons and their corresponding confined acoustic phonons. From the measured terahertz transmission spectra, we found that the photon frequency of the terahertz resonant absorption is inversely proportional to the diameter D of the nanocrystals and agrees with that of dipolar active l=1, n=0 confined acoustic modes. The corresponding absorption cross section shows a D(4) dependence, supporting a charged simple-harmonic-oscillator model. These facts verify the occurrence of dipolar interaction between terahertz photons and confined terahertz acoustic phonons. (c) 2008 American Institute of Physics.
Resonant-Enhanced Dipolar Interaction between THz-Photons and Confined Acoustic Phonons in Nanocrystals
(2008)
Liu, Tzu-Ming
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Lu, Ja-Yu
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Chen, Hung-Ping
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Kuo, Chung-Chiu
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Lai, Chih-Wei
We proved the existence of resonant-enhanced dipolar interaction between THz-photons and confined acoustic phonons in nanocrystals. By a specific core-shell charge separation, the dipolar (l=1) confined acoustic modes was activated to absorb THz waves. (C) 2007 Optical Society of America
Resonant-enhanced dipolar interaction between THz-photons and confined acoustic phonons in nanostructures
(2008-01-01)
Liu, Tzu-Ming
;
Lu, Ja-Yu
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Kuo, Chung-Chiu
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Yang, Meng-Ju
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Lai, Chih-Wei
By using a frequency-controlled narrow band THz source, a Fourier Transform Infrared (FTIR) spectroscopy system, and a frequency-controlled terahertz (THz) emitter, for the first time, we studied the THz photon absorption related to the THz confined acoustic vibrations in semiconductor nanocrystals. Through a specific charge separation in the CdSe/CdTe type-II nanocrystals and a piezoelectric coupling in the wurtzite CdSe nanocrystals, the THz photons can be resonantly coupled with (l=1) dipolar modes and the (l=0) breathing modes, respectively. Our results provide new mechanisms for low dimensional systems to convert a THz photon into a phonon of the same frequency.
Room temperature spin-polarized polariton lasers
(2013-01-01)
Hsu, Feng-Kuo
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Li, Yi-Shan
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Lin, Sheng-Di
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Lai, Chih-Wei
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電子工程學系及電子研究所
We report room temperature spin-polarize polariton lasing characteristics and dynamics of a planar InGaAs/GaAs microcavity under non-reasonant circularly polarized picosecond optical excitation. (C) 2013 Optical Society of America
Room-Temperature Macroscopic Coherence of Two Electron-Hole Plasmas in a Microcavity
(2020-04-16)
Jie, Qi
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Zhang, Keye
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Lai, Chih-Wei
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Hsu, Feng-Kuo
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Zhang, Weiping
Macroscopic coherence of Bose condensates is a fundamental and practical phenomenon in many-body systems, such as the long-range correlation of exciton-polariton condensates with a dipole density typically below the exciton Mott-transition limit. Here we extend the macroscopic coherence of electron-hole-photon interacting systems to a new region in the phase diagram-the high-density plasma region, where long-range correlation is generally assumed to be broken due to the rapid dephasing. Nonetheless, a cooperative state of electron-hole plasma does emerge through the sharing of the superfluorescence field in an optical microcavity. In addition to the in situ coherence of e-h plasma, a long- range correlation is formed between two 8-mu m-spaced plasma ensembles even at room temperature. Quantized and self-modulated correlation modes are generated for e-h ensembles in the plasma region. By controlling the distance between the two ensembles, multiple coupling regimes are revealed, from strong correlation to perturbative phase correlation and finally to an incoherent classical case, which has potential implications for tunable and high-temperature-compatible quantum devices.
The Experimental Study of THz Image Sensor in 0.18 mu m CMOS Technology
(2014)
Lai, Chih-Wei
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Chen, Wei-Cheng
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Yan, Tzu-Chao
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Li, Chun-Hsing
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Kuo, Chien-Nan
In this study, four different types of power detectors are implemented in 0.18 mu m CMOS technology for the THz image sensor application. These power detectors include common-source with and without supply voltage, and common gate with and without supply voltage. The measured responsivities at 332 GHz are 632 kV/W, 13.2 kV/W, 16.2 kV/W, and 9.1 kV/W, respectively. The image resolution of the proposed THz sensor is 2 mm.
Ultrafast spin-polarized lasing in a highly photoexcited semiconductor microcavity at room temperature
(2015-05-14)
Hsu, Feng-kuo
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Xie, Wei
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Lee, Yi-Shan
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Lin, Sheng-Di
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Lai, Chih-Wei
We demonstrate room-temperature spin-polarized ultrafast (similar to 10 ps) lasing in a highly optically excited GaAs microcavity. This microcavity is embedded with InGaAs multiple quantum wells in which the spin relaxation time is less than 10 ps. The laser radiation remains highly circularly polarized even when excited by nonresonant elliptically polarized light. The lasing energy is not locked to the bare cavity resonance, and shifts similar to 10 meV as a function of the photoexcited density. Such spin-polarized lasing is attributed to a spin-dependent stimulated process of correlated electron-hole pairs. These pairs are formed near the Fermi edge in a high-density electron-hole plasma coupled to the cavity light field.