Graduate Institute of Electronics Engineering

Electronics, Taiwan

Graduate Institute of Electronics Engineering

Electronics, Taiwan
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Wu K.-I.,National Taiwan University | Hwang B.-T.,Richtek Technology Corporation | Chen C.C.-P.,Graduate Institute of Electronics Engineering
IEEE Transactions on Power Electronics | Year: 2017

While the fast transient techniques have been extensively investigated, the research aiming at current-mode pulse width modulation (PWM) converters is relatively unexplored. This paper presents a synchronous double-pumping (SDP) technique for current-mode PWM dc-dc converters to achieve fast-transient response between different load conditions. The advantages and limitations of the existing conventional techniques are discussed and analyzed. With the proposed SDP technique, a nearly optimized recovery time speedup and voltage drop minimization for every different conventional current-mode converters can be obtained. The prototype chip was fabricated using a TSMC 0.35-μm CMOS process occupies the area of 2.242 mm2 including all bonding pads and ESD protection circuits. The output voltage ripple is measured about 15 mV in peak-to-peak value. The recovery time is 2.4 and 2.6 μs, respectively, in response to the 400-mA step-up and step-down load changes. Those are improved by a factor of 8.33 and 8.23, respectively. © 2016 IEEE.

Wu Y.-L.,Graduate Institute of Electronics Engineering | Chen C.-Y.,Graduate Institute of Electronics Engineering | Huang Y.-H.,Graduate Institute of Electronics Engineering | Lu Y.-J.,Innolux Corporation | And 2 more authors.
Applied Optics | Year: 2014

In this work, we conducted studies of tandem organic light-emitting devices (OLEDs) based on the connecting structure consisting of n-doped electron-transport layer (n-ETL)/1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (HATCN)/hole-transport layer. We investigated effects of different n-ETL materials and different HATCN thicknesses on characteristics of tandem OLEDs. Results show that the tandem OLEDs with n-BPhen and a 20 nm layer of HATCN in the connecting structure exhibited the best performance. With these, highly efficient and bright green phosphorescent two-emitting-unit tandem OLEDs, with drive voltages significantly lower than twice that of the single-unit benchmark device and current efficiencies higher than twice that of the single-unit benchmark device, were demonstrated. © 2014 Optical Society of America.

Hsu W.-W.,National Taiwan University | Chen J.Y.,National Taiwan University | Cheng T.-H.,National Taiwan University | Lu S.C.,National Taiwan University | And 6 more authors.
Applied Physics Letters | Year: 2012

With Al 2O 3 passivation on the surface of Cu(In,Ga)Se 2, the integrated photoluminescence intensity can achieve two orders of magnitude enhancement due to the reduction of surface recombination velocity. The photoluminescence intensity increases with increasing Al 2O 3 thickness from 5 nm to 50 nm. The capacitance-voltage measurement indicates negative fixed charges in the film. Based on the first principles calculations, the deposition of Al 2O 3 can only reduce about 35 of interface defect density as compared to the unpassivated Cu(In,Ga)Se 2. Therefore, the passivation effect is mainly caused by field effect where the surface carrier concentration is reduced by Coulomb repulsion. © 2012 American Institute of Physics.

Lin Y.-T.,Graduate Institute of Electronics Engineering | Huang J.-L.,Graduate Institute of Electronics Engineering | Huang J.-L.,National Taiwan University | Wen X.,Kyushu Institute of Technology
Proceedings of the Asian Test Symposium | Year: 2012

Shift and capture power management has become indispensable for modern complex low-power designs. Excessive shift power increases test application time and may jeopardize the shift operation correctness, excessive capture power during at-speed scan testing may lead to yield loss. This paper proposes a scan cell design which isolates scan cells output transitions in both shift and capture modes. Experimental results on larger ISCAS'89, ITC'99, and IWLS'05 benchmark circuits show that the proposed scan cell design lowers capture power consumptions with reasonable CPU times and test set inflation. © 2012 IEEE.

Li W.-T.,National Taiwan University | Tsai J.-H.,National Taiwan Normal University | Yang H.-Y.,National Taiwan University | Chou W.-H.,HTC Corp | And 4 more authors.
IEEE Transactions on Microwave Theory and Techniques | Year: 2012

Two V-band low-noise amplifiers (LNAs) with excellent linearity and noise figure (NF) using 90-nm CMOS technology are demonstrated in this paper, employing parasitic-insensitive linearization topologies, i.e., cascode and common source, for comparative purposes. To improve the linearity without deteriorating the NF, the 54-69-GHz cascode LNA is linearized by the body-biased post-distortion, and the 58-65-GHz common-source LNA is linearized by the distributed derivative superposition. Using these parasitic-insensitive linearization methods at millimeter-wave frequency, the cascode LNA can achieve an IIP 3 of 11 dBm and an NF of 3.78 dB at 68.5 GHz with a gain of 13.2 dB and 14.4-mW dc power. The common-source LNA has an IIP 3 of 0 dBm and an NF of 4.1 dB at 64.5 GHz with a gain of 11.3 dB and 10.8-mW dc power. To the best of our knowledge, the proposed cascode LNA has up to 11-dBm IIP 3 performance and the highest figure-of-merit of 156.2, among all reported V-band LNAs. © 1963-2012 IEEE.

Wei K.-C.,Graduate Institute of Electronics Engineering | Huang Y.-L.,National Taiwan University | Chien S.-Y.,Graduate Institute of Electronics Engineering
Proceedings - IEEE International Conference on Multimedia and Expo | Year: 2013

View synthesis, composed of depth-image-based rendering followed by hole-filling, is a crucial technology for 3D TV and free-viewpoint TV. To realize view synthesis in practical systems, the efficiency of view synthesis must be considered to achieve good a trade-off between the image quality and the computational complexity. We propose a efficient view synthesis scheme that, when compared to state-of-the-art backward warping, requires only half of the runtime with comparable quality. Specifically, the proposed scheme uses ray casting and pull-push processing to render in one pass, which can be regarded as applying 3D filters in the depth-image-based rendering. Moreover, the proposed scheme can benefit the hole-filling process to further improve the efficiency of view synthesis. © 2013 IEEE.

Chen Y.-J.E.,Graduate Institute of Electronics Engineering | Yang H.-S.,Graduate Institute of Electronics Engineering | Chen J.-H.,National Taiwan University
2014 IEEE International Wireless Symposium, IWS 2014 | Year: 2014

The pulse-modulated polar transmitters have been developed to answer the call for the need of linear and efficient power amplification for wireless applications. The envelope of the modulated RF signal is converted into the pulse train by means of pulse width modulation or delta-sigma modulation. The power amplification of the pulse train can be performed by the highly efficient power amplifiers without the constraint of linearity. The modulated RF signal are restored by low-pass or band-pass filtering of the amplified pulse train. With both high linearity and high efficiency, the pulse-modulated polar transmitter is an excellent candidate for spectrum efficient wireless applications. © 2014 IEEE.

Wei K.-C.,Graduate Institute of Electronics Engineering | Huang Y.-L.,National Taiwan University | Chien S.-Y.,Graduate Institute of Electronics Engineering
Proceedings 2013 IEEE 3rd International Conference on Consumer Electronics - Berlin, ICCE-Berlin 2013 | Year: 2013

Free-viewpoint TV provides an interactive selection of viewpoints when people watch 3D videos. In this paper, to give more fascinating viewing experience, constructing point-based models for 3D video processing in free-viewpoint TV is proposed. The results show the constructed models from two types of 3D videos. Furthermore, the subsequent processing can be benefited because the point-based model is compact and quite suitable for computer graphics techniques and the existing GPU hardware. © 2013 IEEE.

Chang Y.-C.,Graduate Institute of Communication Engineering | Hong C.-H.,Graduate Institute of Electronics Engineering | Liu K.-A.,National Taiwan University | Lu H.-C.,Graduate Institute of Communication Engineering | And 2 more authors.
Asia-Pacific Microwave Conference Proceedings, APMC | Year: 2016

Polarization and antenna pattern misalignment between transmitting and receiving antennas will reduce received power in wireless power transfer. In 2D case, two transmitting and one receiving dipole antennas are at same plane. When rotating receiving antenna, received power will change due to antenna pattern misalignment. 90° phase different between two orthogonal transmitting antennas can realize stable reception for receiving antenna in all rotation angles at a 2D plane. But this technique can not be used in 3D case. Time switching among transmitting antennas can achieve stable reception in all rotation angles in both 2D and 3D cases. The efficiency in 2D case is 1/2, and 1/3 in 3D case. Experiment results using RFID show stable reception at different rotation angles and good agreement with theoretical prediction on efficiency in both 2D and 3D cases. © 2015 IEEE.

Ou S.-H.,Graduate Institute of Electronics Engineering | Ou S.-H.,Intel Corporation | Lee C.-H.,Intel Corporation | Lee C.-H.,Academia Sinica, Taiwan | And 4 more authors.
IEEE Journal on Selected Topics in Signal Processing | Year: 2015

Battery lifetime is critical for wireless video sensors. To enable battery-powered wireless video sensors, low-power design is required. In this paper, we consider applying multi-view summarization to wireless video sensors to remove redundant contents such that the compression and transmission power can be reduced. A low-complexity online multi-view video summarization scheme is proposed. Experiments show that the proposed summarization method successfully reduces the video content while keeping important events. A power analysis of the system also shows that a significant amount of energy can be saved. © 2014 IEEE.

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