Browsing by Author "Lee, H."

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Design of X-band complementary metal-oxide semiconductor-based frequency-modulation continuous-wave sensor
(2009-12-01)
Chang, C. -H.
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Wang, S.
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Wu, H. -S.
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Liang, E. -C.
;
Liu, A. -S.
This study presents an X-band complementary metal-oxide semiconductor-based frequency-modulation continuous-wave (FMCW) sensor system for transportation management. The proposed sensor system has two antennas, one to transmit signals and the other to receive them. The complete radio frequency (RF) transceiver is based on standard 0.18 mm one-poly six-metal (1P6M) CMOS technology with a chip area of 1.68 mm x 1.6 mm. Two planar leaky-mode antenna arrays with a gain of 18 dB are also designed. Experimental results indicate that the isolation between two antenna arrays that are 5.0 mm apart exceeds 42.0 dB at 10.5 GHz. The prototype of the FMCW sensor system is used in the range measurement of multiple lanes for the transportation management system (TMS). The major contribution of this study is that it integrates a 0.18 mm CMOS transceiver and antenna arrays into an FMCW RF front end, and employs an IF amplifier and a digital signal processor to demonstrate that the beat frequencies are linear. Measurements made in field tests agree closely with the simulation results.
Feasibility of using a 2D array detector to verify composite IMRT delivery for helical tomotherapy and linac
(2008)
Shueng, P.
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Choug, N.
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Lee, H.
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Tien, H.
;
Kung, W.
Graded index and randomly oriented core-shell silicon nanowires for broadband and wide angle antireflection
(2011-09-01)
Pignalos, P.
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Lee, H.
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Qiao, L.
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Tseng, M.
;
Yi, Y.
Antireflection with broadband and wide angle properties is important for a wide range of applications on photovoltaic cells and display. The SiOx shell layer provides a natural antireflection from air to the Si core absorption layer. In this work, we have demonstrated the random core-shell silicon nanowires with both broadband (from 400nm to 900nm) and wide angle (from normal incidence to 60 degrees) antireflection characteristics within AM1.5 solar spectrum. The graded index structure from the randomly oriented core-shell (Air/SiOx/Si) nanowires may provide a potential avenue to realize a broadband and wide angle antireflection layer. Copyright 2011 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [doi:10.1063/1.3624838]
Graded index and randomly oriented core-shell silicon nanowires for broadband and wide angle antireflection
(2011-09-01)
Pignalos, P.
;
Lee, H.
;
Qiao, L.
;
Tseng, M.
;
Yi, Y.
Antireflection with broadband and wide angle properties is important for a wide range of applications on photovoltaic cells and display. The SiOx shell layer provides a natural antireflection from air to the Si core absorption layer. In this work, we have demonstrated the random core-shell silicon nanowires with both broadband (from 400nm to 900nm) and wide angle (from normal incidence to 60 degrees) antireflection characteristics within AM1.5 solar spectrum. The graded index structure from the randomly oriented core-shell (Air/SiOx/Si) nanowires may provide a potential avenue to realize a broadband and wide angle antireflection layer. Copyright 2011 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [doi:10.1063/1.3624838]