Browsing by Author "Lin, WJ"

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40-GHz coplanar waveguide bandpass filters on silicon substrate
(2002-11-01)
Chan, KT
;
Chen, CY
;
Chin, A
;
Hsieh, JC
;
Liu, J
We report a very simple process to fabricate high performance filter on Si at 40 GHz; using proton implantation. The filter has only -3.4-dB loss at peak transmission of 40 GHz; with a broad 9-GHz bandwidth. In sharp contrast, the filter on 1.5-mum SiO2 isolated Si has much worse transmission and reflection loss. This is the first demonstration of high performance filter at millimeter-wave regime on Si with process compatible to current VLSI technology.
A novel two-stage channel estimation method for wireless communications
(2004-06-01)
Lin, WJ
;
Lin, TT
;
Huang, CC
;
電信工程研究所
;
Institute of Communications Engineering
In this paper, we proposed a novel two-stage channel estimation (2S-CE) method. In contrast to conventional channel estimation methods, this method makes the maximum use of the information contributed by the known data in every transmission burst. In the first stage, the least-squares (LS) algorithm was used to estimate the channel impulse response (CIR) based on the normal training sequence. Then the maximum channel memory was estimated and used to locate the uncorrupted data in the guard interval. In the second stage, the uncorrupted data together with the normal training sequence were sent to the LS algorithm again to obtain the fine-tuned CIR. To verify the efficiency of the proposed 2S-CE method, both a theoretical analysis and computer simulations have been done. Computer simulation results confirm the analysis results and demonstrate that the proposed 2S-CE method outperforms a conventional single-stage channel estimation method.
AuBe Ohmic contacts to p-type ZnTe
(1998-12-10)
Lan, WH
;
Lin, WJ
;
Cheng, YC
;
Tai, K
;
Tasi, CM
Ohmic contacts of AuBe to p-ZnTe show a minimum specific contact resistance of 3.0 x 10(-6) Ohm cm(2) for a p-doping level of 1.6 x 10(19) cm(-3) and at an annealing temperature of 200 degrees C. The beryllium is very effective at improving the electrical properties of p-type contacts to ZnTe.
Color quantization by preserving color distribution features
(1999-10-01)
Lin, WJ
;
Lin, JC
;
資訊工程學系
;
Department of Computer Science
A color quantization method is proposed. The method hierarchically uses a bisection tool that preserves certain color-distribution features. The preserved features are average color, variance in each color dimension, and average color radius. An algorithm is given that includes the histogram simplification procedure, color palette generation, and pixel mapping. Experiments show that the proposed method usually obtains acceptable quantized images with competitive speed. (C) 1999 Elsevier Science B.V. All rights reserved.
Formation of self-organized GaN dots on Al0.11Ga0.89N by alternating supply of source precursors
(2004-06-15)
Ke, WC
;
Huang, HY
;
Ku, CS
;
Yen, KH
;
Lee, L
The self-organized GaN dot structure is successfully grown on a slightly lattice-mismatched Al0.11Ga0.89N epilayer using flow-rate modulation epitaxy (FME) growth technique. From the variation of dot density with growth temperature, we can observe that the GaN dot growth is controlled predominately by the surface diffusion of Ga adatoms at substrate temperatures below 915degreesC and by re-evaporation at higher temperatures. Because of the special alternating gas supply feature in FME, during the Ga source step, it is the Ga metal that is deposited on the underlying Al0.11Ga0.89N layer. This is because of the large lattice mismatch of 41.8% between the Ga metal (4.51 Angstrom) and Al0.11Ga0.89N (3.18 Angstrom). We consider that the GaN dot growth in our study is mainly through the Volmer-Weber growth mode, not the commonly used Stranski-Krastanow growth mode.
Growth and fatigue properties of pulsed laser deposited Pb1-xLax(ZryTiz)O-3 thin films with [001] preferred orientation
(1996-12-01)
Lin, WJ
;
Tseng, TY
;
Wu, YZ
;
Lin, SP
;
Tu, SL
Growth of [00/] preferentially oriented Pb1-xLax(ZryTiz) O-3 (PLZT) thin films was carried out by using targets of either tetragonal or rhombohedral structure. The tetragonal films grew in a similar manner to the rhombohedral films. Both the substrate temperature (500 or 550 degrees C) and oxygen pressure (0.1 mbar, 10 Pa) required stringent control in order to deposit [00/]-textured PLZT thin films. The ferroelectric and fatigue properties were examined. The films deposited on YBa2Cu3O7-x and CeO2 coated silicon (YBCO/CeO2/Si) substrates possessed substantially lower remanent polarization than those grown on YBCO coated SrTiO3 (YBCO/STO) substrates; this is ascribed to inferior crystallinity of the PLZT/BCO/CeO2/Si films. The remanent polarization of tetragonal PLZT films was degraded insignificantly up to 10(8) polarization switching cycles, whereas that of rhombohedral PLZT films was already reduced to 80% of the initial value after 10(8) cycles. Low endurance of rhombohedral films was ascribed to the periodic stress induced when the inclined spontaneous polarization vector (P=[111]) switched. On the other hand, high endurance of tetragonal films was explained by the fact that the spontaneous polarization vector (P=[001]) lies along the film's normal such that switch cycles cause no lateral stress.
High-performance microwave coplanar bandpass and bandstop filters on Si substrates
(2003-09-01)
Chan, KT
;
Chin, A
;
Li, MF
;
Kwong, DL
;
McAlister, SP
High-performance bandpass and bandstop microwave coplanar filters, which operate from 22 to 91 GHz, have been fabricated on Si substrates. This was achieved using an optimized proton implantation process that converts the standard low-resistivity (similar to10 Omega (.) cm) Si to a semi-insulating state. The bandpass filters consist of coupled lines to form a series resonator, while the bandstop filter was designed in a double-folded short-end stub structure. For the bandpass filters at 40 and 91 GHz, low insertion loss was measured, close to electromagnetic simulation values. We also fabricated excellent bandstop filters with very low transmission loss of similar to1 dB and deep band rejection at both 22 and 50 GHz. The good filter performance was confirmed by the higher substrate impedance to ground, which was extracted from the well-matched S-parameter equivalent-circuit data.
Identification of V23RalA-Ser(194) as a critical mediator for aurora-A-induced cellular motility and transformation by small pool expression screening
(2005-03-11)
Wu, JC
;
Chen, TY
;
Yu, CTR
;
Tsai, SJ
;
Hsu, JM
Human Aurora kinases have three gene family members: Aurora-A, Aurora-B, and Aurora-C. It is not yet established what the specificity of these kinases are and what signals relayed by their reactions. Therefore, we employed small pool expression screening to search for downstream substrates of Aurora-A. Interestingly, all of the identified Aurora-A substrates were resistant to serve as substrates for Aurora-B or Aurora-C, suggesting that these Aurora family members may have distinct substrate specificity for propagation of diverse signaling pathways, even though they share a conserved catalytic kinase domain. Of the candidate substrates, Aurora-A could increase the functional activity of RalA. Mutational analysis revealed that RalA-Ser(194) was the phosphorylation site for Aurora-A. Ectopic expression of V23RalA-WT could enhance collagen I-induced cell migration and anchorage-independent growth in Madin-Darby canine kidney (MDCK) Aurora-A stable cell lines. In contrast, overexpression of V23RalA-S194A in MDCK Aurora-Astable cell lines abolished the intrinsic migration and transformation abilities of Aurora-A. To our knowledge, this is the first systematic search for the downstream substrates of Aurora-A kinase. Moreover, these results support the notion that Aurora-A may act in concert with V23RalA through protein phosphorylation on Ser(194) to promote collagen I-induced cell motility and anchorage-independent growth in MDCK epithelial cells.
Influence of crystal structure on the fatigue properties of Pb1-xLax(Zr-y,Ti-z)O-3 thin films prepared by pulsed-laser deposition technique
(1997-05-01)
Lin, WJ
;
Tseng, TY
;
Lin, SP
;
Tu, SL
;
Chang, H
Lead lanthanum zirconate titanate (Pb1-xLax(Zr-y,Ti-z)O-3, PLZT) films containing [00l] preferentially oriented grains were produced successfully on YBa2Cu3O7-x-coated (YBCO-coated) SrTiO3, (STO) or YBCO/CeO2-coated silicon substrates; films containing randomly oriented grains were created on platinum-coated silicon substrates. The latter possessed significantly inferior ferroelectric properties, a fact ascribed to the presence of a paraelectric phase (TiO2,) at the PLZT/platinum interface. On the other hand, the PLZT/YBCO/STO films exhibited better electrical properties than did the PLZT/YBCO/CeO2/Si films, and this phenomenon was attributed to better alignment of the grains in normal and in-plane orientations. In terms of fatigue properties, the [00l] textured films that were deposited on YBCO/CeO2/Si substrates possessed substantially superior polarization-switching-cycle endurance versus the randomly oriented films grown on Pt(Ti)/Si substrates. Moreover, the tetragonal films behaved much more satisfactorily than did the rhombohedral PLZT films. The ferroelectric parameters of tetragonal PLZT films showed no significant degradation up to 10(9) polarization switching cycles, whereas the remnant polarization and coercive force of the rhombohedral PLZT films had already degraded to 80% of their initial values after 10(8) cycles.
Influence of crystal structure on the fatigue properties of Pb1-xLax(Zr-y,Ti-z)O-3 thin films prepared by pulsed-laser deposition technique
(1997-05-01)
Lin, WJ
;
Tseng, TY
;
Lin, SP
;
Tu, SL
;
Chang, H
Lead lanthanum zirconate titanate (Pb1-xLax(Zr-y,Ti-z)O-3, PLZT) films containing [00l] preferentially oriented grains were produced successfully on YBa2Cu3O7-x-coated (YBCO-coated) SrTiO3, (STO) or YBCO/CeO2-coated silicon substrates; films containing randomly oriented grains were created on platinum-coated silicon substrates. The latter possessed significantly inferior ferroelectric properties, a fact ascribed to the presence of a paraelectric phase (TiO2,) at the PLZT/platinum interface. On the other hand, the PLZT/YBCO/STO films exhibited better electrical properties than did the PLZT/YBCO/CeO2/Si films, and this phenomenon was attributed to better alignment of the grains in normal and in-plane orientations. In terms of fatigue properties, the [00l] textured films that were deposited on YBCO/CeO2/Si substrates possessed substantially superior polarization-switching-cycle endurance versus the randomly oriented films grown on Pt(Ti)/Si substrates. Moreover, the tetragonal films behaved much more satisfactorily than did the rhombohedral PLZT films. The ferroelectric parameters of tetragonal PLZT films showed no significant degradation up to 10(9) polarization switching cycles, whereas the remnant polarization and coercive force of the rhombohedral PLZT films had already degraded to 80% of their initial values after 10(8) cycles.
Integrated antennas on Si with over 100 GHz performance, fabricated using an optimized proton implantation process
(2003-11-01)
Chan, KT
;
Chin, A
;
Lin, YD
;
Chang, CY
;
Zhu, CX
We have improved the performance of integrated antennas on Si for possible application in wireless communications and wireless interconnects. For practical VLSI integration, we have reduced the antenna size and optimized the proton implantation to a low energy of similar to 4 MeV with a depth of similar to 175 mum. To avoid any possible contamination, the ion implantation is applied after device fabrication. Excellent performance such as very low RF power loss up to 50 GHz, record high 103 GHz antenna resonance, and sharp 5 GHz bandwidth have been achieved.
Interdiffusion of multilayer ferroelectric thin films using YBa2Cu3O7-x as an intermediate layer
(1996-05-15)
Wang, JP
;
Ling, YC
;
Lin, IN
;
Lin, WJ
;
Tseng, TY
Interdiffusion between layers in multilayer ferroelectric thin films was studied from their elemental depth profiles using secondary ion mass spectrometry. Among the films deposited on YBa2Cu3O7-x/CeO2/Si substrates, the interdiffusion is most pronounced for [Sr0.5Ba0.5]Nb2O6(SBN) films, less marked for Pb0.97La0.03(Zr1-xTix)(0.9925)O-3 (PLZT, x=0.54 or 0.34) films, and is least significant for BaTiO3 films. Higher substrate temperature used for growing SBN films is believed to be the main cause of interdiffusion. The larger proportion of cationic vacancies existing in PLZT films is another possible source inducing interdiffusion. Using YBa2Cu3O7-x/SrTiO3 as substrates substantially reduces the interdiffusion between layers. This is ascribed to the better crystallinity of the YBa2Cu3O7-x layers deposited on SrTiO3 substrates. These results indicate that both the characteristics of ferroelectric films and the underlying YBa2Cu3O7-x layers substantially modify the interdiffusion behavior between the layers. (C) 1996 American Institute of Physics.
Low RF loss and noise of transmission lines on Si substrates using an improved ion implantation process
(2003)
Chan, KT
;
Chin, A
;
McAlister, SP
;
Chang, CY
;
Tseng, C
Very low power loss less than or equal to 0.6 dB at 110 GHz and noise of < 0.25 dB at 18 GHz have been measured on transmission lines fabricated on Si substrates and implanted with proton. In contrast, much worse power loss of 5 dB and higher noise of 2.5 dB were measured without implantation. This large improvement arises from the high resistivity by proton implantation, which was also done after forming the transmission lines and at a reduced energy of similar to 4 MeV for easier process integration into current VLSI technology.
Microphotoluminescence spectra of hillocks in Al0.11Ga0.89N films
(2004-10-11)
Ke, WC
;
Ku, CS
;
Huang, HY
;
Chen, WC
;
Lee, L
The spatial variation of the optical properties of hillocks in Al0.11Ga0.89N films has been studied by using microphotoluminescence (mu-PL) microscopy. The mu-PL spectrum revealed a strong emission (I-H) at 351 nm from the hillock, besides the near-band-edge emission (I-nbe) at 341 nm. Moreover, the I-H intensity increases significantly and its full width at half maximum decreases from similar to76 to similar to53 meV by probing across the hillock center. These indicated that the hillock structure is a strong emission center. The temperature-dependent mu-PL, measurements showed that the I-H also has the S-shape behavior with a transition temperature of similar to120 K which is lower than that of I-nbe. The redshift of I-H is also smaller than I-nbe. Both indicated that the Al composition in hillocks is lower than the surrounding area. (C) 2004 American Institute of Physics.
Microwave coplanar filters on Si substrates
(2003)
Chan, KT
;
Chin, A
;
Kuo, JT
;
Chang, CY
;
Duh, DS
High performance band-pass and band-stop microwave coplanar filters operating from 22 to 94 GHz have been realized on Si substrate using proton implantation process. Very good insertion loss and filter characteristics close to ideal E-M simulation are. measured that demonstrates the excellent filter performance to 91 GHz.
Real-time and automatic two-class clustering by analytical formulas
(1996-11-01)
Lin, JC
;
Lin, WJ
;
交大名義發表
;
資訊工程學系
;
National Chiao Tung University
Several feature-preserving two-class clustering methods are investigated in this paper. By preserving certain features of the input data, some formulas useful in calculating the two class representatives and population percentages are derived. The derived formulas are expressed in general forms suitable for any dimensionality higher than two. The complexities of the investigated methods are all of order N if the data size is N and hence are much faster than any other clustering method which uses N x N dissimilarity matrix. Additionally, all investigated methods use no initial guesses. Experimental results are included to make a comparison among the four investigated methods so that only two methods are recommended. Further comparisons with the k-means method and hierarchical clustering methods also are included. The proposed feature-preserving approach was found to be fast, automatic and suitable for any held requiring fast high-dimensional two-class clustering. Copyright (C) 1996 Pattern Recognition Society.
Reduction of spontaneous surface segregation in (InP)(2)/(GaP)(2) quantum wells grown on tilted substrates
(1999-01-01)
Cheng, YC
;
Tai, KC
;
Chou, ST
;
Huang, KF
;
Lin, WJ
We have studied the growth mechanism of (InP)(2)/(GaP)(2) short-period superlattices (SPS) and In(0.5)Gao(0.5)P quantum wells grown on tilted substrates using solid-source molecular beam epitaxy (SSMBE). Both the (InP)(2)/(GaP)(2) SPS and In0.5Ga0.5P quantum wells show blue shifts of photoluminescence (PL) wavelengths when the substrate's tilting angle is increased. The blue shift is more prominent in the SPS structure than in the In0.5Ga0.5P quantum wells. By comparing FL, polarized PL spectra and transmission electron micrographs, we confirm that the ordering effect exists in both the (InP)(2)/(GaP)(2) SPS and In0.5Ga0.5P quantum wells when the substrate tilt angle is small, and can be greatly reduced when the substrate lilt angle is increased. We believed that the height and density of steps on substrates with larger tilt angles repress the segregation of group III adatoms.
RF passive devices on Si with excellent performance close to ideal devices designed by electro-magnetic simulation
(2003)
Chin, A
;
Chan, KT
;
Huang, CH
;
Chen, C
;
Liang, V
High quality RF inductors, very low loss and noise CPW and microstrip lines, advanced broad and narrow band filters, and ring resonators have been achieved on Si substrates, using an optimized proton implantation process. The RF performance up to 100 GHz is close to that for ideal devices designed by EM simulation for lossless substrates.
Synthesis of furan-, thiophene- and pyrrole-fused sultines and their application in Diels-Alder reactions
(1995-12-21)
Chung, WS
;
Lin, WJ
;
Liu, WD
;
Chen, LG
;
交大名義發表
The synthesis of 1,4-dihydrofurano[3,4-d]-3,2-oxathiine 2-oxide 8, 5,7-dimethyl-1,4-dihydrothieno[3,4-D]-3,2-oxathiine 2-oxide 9 and 1,4-dihydro-6-tosylpyrrolo[3,4-D]-3,2-oxathiine 2-oxide 10, precursors for nonclassical heteroaromatic o-quinodimethanes, and their application in the Diels-Alder reactions are reported.
Thermal-treatment induced deep electron traps in AlInP
(2001-08-01)
Sung, WJ
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Huang, KF
;
Lin, WJ
;
Tseng, TY
;
電子物理學系
The effects of thermal treatment on the quality of AlInP film, grown by metal-organic chemical vapor deposition (MOCVD), have been carefully investigated using deep level transient spectroscopy (DLTS). Two thermal-treatment-induced deep levels were observed in the samples thermal-treated above 500 degreesC and shall be attributed to the generation of phosphorus vacancies (V-p) by evaporation of phosphorus from AlInP surface. Examination of these deep levels provided a relatively simple means of understanding the thermal-treatment-induced behavior, thus allowing us to determine an appropriate process for manufacturing AlInP-based products.