Browsing by Author "Yen, Ying-Chieh"

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5.7 GHz Gilbert I/Q downconverter integrated with a passive LO quadrature generator and an RF Marchand balun
(2008-02-01)
Syu, Jin-Siang
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Meng, Chinchun
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Yen, Ying-Chieh
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電信工程研究所
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Institute of Communications Engineering
A 5.7 GHz I/Q downconversion mixer is demonstrated in this letter using 0.35 mu m SiGe BiCMOS technology. A quarter-wavelength coupled line and two center-tapped transformers are utilized to generate differential quadrature LO signals. A miniaturized Marchand balun is placed before the common-base-configured RF input stage of each I/Q Gilbert mixer to generate balanced RF signals. All the reactive passive elements are placed directly on the standard silicon substrate. The 5.7 GHz I/Q downconverter achieves 7 dB conversion gain, -26 dBm IP1dB, and -18 dBm IIP3 at the power consumption of 3.875 mW and 2.5 V supply voltage.
A "Plug and Play" polymer through biocomplementary hydrogen bonding
(2008-10-01)
Cheng, Chih-Chia
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Huang, Chih-Feng
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Yen, Ying-Chieh
;
Chang, Feng-Chih
;
應用化學系
This article describes a DNA-like polymer that exhibits the ability to self-assemble through hydrogen bonding. We synthesized poly[1-(4-vinylbenzyl)thymine] (PVBT) and 9-bexadecyladenine (A-C16) through an atom transfer radical polymerization (ATRP) and alkylation, respectively. Biocomplementary PVBT/A-C16 hierarchical supramolecular complexes formed in dilute DMSO solution through nucleobase recognition, that is, hydrogen bonding interactions between the thymine (T) groups of PVBT and the adenine (A) group of A-C16; evidence for this molecular recognition was also gained from dynamic light scattering studies. H-1 NMR titration studies in CDCl3 showed that T-A complexes formed rapidly on the NMR time scale with high association constants (up to 534 M-1). Moreover, FTIR spectroscopic, differential scanning calorimetry, wide-angle X-ray diffraction, and small-angle X-ray scattering analyses provided further details into the nature of the self-assembly of these systems. In the bulk state, these complexes self-assemble into well-ordered lamellar structures; the changing d-spacing distance (ranging from 4.98 to 2.32 nm) at different A-C16 loadings reveals that the molecular structures of the PVBT/A-C16 complexes are readily tailored. (C) 2008 Wiley Periodicals, Inc.
A new benzoxazine containing uracil, complementary functionality
(2011)
Yen, Ying-Chieh
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Cheng, Chih-Chia
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Chu, Yu-Lin
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Chang, Feng-Chih
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應用化學系
A new benzoxazine, uracil containing benzoxazine (UBz), has been successfully synthesized. The FTIR and DSC measurement of the poly(UBz)/poly(BA-a) blends indicated that hydrogen bonding interactions between uracil groups would result in a decrease in the exothermic peak temperature. In addition, the PL measurement confirmed that the poly(UBz)/poly(BA-a) blend possessed complementary behavior.
A new organic/inorganic electroluminescent material with a silsesquioxane core
(2009-04-01)
Cheng, Chih-Chia
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Chien, Chen-Han
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Yen, Ying-Chieh
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Ye, Yun-Sheng
;
Ko, Fu-Hsiang
This paper describes a new polyhedral oligomeric silsesquioxane (POSS)-based blue-light electroluminescent nanoparticle, octakis[N-(9-ethyl-9-H-carbazol-3-yl)undecanamide-11-dimethylsiloxy]silsesquioxane (POSS-C11-Cz), which contains eight carbazole chromophore arms, synthesized through the hydrosilation reaction of octakis(dimethylsiloxy)silsesquioxane with the terminal olefin Cz-C11ene. POSS-C11-Cz exhibits good thermal and electrochemical stabilities and good film-forming properties. The optical and photoluminescence spectra of POSS-C11-Cz in solution and in the solid state indicate a reduction in the degrees of aggregation and excimer formation because inter-chain interactions were prohibited by the bulky POSS core. Moreover, photoluminescence spectra of a POSS-C11-Cz (3 wt.%,)/polyfluorene (97 blend revealed that the color was stable after heating the sample at 200 degrees C for 5 h; in contrast, the pure polyfluorene exhibited a significant green emission at 530 nm. A triple-layer device based on this blend exhibited higher maximum brightness and luminance efficiencies relative to those of the pure polyfluorene. Thus, the organic/inorganic POSS-C11-Cz/polyfluorene blend has potential for use in polymeric light-emitting diodes because of its improved thermal and optoelectronic characteristics. Published by Elsevier Ltd on behalf of Acta Materialia Inc.
A New Poly(amide urethane) Solid State Electrolyte Containing Supramolecular Structure
(2010-03-09)
Yen, Ying-Chieh
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Cheng, Chih-Chia
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Kuo, Shiao-Wei
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Chang, Feng-Chih
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應用化學系
A new supramolecular film formed from a silsesquioxane derivative for application in proton exchange membranes
(2012-01-14)
Cheng, Chih-Chia
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Yen, Ying-Chieh
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Ko, Fu-Hsiang
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Chu, Chih-Wei
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Fan, Shih-Kang
A new polyhedral oligomeric silsesquioxane ionomer (HO-doped PUSS-C11-Py) has been investigated. This new ionomer is able to self-assemble through macromers by quadruple hydrogen bonding interactions into a physically crosslinked polymer-like material that can be easily fabricated into films with micro-phase separation. This HCl-doped POSS-C11-Py membrane exhibits higher proton conductivity than a typical Nafion membrane at high temperature, which is extremely rare for a non-sulfonic acid system. This newly developed material may provide an alternative route toward design and fabrication of a new type of proton exchange membranes.
A New Supramolecular Hole Injection/Transport Material on Conducting Polymer for Application in Light-Emitting Diodes
(2012-04-10)
Chu, Yu-Lin
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Cheng, Chih-Chia
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Yen, Ying-Chieh
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Chang, Feng-Chih
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應用化學系
A new supramolecular POSS electroluminescent material
(2012)
Chu, Yu-Lin
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Cheng, Chih-Chia
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Chen, Ya-Ping
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Yen, Ying-Chieh
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Chang, Feng-Chih
A new polyhedral oligomeric silsesquioxane (POSS) core star-like supramolecular blue-light electroluminescent material, 4-uracilbutyl-1-methylpyrene ether (U-PY)/octakis[dimethyl(N-(6-acetamidopyridin- 2 yl))siloxy] silsesquioxane (ODAP-POSS) has been synthesized. This U-PY/ODAP-POSS contains eight pyrene chromophore arms formed through complementary uracil-diamidopyridine (U-DAP) pairs and exhibits high quantum efficiencies and good solution processing properties. The photoluminescence spectra of U-PY/ODAP-POSS (50/50) reveal that the color is stable after heating the sample at 150 degrees C for 1 h, in contrast, the pyrene/ODAP-POSS (50/50) shows significant thermal quenching. An electroluminescence (EL) device based on U-PY/ODAP-POSS exhibits higher maximum brightness and higher luminance efficiency relative to that of the U-PY. In addition, U-PY/ODAP-POSS also behaves as an effective dopant that enhances energy transfer from itself to MEH-PPV. The U-PY/ODAP-POSS-doped MEH-PPV blends exhibit high luminance efficiency, 1.45 times greater than MEH-PPV.
A simple approach toward low-dielectric polyimide nanocomposites: Blending the polyimide precursor with a fluorinated polyhedral oligomeric silsesquioxane
(2008-09-15)
Ye, Yun-Sheng
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Yen, Ying-Chieh
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Chen, Wen-Yi
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Cheng, Chih-Chia
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Chang, Feng-Chih
This article describes a new and simple method for preparing polyimide nanocomposites that have very low dielectric constants and good thermal properties: simply through blending the polyimide precursor with a fluorinated polyhedral oligomeric silsesquioxane derivative, octakis(dimethylsiloxyhexafluoropropyl) silsesquioxane (OF). The low polarizability of OF is compatible with polyimide matrices, such that it can improve the dispersion and free volume of the resulting composites. Together, the higher free volume and lower polarizability of OF are responsible for the lower dielectric constants of the PI-OF nanocomposites. This simple method for enhancing the properties of polyimides might have potential applicability in the electronics industry. (C) 2008 Wiley Periodicals, Inc.
Biocomplementary Interaction Behavior in DNA-Like and RNA-Like Polymers
(2009-12-01)
Cheng, Chih-Chia
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Yen, Ying-Chieh
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Ye, Yun-Sheng
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Chang, Feng-Chih
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應用化學系
A series of nucleobased polymers and copolymers were synthesized through atom transfer radical polymerization (ATRP). Biocomplementary DNA-and RNA-like supramolecular complexes are formed in dilute DMSO solution through nucleobase recognition. (1)H NMR titration studies of these complexes in CDCl(3) indicated that thymine-adenine (T-A) and uracil-adenine (U-A) complexes form rapidly on the NMR time scale with high association constants (up to 534 and 671 M(-1), respectively) and result in significant T(g) increase. WAXD and differential scanning calorimetry analyzes in the bulk state indicate the presence of highly physical crosslinked structures and provide further details into the nature of the self-assembly of these systems. Furthermore, this study is of discussion on the difference in the hydrogen bond strength between T-A and U-A base pairs within polymer systems, indicating that the strength of hydrogen bonds in RNA U-A pairs is stronger than that in DNA T-A base pairs. (C) 2009 Wiley Periodicals, Inc. J Polym. Sci Part A: Polym Chem 47:6388-6395, 2009
Bioinspired hole-conducting polymers for application in organic light-emitting diodes
(2012)
Cheng, Chih-Chia
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Chu, Yu-Lin
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Huang, Pei-Hsiu
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Yen, Ying-Chieh
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Chu, Chih-Wei
A novel uracil-functionalized poly(3-thiophene) as a hole-injecting/transporting layer in an organic light-emitting device is able to form physical crosslinkages resulting in high thermal stability, non-corrosion, excellent hole injection/transport and electron-blocking capabilities in the solid state, and it achieves up to 10 times higher performance than that of conventional poly(3-thiophene)s under similar experimental conditions.
Bioinspired Photo-Cross-Linked Nanofibers from Uracil-Functionalized Polymers
(2012-01-01)
Wang, Yeh-Sheng
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Cheng, Chih-Chia
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Ye, Yun-Sheng
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Yen, Ying-Chieh
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Chang, Feng-Chih
In this study, we used electrospinning to fabricate nucleobase-functionalized and photo-cross-linkable poly[1-(4-vinylbenzyl uracil)] (PVBU) nanofibers. PVBU of high-molecular-weight (M-n > 250 550 g/mol) possessed a high thermal stability and sufficient chain entanglement to produce uniform fibers without forming beads. These uracil-functionalized nanofibers were further photo-cross-linked through exposure to UV light at a wavelength of 254 nm. After immersing in N,N-dimethylacetamide, the pristine PVBU fibers dissolved, while the cross-linked PVBU fibers maintained their shape; thus, the cross-linked PVBU nanofibers exhibited good dimensional stability and improved solvent resistance.
Block-copolymer-like supramolecules confined in nanolamellae
(2012)
Wang, Jui-Hsu
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Cheng, Chih-Chia
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Yen, Ying-Chieh
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Miao, Chia-Chun
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Chang, Feng-Chih
This paper describes the development of a new concept in supra-molecular assembly of existing functional polypeptides to form diblock-like molecular clusters through complementary hydrogen-bonding interactions, providing a potential route toward design and fabrication of block copolymer-like supramolecular materials.
Characteristics of GaAs transformers for RFIC applications
(2008-11-01)
Meng, Chinchun
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Teng, Ya-Hui
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Syu, Jin-Siang
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Lin, Yi-Chen
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Jhong, Jhin-Ci
In this article, stacked transformers, coupling stacked transformers, interleave transformers, and symmetrical transformers on GaAs substrate are systematically studied. Two kinds of stacked transformer are under study. One has the symmetrical electric property while the other one has a better quality factor for the primary port. The stack transformers have achieved the highest coupling coefficient (similar to 0.9) at the cost of lower self-resonance frequency. The interleave transformers have the identical electrical properties for the primary and the secondary ports. However, the layout is incompatible with the differential operation. Oil the other hand, the symmetrical transformer is compatible with the differential operation (aid call have the center-tapped biasing option. The data established here provides a useful design library for the GaAs RFIC. (C) 2008 Wiley Periodicals, Inc.
Characteristics of Integrated RF Transformers on GaAs Substrate
(2007)
Meng, Chinchun
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Teng, Ya-Hui
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Lin, Yi-Chen
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Jhong, Jhin-Ci
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Yen, Ying-Chieh
Stacked transformers, coupling stacked transformers, interleave transformers and symmetrical transformers on GaAs substrate are systematically studied in this paper. Two kinds stacked transformer are under study. One has the symmetrical electric property while the other one has a better quality factor for the primary port. The stack transformers have achieved the highest coupling coefficient (similar to 0.9) at the cost of lower self-resonance frequency. The interleave transformers have the identical electric properties for the primary and the secondary ports. However, the layout is incompatible with the differential operation. On the other hand, the symmetrical transformer is compatible with the differential operation and can have the center-tapped biasing option. The data established here provide a useful design library for the GaAs RFIC.
Dual-Band Upconversion Gilbert Mixer Utilizing an LC Current Mirror
(2008)
Syu, Jin-Siang
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Meng, Chinchun
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Yen, Ying-Chieh
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Huang, Guo-Wei
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電信工程研究所
Effect of LiClO4 on the thermal and morphological properties of organic/inorganic polymer hybrids
(2008-08-11)
Yen, Ying-Chieh
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Ye, Yun-Sheng
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Cheng, Chih-Chia
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Chen, Hsiu-Mei
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Sheu, Hwo-Shuenn
This paper describes the thermal properties, morphologies, and interactions within the binary and ternary blends of poly(methyl methacrylate) (PMMA), octa(phenol)octasilsesquioxane (OP-POSS), and LiClO4. In the binary PMMA/OP-POSS blends, the OP-POSS molecules tend to aggregate and result in a decrease (19 degrees C) in the glass transition temperature. In the ternary PMMA/LiClO4/OP-POSS blends, however, the OP-POSS molecules form small sphere-like domains (20 nm) leading to the composite's glass transition temperature increasing by up to 30 degrees C. Based on these FF-IR spectra, the addition of LiClO4 influenced the probability of hydrogen bonds formed between PMMA and OP-POSS and these SEM micrographs, DSC, and XRD data indicated that the addition of LiClO4 is a convenient and simple approach toward dispersing the OP-POSS nanoparticles within PMMA, where the presence of LiClO4 changes the physical effect of OP-POSS from that of a diluent role to a cross-linker role. (c) 2008 Elsevier Ltd. All rights reserved.
Enhanced processability of MWCNT through surface treatment by octa(phenol) polyhedral oligomeric silsesquioxane nano-crosslinking
(2014-01-06)
Omrani, Abdollah
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Yen, Ying-Chieh
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Cheng, Chih-Chia
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Chang, Feng-Chih
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應用化學系
A facile method was developed to prepare MWCNT/POSS nanocomposites by direct esterification between carboxylic acid functionalized MWCNT and octa(phenol) octasilsesquioxane. Completeness of the MWCNT surface modification was confirmed by FT-IR. The hybrid nano-MWCNT-OP-POSS composite structure and properties was characterized using DSC, TGA, optical microscopy, WAXD, and AFM. The results indicated the solubility and processability of MWCNT-COOH improved because of OP-POSS grafting on MWCNT surface. The T-g and thermal stability of the nanocomposites was higher than that of the OP-POSS as a result of the cross-linking reaction. AFM observations revealed that the nanocomponents were reacted in a homogeneous phase at nanoscale level. (C) 2013 Elsevier B.V. All rights reserved.
Functionalized graphene nanomaterials: new insight into direct exfoliation of graphite with supramolecular polymers
(2016-01-01)
Cheng, Chih-Chia
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Chang, Feng-Chih
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Wang, Jui-Hsu
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Chen, Jem-Kun
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Yen, Ying-Chieh
A novel urea-cytosine end-capped polypropylene glycol (UrCy-PPG) can self-assemble into a long-range ordered lamellar microstructure on the surface of graphene, due to the strong specific interactions between UrCy-PPG and graphene. In addition, the graphene composite produced exhibits a high conductivity (similar to 1093 S m(-1)) with a dramatic thermo-responsive ON/OFF resistance-switching behavior (10 consecutive cycles).
GILBERT UPCONVERSION MIXERS USING SINGLE-BAND/DUAL-BAND LC CURRENT COMBINERS
(2009-07-01)
Syu, Jin-Siang
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Meng, Chinchun
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Yen, Ying-Chieh
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Huang, Guo-Wei
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電信工程研究所
The 0.35-mu m SiGe BiCMOS high linearity Gilbert upconverters are demonstrate in this article by utilizing NMOS and PMOS transconductance amplifiers (TCAs), respectively. To improve the linearity of a Gilber upconverter, the IF input TCA is rerplaced by a bias-offset differential pair. A reactive LC current combiner is used as the load of the Gilber mixer to double the output current. The upconverter with an NMOS TCA archieves the conversion gain of -4 dB, the OP(ldB) of -11 dBm, and the OIP(3) of 5.5 dBm, whereas the other one with a PMOS TCA has the conversion gain, OP(ldB), and OIP(3) of -6 dB, -11 dBm, and 9.5 dBm, respectively. Furthermore, the LC current combiner can be extended to a dual-band version. The 2.4/5.7 GHz dual-band upconverters is also demonstrated in this work. The conversion gain at 2.4/5.7 GHz is -3/-3.5 dB with the OP(ldB) of -15.5/-15 dBm and the OIP(3) of -2.5/-3 dBm, respectively. (C) 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1718-1722, 2009; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/mop.24433