Low LO Power V-Band CPW Down-Converter Using a GaAs PHEMT

DanAn,BokHyungLee,YeonSikChae,HyunChangPark,HyungMooPark,이진구 한국물리학회 2002 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.41 No.6

We have designed and fabricated a low local oscillator (LO) power V-band coplanar waveguide (CPW) down-converter using GaAs Pseudomorphic high electron mobility transistor (PHEMT) technology for applications to millimeter-wave wireless communication systems. The down-converter was designed using a MIMIC library, including a 0.1-$\mu$m GaAs PHEMT and CPW transmission lines. The fabricated down-converter exhibited a good conversion gain of 2 dB at a low LO power of 0 dBm. The 1 dB compression point was $-$5.2 dBm for an RF input power of $-$6 dBm. Isolations between the LO port and other ports were excellent. The total chip size was 1.8$\times$1.7 mm.

Design and Fabrication of Low LO Power V-band CPW Mixer Module

Dan An,Bok Hyung Lee,Yeon Sik Chae,Hyun Chang Park,Hyung Moo Park,Young Hoon Chun,Jin Koo Rhee 대한전자공학회 2002 ITC-CSCC :International Technical Conference on Ci Vol.2002 No.7

V-band Self-heterodyne Wireless Transceiver using MMIC Modules

Dan An,Mun-Kyo Lee,Sang-Jin Lee,Du-Hyun Ko,Jin-Man Jin,Sung-Chan Kim,Sam-Dong Kim,Hyun-Chang Park,Hyung-Moo Park,Jin-Koo Rhee 대한전자공학회 2005 Journal of semiconductor technology and science Vol.5 No.3

We report on a low-cost V-band wireless transceiver with no use of any local oscillator in the receiver block using a self-heterodyne architecture. Vband millimeter-wave monolithic IC (MMIC) modules were developed to demonstrate the wireless transceiver using coplanar waveguide (CPW) and GaAs PHEMT technologies. The MMIC modules such as the MMIC low noise amplifier (LNA), medium power amplifier (MPA) and the up/down-mixer were installed in the transceiver system. To interface the MMIC chips with the component modules for the transceiver system, CPW-to-waveguide fin-line transition modules of WR-15 type were designed and fabricated. The fabricated LNA modules showed a S21 gain of 8.4 ㏈ and a noise figure of 5.6 ㏈ at 58 ㎓. The MPA modules exhibited a gain of 6.9 ㏈ and a P₁㏈ of 5.4 ㏈m at 58 ㎓. The conversion losses of the up-mixer and the down-mixer module were 14.3 ㏈ at a LO power of 15 ㏈m, and 19.7 ㏈ at a LO power of 0 ㏈m, respectively. From the measurement of V-band wireless transceiver, a conversion gain of 0.2 ㏈ and a P₁㏈ of 5.2 ㏈m were obtained in the transmitter block. The receiver block showed a conversion gain of 2.1 ㏈ and a P₁㏈ of -18.6 ㏈m. The wireless transceiver system demonstrated a successful data transfer within a distance of 5 meters.

코코넛 오일로부터 유래된 아미노산계 음이온 계면활성제의 합성 및 계면 특성 연구

예다난 ( Danan Yea ),조선희 ( Seonhui Jo ),임종주 ( Jongchoo Lim ) 한국공업화학회 2018 공업화학 Vol.29 No.5

본 연구에서는 천연 유래의 코코넛 오일을 원료로 사용하여 2종류의 아미노산계 음이온 생체계면활성제 포타슘 코코일 글루타메이트(potassium cocoyl glutamate, CTK)와 소듐 코코일 글루타메이트(sodium cocoyl glutamate, CTN)를 합성하였으며, 합성한 계면활성제의 구조를 FT-IR, ¹H-NMR 및 ¹³C-NMR 분석을 통하여 규명하였다. 합성한 계면활성제에 대하여 정적 및 동적 표면장력과 유화력 등의 계면 물성을 측정한 결과, CTK와 CTN 모두 계면 활성이 우수하고 계면 에너지를 낮추는데 효과적임을 알 수 있었다. 특히, CTK 계면활성제가 CTN 계면활성제와 비교하여 계면 에너지를 낮추는데 보다 효과적이었는데 이는 CTK가 소수성이 더 크고 계면활성제 단분자가 벌크 용액으로부터 공기와 수용액의 계면으로 이동하는 속도가 빨라서 공기와 수용액의 계면이 계면활성제 단분자에 의하여 더 짧은 시간에 포화되기 때문임을 알 수 있었으며, 생활용품이나 화장품 제조에 적용될 수 있을 것으로 기대된다. In this study, two types of amino acids-based anionic biosurfactants such as potassium cocoyl glutamate (CTK) and sodium cocoyl glutamate (CTN) were synthesized from coconut oils and the structure elucidation of CTK and CTN was carried out by using FT-IR, ¹H-NMR and ¹³C-NMR spectrophotometries. Measurements of interfacial properties such as static and dynamic surface tensions and emulsification activity showed that both CTK and CTN were surface-active and effective in lowering the interfacial free energy. In particular, the CTK surfactant was found to be more efficient in reducing the interfacial free energy since the larger number of CTK molecules was preferentially adsorbed at the air-water interface due to the higher hydrophobicity and larger mobility of CTK than those of using CTN, indicating possible uses in cosmetics and household products formulation.

Low-Characteristic-Impedance Transmission Line of a Benzocyclobutene- Based 3-Dimensional Structure at Millimeter-Wave Frequencies

설우석,김삼동,이성대,강태신,DanAn,전영훈,In-SeokHwang,이진구,Ki-HyunRyu 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.43 No.6

A variety of three-dimensional (3-D) transmission line structures were fabricated using lowdielectric- constant benzocyclobutene (BCB) interlayers to achieve low characteristic impedances (Zo) at millimeter wave frequencies. The eects of structural variations on the Zo of the transmission line structures were examined at a frequency of 50 GHz. Two dierent 3-D coplanar waveguide (CPW) structures, the bottom-ground and the double-ground structures, showed very low Zo values of 7.3 and 9.4 , respectively, at a signal linewidth of 100 m and a bottom-ground spacing of 20 m. When the ratio of the spacing of bottom-ground width to the signal linewidth became greater than 2.5, the Zo was nearly saturated, showing a minimum Zo. The thin-lm microstrip lines fabricated using the BCB inter layers showed a higher minimum Zo of 25.5 at a ground plane width of 55 m and a signal linewidth of 35 m than the 3-D CPW structures did. Among the 3-D transmission structures, the bottom-ground CPW was shown to be the most ecient structure to achieve a low Zo by maximizing the capacitance between the signal and the ground lines at 50 GHz. A variety of three-dimensional (3-D) transmission line structures were fabricated using lowdielectric-constant benzocyclobutene (BCB) interlayers to achieve low characteristic impedances(Zo) at millimeter wave frequencies. The eects of structural variations on the Zo of the transmissionline structures were examined at a frequency of 50 GHz. Two dierent 3-D coplanar waveguide(CPW) structures, the bottom-ground and the double-ground structures, showed very low Zo valuesof 7.3 and 9.4, respectively, at a signal linewidth of 100 m and a bottom-ground spacingof 20 m. When the ratio of the spacing of bottom-ground width to the signal linewidth becamegreater than 2.5, the Zo was nearly saturated, showing a minimum Zo. The thin-lm microstriplines fabricated using the BCB inter layers showed a higher minimum Zo of 25.5at a groundplane width of 55 m and a signal linewidth of 35 m than the 3-D CPW structures did. Among the3-D transmission structures, the bottom-ground CPW was shown to be the most ecient structureto achieve a low Zo by maximizing the capacitance between the signal and the ground lines at 50GHz.

FABRICATION OF SQUARAINE DYE SENSITIZED SPHERICAL ZINC OXIDE NANOCOMPOSITES AND THEIR VISIBLE-LIGHT INDUCED PHOTOCATALYTIC ACTIVITY

YONGLING FANG,SONG XU,ZHONGYU LI,DANAN HAN,DAYONG LU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.3

A 1,3-bis[(3,3-dimethylindolin-2-ylidene)methyl]squaraine (ISQ) dye sensitized ZnO nanocompo-sites via two di®erent preparation methods including hydrothermal and ultrasonic sensitizationprocesses are discussed in this paper. The as-prepared composites were characterized by the X-raydi®raction (XRD), UV-Vis di®use re°ectance spectroscopy (DRS), Raman spectroscopy, andtransmission electron microscopy (TEM). Based on the XRD patterns and TEM images, the ISQ/ZnO nanocomposites still kept the characteristic peaks and the basic morphology of ZnO and ISQdye. The photocatalytic activity of ISQ/ZnO nanocomposites was investigated by degradingmethylene blue (MB) under visible-light illumination. Compared with the MB self-degradation rate,the photocatalytic activity of the ISQ/ZnO composites was enhanced remarkably. The ISQ/ZnOnanocomposites fabricated by ultrasonic sensitization method exhibited excellent photocatalyticdegradation rate, approximately 20% higher than that of the hydrothermal sensitization one.

Revisiting the Metabolism and Bioactivation of Ketoconazole in Human and Mouse Using Liquid Chromatography–Mass Spectrometry-Based Metabolomics

Kim, Ju-Hyun,Choi, Won-Gu,Lee, Sangkyu,Lee, Hye Suk,Teschke, Rolf,Danan, Gaby MDPI 2017 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.18 No.3

<P>Although ketoconazole (KCZ) has been used worldwide for 30 years, its metabolic characteristics are poorly described. Moreover, the hepatotoxicity of KCZ limits its therapeutic use. In this study, we used liquid chromatography–mass spectrometry-based metabolomics to evaluate the metabolic profile of KCZ in mouse and human and identify the mechanisms underlying its hepatotoxicity. A total of 28 metabolites of KCZ, 11 of which were novel, were identified in this study. Newly identified metabolites were classified into three categories according to the metabolic positions of a piperazine ring, imidazole ring, and <I>N</I>-acetyl moiety. The metabolic characteristics of KCZ in human were comparable to those in mouse. Moreover, three cyanide adducts of KCZ were identified in mouse and human liver microsomal incubates as “flags” to trigger additional toxicity study. The oxidation of piperazine into iminium ion is suggested as a biotransformation responsible for bioactivation. In summary, the metabolic characteristics of KCZ, including reactive metabolites, were comprehensively understood using a metabolomics approach.</P>