A broadband linearization method using a novel opto-electrical predistorter for radio-over-fiber systems

Moon, Yon-Tae,Choi, Woon-Kyung,Choi, Young-Wan Wiley Subscription Services, Inc., A Wiley Company 2010 MICROWAVE AND OPTICAL TECHNOLOGY LETTERS Vol.52 No.7

<P>A broadband linearization method with a novel opto-electrical predistorter was experimentally demonstrated. With the proposed method, the third-order intermodulation distortion was simultaneously enhanced by more than 10 dB for 510 MHz ranges and by 24 dB at 2.2 GHz without any change in electrical circuitry. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1638–1640, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.25240</P>

On triple Veronese embeddings of \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}<tex> $\mathbb {P}^n$</tex>\end{document}<img src='/wiley-blackwell_img/equation/tex2gif-ueqn-1.gif' alt='equation image'> in the Grassmannians

WILEY‐VCH Verlag 2011 Mathematische Nachrichten Vol.284 No.11

<P><B>Abstract</B></P><P>We classify all the embeddings of \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}<TEX>$\mathbb {P}_n$</TEX>\end{document}<IMG src='/wiley-blackwell_img/equation/tex2gif-ueqn-2.gif' alt ='equation image'/> in a Grassmannian <I>Gr</I>(1, <I>N</I>) such that the composition with the Plücker embedding is given by a linear system of cubics on \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}<TEX>$\mathbb {P}_n$</TEX>\end{document}<IMG src='/wiley-blackwell_img/equation/tex2gif-ueqn-3.gif' alt ='equation image'/>. As a direct corollary, we prove that every vector bundle giving such an embedding, splits if <I>n</I> ⩾ 3. © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim</P>

A new K-band push-push VCO using a miniaturized hairpin resonator

Lee, Hyun-Wook,Yoon, Ki-Cheol,Nam, Hee,Eo, Yun-Seong,Lee, Jong-Chul Wiley Subscription Services, Inc., A Wiley Company 2010 MICROWAVE AND OPTICAL TECHNOLOGY LETTERS Vol.52 No.3

<P>In this article, a K-band push-push Voltage Controlled Oscillator (VCO) is presented using a miniaturized hairpin resonator (MHR) with a higher loaded quality factor and the reduced circuit area within 50% compared to the conventional one at 9.2 GHz.The MHR combined with the GaAs MESFET varactor shows a tuning range of 140 MHz, and this voltage tunable MHR is used to compose a push-push VCO. It provides the frequency tuning range of 71 MHz with flatness of +0.13 dB, which is increased by 31 MHz compared to the conventional VCO. The voltage controlled push-push oscillator based on the series feedback topology is implemented on 0.54 mm-thick Teflon substrate with a dielectric constant of 2.54. The measurement shows the output power of 1.18 dBm, the fundamental signal power suppression of −33 dBc, and phase noise performance of −86.78 dBc/Hz at 100 kHz offset. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 699–701, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.25007</P>

Analog predistortion linearization of Doherty power amplifiers using bandwidth reduction of error signal

Lee, Yong-Sub,Lee, Mun-Woo,Kam, Sang-Ho,Jeong, Yoon-Ha Wiley Subscription Services, Inc., A Wiley Company 2010 MICROWAVE AND OPTICAL TECHNOLOGY LETTERS Vol.52 No.6

<P>This article represents analog predistortion linearization of Doherty power amplifier (DPA) using bandwidth reduction of error signal. To verify our methods, two DPAs are implemented using a push-pull GaN HEMT and a push-pull Si LDMOS at 2.14 GHz and tested using the memory-compensated analog predistorter with transistor-based error generators and three-branch nonlinear paths. From the measured four-carrier WCDMA results, the proposed analog predistortion DPAs show the significant linearity improvement. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1313–1316, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.25190</P>

Platinum-Catalyzed Hydrogenative Cyclization of Yne-Enones, Yne-Aldehydes, and Yne-Dienes

Shinde, Mahadev P.,Wang, Xi,Kang, Eun Joo,Jang, Hye-Young WILEY-VCH Verlag 2009 EUROPEAN JOURNAL OF ORGANIC CHEMISTRY Vol.2009 No.35

<P>Pt complexes were used in the presence of phosphane ligands, SnCl<SUB>2</SUB>, and H<SUB>2</SUB> for coupling reactions of alkynes with electrophiles under environmentally benign hydrogenation conditions, providing five- and six-membered cycloreduction products in moderate to good yield. Deuterium labeling studies suggested the occurrence of a catalytic cycle including the diploar intermediate derived from hydrometalation of a platinum–hydride complex to the alkyne. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)</P> <B>Graphic Abstract</B> <P>Using Pt<SUP>II</SUP> complexes and hydrogen, the reductive cyclizations of yne-enones, yne-aldehydes, and yne-dienes were conducted, which showed expanded reactivity of the Pt–alkyne complex with various electrophiles. <img src='wiley_img/1434193X-2009-2009-35-EJOC200901005-fig000.gif' alt='wiley_img/1434193X-2009-2009-35-EJOC200901005-fig000'> </P>

Synthesis, Structure, Magnetic Properties and Aqueous Optical Citrate Detection of Chiral Dinuclear Cu^II Complexes

Khatua, Snehadrinarayan,Kim, Kibong,Kang, Jina,Huh, Jung Oh,Hong, Chang Seop,Churchill, David G. WILEY-VCH Verlag 2009 European journal of inorganic chemistry Vol.2009 No.22

<P>Two chiral dimeric Cu<SUP>II</SUP> Schiff base complexes, Na<SUB>2</SUB>[Cu(S-lys)<SUB>2</SUB>·(H<SUB>2</SUB>O)<SUB>2</SUB>]·(ClO<SUB>4</SUB>)<SUB>2</SUB> (1) and [Cu(S-ornH)<SUB>2</SUB>·(H<SUB>2</SUB>O)<SUB>2</SUB>]·(ClO<SUB>4</SUB>)<SUB>2</SUB> (2) have been prepared by an easy one-pot method in which the L-lysine and L-ornithine-based Schiff base ligands are generated in situ. These complexes have been characterized by various spectroscopic techniques and single-crystal X-ray diffraction. The molecular structures show that both complexes are indeed dimeric with Cu<SUP>II</SUP> centers that are phenolate-bridged. Variable-temperature magnetic analysis revealed that a strong antiferromagnetic coupling interaction was mediated through the phenolate bridge between the two Cu<SUP>II</SUP> centers. Since these compounds were highly soluble in water, we explored carboxylate sensing capability through colorimetric indicator displacement assays (IDAs). By using pyrocatechol violet (PV) as a displaceable colorimetric indicator, citrate ion selectivity was demonstrated in 100 % water solution in the physiological pH range.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)</P> <B>Graphic Abstract</B> <P>Two chiral dimeric Cu<SUP>2+</SUP> complexes 1 and 2 have been prepared by a one pot method in which the L-lysine- and L-ornithine-based Schiff base ligands are generated in situ. Variable-temperature magnetic susceptibility measurements reveal strong antiferromagnetic coupling interactions. Selective citrate ion sensing was enabled through colorimetric indicator displacement assays in water at physiological pH. <img src='wiley_img/14341948-2009-2009-22-EJIC200900357-fig000.gif' alt='wiley_img/14341948-2009-2009-22-EJIC200900357-fig000'> </P>

Synthesis and Aqueous Colloidal Solutions of RE₂(OH)₅NO₃·nH₂O (RE = Nd and La)

Lee, Kyung-Hee,Byeon, Song-Ho WILEY-VCH Verlag 2009 European journal of inorganic chemistry Vol.2009 No.31

<P>A new, simple route leading to layered rare-earth hydroxy nitrates was developed. The pH-independent procedure uses ethanol containing alkali-metal hydroxide (KOH, RbOH, or CsOH) as a solvothermal medium. Two new, layered rare-earth hydroxy nitrates (LRHs), Nd<SUB>2</SUB>(OH)<SUB>5</SUB>NO<SUB>3</SUB>·nH<SUB>2</SUB>O and La<SUB>2</SUB>(OH)<SUB>5</SUB>NO<SUB>3</SUB>·nH<SUB>2</SUB>O, were prepared by this nonaqueous solvothermal reaction. Because the RE = Nd and La members have not yet been synthesized in an aqueous system, the successful synthesis of these compounds implies the completion of the RE<SUB>2</SUB>(OH)<SUB>5</SUB>NO<SUB>3</SUB>·nH<SUB>2</SUB>O (RE = rare earths) series. The typical properties of a layered structure was demonstrated by ready ion-exchange reactions between NO<SUB>3</SUB><SUP>–</SUP> and some organic anions such as decanoate, decanesulfonate, and decyl sulfate. In particular, the as-synthesized hydroxide from solvothermal reaction, where the alkali-metal nitrates are partially intercalated in the interlayer gallery, form an aqueous colloidal solution under ultrasonic treatment. Hydration of the LRHs intercalated with alkali-metal salts results in the formation of colloidal LRH suspensions in water. The colloidal character of the LRH solutions is supported by the Tyndall effect, TEM, and AFM images.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)</P> <B>Graphic Abstract</B> <P>A new, simple route was developed to synthesize the complete rare-earth series of the RE<SUB>2</SUB>(OH)<SUB>5</SUB>NO<SUB>3</SUB>·nH<SUB>2</SUB>O family. The hydration of La<SUB>2</SUB>(OH)<SUB>5</SUB>NO<SUB>3</SUB>·nH<SUB>2</SUB>O and Nd<SUB>2</SUB>(OH)<SUB>5</SUB>NO<SUB>3</SUB>·nH<SUB>2</SUB>O synthesized by this nonaqueous solvothermal method yielded transparent aqueous colloidal solutions. <img src='wiley_img/14341948-2009-2009-31-EJIC200900635-fig000.gif' alt='wiley_img/14341948-2009-2009-31-EJIC200900635-fig000'> </P>

Change in Supramolecular Networks through In Situ Esterification of Porphyrins

Chen, Wentong,Fukuzumi, Shunichi WILEY-VCH Verlag 2009 European journal of inorganic chemistry Vol.2009 No.36

<P>A series of porphyrins, M[TCPP-Et<SUB>4</SUB>] [M = Zn (1), Cu (2), and Ni (3); Et = CH<SUB>2</SUB>CH<SUB>3</SUB>; TCPP = meso-tetra(4-carboxyphenyl)porphyrin], M[TCPP-Me<SUB>4</SUB>] [M = Zn (4), Cu (5), and Co (6); Me = CH<SUB>3</SUB>], and two nonmetalated compounds, TCPP-Et<SUB>4</SUB> (7) and TCPP-Me<SUB>4</SUB>·H<SUB>2</SUB>O (8), were synthesized by solvothermal reactions and characterized by single-crystal X-ray diffraction. Compounds 1–3 feature an isolated structure with a planar macrocycle and an embedded metal-ion coordinating to four pyrrole nitrogen atoms. Compound 4 is characterized as a two-dimensional coordination polymer, and the zinc ion coordinates to four nitrogen atoms and two oxygen atoms. Compound 4 possesses a large void space (361 Å<SUP>3</SUP>), which corresponds to 14 % of the unit-cell volume. Compounds 5 and 6 are characteristic of an isolated motif with a four-coordinate metal ion and a saddle-distorted nonplanar porphyrin macrocycle. Nonmetalated compounds 7 and 8 also show an isolated structure with a planar macrocycle. For compounds 1–3 and 7, the TCPP is esterified with ethanol, while for compounds 4–6 and 8, the TCPP is esterified with methanol. The molecules in 1 and 6–8 are interconnected by hydrogen bonds and π–π interactions to yield 3D supramolecular networks, while in 2–5, 2D supramolecular motifs are formed. The reaction mechanism was explored. Esterification plays an important role in changing the properties of the compounds as well as in the formation of different structural motifs and supramolecular networks. The UV/Vis, FTIR, fluorescence, phosphorescence, and MALDI-TOF MS spectra, quantum yields, luminescence lifetimes, and cyclic voltammograms were also studied in detail.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)</P> <B>Graphic Abstract</B> <P>Eight esterified TCPP compounds were successfully synthesized by solvothermal reactions and characterized. The reaction mechanism was investigated. Esterification plays a vital role in the properties, structural motifs and supramolecular networks. <img src='wiley_img/14341948-2009-2009-36-EJIC200900801-fig000.gif' alt='wiley_img/14341948-2009-2009-36-EJIC200900801-fig000'> </P>

Unprecedented N-Inserted Disulfide Ligand Stabilized by Coordination to the Electropositive Co^III Center

Yoo, Houng Sik,Yoon, Jung Hee,Kim, Jae Il,Koh, Eui Kwan,Hong, Chang Seop WILEY-VCH Verlag 2008 European journal of inorganic chemistry Vol.2008 No.20

<P>The reaction of Co<SUP>II</SUP> and 2,2′-dipyridyldisulfide (PySSPy) in the presence of azide produced a peculiar monomeric complex [Co<SUP>III</SUP>(PyS)(PyS-N-SPy)(N<SUB>3</SUB>)] (1). In this reaction, redox chemistry takes place, which is associated mainly with the oxidation of Co<SUP>II</SUP> to Co<SUP>III</SUP> and the reduction of PySSPy. During the reaction, the azide ion decomposes and donates a nitrogen atom to PySSPy. The crystal structure of 1 provides evidence that the unusual, N-inserted ligand PyS-N-SPy can be stabilized through coordination to the electropositive Co<SUP>III</SUP> ion. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)</P> <B>Graphic Abstract</B> <P>The reaction of Co<SUP>II</SUP> and 2,2′-dipyridyldisulfide (PySSPy) in the presence of azide produced a monomeric complex [Co<SUP>III</SUP>(PyS)(PyS-N-SPy)(N<SUB>3</SUB>)] (1), which was characterized by means of UV/Vis, X-ray crystallography, XPS, and cyclic voltammetry. The unusual, N-inserted ligand PyS-N-SPy can be stabilized through coordination to the electropositive Co<SUP>III</SUP> ion. <img src='wiley_img/14341948-2008-2008-20-EJIC200800439-fig000.gif' alt='wiley_img/14341948-2008-2008-20-EJIC200800439-fig000'> </P>

Glycerol as Ligand: The Synthesis, Crystal Structure, and Properties of Compounds [Ln₂(H₂L)₂(H₃L)₄][Re₆Q₈(CN)₆], Ln = La, Nd, Gd, Q = S, Se

Naumov, Nikolai G.,Tarasenko, Maria S.,Virovets, Alexander V.,Kim, Youngmee,Kim, Sung-Jin,Fedorov, Vladimir E. Wiley-VCH 2006 European journal of inorganic chemistry Vol. No.

<P>The interaction of aqueous solutions of octahedral cluster anions [Re<SUB>6</SUB>Q<SUB>8</SUB>(CN)<SUB>6</SUB>]<SUP>4–</SUP> with rare earth cations in the presence of glycerol resulted in the formation of a new family of compounds [Ln<SUB>2</SUB>(H<SUB>2</SUB>L)<SUB>2</SUB>(H<SUB>3</SUB>L)<SUB>4</SUB>][Re<SUB>6</SUB>Q<SUB>8</SUB>(CN)<SUB>6</SUB>] (where Ln = La, Nd, and Gd; Q = S, Se; H<SUB>3</SUB>L = glycerol; H<SUB>2</SUB>L<SUP>–</SUP> = glycerolate anion). All compounds are isostructural and crystallize in the P<TEX>$\bar {1}$</TEX> space group. Crystal structures are built from octahedral cluster anions [Re<SUB>6</SUB>Q<SUB>8</SUB>(CN)<SUB>6</SUB>]<SUP>4–</SUP> and centrosymmetrical dimers [Ln<SUB>2</SUB>(H<SUB>2</SUB>L)<SUB>2</SUB>(H<SUB>3</SUB>L)<SUB>4</SUB>]<SUP>4+</SUP> that have three different binding modes of glycerol. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)</P> <B>Graphic Abstract</B> <P> <img src='wiley_img/14341948-2006-2006-2-EJIC200500542-fig000.gif' alt='wiley_img/14341948-2006-2006-2-EJIC200500542-fig000'> </P>