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Divider
Kinds of Divider Selected AbstractsInternational comparison test in Asia-Pacific region for impulse voltage measurementsELECTRICAL ENGINEERING IN JAPAN, Issue 3 2009Takayuki Wakimoto Abstract The national standard class divider for the lightning impulse voltage measurements in Japan was developed in 1998. After three years, the standard impulse voltage calibrator has also been manufactured. These standard equipment are used as an industrial standard, and the performance had been evaluated annually supported by the Ministry of Economy, Trade and Industry (METI). The standard impulse measuring system including the standard divider participated in the worldwide comparison test and its good performance was confirmed in 1999. Another international comparison test was carried out among three countries in the Asia-Pacific region in 2004 again and the standard measuring system participated in the test. In this paper, the details and the results of the international comparison tests in 2004 are described. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(3): 46, 54, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20677 [source] Bond rolling resistance and its effect on yielding of bonded granulates by DEM analysesINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 8 2006M. J. Jiang Abstract A discrete element modelling of bonded granulates and investigation on the bond effect on their behaviour are very important to geomechanics. This paper presents a two-dimensional (2-D) discrete element theory for bonded granulates with bond rolling resistance and provides a numerical investigation into the effect of bond rolling resistance on the yielding of bonded granulates. The model consists of mechanical contact models and equations governing the motion of bonded particles. The key point of the theory is that the assumption in the original bond contact model previously proposed by the authors (55th CSCE-ASCE Conference, Hamilton, Ont., Canada, 2002; 313,320; J. Eng. Mech. (ASCE) 2005; 131(11):1209,1213) that bonded particles are in contact at discrete points, is here replaced by a more reliable assumption that bonded particles are in contact over a width. By making the idealization that the bond contact width is continuously distributed with the normal/tangential basic elements (BE) (each BE is composed of spring, dashpot, bond, slider or divider), we establish a bond rolling contact model together with bond normal/tangential contact models, and also relate the governing equations to local equilibrium. Only one physical parameter , needs to be introduced in the theory in comparison to the original bond discrete element model. The model has been implemented into a 2-D distinct element method code, NS2D. Using the NS2D, a total of 86 1-D, constant stress ratio, and biaxial compressions tests have been carried out on the bonded granular samples of different densities, bonding strengths and rolling resistances. The numerical results show that: (i) the new theory predicts a larger internal friction angle, a larger yielding stress, more brittle behaviour and larger final broken contact ratio than the original bond model; (ii) the yielding stress increases nonlinearly with the increasing value of ,, and (iii) the first-yield curve (initiation of bond breakage), which define a zone of none bond breakage and which shape and size are affected by the material density, is amplified by the bond rolling resistance in analogous to that predicted by the original bond model. Copyright © 2006 John Wiley & Sons, Ltd. [source] Design and optimization of multi-band Wilkinson power dividerINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 1 2008Nihad Dib Abstract In this paper, a general and easy procedure for designing the symmetrical Wilkinson power divider that achieves equal-power split at N arbitrary frequencies is introduced. Each quarter-wave branch in the conventional Wilkinson divider is replaced by N sections of transmission lines, and the isolation between the output ports is achieved by using N resistors. The design parameters are the characteristic impedances and lengths of the N transmission line sections, and the N isolation resistors. The even,odd modes of analysis are used to derive the design equations. Closed-form expressions, which are suitable for CAD purposes, are derived for the dual-band divider. For N , 3, closed-form expressions are not available, and therefore, the powerful particle swarm optimization method is used to obtain the design parameters. Examples of the dual-, triple-, and quad-band dividers are presented to validate the proposed design procedure, and the results are compared, wherever possible, with published results using other methods. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008. [source] Prenatal and early postnatal morphogenesis and growth of human laryngotracheal structuresJOURNAL OF ANATOMY, Issue 2 2008Pierre Fayoux Abstract Advances in neonatal medicine have resulted in increased care of fetal and neonatal airways. These advances have required an exhaustive knowledge of fetal airway anatomy and development. The aim of this study was to determine the anatomical development of laryngotracheal structures during the fetal and immediate postnatal period and to correlate these observations with other fetal biometric parameters to estimate developmental particularities of the fetal airway. An anatomical prospective study was based on examination of larynx and trachea from 300 routine autopsies of fetuses and infants, free of malformation and never intubated. Anatomical measurements of cricoid cartilage, thyroid cartilage, glottis, arytenoid cartilage and trachea were performed using a precision calliper and precision divider. Statistical analysis was performed to represent the growth of anatomical structures and to evaluate the correlation with biometric data. Raw data and 10th and 90th percentile curves were fitted satisfactorily with a linear model for gestational age. A linear relationship between laryngotracheal measurement and body weight and height was observed except for glottis length, interarytenoid distance and anterior cricoid height. The diameter of the cricoid lumen was significantly less than that of the trachea and glottis lumen. A sexual dysmorphism was noted for thyroid cartilage measurements and interarytenoid distance, with measurements significantly smaller in females. This study reports the anatomical development of normal laryngotracheal structures during the fetal period. Despite the fact that this study was performed during postmortem examination, these observations can be useful to develop criteria, materials and surgical procedures adapted to fetal and neonatal airways as well as for the purposes of early diagnosis and management of laryngotracheal malformations. [source] A 60-GHz CMOS receiver front-end with integrated 180° out-of-phase Wilkinson power dividerMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2010Jen-How Lee Abstract A 60-GHz receiver front-end with an integrated 180° out-of-phase Wilkinson power divider using standard 0.13 ,m CMOS technology is reported. The receiver front-end comprises a wideband low-noise amplifier (LNA) with 12.4-dB gain, a current-reused bleeding mixer, a baseband amplifier, and a 180° out-of-phase Wilkinson power divider. The receiver front-end consumed 50.2 mW and achieved input return loss at RF port better than ,10 dB for frequencies from 52.3 to 62.3 GHz. At IF of 20 MHz, the receiver front-end achieved maximum conversion gain of 18.7 dB at RF of 56 GHz. The corresponding 3-dB bandwidth (,3 dB) of RF is 9.8 GHz (50.8,60.6 GHz). The measured minimum noise figure (NF) was 9 dB at 58 GHz, an excellent result for a 60-GHz-band CMOS receiver front-end. In addition, the measured input 1-dB compression point (P1 dB) and input third-order inter-modulation point (IIP3) are ,20.8 dBm and ,12 dBm, respectively, at 60 GHz. These results demonstrate the adopted receiver front-end architecture is very promising for high-performance 60-GHz-band RFIC applications. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2688,2694, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25559 [source] Low power dual transformer injection locked frequency divider using 0.5 ,m GaAs E/D-mode PHEMTs processMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2010Po-Yu Ke Abstract This letter proposes a new divide-by-2 injection locked frequency divider (ILFD) fabricated by 0.5 ,m GaAs ED-Mode PHEMTs process and describes the operation principle of the dual-transformer ILFD. The first transformer is applied to replace two inductors of the cross-couple LC-tank oscillator circuit. The injection signal of the ILFD transmits into a transistor through a second transformer, which consisted of a bandpass filter achieving a high injection signal power and wide locking range. The measurement results show that the divider's free-running frequency were from 6.47 to 9.54 GHz (32.2%) with 3 V supply voltage. With an incident power of 0 dBm, the locking range is 3.07 GHz from the incident frequency 16.41 to 19.45 GHz (15.6%). The measured phase noise of free running VCO is ,92.2 dBc/Hz at 1 MHz offset frequency at 9.45 GHz and this value of the locked ILFD is ,128.4 dBc/Hz, which is 36.2 dB lower than the free running VCO. The core power consumption was 42 mW. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2302,2306, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25442 [source] Compact microstrip power divider with both sides capacitor loadingMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 7 2010Jun He Abstract A compact microstrip Wilkinson power divider with both sides capacitor loading is presented in this letter. The new divider, not only effectively reduces the occupied area to 33.6% of the conventional one at 1.0 GHz, but also has good harmonic suppression performance over a wide band. Furthermore, the new structure has only two variable parameters and can be easily designed. The design is validated both by simulation and measurement. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1663,1664, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25286 [source] A 90 nm CMOS dual-band divide-by-2 and -4 injection-locked frequency dividerMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2010Sheng-Lyang Jang Abstract A fourth-order resonator has been implemented to design a 65 GHz injection-locked frequency divider (ILFD) implemented in a 90 nm CMOS process. The ILFD is realized with a cross-coupled nMOS LC-tank oscillator with an inductor switch for frequency band selection. The LC tank can be a second-or fourth-order resonator depending upon the on/off state of a switch across a series-tuned inductor. Measurement results show that at the supply voltage of 0.5 V, the free-running frequency is from 8.68 (16.147) to 9.928 (17.89) GHz for the low- (high-) frequency band. The divide-by-2 operational locking range is from 14.9 (30.64) to 22.2 (37.74) GHz for the low-(high)-frequency band. The divide-by-4 operational locking range is from 34.4 (64.6) to 40.35 (67) GHz for the low-(high)-frequency band. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1421,1425, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25217 [source] Planar ultrawideband antenna array for short-range wireless communicationsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2010Osama M. H. Ahmed Abstract In this article, novel 2-element and 4-element planar ultrawideband (UWB) antenna arrays with bidirectional radiation patterns based on identical UWB antenna elements for UWB communications applications have been proposed, simulated and experimentally investigated. Each array is constructed by means of feeding omni-directional printed UWB monopole antennas with a UWB power divider. The proposed 2-element antenna array yields an impedance bandwidth of 110% (3.1,10.6 GHz) covering the whole UWB frequency bandwidth while the impedance bandwidth is multi-band in case of the 4-element antenna array because of the increasing effect of mutual coupling among antenna elements. The calculated gain of the 2-element and 4-element array is quite stable with about 3 and 6 dB higher than that of the single element, respectively. Both measured and calculated E-plane radiation patterns of the array and the single element are almost the same while the H-plane radiation patterns of the array are distinctively bidirectional compared to the omni-directional pattern of the single element. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1061,1066, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25140 [source] Analytical design of a half-mode substrate integrated waveguide Wilkinson power dividerMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2010A. Suntives Abstract This article presents a new approach in designing half-mode substrate integrated waveguide Wilkinson power dividers based on analytical relations. Even- and odd-mode analysis is used to determine the required value of the branch resistance and optimize the power divider performance, namely the output ports' isolation. In this manner, the design process for this microwave component is simplified and expedited, while an excellent correlation with full-wave simulations is maintained. Measurements of the fabricated prototype corroborate the calculated results and demonstrate a wide output-port isolation bandwidth of 71%. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1066,1069, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25145 [source] Rectangle waveguide to substrate integrated waveguide transition and power dividerMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2010Chao Li Abstract A novel Ku-band transition and power divider between rectangle waveguide (RWG) and substrate integrated waveguide (SIW) is proposed. This transition and power divider is realized by a radiating metal patch located on the backside of a middle dielectric substrate and a coupling aperture etched on the SIW's ground plane. The transition and power divider is studied both simulatively and experimentally. As reported, low insertion loss of not higher than 0.6 dB and good return loss of ,15 dB may be achieved at the frequency range of 12.1,12.8 GHz. The method to increase the bandwidth is investigated. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 375,378, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24902 [source] Micro-coaxial Ka-band Gysel power dividersMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2010Yuya Saito Abstract Monolithic, 450-,m tall, rectangular coaxial Gysel divider is presented in this article. The divider is fabricated by a surface micromachining process with six sequentially deposited copper layers. Athree-port, resistor-less divider has overall loss of 0.6 dB at 30 GHz, input port reflection coefficient better than ,10 dB, and output amplitude and phase misbalances of ±0.18 dB and ±1.8°, respectively, throughout Ka-band. The device is designed in a way that permits straightforward realization of a Gysel divider with integrated resistors. Electromagnetic and electrothermal analyses and design of the divider are conducted, and good agreement with measurements is obtained. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 474,478, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.24956 [source] Effects of interconnecting transmission lines on four-way Wilkinson power dividerMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2009Jiafeng Zhou Abstract A four-way power divider can be designed by interconnecting three two-way Wilkinson power dividers. This article investigates how the two-way elements can be interconnected to achieve optimal response. It will be shown that by using properly chosen lengths of interconnecting transmission lines, the bandwidth of the power divider can be significantly broadened. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2850,2852, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24786 [source] Low power wide-locking range CMOS quadrature injection-locked frequency dividerMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2009Sheng-Lyang Jang Abstract This letter presents a new low power and wide-locking range divide-by-2 injection-locked frequency divider (ILFD). The ILFD consists of a new 5.35 GHz quadrature voltage controlled oscillator (QVCO) and two NMOS switches, which are in parallel with the QVCO resonators for signal injection. The proposed CMOS ILFD has been implemented with the TSMC 0.18 ,m CMOS technology and the core power consumption is 5.72 mW at the supply voltage of 0.8 V. The free-running frequency of the QILFD is tunable from 5.24 to 5.55 GHz. At the input power of 0 dBm, the divide-by-2 locking range is from 8.2 to 13.3 GHz as the tuning voltage is biased at 0.8 V. The phase noise of the locked output spectrum is lower than that of free running ILFD in the divide-by-2 mode. The phase deviation of quadrature output is about 1.28°. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2420,2423, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24640 [source] Metamaterial transmission lines with tunable phase and characteristic impedance based on complementary split ring resonatorsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2009Adolfo Vélez Abstract In this article, resonant-type tunable metamaterial transmission lines with independent control over the electrical parameters of the line, that is, the electrical length and characteristic impedance, are presented for the first time. Tuning is achieved by loading a host microstrip line with varactor-loaded complementary split ring resonators (VLCSRRs) and varactor diodes. By locating the varactor diodes in series configuration with the line, outside the region occupied by the VLCSRRs, it is possible to control the characteristic impedance and the electrical length (phase shift), over a wide band. As an illustrative example, a tunable 35 ,/90° line functional between 0.4 and 0.8 GHz (which represents more than 65% tuning range), is presented and applied to the design of a transmission line power divider. The device is small and it exhibits reasonable performance. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1966,1970, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24480 [source] Design of meander square-ring resonator and its application in RF power dividerMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2009Fei Zhang Abstract First, this letter presents a novel meander square-ring resonator (MSRR) and its stop-band and slow-wave effects are investigated. Served by the proposed MSRR, unwanted higher-order 2nd and 3rd harmonics of power divider are effectively rejected benefiting from its stop-band effect without any additional filter, and the physical length of quarter-wavelength 70.7 ohm microstrip in power divider is halved utilizing its slow-wave effect without decreasing the electrical length. Finally, power divider with area reduction by 42.6% is successfully obtained, compared with conventional design. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1602,1604, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24394 [source] Divide-by-3 LC injection-locked frequency divider with inductor over MOS topologyMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2008Sheng-Lyang Jang Abstract This letter proposes a divide-by-3 frequency divider employing inductor-over MOS topology to reduce the chip area and chip cost; the divider was fabricated using the 0.35-,m 2P4M CMOS technology. The divider consists of an nMOS cross-coupled LC oscillator and two injection MOSFETs in series with the cross-coupled NMOSFETs, and the LC resonator is composed of two inductors and varactors. At the supply voltage of 1.6 V, the divider free-running frequency is tunable from 2.17 to 2.43 GHz, and at the incident power of 0 dBm the locking range is about 1.03 GHz (14.9%), from the incident frequency 6.41 to 7.44 GHz. The core power consumption is 15.1 mW. The die area is 0.753 × 0.786 mm2. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 988,992, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23279 [source] A varactorless CMOS direct-injection locked frequency dividerMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2008S.-L. Jang Abstract This paper presents a new integrated direct-injection locked frequency (ILFD) with the capability of quadrature generation. The circuit consists of a quadrature VCO, based on the cross-coupling of two differential LC-tank VCOs and with the coupling transistors placed in parallel with the switch transistors, and two direct injection MOSFETs. No varactors are used, and feedback is applied for frequency tuning. The circuit is implemented using a standard 0.35 ,m CMOS process. Measurement results show that at the supply voltage of 3.3 V, the core power consumption is 27 mW. The free-running ILFD is tunable from 1.5 to 1.98 GHz and the locking range is 2.92,4.26 GHz at 0 dBm. The measured phase noise of free-running ILFD is ,118.3 dBc/Hz while the locked quadrature output phase noise is ,126.7 dBc/Hz at 1 MHz offset frequency from the oscillation frequency of 1.98 GHz, which is 8.4 dB lower than the free running ILFD. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 608,611, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23165 [source] A Ka-band equal-branch waveguide power dividerMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2007Yunchuan Guo Abstract A Ka-band equal-branch waveguide power divider is proposed in this letter. This waveguide power divider has the uniform main guide and all the branches in same size to minimize the difficulty and sensitivity in the mechanical fabrication. Full-wave simulation and in-door measurement are also carried to validate this design. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2637,2639, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22811 [source] A complementary Hartley injection-locked frequency dividerMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2007Sheng-Lyang Jang Abstract This work proposes a new injection-locked frequency divider (ILFD) based on the differential complementary Hartley VCO topology. At the supply voltage of 1.8 V, the tuning range of the free running ILFD is from 7.54 to 7.94 GHz, about 400 MHz, and the locking range of the ILFD is from 14.94 to 16.05 GHz, about 1.11 GHz, at the injection signal power of 0 dBm. The ILFD dissipates 13.54 mW at the supply voltage of 1.8 V and was fabricated in the 1P6M 0.18 ,m CMOS process. The phase noise of the locked ILFD tracks with the low-phase-noise injection source. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2817,2820, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22834 [source] Injection-locked GaInp/GaAs HBT frequency divider with stacked transformersMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2007Hung-Ju Wei Abstract The first integrated GaInP/GaAs heterojunction bipolar transistor (HBT) injection-locked frequency divider (ILFD) with the stacked transformers is demonstrated around 10 GHz. The stacked transformers formed by only two metal layers provide the inductive coupling in the cross feedback and separate biasing for base and collector to allow for the larger output swing in the LC tank and obtaining wide locking range. Under the supply voltage of 5 V and core power consumption of 20.5 mW, the locking range is 7.8% of the center operating frequency. The chip size of the entire ILFD including probing pads is 1.0 × 1.0 mm2. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2602,2605, 2007; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.22737 [source] A new wideband three-way power dividerMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 7 2007Guan-Yu Chen Abstract A new three-way power divider that provides equal power split over a wide bandwidth implemented on a single-layer printed circuit board (PCB) is presented. It can be easily extended to an arbitrary number of output ports. The proposed power divider exhibits fairly good performance validated by measurement and simulation. Measured results show that the three output ports across the bandwidth from 1.8 to 10.5 GHz for 10 dB return loss are attainable. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1600,1603, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22547 [source] Broad-band power divider based on radial waveguideMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2007Kaijun Song Abstract A broad-band power divider using coaxial probes and a radial waveguide is presented. The simple modeling of this power divider and design method based on equivalent circuits has been developed. A four-way radial waveguide power divider has been designed, fabricated, and measured. Close agreement is obtained between the measured results and the simulated results. The measured 15-dB return loss bandwidth of the broad-band multiple-port structure is demonstrated to be 81.5% and its 0.5-dB insertion loss bandwidth 84.6%. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 595,597, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22216 [source] A compact harmonic-suppressed Wilkinson power divider using C-SCMRC resonatorsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2006Jian-Zhong Gu Abstract This letter describes a compact Wilkinson power divider using compensated spiral compact microstrip resonant cell (C-SCMRC) resonators for harmonic suppression and size reduction. The size length of quarter wavelength transmission line is only 0.14 ,g because of the slow-wave characteristic. Furthermore, the proposed power divider rejected the 2nd and 3rd harmonic signals using the stopband of C-SCMRC resonators. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2382,2384, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21961 [source] Bridging the black hole of trauma: the evolutionary significance of the artsPSYCHOTHERAPY AND POLITICS INTERNATIONAL, Issue 3 2010Sandra L. BloomArticle first published online: 5 SEP 2010 Abstract One word for the Devil is ,Diabolos', the divider, the splitter-into-fragments. Healing likewise has always been associated with integration, integrity and becoming whole. From ncient times to the present, artistic performance in all its variety has been connected to healing of self and community and yet a recurrent question arises, ,What are the arts for?'. A less than concrete answer to this question appears to justify reducing or eliminating funding to arts-related programs whenever financial crisis occurs. This paper explores the evolutionary significance of trauma, dissociation, and the human brain and raises the possibility that the evolutionary selection of artistic performance is as a primary integrating mechanism for traumatized individuals and groups, without which human beings may not be able to fully heal. Copyright © 2010 John Wiley & Sons, Ltd. [source] Humor as a Double-Edged Sword: Four Functions of Humor in CommunicationCOMMUNICATION THEORY, Issue 3 2000John C. Meyer The compelling power of humor makes it a recurrent topic for research in many fields, including communication. Three theories of humor creation emerge in humor research: the relief theory, which focuses on physiological release of tension; the incongruity theory, singling out violations of a rationally learned pattern; and the superiority theory, involving a sense of victory or triumph. Each theory helps to explain the creation of different aspects of humor, but each runs into problems explaining rhetorical applications of humor. Because each theory of humor origin tries to explain all instances of humor, the diverging communication effects of humor remain unexplained. Humor's enactment leads to 4 basic functions of humor in communication. Two tend to unite communicators: the identification and the clarification functions. The other 2 tend to divide 1 set of communicators from others: the enforcement and differentiation functions. Exploration of these effects-based functions of humor will clarify understanding of its use in messages. Humor use unites communicators through mutual identification and clarification of positions and values, while dividing them through enforcement of norms and differentiation of acceptable versus unacceptable behaviors or people. This paradox in the functions of humor in communication as, alternately, a unifier and divider, allows humor use to delineate social boundaries. [source] Using MOS current dividers for linearization of programmable gain amplifiersINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 4 2008M. Teresa Sanz Abstract Two highly linear, digitally programmable gain amplifiers are presented and compared in terms of linearity, frequency, area and power consumption. High linearity and wide gain tuning range with moderate area consumption are the main benefits of both configurations. Furthermore, constant bandwidth is achieved by means of switched compensation capacitor arrays. Three-bit prototypes were integrated in a 0.35,µm,3.3,V CMOS process with 2.5,V supply voltage. Experimental distortion levels are better than ,68,dB for 1,MHz and 1,Vp,p output signals in both configurations; hence, the suitability of the linearization technique based on MOS current dividers is shown. Copyright © 2007 John Wiley & Sons, Ltd. [source] Design and optimization of multi-band Wilkinson power dividerINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 1 2008Nihad Dib Abstract In this paper, a general and easy procedure for designing the symmetrical Wilkinson power divider that achieves equal-power split at N arbitrary frequencies is introduced. Each quarter-wave branch in the conventional Wilkinson divider is replaced by N sections of transmission lines, and the isolation between the output ports is achieved by using N resistors. The design parameters are the characteristic impedances and lengths of the N transmission line sections, and the N isolation resistors. The even,odd modes of analysis are used to derive the design equations. Closed-form expressions, which are suitable for CAD purposes, are derived for the dual-band divider. For N , 3, closed-form expressions are not available, and therefore, the powerful particle swarm optimization method is used to obtain the design parameters. Examples of the dual-, triple-, and quad-band dividers are presented to validate the proposed design procedure, and the results are compared, wherever possible, with published results using other methods. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008. [source] Application of the envelope-transient method to the analysis and design of autonomous circuitsINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 6 2005Almudena Suárez Abstract The envelope transient enables a very efficient simulation of circuits with two different time scales, such as those that contain modulated signals (for example, amplifier or mixers), where an accurate prediction of intermodulation distortion is needed. The method has also been extended to oscillator analysis, where it requires additional techniques in order to avoid convergence to degenerate mathematical solutions, for which the circuit is not actually oscillating. It allows an efficient analysis of transients in these circuits and an accurate prediction of the phase-noise spectrum. This article presents an overview of the envelope-transient method and its most recent applications to the simulation of autonomous circuits, such as free and forced oscillators, frequency dividers, and phase-locked loops. Using this method, the operation bands of these circuits (which are delimited by qualitative stability changes or bifurcations) can be determined in a straightforward manner. This technique can also be applied to predict intermodulation distortion in self-oscillating mixers and to simulate the response of synchronized oscillators containing modulated signals. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005. [source] The determination of freeway space using two different methodsJOURNAL OF ORAL REHABILITATION, Issue 10 2002A. Johnson summary, The aim of this study was to determine the average freeway space of dentate subjects and relate this to recommended ranges for edentulous patients, also to see if any differences were observed between two different methods of measuring freeway space. The freeway space of 72 dentate subjects was measured, first using a Willis gauge, and secondly using a pair of sprung dividers. The intra- and interoperator variability was evaluated as was the reproducibility of the accuracy of both techniques. The mean freeway space using the Willis gauge was 3·3 mm, for both intra and inter operator variability, and with the sprung dividers 3·1 and 2·9 mm, respectively, with no significant difference being seen between any combination of results (P > 0·05). Individual measurements within the two measuring methods being assessed showed significant differences (P < 0·05). The mean measurements of freeway space in dentate subjects found in this study were within the recommended 2,4 mm range, however, 15% of the subjects in the study had freeway space measurements outside this range. This study would suggest that the range for freeway space measurement could more realistically be 2,7 mm. [source] | |||||||||||||||||||