Operating Bandwidth (operating + bandwidth)

Distribution by Scientific Domains


Selected Abstracts


High isolation microstrip GaN-HEMT Single-FET Switch

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 4 2010
Walter Ciccognani
Abstract In this contribution an analytical approach to the design of high-isolation microwave transmission line-resonated switches is presented. Simulated and measured performance of a GaN HEMT single-FET switch cell topology and the one of a complete SPDT using the proposed approach are presented to demonstrate the approach feasibility and effectiveness. The resulting SPDT, operating at X Band, is featured by 1 dB insertion loss, isolation better than 37 dB all over the operating bandwidth and a power handling capability higher than 39 dBm. 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010. [source]


A reconfigurable design for bandwidth enhancement of circularly polarized slot antennas

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2010
Tsung-Hsun Hsieh
Abstract A reconfigurable design is proposed to improve the circular polarization (CP) operating bandwidth of an annular-ring slot antenna fed with an L-shaped coupling strip. The design involves four voltage-controlled varactor diodes, which are placed below the slot and symmetrically distributed along the circumference of the slot. When all antenna dimensions remain constant, the CP operating frequency of the slot antenna can be decreased by varying dc voltage values. In addition, theses CP operating frequencies, which are corresponding to different dc voltage values can form a successive frequency band, and the available CP bandwidth is thus improved. Experimental results indicate that with the reconfigurable design, the 3-dB axial-ratio CP bandwidth can be increased by a factor of 4 for the annular-ring slot antenna with a reflector. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1377,1380, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25192 [source]


A slot-coupling coplanar waveguide-fed fan-shaped antenna embedded in semicircle aperture

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2009
Qin-Yi Li
Abstract A novel design of a fan-shaped antenna embedded in semicircle aperture is proposed and experimentally studied in this article. The proposed antenna is fed by a tapered coplanar waveguide (CPW) and has an ultrawide band owing to the coupling between the fan-shaped radiation unit and the ground. From experimental results, the measured impedance bandwidth of the antenna, determined by ,10 dB return loss, can reach an operating bandwidth of 23.36 GHz (1.64,25 GHz), more than 175% with the center frequency operating at about 13.32 GHz. Good radiation patterns and gains covering the operating band have been observed. Details of the antenna design and experimental results are discussed in this article. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2385,2387, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24655 [source]


Internal wideband monopole antenna for MIMO access-point applications in the WLAN/WIMAX bands

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2008
Jui-Hung Chou
Abstract A three-antenna MIMO system capable of generating a wide operating bandwidth of 2400,5850 MHz for access-point applications is introduced. The proposed design is based on a bent metal-plate monopole antenna with a compact size of 20 20 14 mm3. The three antennas are equally spaced along the perimeter of a circular ground and all generate a wide bandwidth of larger than 4 GHz. With the antenna short-circuiting facing the center of the ground, not only the overall antenna size is reduced but also good isolation of less than ,20 dB can easily be obtained. Calculated envelope correlation is also less than 0.002 across the operating band. The design prototype of the antenna is discussed in detail in the article. 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1146,1148, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23333 [source]


Cost-effective metal-plate shorted dipole antenna with wide bandwidth for WLAN/WiMAX applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2007
Jui-Hung Chou
Abstract A wideband shorted dipole antenna well suited to applications for WLAN/WiMAX dual-mode operation is presented. The dipole antenna is structured to be of an L shape to fit in corners of possible wireless communications devices. Two radiating arms of the dipole antenna are further short-circuited, which allows the antenna to be cost-effectively fabricated by stamping a single metal plate only one time. In addition, by widening the end portion of each radiating arm, much more improved impedance matching across a wide operating bandwidth can easily be achieved. Details of the proposed dipole antenna are described, and experimental and simulation results of a design prototype are elaborated and discussed. 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 3044,3046, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22911 [source]


Broadband planar DTV antenna in the portable media player held by the user's hands

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2007
Wei-Yu Li
Abstract Effects of the user's hands on the broadband planar DTV antenna in the portable media player (PMP) are studied. The antenna has a wide operating bandwidth covering the 470,806 MHz band for DTV signal reception and a one-layer equivalent simulation hand model including the user's forearm with a relative permittivity of 33.5 and a conductivity of 0.47 S/m is used for the simulation study. Three different conditions of the user's hands (right hand only, left hand only, and both hands) holding the PMP are studied, and their effects on the return loss, radiation efficiency, and radiation patterns of the studied DTV antenna are analyzed. In addition, effects of the user's hands holding the PMP at different positions relative to the studied DTV antenna are analyzed. Results have shown that, for the worst case, the radiation efficiency of the studied DTV antenna is still larger than 60% over the operating band, making the antenna very promising for practical applications. 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1841,1844, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22639 [source]


Magnetic loading of EBG AMC ground planes and ultrathin absorbers for improved bandwidth performance and reduced size

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2006
D. J. Kern
Abstract This paper demonstrates the advantages of magnetic loading within the substrate of an electromagnetic bandgap (EBG) surface. A conventional EBG surface has been shown to act as an artificial magnetic conductor over a narrow bandwidth. This paper demonstrates that by magnetic loading of the substrate, increased operating bandwidth is achieved for each resonant frequency. In addition, previous research has revealed that an ultrathin electromagnetic absorber design can be obtained by introducing loss into the frequency selective surface of an EBG absorber. It is now shown that a further reduction in thickness is possible by including a small amount of magnetic permeability within the dielectric substrate material. 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2468,2471, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21972 [source]


Broadband coaxial antenna for WiMAX access-point application

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2006
Kin-Lu Wong
Abstract A broadband coaxial antenna mainly comprising an upper square cylindrical plate and a lower square cylindrical ground is presented. The antenna functions like a two-wire dipole antenna, and furthermore provides a wide operating bandwidth of about 4 GHz (about 1.9 to 5.9 GHz in the study), making it very promising for application in Worldwide Interoperability for Microwave Access Forum (WiMAX) access points. The antenna has been successfully implemented, and experimental results are presented. The effects of the lower square cylindrical ground on the antenna performances are also analyzed. 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 641,644, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21432 [source]


Printed short-circuited wideband monopole antenna with band-notched operation

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2005
Kin-Lu Wong
Abstract This paper presents the band-notched operation of a printed short-circuited wideband monopole antenna. The notched or rejected band within a wide operating bandwidth is obtained by embedding an inverted U-shaped slot close to the shorting point of the antenna, where strong excited surface currents in the antenna are usually present. The notched band is controllable by adjusting the lengths of the inner and outer perimeters of the embedded U-shaped slot. A constructed prototype of the antenna is demonstrated, and a parametric study of the embedded slot used for band-notched operation is also presented. 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 58,61, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20900 [source]


Broadband omnidirectional U-shaped metal-plate monopole antenna

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2005
Saou-Wen Su
Abstract This paper presents a new broadband omnidirectional monopole antenna. The antenna is a U-shaped metal-plate monopole antenna that is easily fabricated by bending a rectangular metal plate. The antenna can provide a very wide operating bandwidth of larger than 5 GHz (about 2.0 to 7.1 GHz). In addition, for frequencies across the operating bandwidth, good omnidirectional radiation is obtained. Details of the antenna design are described, and experimental results of the constructed prototypes are presented. 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 365,369, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20636 [source]


Band-notched ultra-wideband planar-monopole antenna

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2005
Saou-Wen Su
Abstract An ultra-wideband (UWB) planar metal-plate monopole antenna with a band-notch characteristic is presented. The proposed planar metal-plate monopole antenna is embedded with an inverted U-shape slot, whose length is selected to be a half-wavelength at the desired notched frequency. By adjusting the slot length, the notched frequency band within the antenna's operating bandwidth can be easily controlled. A design example for an UWB (3.1,10.6 GHz) planar metal-plate monopole antenna with a notched frequency band at 5 GHz is demonstrated. 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 217,219, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20592 [source]


Optimization of a small to-can package electrical design for SFF/SFP optical transceiver modules

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2004
Sang-Hoon Lee
Abstract In this paper, we present an optimum TO-38 package design for SFF/SFP optical transceiver modules in order to improve the 3-dB bandwidth. The frequency response of the TO-38 package is measured and compared to simulation where the 3-dB-bandwidth was 3.5 GHz. For a higher operating bandwidth (>15 GHz), new optimized physical geometries for the TO-can package, such as bonding wires, leads, and material, are suggested. The optimal result of simulation shows that this TO-can package can be used at a higher-bit-rate optical module of 10 Gb/s. 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 239,242, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11340 [source]