229 research outputs found

    Integrated Antenna for Multiband Multi-national Wireless Combined with GSM1800/PCS1900/IMT2000 + Extension

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    A printed triple-band monopole antenna appropriate for use as a terminal antenna in modern wireless multiband systems is proposed. The impedance bandwidth of each band has been optimised using a quasi-Newton technique and the bandwidth includes virtually all wireless bands. Various parameter sweeps are presented which improve our understanding of the antenna, in particular, the effect of groundplane-size and branch-off point on impedance bandwidth and radiation pattern

    Small Patch/Slot Antenna with 53% Input Impedance Bandwidth

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    A small microstrip patch/slot antenna, which achieves a very large bandwidth on a relatively thin substrate (about 0.01lambda0), is presented. The performance is achieved by employing a combination of annular-ring loading on the patch radiator and the use of a crossed-slot for miniaturisation. An additional ring-slot in the ground plane is used to produce the wideband characteristics of the antenna. Simulated and measured results indicate that a 53% fractional impedance bandwidth is achieved with respect to the centre frequency of 1.409 GHz and the size of the antenna is reduced by 50% compared to the conventional circular patch antenna with respect to a given frequenc

    Low-cost Multimode Patch Antenna for Dual MIMO and Enhanced Localization Use

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    This paper proposes a simple, low-cost multi-mode patch antenna combining good MIMO performance with precise Angle of Arrival (AoA) estimation. The AoA is based on the monopulse antenna concept, however, unlike in radar applications, the necessity for complex circuitry is replaced by the intrinsic properties of even and odd resonant patch modes. This capability is advantageous for future ‚ÄúInternet of Things‚ÄĚ antennas, embedded into low-cost and size-constrained devices. The envelope correlation coefficient, measured in an anechoic chamber, is below 1.5 %, ensuring good MIMO performance. An exemplary addition to localization algorithm exploiting antenna properties is demonstrated

    Antenna Optimization with a Computationally Efficient Multiobjective Evolutionary Algorithm

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    An efficient multiobjective evolutionary algorithm is described for optimizing a novel spline based printed monopole antenna. The antenna geometry is based on spline outlines. Both radiating element and groundplane are simultaneously optimized by the algorithm. The resulting antenna performance is evaluated. It is shown that the evolutionary algorithm and the spline geometry can be used to efficiently generate ultrawideband antennas on limited computing resources

    Wideband Printed Monopole Design Using a Genetic Algorithm

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    A method for the design and optimisation of wide-band printed planar monopoles using a genetic algorithm is presented. This novel technique employs overlapping sub-patches which ensures electrical contact in such constellations where two sub-patches are touching only at the corner, hence re-ducing losses. The method was usd optimisation of wide-band printed planar monopoles using a genetic algorithm is presented. This novel technique employs overlapping sub-patches which ensures electrical contact in such constellations where two sub-patches are touching only at the corner, hence re-ducing losses. The method was used to design a wideband monopole antenna with application in higher cellular, WLAN and UWB. Furthermore, the technique is modified for multi-goal optimisation to achieve multiple bands and reduce the lower edge frequencyed to design a wideband monopole antenna with application in higher cellular, WLAN and UWB. Furthermore, the technique is modified for multi-goal optimisation to achieve multiple bands and reduce the lower edge frequency. The best solutions were prototyped and a full experimental evaluation was made

    Reconfigurable Antenna with Elevation and Azimuth Beam Switching

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    A reconfigurable microstrip antenna is proposed for low-cost adaptive beam-switching applications. A small patch-slot-ring structure is used as the radiating element where an asymmetrical arrangement of p-i-n diodes is employed to switch the pattern in four directions. The antenna provides pattern switching of 65¬į and 45¬į in its fundamental mode for the elevation and azimuth planes, respectively. By maintaining the resonant frequency and beamwidth as relatively constant, beam switching is realized using a single feed point

    Dual-band Monopole Antenna with Stagger-tuned Arms for Broadbanding

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    The paper describes a dual-band miniaturized printed monopole for integration in modern wireless systems. The printed monopole is augmented with two arms, resonant at slightly different frequencies, providing a broadened response for the upper band. The achieved bandwidth for the high band is 36%. These antennas are proposed for the emerging dual-mode multi-band WLAN transceivers, which operate over a wide range of bands as dictated by national authorities. Measured and simulated data, including return loss, antenna gain and radiation patterns, are presented. The numerical method employed was the finite integration technique

    Omnidirectional Circularly Polarized Antennas ‚Äď a Small Antenna Perspective

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    The paper discusses recent developments and challenges in the design of small omnidirectionalcircularly-polarized (CP) antennas. Although omnidirectional CP coverage is easily achievable using antenna arrays, it is just recently that small and low-cost antennas delivered this functionality.The paper addresses practical design problems for these antennas, not reported in previous publications.This includes selection of the omnidirectional plane relative to the ground plane and measurement challenges. Future perspectives on how these antennas can provide electronically steerable beams are investigated using simulated results

    Miniaturized Annular Ring Loaded Patch Antennas

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    The proliferation of wireless communication systems has promoted the development of miniaturized antenna designs. Annular ring patch antennas are reported to reduce antenna size. In this paper, several novel compact probe-fed annular-ring microstrip patch antennas are presented. In order to reduce the antenna size and provide a suitable input impedance match, two techniques are employed; the insertion of strips into the annular ring and placing a cross-slot into the ground plane. The proposed annular-ring patch antennas with a cross-slotted ground plane yield a much smaller size for a given frequency and are easily matched to 50 Ohms. These novel patch antennas can effectively be reduced by about 55 percent in size compared to conventional annular-ring patch antennas. The antenna can be designed for single band circular-polarization, dual-band circular polarization, triple band, or wideband operation, depending on parameter selection. Some significant advantages are evident for these structures, such as the centre-frequency exhibiting weak dependence on the position of the feedpoint as well as compact size. Good circularly polarized properties and wide CP bandwidths are obtained for these compact antennas. The multiband versions can provide small frequency ratios. The optimized dimensions for four different type antennas are displayed
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