The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Kin-lu Wong - One of the best experts on this subject based on the ideXlab platform.
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very low profile dual wideband loop antenna for lte tablet computer
Microwave and Optical Technology Letters, 2015Co-Authors: Kin-lu Wong, Meng-ting ChenAbstract:A very-low-profile (8 mm in height), small-size (8 × 3 × 40 mm3), and dual-wideband loop antenna suitable for applications in the LTE tablet device such as a tablet computer is presented. Dual-wideband operation of the proposed loop antenna is achieved using a wideband feed structure formed by a coupling feed, a high-pass Matching Circuit, and a tuning inductor. The coupling feed leads to successful excitation of a quarter-wavelength loop mode in the desired lower band. The high-pass Matching Circuit causes an additional resonance occurred near the excited quarter-wavelength loop mode to widen the low-band bandwidth to cover the 698–960 MHz band. The tuning inductor can adjust the frequency ratio of the first two higher-order loop modes to form a wide higher band to cover the 1710–2690 MHz band. Dual-wideband operation of the proposed loop antenna for the LTE operation is hence obtained. Details of the proposed loop antenna are addressed. Working principle of the antenna, especially the function of the wideband feed structure thereof, is described. Experimental results of the fabricated prototype are also presented. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:141–146, 2015
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low profile multibranch monopole antenna with integrated Matching Circuit for lte wwan wlan operation in the tablet computer
Microwave and Optical Technology Letters, 2014Co-Authors: Powei Lin, Kin-lu WongAbstract:A low profile, small-size, planar tablet computer antenna for the long-term evolution (LTE)/wireless wide area network and 2.4-GHz WLAN operation is presented. The antenna is formed by three monopole strips configured into a compact configuration and printed on a thin FR4 substrate of size 10 × 40 mm2. A high-pass Matching Circuit is integrated thereon, without increasing the antenna size, to greatly enhance the antenna's low-band bandwidth to cover the LTE700/GSM850/900 operation (704–960 MHz) with a low-antenna profile of 10 mm. The antenna's higher band is formed by two wide resonant modes contributed by the monopole strips and can cover the GSM1800/1900/UMTS/LTE2300/2500 operation (1710–2170/2300–2400/2500–2690 MHz). In addition, one of the resonant modes in the higher band can be adjusted to occur at about 2.4 GHz such that enhanced radiation characteristics for frequencies in the 2400–2484-MHz WLAN band are obtained for the proposed antenna. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1662–1666, 2014
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small size lte wwan coupled fed loop antenna with band stop Matching Circuit for tablet computer
Microwave and Optical Technology Letters, 2012Co-Authors: Kin-lu Wong, Tsungju WuAbstract:By combining the use of a coupling feed and a band-stop Matching Circuit, the proposed small-size loop antenna for the tablet computer application can operate at its quarter-wavelength mode as the lowest resonant mode and provide two wide operating bands (704–960 and 1710–2690 MHz) to cover the eight-band LTE/WWAN operation (LTE700/GSM850/900 and GSM1800/1900/UMTS/LTE2300/2500 bands).The loop antenna comprises a T-shape radiating feed, a coupled shorted strip, an antenna ground, and a band-stop Matching Circuit on the antenna ground. The antenna's metal pattern includes a printed pattern on a thin FR4 substrate of planar size 10 × 55 mm2 and a metal strip of size 4 × 55 mm2 formed a part of the coupled shorted strip and connected orthogonally to the printed pattern. The antenna's occupied volume and the required length of 55 mm along the top edge of the display ground are both the smallest among the internal LTE/WWAN antenna for the tablet or laptop computers that have been reported for the present. Detailed operating principle of the proposed antenna including the effects of the coupling feed using the T-shape radiating feed and the band-stop Matching Circuit for bandwidth enhancement is discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1189–1193, 2012
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small size wwan monopole slot antenna with dual band band stop Matching Circuit for tablet computer application
Microwave and Optical Technology Letters, 2012Co-Authors: Kin-lu WongAbstract:A monopole slot antenna printed on a small-size FR4 substrate of 40 × 10 mm2 to provide two wide operating bands of 824–960 and 1710–2170 MHz for the wireless wide area network operation in the tablet computer is presented. The monopole slot is folded to achieve a compact configuration and is fed by a microstrip feedline loaded with a dual-band band-stop Matching Circuit on the same FR4 substrate. The band-stop Matching Circuit can generate two separate parallel resonances at about 1050 and 2250 MHz, which respectively leads to additional resonance occurred nearby the resonant frequencies of the quarter-wavelength slot mode at about 850 MHz and higher-order slot mode at about 1900 MHz, thereby resulting in dual-resonance excitation of the two excited slot modes to respectively cover the GSM850/900 and GSM1800/1900/UMTS operation. The bandwidth-enhancement technique of using a dual-band band-stop Matching Circuit is reported for the first time in published articles, and its detailed operating principle is described in this study. Performances of the proposed antenna are also discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:875–879, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26723
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small planar internal wireless wide area network tablet computer antenna
Microwave and Optical Technology Letters, 2012Co-Authors: Kin-lu Wong, Tsungju WuAbstract:A planar penta-band wireless wide area network (WWAN) antenna with a small size of 12 × 35 mm2 for application in the tablet computer as an internal antenna is presented. The antenna is printed on a 0.8-mm thick FR4 substrate on which a radiating portion and an antenna ground for accommodating a Matching Circuit are formed. The antenna is mounted at the top edge of the display ground which supports a 9.7-inch display for the tablet computer. The antenna's radiating portion comprises a feeding strip, a parasitic strip short-Circuited to the antenna ground, and a printed distributed parallel resonant Circuit. The latter two contribute a 0.25-wavelength dual-resonance mode at about 850 MHz for the GSM850/900 operation. The feeding strip generates a 0.25-wavelength resonant mode at about 1800 MHz to combine with a higher-order resonant mode at about 2200 MHz contributed by the shorted strip for the GSM1800/1900/UMTS operation. Additionally, the Matching Circuit on the antenna ground replacing the function of the Matching Circuit that is usually disposed on the system Circuit board and provides a convenient means to adjust the impedance Matching of the antenna to cover the desired operating bands. Owing to the new configuration of the antenna, the size of the proposed antenna is about the smallest among the internal WWAN antennas that have been reported for the tablet or laptop computer applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:426–431, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26559
Jo Bito - One of the best experts on this subject based on the ideXlab platform.
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A Novel Heuristic Passive and Active Matching Circuit Design Method for Wireless Power Transfer to Moving Objects
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, 2017Co-Authors: Jo Bito, S. Jeong, M.m. Manos M. TentzerisAbstract:In this paper, a novel Matching Circuit design method utilizing a genetic algorithm (GA) and the measured S-parameters of randomly moved coil configurations is discussed. Through the detailed comparison of different Matching Circuit topologies, the superiority of active Matching Circuits is clearly demonstrated, and potentially there is 21.4% improvement in the wireless power transfer efficiency by using a four-cell active Matching Circuit, which can create 16 different impedance values. Also, the Matching Circuit design simulation can be further simplified by choosing a much smaller subset of representative impedance values for the utilized time-changing coil configuration through the employment of k-means clustering and use only these values for the derivation of the optimal Matching Circuit. This heuristic approach could drastically reduce the time for the Matching Circuit design simulation, especially for Matching Circuit topologies with a larger number of cells.
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a real time electrically controlled active Matching Circuit utilizing genetic algorithms for wireless power transfer to biomedical implants
IEEE Transactions on Microwave Theory and Techniques, 2016Co-Authors: Jo Bito, Soyeon Jeong, Manos M TentzerisAbstract:This paper discusses the feasibility of a real-time active Matching Circuit (MC) for wireless power transfer applications, especially for biomedical systems. One prototype of low-cost real-time automatic MC, utilizing a variable Circuit topology, including discrete passives and p-i-n diodes, has been implemented and the principle has been verified by measurements. One genetic algorithm was introduced to optimize the design over a wide range of impedances to match. As a result of preliminary operation verification tests, the proposed real-time MC system results in improving the transfer coefficient in the range of 10–16-cm coil separation distance a maximum of 3.2 dB automatically in about 64 ms. Similar performance improvement results were observed in additional tests under misaligned conditions, as well as for nonsymmetrical Tx–Rx coil configurations further verifying the potential applicability of the proposed system to practical biomedical devices.
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a real time electrically controlled active Matching Circuit utilizing genetic algorithms for biomedical wpt applications
IEEE Wireless Power Transfer Conference, 2015Co-Authors: Jo Bito, Soyeon Jeong, Manos M TentzerisAbstract:In this research, the feasibility of a real-time active Matching Circuit for biomedical WPT applications is discussed. Also, the genetic-algorithm based Matching Circuit design method utilizing discrete Circuit components is introduced and the practicality of active Matching Circuits for WPT is verified with preliminary measurement results featuring a maximum of 3 dB of improvement in transmission coefficient for a range of spanning a coil to coil distance of 10 to 12 cm, which was achieved by inserting the active Matching Circuit.
Manos M Tentzeris - One of the best experts on this subject based on the ideXlab platform.
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a real time electrically controlled active Matching Circuit utilizing genetic algorithms for wireless power transfer to biomedical implants
IEEE Transactions on Microwave Theory and Techniques, 2016Co-Authors: Jo Bito, Soyeon Jeong, Manos M TentzerisAbstract:This paper discusses the feasibility of a real-time active Matching Circuit (MC) for wireless power transfer applications, especially for biomedical systems. One prototype of low-cost real-time automatic MC, utilizing a variable Circuit topology, including discrete passives and p-i-n diodes, has been implemented and the principle has been verified by measurements. One genetic algorithm was introduced to optimize the design over a wide range of impedances to match. As a result of preliminary operation verification tests, the proposed real-time MC system results in improving the transfer coefficient in the range of 10–16-cm coil separation distance a maximum of 3.2 dB automatically in about 64 ms. Similar performance improvement results were observed in additional tests under misaligned conditions, as well as for nonsymmetrical Tx–Rx coil configurations further verifying the potential applicability of the proposed system to practical biomedical devices.
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a real time electrically controlled active Matching Circuit utilizing genetic algorithms for biomedical wpt applications
IEEE Wireless Power Transfer Conference, 2015Co-Authors: Jo Bito, Soyeon Jeong, Manos M TentzerisAbstract:In this research, the feasibility of a real-time active Matching Circuit for biomedical WPT applications is discussed. Also, the genetic-algorithm based Matching Circuit design method utilizing discrete Circuit components is introduced and the practicality of active Matching Circuits for WPT is verified with preliminary measurement results featuring a maximum of 3 dB of improvement in transmission coefficient for a range of spanning a coil to coil distance of 10 to 12 cm, which was achieved by inserting the active Matching Circuit.
E A Laird - One of the best experts on this subject based on the ideXlab platform.
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measuring carbon nanotube vibrations using a single electron transistor as a fast linear amplifier
Applied Physics Letters, 2018Co-Authors: Yutian Wen, N Ares, Tian Pei, G A D Briggs, E A LairdAbstract:We demonstrate sensitive and fast electrical measurements of a carbon nanotube mechanical resonator. The nanotube is configured as a single-electron transistor, whose conductance is a sensitive transducer for its own displacement. Using an impedance-Matching Circuit followed by a cryogenic amplifier, the vibrations can be monitored at radio frequency. The sensitivity of this continuous displacement measurement approaches within a factor 470 of the standard quantum limit.We demonstrate sensitive and fast electrical measurements of a carbon nanotube mechanical resonator. The nanotube is configured as a single-electron transistor, whose conductance is a sensitive transducer for its own displacement. Using an impedance-Matching Circuit followed by a cryogenic amplifier, the vibrations can be monitored at radio frequency. The sensitivity of this continuous displacement measurement approaches within a factor 470 of the standard quantum limit.
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measuring carbon nanotube vibrations using a single electron transistor as a fast linear amplifier
arXiv: Mesoscale and Nanoscale Physics, 2018Co-Authors: Yutian Wen, N Ares, Tian Pei, G A D Briggs, E A LairdAbstract:We demonstrate sensitive and fast electrical measurements of a carbon nanotube mechanical resonator. The nanotube is configured as a single-electron transistor, whose conductance is a sensitive transducer for its own displacement. Using an impedance-Matching Circuit followed by a cryogenic amplifier, the vibrations can be monitored in real time. The sensitivity of this continuous displacement measurement approaches within a factor 470 of the standard quantum limit.
M.m. Manos M. Tentzeris - One of the best experts on this subject based on the ideXlab platform.
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A Novel Heuristic Passive and Active Matching Circuit Design Method for Wireless Power Transfer to Moving Objects
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, 2017Co-Authors: Jo Bito, S. Jeong, M.m. Manos M. TentzerisAbstract:In this paper, a novel Matching Circuit design method utilizing a genetic algorithm (GA) and the measured S-parameters of randomly moved coil configurations is discussed. Through the detailed comparison of different Matching Circuit topologies, the superiority of active Matching Circuits is clearly demonstrated, and potentially there is 21.4% improvement in the wireless power transfer efficiency by using a four-cell active Matching Circuit, which can create 16 different impedance values. Also, the Matching Circuit design simulation can be further simplified by choosing a much smaller subset of representative impedance values for the utilized time-changing coil configuration through the employment of k-means clustering and use only these values for the derivation of the optimal Matching Circuit. This heuristic approach could drastically reduce the time for the Matching Circuit design simulation, especially for Matching Circuit topologies with a larger number of cells.