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  • 1.
    Bajpai, O.
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Östh, Joakim
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Differential six-port modulator in 2011 International Conference on Wireless Communications and Signal Processing, WCSP 2011, vol , issue , pp2011In: 2011 International Conference on Wireless Communications and Signal Processing, WCSP 2011, 2011Conference paper (Refereed)
    Abstract [en]

    A differential six-port modulator for the 7-8 GHz band is reported for the first time. It is composed of a differential six-port correlator with cold-mode field effect transistors used as impedance terminations, controlled via baseband signal on the gate to source terminal. It is fabricated using double-sided parallel-strip lines. The differential modulator has the advantage of low power consumption, compactness and high signal to noise ratio. A prototype has been fabricated and data transmission with 256-quadrature amplitude modulation at 50 Msymbol/s is demonstrated. © 2011 IEEE.

  • 2.
    Bondarevs, Andrejs
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Huss, Patrik
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Weister, Ola
    Vertical Plants System Sweden AB.
    Liljedahl, Roger
    Vertical Plants System Sweden AB.
    Green walls utilizing Internet of Thing2015In: Sensors & Transducers Journal, ISSN 2306-8515, E-ISSN 1726-5479, Vol. 192, no 9, p. 16-21Article in journal (Refereed)
    Abstract [en]

    A wireless sensor network was used to automatically control the life-support equipment of a green wall and to measure its influence on the air quality. Temperature, relative humidity, particulate matter, volatile organic compound and carbon dioxide were monitored during different tests. Green wall performance on improving the air quality and the influence of the air flow through the green wall on its performance were studied. The experimental results show that the green wall is effective to absorb particulate matter and volatile organic compound. The air flow through the green wall significantly increases the performance. The built-in fan increases the absorption rate of particulate matter by 8 times and that of formaldehyde by 3 times.

  • 3.
    Gong, Shaofang
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Huynh, Allan
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Karlsson, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Serban, Adriana
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Owais, Owais
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Östh, Joakim
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Truly Differential RF and Microwave Front-End Design2010In: IEEE 11th Annual Wireless and Microwave Technology Conference (WAMICON), Piscataway, NJ, USA: IEEE , 2010, p. 1-5Conference paper (Refereed)
    Abstract [en]

    New design methodology for truly differential RF and microwave front-ends has been presented in this paper. Baluns are avoided using this design methodology, while achieving differential signaling for high noise immunity. A case study on an ultra-wide band RF front-end in the frequency band 6-9 GHz has been performed using the new design methodology, indicating that both wide bandwidth and high performance can be achieved using this design methodology. A direct comparison between single-ended and differential designs of the RF filter has also been presented in order to verify the correctness of the design methodology.

  • 4.
    Gong, Shaofang
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Karlsson, Magnus
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Serban, Adriana
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Östh, Joakim
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Owais, Owais
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Haartsen, Jaap
    Sony Ericsson Mobile Communications AB, Lund, Sweden.
    Karlsson, Peter
    Sony Ericsson Mobile Communications AB, Lund, Sweden.
    Radio Architecture for Parallel Processing of Extremely High Speed Data2009In: IEEE International Conference on Ultra-Wideband, ICUWB, Vancouver, Canada, 9-11 Sept., IEEE , 2009, p. 433-437Conference paper (Refereed)
    Abstract [en]

    Using our own-developed frequency multiplexing network, a radio architecture for parallel radio signal processing has been proposed for achieving extremely high data rate above 10 Gbit/s. To meet the high requirement on phase linearity, amplitude balance and low noise figure in a very large bandwidth, our own-developed ultra-wideband six-port correlator has been utilized for the modulator and demodulator in the radio architecture.

  • 5.
    Gong, Shaofang
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Karlsson, Magnus
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Serban Craciunescu, Adriana
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Design of a radio front-end module at 5 GHz2004In: 6th Circuits and System Symposium on Emerging Technologies: Frontiers of Mobile and Wireless Communication,2004, Piscataway, CA, USA: IEEE , 2004, p. 241-Conference paper (Refereed)
  • 6.
    Gong, Shaofang
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Östh, Joakim
    Serban, Adriana
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Karlsson, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Six-port Modulators for High Speed Data2016In: GigaHertz Symposium 2016, Linköping, 2016, p. 65-Conference paper (Refereed)
    Abstract [en]

    Results from our recent study on six-port modulators and demodulators for high speed data transmission have shown that the six-port radio technology has the potential to catch up the speed of the Internet. This is due to the fact that the binary baseband data, either electrical or optical, can be converted directly to high order modulated RF signal without any D/A conversion. The six-port modulators and demodulators can also be designed with differential circuitry to improve the signal-to-noise ration and dynamic range. In addition, antennae and radio front-end components can be integrated on the same substrate with the six-port modulator and demodulator.

  • 7.
    Huynh, Allan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Gong, Shaofang
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    A Comparison Between Parallel Single-Ended Microstrips and Broadside-Coupled Coplanar-Waveguides2006Report (Other academic)
  • 8.
    Huynh, Allan
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Håkansson, Pär
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Odselius, Leif
    Micronic Laser System Inc., P.O Box 3141, SE-183 03 Täby, Sweden.
    High-Speed Board-to-Board Interconnects utilizing Flexible Foils and Elastomeric Connectors2006In: HDP'06. Conference on High Density Microsystem Design and Packaging and Component Failure Analysis, IEEE , 2006, p. 157-160Conference paper (Refereed)
    Abstract [en]

    This paper presents a board-to-board interconnect technique utilizing elastomeric connectors and parallel microstrip lines on a flexible foil cable with low dielectric loss (tandelta = 0.002). It is shown that a pad structure combined with an elastomeric connector can be co-designed such that a good signal integrity and thus a high data transmission rate is achieved. It is also shown that 2 Gbps data transmission rate can be achieved with a 490-mm-long microstrip on the flexible cable, where crosstalk is taken into account. Utilizing the elastomeric connector together with the flat and flexible cable, dense parallel microstrips can easily be designed and processed since standard printed circuit board processing techniques can be utilized

  • 9.
    Huynh, Allan
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Odselius, Leif
    Micronic Laser System Inc., P.O Box 3141, Nytorpsvägen 9, SE-183 03 Täby, Sweden.
    Study of high-speed data transfer utilizing flexible and parallel transmission lines2005In: Procedings of International Microelectronics and Packaging Society Nordic,, Pelkosen Painotuote in Kiiminki, Finland , 2005, p. 230-234Conference paper (Other academic)
    Abstract [en]

    Today many systems use serial data transfer techniques like serial AT attachment (SATA), Firewire and universal serial bus (USB). However, with parallel techniques the data transfer can be raised to a much higher speed. Having wires in parallel, one must also deal with phenomena such as crosstalk. To overcome crosstalk between parallel lines one must follow some design rules to avoid interference, like optimizing spaces between transmission lines. In this work simulations on high-speed single-ended and parallel channels utilizing microstrips and striplines have been done to show parameters that limit the channel bandwidth and thus the data rate. Design and simulations have been done using the Computer Aided Design (CAD) tool, Advanced Design System (ADS) provided by Agilent Technologies Inc. It is shown that both conductor surface roughness and dielectric loss will introduce extra AC noise to the signal. When having parallel conductors the AC noise increases with decreased rise/fall time, introduced by skin effect, conductor surface roughness and dielectric loss.

  • 10.
    Huynh, Allan
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Håkansson, Pär
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Single-ended to Mixed-Mode S-Parameter Conversion for Networks with Coupled Differential Signaling2007In: 36th European Microwave Conference, Munich: EUMC , 2007, p. 238-241Conference paper (Refereed)
    Abstract [en]

    It is shown in this paper that the commonly used method for converting from standard single-ended to mixed- mode S-parameters for networks with differential signaling only works for odd- and even-mode impedance equal to 50Omega. A correct conversion matrix equation must include the odd- and even-mode impedances which are not equal to the unique characteristic impedance owing to signal coupling in the network.

  • 11.
    Huynh, Allan
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Håkansson, Pär
    Gong, Shaofang
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Odselius, Leif
    Micronic Laser System Inc., P.O Box 3141, SE-183 03 Täby, Sweden.
    High-speed parallel data transmission utilizing a flex-rigid concept2005Conference paper (Refereed)
    Abstract [en]

    Transmission lines utilizing microstrips on a flex-foil with low dielectric loss (tanδ = 0.002) have been simulated to compare with the transmission lines laminated with a rigid part, a so-called flex-rigid structure. At high speeds, even solders, pads and connectors affect the signal integrity because of their parasitic effects. The flex-rigid structure does not require these extra parts, resulting in good signal integrity and thus high data transfer rates. Another advantage with a flexible cable is that dense parallel microstrips can easily be designed. Although many wired data communications utilize serial techniques like Serial AT Attachment (SATA), Universal Serial Bus (USB) and Firewire, the serial data link has its limitations when very high data speeds are required. With a parallel data transmission technique, the data transfer rate can be raised to a very high speed. However, a parallel data transmission technique has some disadvantages such as crosstalk and skew between the signals which must be considered.

  • 12.
    Huynh, Allan
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Karlsson, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Mixed-Mode S-Parameters and Conversion Techniques2010In: Advanced Microwave Circuits and Systems / [ed] Vitaliy Zhurbenko, INTECH , 2010, p. 1-12Chapter in book (Other academic)
    Abstract [en]

    This book is based on recent research work conducted by the authors dealing with the design and development of active and passive microwave components, integrated circuits and systems. It is divided into seven parts. In the first part comprising the first two chapters, alternative concepts and equations for multiport network analysis and characterization are provided. A thru-only de-embedding technique for accurate on-wafer characterization is introduced. The second part of the book corresponds to the analysis and design of ultra-wideband low- noise amplifiers (LNA).

  • 13.
    Huynh, Allan
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Zhang, Jingcheng
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Ye, Qin-Zhong
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Wireless Remote Monitoring System for Cultural Heritage2010In: Sensors & Transducers Journal, ISSN 1726-5479, Vol. 118, no 7, p. 1-12Article in journal (Refereed)
    Abstract [en]

    Existing systems to collect temperature and relative humidity data at cultural heritage buildings require technical knowledge by people who are working with it, which is very seldom that they do have. The systems available today also require manual downloading of the collected data from the sensor to a computer for central storage and for further analysis. In this paper a wireless remote sensor network based on the ZigBee technology together with a simplified data collection system is presented. The system does not require any knowledge by the building administrator after the network is deployed. The wireless sensor device will automatically join available network when the user wants to expand the network. The collected data will be automatically and periodically synchronized to a remote main server via an Internet connection. The data can be used for centralized monitoring and other purpose. The power consumption of the sensor module is also minimized and the battery lifetime is estimated up to 10 years.

  • 14.
    Huynh, Allan
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Zhang, Jingcheng
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Ye, Qin-Zhong
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    ZigBee Radio with External Low-Noise Amplifier2010In: Sensors & Transducers Journal, ISSN 1726-5479, Vol. 114, no 3, p. 184-191Article in journal (Refereed)
    Abstract [en]

    This article presents the performance study of a ZigBee module with an external low-noiseamplifier, measured in both outdoor and indoor environments. Our previous study has already shownthat the indoor campus environment such as walls and floors would reduce the radio link rangedrastically and the packet error rate increased. In this study, an external low-noise amplifier has beenadded to a ZigBee module to increase the receiver sensitivity. It is shown that with an external lownoiseamplifier the outdoor radio range can reach up to 403 m with a negligible packet error ratecompared to 144 m without the low-noise amplifier for point-to-point connection. Thus, by increasingthe receiver sensitivity the radio range can be increased without increasing of the radio power outputso that the power consumption can still be kept low to obtain long battery lifetime.

  • 15.
    Huynh, Allan
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Zhang, Jingcheng
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Ye, Qin-Zhong
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    ZigBee Radio with External Power Amplifier and Low-Noise Amplifier2010In: Sensors & Transducers Journal, ISSN 1726-5479, Vol. 118, no 7, p. 110-121Article in journal (Refereed)
    Abstract [en]

    This paper presents the performance study of a ZigBee module with both an external power amplifier and a low-noise amplifier, measured in outdoor and indoor environments, respectively. Our previous study has already shown that the indoor campus environment such as walls and floors would reduce the radio link range drastically and the packet error rate increased. In this study, both an external power amplifier and a low-noise amplifier have been added to a ZigBee module to increase both the transmitter power and receiver sensitivity. It is shown that with an external power amplifier and a low-noise amplifier the outdoor radio range can reach up to 1600 m with a negligible packet error rate compared to 144 m without any external amplifier for point-to-point radio connection. Thus, by increasing both the transmitter power and receiver sensitivity the radio range can be increased significantly. The power consumption issue with the added amplifiers is studied as well, indicating that the module can still be battery driven with a battery lifetime of about 9 years at a normal sampling rate to the sensor.

  • 16.
    Håkansson, Pär
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Ultra-Wideband Six-port Transmitter and Receiver Pair 3.1-4.8 GHz2008In: Proceedings of 2008 Asia Pacific Microwave Conference: Vol. 1-5, Piscataway, NJ, USA: IEEE , 2008, p. 1858-1861Conference paper (Refereed)
    Abstract [en]

    This paper presents an ultra-wideband transmitter and receiver pair covering the frequency band of 3.1-4.8 GHz, based on the six-port technique. This six-port circuit utilizes three ultra-wideband 3-dB 90 degrees branch couplers and one 3-dB 0 degrees Wilkinson power divider. It is manufactured utilizing microstrips on a printed circuit board. The measurement shows that the transmitter and receiver are able to demodulate and modulate QPSK signals in the frequency range 3.1 to 4.8 GHz.

  • 17.
    Håkansson, Pär
    et al.
    Linköping University, Department of Science and Technology.
    Huynh, Allan
    Linköping University, Department of Science and Technology.
    Gong, Shaofang
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    A new concept of wireless data transmission of extremely high data rate over 10 Gbps2005Report (Other academic)
  • 18.
    Håkansson, Pär
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Huynh, Allan
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Gong, Shaofang
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    A Study of Wireless Parallel Data Transmission of Extremely High Data Rate up to 6.17 Gbps per Channel2006In: Asia Pacific Microwave Conference,2006, Tokyo: Institute of Electronics, Information and Communication Engineers , 2006, p. 975-Conference paper (Refereed)
  • 19.
    Håkansson, Pär
    et al.
    Linköping University, Department of Science and Technology.
    Huynh, Allan
    Linköping University, Department of Science and Technology.
    Gong, Shaofang
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Wireless data transmission2005Patent (Other (popular science, discussion, etc.))
  • 20. Jakobsson, Anders
    et al.
    Grewing, Christian
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Serban, Adriana
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Dual Loop Gain Calibration of Frequency Synthesizer2013Conference paper (Refereed)
  • 21.
    Jakobsson, Anders
    et al.
    Huawei Technologies Sweden, Kista, Sweden .
    Grewing, Christian
    Huawei Technologies Sweden, Kista, Sweden .
    Serban, Adriana
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Frequency Synthesizer With Dual Loop Frequency and Gain Calibration2013In: IEEE Transactions on Circuits and Systems Part 1: Regular Papers, ISSN 1549-8328, E-ISSN 1558-0806, Vol. 60, no 11, p. 2911-2919Article in journal (Refereed)
    Abstract [en]

    A 3600-MHz phase-locked loop based frequency synthesizer for UMTS applications has been developed in 0.18 $mu$ m CMOS. It incorporates a VCO frequency and loop-gain calibration technique that allows an integrated VCO frequency tuning range of 28% and a low VCO gain ($K_{rm VCO}$ of 30 MHz/V. The loop-gain calibration can compensate for not only variations in VCO gain and divider modulus, but also charge-pump current and loop filter capacitance to an accuracy of 5%. The PLL settles in 150 $mu$s including frequency and gain calibrations. No switches are used in the loop filter. The output phase noise at 1-MHz offset is ${-}123$ dBc/Hz and the integrated phase error (1 kHz–2 MHz) is 1.26 $^{circ}$.

  • 22.
    Jakobsson, Anders
    et al.
    Huawei Technologies Sweden AB, Kista, Sweden.
    Serban, Adriana
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    A Low Noise RC-based Phase Interpolator in 16-nm CMOS2019In: IEEE Transactions on Circuits and Systems - II - Express Briefs, ISSN 1549-7747, E-ISSN 1558-3791, Vol. 66, no 1Article in journal (Refereed)
    Abstract [en]

    This paper describes a passive analog phase interpolator, utilizing a switched RC-network. The proposed circuit eliminates the current sources in a phase interpolator based on constant-slope charging. By eliminating the current source, the noise is significantly reduced due to the reduction in thermal and flicker noise. The phase interpolator has a resolution of 6 bits and is implemented in a 16-nm CMOS process. The maximum differential non-linearity is measured to be 0.1 LSBs at a 192 ps input time delta. The circuit draws 0.2 mW from a 0.8 V supply, and occupies 0.004 mm2.

  • 23.
    Jakobsson, Anders
    et al.
    Huawei Technol Sweden AB, S-16494 Kista, Sweden.
    Serban, Adriana
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Implementation of Quantized-State System Models for a PLL Loop Filter Using Verilog-AMS2015In: IEEE Transactions on Circuits and Systems Part 1: Regular Papers, ISSN 1549-8328, E-ISSN 1558-0806, Vol. 62, no 3, p. 680-688Article in journal (Refereed)
    Abstract [en]

    A method to implement quantized-state system (QSS) models in industry standard RF-IC design tools is proposed. The method is used to model a GHz-range 0.18 um CMOS phase-locked loop (PLL), and enables a truly event-driven simulation of the entire mixed-signal PLL circuit. First- and second-order (QSS and QSS2, respectively) models of the PLL loop-filter implemented in Verilog-AMS are first described in detail. These models do not rely on analog nets, and use only the event-based solver. Then, simulation results are compared to reference SPICE simulation results to prove the validity of the QSS method. The entire PLL circuit is finally simulated using the QSS model of the loop-filter, charge-pump and VCO, in conjunction with standard high-level models of the PLL digital circuits. To verify the proposed QSS method, measured phase noise is compared with simulated phase noise. It is shown that simulated phase noise accurately predicts the measured phase noise with improved accuracy, and an increase in simulation efficiency by more than 50 times. Measured and simulated results generally demonstrate the feasibility of the QSS modeling for mixed-signal circuit simulation and design.

  • 24.
    Karlsson, Magnus
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Air core patch antennas suitable for multi-band UWB2005In: Proc. GigaHertz 2005, Uppsala, Sweden, 2005, p. 218-221Conference paper (Refereed)
    Abstract [en]

    As wireless communication applications grow rapidly, the demand for modular solutions with high performance and low profile antennas increases. For instance, the ultra wideband radio (UWB) utilizes the frequency band of 3.1-10.6 GHz. Integrateable antennas should be of planar structures. A Planar structure limits design options, regarding various performance aspects. For instance, the spectral efficiency, i.e., the bandwidth (BW) relative to the center frequency (CF) is limited. The antenna efficiency, i.e., gain relative to directivity is also limited. The antenna efficiency is important for receiver sensitivity, which is important in UWB systems. The efficiency is dependant of the antenna structure and material used. The Rogers 4350B material is suitable for high frequency modules since it has a low loss tangent that is stable over a wide frequency range, but the substrate height is limited. In this study a printed circuit board (PCB) with an air core was introduced to increase the antenna efficiency. The module is processed as two separate double-layer PCBs. This technique can be implemented to increase the performance in a narrowband as well as in a wideband antenna system. An advantage is that components can be placed on the other side of the ground plane without interference since the ground plane shields components from antenna radiation. A study of how the antenna bandwidth and efficiency are improved with the proposed structure at 3.5 and 10 GHz was conducted and presented.

  • 25.
    Karlsson, Magnus
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    A Frequency-Triplexed Inverted-F Antenna System for Ultra-wide Multi-band Systems 3.1-4.8 GHz2007In: ISAST Transactions on Electronics and Signal Processing, ISSN 1797-2329, Vol. 1, no 1, p. 95-100Article in journal (Refereed)
    Abstract [en]

    A fully integrated triplex antenna system for multibandUWB 3.1-4.8 GHz is presented. The system utilizes amicrostrip network and three combined broadside- and edgecoupledfilters to connect three inverted-F antennas in parallel.The triplexd antenna system is fully integrated in a printedcircuit board with low requirements on the printed circuit boardprocess tolerance. The group delay variation within the triplexerwas measured to be less than 1 ns. Furthermore, a goodagreement between simulation and measurement results wasobserved.

  • 26.
    Karlsson, Magnus
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    An integrated spiral antenna system for UWB2005In: Proc. IEEE 35th European Microwave Conference, 4-6 October, Paris, France, 2005, p. 2007-2010Conference paper (Refereed)
    Abstract [en]

    As wireless communication applications require more and more bandwidth, the demand for wideband antennas increases as well. For instance, the ultra wideband radio (UWB) utilizes the frequency band of 3.1-10.6 GHz. The spiral antenna has a higher spectral efficiency than other planar antennas like the patch antenna. Theoretically, any type of antennas can be combined into different kind of arrays, in order to improve performance beyond that from one single antenna. The electrically coupled parallelism is one solution to extend bandwidth. By combining two spiral antennas with different radius of the radiation zone, the standing wave ratio (SWR) can be kept low for a large bandwidth, resulting in an improved spiral antenna performance for UWB. Furthermore, a study of how spiral dimensions impact on gain and SWR was conducted and presented.

  • 27.
    Karlsson, Magnus
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Circular Dipole Antenna for Mode 1 UWB Radio With Integrated Balun Utilizing a Flex-Rigid Structure2009In: IEEE Transactions on Antennas and Propagation, ISSN 0018-926X, E-ISSN 1558-2221, Vol. 57, no 10, p. 2967-2971Article in journal (Refereed)
    Abstract [en]

    Abstract—Afully integrated dipole antenna with balun for ultra-wideband (UWB) radio utilizing a flexible and rigid printed circuit board is presented in this paper. The concept in this paper is to take advantage of the respective possibilities of the rigid and flex-ible parts. The balun utilizes broadside-coupled microstrips and is integrated in the rigid part of the printed circuit board, whereas the radiator is placed in the flexible part. The antenna with thebalun covers the mode 1 UWB frequency-band 3.1–4.8 GHz (with margin) at voltage standing wave ratio (VSWR) < 2. Further-more, good radiation characteristics and a linear phase responseare observed with measurements.

  • 28.
    Karlsson, Magnus
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Gong, Shaofang
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Circular Monopole and Dipole Antennas for UWB Radio Utilizing a Flex-rigid Structure2008In: GHz 2008,2008, 2008, p. 75-75Conference paper (Other academic)
    Abstract [en]

      

  • 29.
    Karlsson, Magnus
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Mono- and Di-pole Antennas for UWB Utilizing Flex-rigid Technology2007In: ISAST Transactions on Electronics and Signal Processing, ISSN 1797-2329, Vol. 2, no 1, p. 59-63Article in journal (Refereed)
    Abstract [en]

    Fully integrated monopole and dipole antennas forultra-wideband (UWB) radio utilizing flexible and rigid printedcircuit boards are presented in this paper. A circular monopoleantenna for the entire UWB frequency band 3.1-10.6 GHz ispresented. A circular dipole antenna with an integrated balun forthe frequency band 3.1-4.8 GHz is also presented. The balunutilizes broadside-coupled microstrips, integrated in the rigidpart of the printed circuit board. Furthermore, anomnidirectional radiation pattern and high radiation efficiencyare predicted by simulations.

  • 30.
    Karlsson, Magnus
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Monofilar spiral antennas for UWB with and without air core2007In: ISAST Transactions on Electronics and Signal Processing, ISSN 1797-2329, Vol. 2, no 1, p. 64-70Article in journal (Refereed)
    Abstract [en]

    One of the trends in wireless communicationis that systems require more and more frequency spectrum.Consequently, the demand for wideband antennas increasesas well. For instance, the ultra wideband radio (UWB)utilizes the frequency band of 3.1-10.6 GHz. Such abandwidth is more than what is normally utilized with asingle low-profile antenna. Low profile antennas arepopular because they are integratable on a printed circuitboard. However, the fractional bandwidth is usually anissue for low profile antennas because of the limitedsubstrate height. The monofilar spiral antenna on the otherhand has higher fractional bandwidth, and at GHzfrequencies the physical dimensions of the spiral isreasonable. Furthermore, a study of how spiral dimensionsimpact on antenna gain and standing wave ratio (SWR) wasconducted and presented. Simulated results were comparedwith measurements.

  • 31.
    Karlsson, Magnus
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Wideband patch antenna array for multi-band UWB2004In: Proc. IEEE 11th Symp. on Communications and Vehicular Tech., Ghent, Belgium, November, 2004Conference paper (Refereed)
    Abstract [en]

    As wireless communication applications require more and more bandwidth, the demand for wideband antennas increases as well. For instance, ultra wideband radio (UWB) will utilize the frequency-band of 3.1-10.6 GHz. Microstrip patch antennas have advantages of low cost and compatibility to the printed circuit board (PCB) technology, having the possibility to integrate the antenna with the circuit board. Since patch antennas have ground planes, components can be placed on the other side of the PCB, this allows a compact module design. However, the microstrip patch antenna has drawback of small bandwidth. Bandwidth is limited since the substrate height is limited. To overcome these drawbacks, we have studied a method to use a patch array with varied patch lengths on a low loss PCB. Patches electrically far away from each other will give independent resonances. By choosing several patch lengths so that the standing wave ratio (SWR) plots of the antennas overlap, they can be combined into one wideband with a power-divider. Several arrays can be combined to a multi-band antenna system using switches. A patch antenna array for the multiband UWB in the frequency band of 3.1-10.6 GHz is presented in this paper.

  • 32.
    Karlsson, Magnus
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Huynh, Allan
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Parallel channels using frequency multiplexing techniques2010In: Ultra Wideband / [ed] Boris Lembrikov, SCIYO , 2010, p. 35-54Chapter in book (Other academic)
    Abstract [en]

    Ultra wideband technology is one of the most promising directions in the rapidly developing modern communications. Ultra wideband communication system applications include radars, wireless personal area networks, sensor networks, imaging systems and high precision positioning systems. Ultra wideband transmission is characterized by high data rate, availability of low-cost transceivers, low transmit power and low interference. The proposed book consisting of 19 chapters presents both the state-of-the-art and the latest achievements in ultra wideband communication system performance, design and components. The book is addressed to engineers and researchers who are interested in the wide range of topics related to ultra wideband communications.

  • 33.
    Karlsson, Magnus
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Håkansson, Pär
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    A Frequency Triplexer for Ultra-wideband Systems Utilizing Combined Broadside- and Edge-coupled Filters2008In: IEEE Transactions on Advanced Packaging, ISSN 1521-3323, E-ISSN 1557-9980, Vol. 31, no 4, p. 794-801Article in journal (Refereed)
    Abstract [en]

    A fully integrated triplexer for multiband ultra-wideband radio is presented. The triplexer utilizes a microstrip network and three combined broadside- and edge-coupled filters. It is fully integrated in a printed circuit board with low requirements on the printed circuit board process tolerance. Three flat subbands in the frequency band 3.1-4.8 GHz have been achieved. The group delay variation within each 500-MHz subband was measured to be around 1 ns. A good agreement between simulation and measurement was obtained.

  • 34.
    Karlsson, Magnus
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Håkansson, Pär
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Huynh, Allan
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Frequency-multiplexed Inverted-F Antennas for Multi-band UWB2006In: IEEE Annual Wireless and Microwave Technology Conference WAMICON '06, 2006, p. FF-2-1--FF-2-3Conference paper (Refereed)
    Abstract [en]

    An invented frequency multiplexing technique is used to combine inverted-F antennas for multi-band UWB. The frequency multiplexing technique allows a number of independent antennas to be used in parallel. In this paper a radio front-end system consisting of three antennas and a frequency multiplexing network is built. Using one antenna for each sub-band within a band-group provides equal performance for the entire band. Both the antennas and the frequency multiplexing network can be integrated on a printed circuit board. The antennas were simulated and measured. S-parameters of the antennas were extracted and used for co-simulation with the frequency multiplexing network. The antenna system fulfills the requirement for Mode 1 UWB.

  • 35.
    Karlsson, Magnus
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Owais, Owais
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Östh, Joakim
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Serban, Adriana
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Physics and Electronics.
    Jobs, Magnus
    Uppsala University.
    Gruden, Mathias
    Uppsala University.
    Dipole Antenna With Integrated Balun For Ultra-wideband Radio 6-9 GHz2011In: Microwave and optical technology letters (Print), ISSN 0895-2477, E-ISSN 1098-2760, Vol. 53, no 1, p. 180-184Article in journal (Refereed)
    Abstract [en]

    A fully integrated dipole antenna with a balun fot ulna wideband (UWB) radio in the band 6-9 GHz utilizing a flexible and rigid printed count board is presented in this at tide The balun utilizes broadside coupled microstrips and is integrated in the rigid part of the printed coma boat d whereas the radiator is placed in the flexible pat! The antenna with the balun covets the frequency band 6 0-8 5 GHz at voltage standing mate ratio (VSWR) andlt;2 0 and 55-110 GHz at VSWR andlt; 2 5 Moreover simulated and measured radiation patterns and antenna efficiency above 860% are observed

  • 36.
    Karlsson, Magnus
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Serban, Adriana
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Östh, Joakim
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Owais, Owais
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Frequency Triplexer for Ultra-Wideband Systems (6–9 GHz)2013In: IEEE Transactions on Circuits and Systems Part 1: Regular Papers, ISSN 1549-8328, E-ISSN 1558-0806, Vol. 60, no 3, p. 540-547Article in journal (Refereed)
    Abstract [en]

    A triplexer for ultra-wideband radio implemented entirely with distributed microstrips is presented. The triplexer is composed of a triplex junction network and three bandpass filters. The circuit is integrated in a flex-rigid printed circuit board. Three flat 1 GHz sub-bands in the frequency band 6-9 GHz have been achieved. The group delay variation within each 1 GHz sub-band was measured to be less than 0.4 ns. A good agreement between simulation and measurement was obtained, e.g., less than 0.3 dB difference in the forward transmission in the majority of the frequency band.

  • 37.
    Karlsson, Magnus
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Östh, Joakim
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Serban, Adriana
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Circular Dipole Antennas for Lower and Upper UWB Bands with Integrated Balun2009In: 2009 IEEEInternational Conference on Ultra-Wideband: Proceedings, 9th to 11th September 2009, Vancouver, BC, Canada, Vancover: IEEE , 2009, p. 658-663Conference paper (Refereed)
    Abstract [en]

    Abstract—Two fully integrated dipole antennas with balun for ultra-wideband (UWB) radio utilizing a flexible and rigid printed circuit board are presented in this paper. The concept in this paper is to take advantage of the respective possibilities of the rigid and the flexible part. The balun utilizes broadside-coupled microstrips and is integrated in the rigid part of the printed circuit board, while the radiator is placed in the flexible part. The lower UWB band antenna with the balun covers the frequency-band 3.1-4.8 GHz (with margin) at VSWR<2.0. The upper UWB band antenna with the balun covers the frequency-band 6.0-8.5 GHz (with margin) at VSWR<2.0, and 5.5-11.0 GHz at VSWR<2.5.

  • 38.
    Liu, Yu
    et al.
    Linköping University, Department of Science and Technology, Physics, Electronics and Mathematics. Linköping University, Faculty of Science & Engineering.
    Hassan, Kahin Akram
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering.
    Karlsson, Magnus
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Science and Technology, Physics, Electronics and Mathematics.
    Pang, Zhibo
    Corporate Research, ABB AB, Västerås, Sweden.
    Gong, Shaofang
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Science and Technology, Physics, Electronics and Mathematics.
    A Data-Centric Internet of Things Framework Based on Azure Cloud2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 53839-53858Article in journal (Refereed)
    Abstract [en]

    Internet of Things (IoT) has been found pervasive use cases and become a driving force to constitute a digital society. The ultimate goal of IoT is data and the intelligence generated from data. With the progress in public cloud computing technologies, more and more data can be stored, processed and analyzed in cloud to release the power of IoT. However, due to the heterogeneity of hardware and communication protocols in the IoT world, the interoperability and compatibility among different link layer protocols, sub-systems, and back-end services have become a significant challenge to IoT practices. This challenge cannot be addressed by public cloud suppliers since their efforts are mainly put into software and platform services but can hardly be extended to end devices. In this paper, we propose a data-centric IoT framework that incorporates three promising protocols with fundamental security schemes, i.e., WiFi, Thread, and LoRaWAN, to cater to massive IoT and broadband IoT use cases in local, personal, and wide area networks. By taking advantages of the Azure cloud infrastructure, the framework features a unified device management model and data model to conquer the interoperability challenge. We also provide implementation and a case study to validate the framework for practical applications.

  • 39.
    LiU, Yu
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Hassan, Kahin Akram
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering.
    Karlsson, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Weister, Ola
    Vertical Plants System Sweden AB, Norrrköping, Sweden.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Active Plant Wall for Green Indoor Climate Based on Cloud and Internet of Things2018In: IEEE Access, E-ISSN 2169-3536Article in journal (Refereed)
    Abstract [en]

    An indoor climate is closely related to human health, well-being and comfort. Thus, indoor climate monitoring and management are prevalent in many places, from public offices to residential houses. Our previous research has shown that an active plant wall system can effectively reduce the concentrations of particulate matter and volatile organic compounds and stabilize the carbon dioxide concentration in an indoor environment. However, regular plant care is restricted by geography and can be costly in terms of time and money, which poses a significant challenge to the widespread deployment of plant walls. In this article, we propose a remote monitoring and control system that is specific to the plant walls. The system utilizes the Internet of Things technology and the Azure public cloud platform to automate the management procedure, improve the scalability, enhance user experiences of plant walls, and contribute to a green indoor climate.

  • 40.
    Lönn, Johan
    et al.
    Linköping University, Department of Science and Technology.
    Olsson, Jonas
    Linköping University, Department of Science and Technology.
    Gong, Shaofang
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    ZigBee-ready modules for sensor networking2005In: REALWSN 2005,2005, Proceedings of the 1st workshop on real-world wireless sensor networks: REALWSN 2005 , 2005, p. 6.3-Conference paper (Refereed)
  • 41. Mahmood, Faraz
    et al.
    Kazim, Jalil-ur-Rehman
    Karlsson, Magnus
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Science and Technology, Physics, Electronics and Mathematics.
    Gong, Shaofang
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Science and Technology, Physics, Electronics and Mathematics.
    Ying, Zhinong
    Decoupling techniques of compact and broadband MIMO antennas for handheld devices2012In: IEEE 6th European Conference on Antennas and propagation (EuCAP 2012), 2012, p. 1-5, article id 1569525515Conference paper (Refereed)
    Abstract [en]

    This paper presents an innovative MIMO antenna system consisting of two broadband antennas combined with a 90° or 180° hybrid coupler. The antenna system is suitable for future MIMO systems due to its wide decoupled bandwidth (from 698 to 2700 MHz) covering 23 frequency bands of LTE. Enhanced antenna performance is achieved by radiator slitting and ground plane modification. Moreover, supplemental meandered line ground structures are utilized to miniaturize the antenna size. The low profile antenna with its wide impedance bandwidth, high efficiency, low correlation and quasi-omni directional radiation pattern is attractive for the existing and future 4G mobile communication devices. Simulated and measured results including input reflection, mutual coupling, correlation, and antenna efficiency is presented and analyzed.

  • 42.
    Mohsin, Imran
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Karlsson, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Frequency diplexer network for wireless parallel data transmission and ultrawideband systems utilizing manifold technique2014In: Microwave and optical technology letters (Print), ISSN 0895-2477, E-ISSN 1098-2760, Vol. 56, no 8, p. 1869-1871Article in journal (Refereed)
    Abstract [en]

    A frequency diplexer network for ultrawideband radios focused on wireless parallel data transmission is presented. It has a combination of two bandpass filters utilizing manifold multiplexing technique. In the frequency band 6-9 GHz, two flat sub-bands at center frequencies 6.7 and 8.3 GHz have been achieved with respect to forward transmission, input reflection, and group delay. A maximum group delay variation of 0.6 ns was measured in the sub-bands. For low cost and simple circuit implementation, the design is implemented using the microstrip technology.

  • 43.
    Mohsin, Imran
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Karlsson, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Owais, Owais
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Design and implementation of a UWB six-port correlator for 6-9 GHz frequency band2013In: Microwave and optical technology letters (Print), ISSN 0895-2477, E-ISSN 1098-2760, Vol. 55, no 1, p. 190-193Article in journal (Refereed)
    Abstract [en]

    A compact size six-port correlator using bandwidth enhancing stubs for the 69 GHz ultra wideband radio is presented. The proposed six-port has a center frequency of 7.5 GHz with 50% relative bandwidth. The correlator is based entirely on microstrip technology for low cost and simple circuit implementation.

  • 44.
    Nour, Eiman
    et al.
    Linköping University, Department of Science and Technology. Linköping University, Faculty of Science & Engineering.
    Bondarevs, Andrejs
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Huss, Patrik
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Sandberg, Mats
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering. Acreo AB, Sweden.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Willander, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Nour, Omer
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Low-Frequency Self-Powered Footstep Sensor Based on ZnO Nanowires on Paper Substrate2016In: Nanoscale Research Letters, ISSN 1931-7573, E-ISSN 1556-276X, Vol. 11, no 156Article in journal (Refereed)
    Abstract [en]

    In this work, we design and fabricate a wireless system with the main operating device based on zinc oxide (ZnO) nanowires. The main operating device is based on piezoelectric nanogenerator (NG) achieved using ZnO nanowires grown hydrothermally on paper substrate. The fabricated NG is capable of harvesting ambient mechanical energy from various kinds of human motion, e.g., footsteps. The harvested electric output has been used to serve as a self-powered pressure sensor. Without any storage device, the signal from a single footstep has successfully triggered a wireless sensor node circuit. This study demonstrates the feasibility of using ZnO nanowire piezoelectric NG as a low-frequency self-powered sensor, with potential applications in wireless sensor networks.

  • 45.
    Owais, Owais
    et al.
    Linköping University, Department of Science and Technology.
    Karlsson, Magnus
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Science and Technology, Physics, Electronics and Mathematics.
    Gong, Shaofang
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Science and Technology, Physics, Electronics and Mathematics.
    Circular Monopole Antenna Stability with Regard to Ground Plane Size2008In: Proc. of the 2008 International Symposium on Antenna and Propagation (ISAP'08), Taiwan, Oct. 27-30, 2008., 2008, p. 1-4, article id 1645003Conference paper (Refereed)
    Abstract [en]

    Wireless communications for short range and high data rate require wideband operation that necessitates the demand for miniaturized, low cost and low profile antennas. Miniaturized planar monopole antennas provide wide impedance bandwidth for wireless personal area network applications [1]. Different monopole shapes have been considered and a lot of research has been made to improve the bandwidth and reduce the size by changing the antenna shape [2]-[4]. The radiator part has been the main focus of research to find a shape that provides wide bandwidth [3]-[4], as well on studying how the ground plane affects the bandwidth of antennas. Wide bandwidth has been obtained by bevelling the radiator [5] and use of a modified ground plane [6]. Planar monopoles with parasitic elements and slots give also a wideband [7]. It has been documented that the finite size of the ground plane is an important factor for the antenna performance [8]. Planar monopoles have a benefit of being low cost and compatible to printed circuit board (PCB) allowing compact design. Since the ground plane is coplanar with the antenna, it necessitates that its stability should not change when integrated in PCB with different ground plane size of adjoining circuits. To avoid pre-tuning and achieve cost effectiveness, system development requires a stable planar monopole antenna that can be integrated without depreciation of its performance. This paper studies in detail the effect of ground plane dimension, width and length, on the stability of the coplanar monopole antenna, by changing the ground plane size while keeping feedline and feedap constant. The parametric investigation supported by simulation and experimental results is conducted in this paper to give insights to the stability issue that have not been reported before.

  • 46.
    Owais, Owais
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Karlsson, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Ying, Zhinong
    Sony Ericsson Mobile Commun AB.
    Gruden, Mathias
    Sony Ericsson Mobile Commun AB.
    Job, Magnus
    Uppsala University.
    Wideband Planar Antenna with Modified Ground Plane2010In: Microwave and optical technology letters (Print), ISSN 0895-2477, E-ISSN 1098-2760, Vol. 52, no 11, p. 2581-2585Article in journal (Refereed)
    Abstract [en]

    In this article a miniaturized planar antenna is presented for broadband applications. Antenna miniaturization is achieved by modifying the ground plane that creates a different current path thus increasing the effective dimension of the antenna. In addition, dual chopping, slitting, and radiator position offsetting provide wideband behavior and relatively good impedance matching. The low profile antenna with its wide bandwidth, linear phase response and quasi-omnidirectional radiation pattern is attractive for the existing and future communication devices of small size. Simulated and measured results for the proposed antenna are presented and analyzed.

  • 47.
    Owais, Owais
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Östh, Joakim
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Differential Six-Port Demodulator2011In: Proceedings on International Conference on Wireless Communications and Signal Processing, 2011Conference paper (Other academic)
    Abstract [en]

    A differential six-port demodulator for the 7-8 GHz band is reported for the first time. It is composed of a differential six-port correlator on the two sides of the substrate and zero-bias antiparallel Schottky diodes acting as power detectors. It is theoretically analyzed and also simulated. A prototype has been fabricated and data transmission at 0.8 Gbit/s (but not the maximum) with the 16 quadrature amplitude modulation (QAM) is experimentally demonstrated.

  • 48.
    Owais, Owais
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Östh, Joakim
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Serban, Adriana
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Karlsson, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Differential Six-Port Demodulator2011In: Microwave and optical technology letters (Print), ISSN 0895-2477, E-ISSN 1098-2760, Vol. 53, no 9, p. 2192-2197Article in journal (Refereed)
    Abstract [en]

    A differential six-port demodulator for the 7-8 GHz band is reported for the first time. It is composed of a differential six-port correlator on the two sides of the substrate and zero-bias antiparallel Schottky diodes acting as power detectors. It is theoretically analyzed and also simulated. A prototype has been fabricated and data transmission at 0.8 Gbit/s (but not the maximum) with the 16 quadrature amplitude modulation (QAM) is experimentally demonstrated.

  • 49.
    Owais, Owais
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Östh, Joakim
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Serban, Adriana
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Karlsson, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Differential Six-Port TransceiverManuscript (preprint) (Other academic)
    Abstract [en]

    A differential six-port transceiver for the 7-8 GHz band is presented for the rst time. It is fabricated using double-sided parallel-strip lines. The transmitter is composed of a differential six-port correlator with a quarter wavelength arrangement for carrier suppression. Cold-mode field effect transistors are used as impedance terminations, controlled via baseband signals on the gate to source terminal. The receiver is comprised of a differential six-port correlator and diode detectors. The diodes on the front-side and the back-side are connected in antiparallel, resulting in a differential input and differential output six-port receiver. The main features of the transceiver are low complexity, low power consumption, and high data rate. Data transmission and reception with the transceiver is demonstrated with quadrature phase shift keying (QPSK) and 16-quadrature amplitude modulation (16-QAM) with 100 and 200 M symbol / s , respectively.

  • 50.
    Pettersson, Anders
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Nordlander, Johan
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    ZigBee-Ready Wireless Water Leak Detector2009In: Third International Conference on Sensor Technologies and Applications, 2009. SENSORCOMM '09., Piscataway, NJ, USA: IEEE , 2009, p. 105-108Conference paper (Refereed)
    Abstract [en]

    To prevent water leak from causing damage, the use of centralized alarming system consisting of several water leak detectors can be placed in targeted areas. However, the installation costs for these types of alarming systems are high, especially in already finished buildings since they require a lot of wiring for handling of the alarming system. To solve this problem water leak detectors that use the ZigBee technology to communicate with a control center have been studied and developed in this work. Thanks to the wireless connection, the sensor is easy to place in any area where water leak detection is desired. The wireless water detector system in the ZigBee network has a very high reliability and a long battery lifetime of 10 years.

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