21 research outputs found

    Iot Camera System For Monitoring Strawberry Fields

    Get PDF
    A wireless imaging system for monitoring strawberry fields provides enough quality image data for computer vision algorithms to make meaningful yield predictions. This report contains a design for a wireless sensor network modified with mesh networking techniques to extend coverage range and a solar energy harvesting system to improve sensor node lifetime. A two hop system with six nodes is implemented in a laboratory environment validating the communication systems integrity over an 800’ range. Moving from a primary battery system to solar energy harvesting increases the module lifetime indefinitely

    Hybrid Power Divider and Combiner for Passive RFID Tag Wireless Energy Harvesting

    Get PDF
    This paper presents three- and five-ports radio frequency (R.F) hybrid power divider combiner (HPDC) designs with multiband characteristics operating at 2.4 GHz (ISM, IEEE 802.11b,g); 5.8 GHz (IEEE 802.11n, a and 802.11ac); and 6 GHz (IEEE 802.11ax) wireless standards for energy-efficient 5G-enabled passive Internet of Things (IoTs) sensors; energy harvesting (E.H); passive radio frequency identification (RFID) tags; multiple-input multiple-output (MIMO) antenna beamforming; and data communication applications spanning D.C to the 6-GHz frequency range. The presented HPDC designs operate at a centre-design frequency of 3 GHz on a Rogers RO4350 substrate. The designed novel HPDC demonstrates a good match between the ports, high isolation between the output ports, and equal power distribution between the output ports. Furthermore, the obtained return and isolation losses are less than -10 dB for the Wi-Fi 6E standards. The reported findings hold an excellent promise for R.F energy harvesting and utilisation, adaptive intelligent energy-efficient data communication, and seamless, ubiquitous satellite-cellular convergence connectivity applications

    Spectrum avaílability assessment tool for TV white space

    Get PDF
    The growth of wireless communication relies on the availability of radio frequency for new services. More efficient spectrum allocations are required to serve the increasing data per user. The major regulatory bodies are formulating new spectrum management techniques to forge the growing spectrum scarcity. Exclusive use of spectrum is proved to be inefficient in many spectrum occupancy measurement campaigns. As a result, spectrum sharing methods are being considered. TV broadcasting is not using the allocated frequency in some geographic areas, creating coverage holes known as TV white spaces. Both the industry and the regulators are investigating the capability of TVWS, as a potential source of spectrum for emerging wireless services. The FCC, in the US, has already released the requirements for opportunistic access to the TV whites paces. In a similar fashion, ECC, the pan-European regulator is finalizing the work on the technical and operational requirements for the possible use of cognitive radio in this spectrum. In this thesis work, an integrated web-based spectrum availability assessment tool is developed for Finland. The tool is a front-end visualization of a time intensive computational process to answer key technical questions related to TVWS - what secondary data rate can be supported in the available white space spectrum? The assessment involves estimation of the available TVWS and its capacity for cellular-type secondary systems. The relative effects of the secondary system parameters on the TV system are compared using appropriate signal to noise and interference ratio plots. The tool uses dynamic web technologies for a seamless and user-friendly visualization of the assessment

    Dynamically Controllable Integrated Radiation and Self-Correcting Power Generation in mm-Wave Circuits and Systems

    Get PDF
    This thesis presents novel design methodologies for integrated radiators and power generation at mm-wave frequencies that are enabled by the continued integration of various electronic and electromagnetic (EM) structures onto the same substrate. Beginning with the observation that transistors and their connections to EM radiating structures on an integrated substrate are essentially free, the concept of multi-port driven (MPD) radiators is introduced, which opens a vast design space that has been generally ignored due to the cost structure associated with discrete components that favors fewer transistors connected to antennas through a single port. From Maxwell's equations, a new antenna architecture, the radial MPD antennas based on the concept of MPD radiators, is analyzed to gain intuition as to the important design parameters that explain the wide-band nature of the antenna itself. The radiator is then designed and implemented at 160 GHz in a 0.13 um SiGe BiCMOS process, and the single element design has a measured effective isotropic radiated power (EIRP) of +4.6 dBm with a total radiated power of 0.63 mW. Next, the radial MPD radiator is adapted to enable dynamic polarization control (DPC). A DPC antenna is capable of controlling its radiated polarization dynamically, and entirely electronically, with no mechanical reconfiguration required. This can be done by having multiple antennas with different polarizations, or within a single antenna that has multiple drive points, as in the case of the MPD radiator with DPC. This radiator changes its polarization by adjusting the relative phase and amplitude of its multiple ports to produce polarizations with any polarization angle, and a wide range of axial ratios. A 2x1 MPD radiator array with DPC at 105 GHz is presented whose measurements show control of the polarization angle throughout the entire 0 degree through 180 degree range while in the linear polarization mode and maintaining axial ratios above 10 dB in all cases. Control of the axial ratio is also demonstrated with a measured range from 2.4 dB through 14 dB, while maintaining a fixed polarization angle. The radiator itself has a measured maximum EIRP of +7.8 dBm, with a total radiated power of 0.9 mW, and is capable of beam steering. MPD radiators were also applied in the domain of integrated silicon photonics. For these designs, the driver transistor circuitry was replaced with silicon optical waveguides and photodiodes to produce a 350 GHz signal. Three of these optical MPD radiator designs have been implemented as 2x2 arrays at 350 GHz. The first is a beam forming array that has a simulated gain of 12.1 dBi with a simulated EIRP of -2 dBm. The second has the same simulated performance, but includes optical phase modulators that enable two-dimensional beam steering. Finally, a third design incorporates multi-antenna DPC by combining the outputs of both left and right handed circularly polarized MPD antennas to produce a linear polarization with controllable polarization angle, and has a simulated gain of 11.9 dBi and EIRP of -3 dBm. In simulation, it can tune the polarization from 0 degrees through 180 degrees while maintaining a radiated power that has a 0.35 dB maximum deviation from the mean. The reliability of mm-wave radiators and power amplifiers was also investigated, and two self-healing systems have been proposed. Self-healing is a global feedback method where integrated sensors detect the performance of the circuit after fabrication and report that data to a digital control algorithm. The algorithm then is capable of setting actuators that can control the performance of the mm-wave circuit and counteract any performance degradation that is observed by the sensors. The first system is for a MPD radiator array with a partially integrated self-healing system. The self-healing MPD radiator senses substrate modes through substrate mode pickup sensors and infers the far-field radiated pattern from those sensors. DC current sensors are also included to determine the DC power consumption of the system. Actuators are implemented in the form of phase and amplitude control of the multiple drive points. The second self-healing system is a fully integrated self-healing power amplifier (PA) at 28 GHz. This system measures the output power, gain and efficiency of the PA using radio frequency (RF) power sensors, DC current sensors and junction temperature sensors. The digital block is synthesized from VHDL code on-chip and it can actuate the output power combining matching network using tunable transmission line stubs, as well as the DC operating point of the amplifying transistors through bias control. Measurements of 20 chips confirm self-healing for two different algorithms for process variation and transistor mismatch, while measurements from 10 chips show healing for load impedance mismatch, and linearity healing. Laser induced partial and total transistor failure show the benefit of self-healing in the case of catastrophic failure, with improvements of up to 3.9 dB over the default case. An exemplary yield specification shows self-healing improving the yield from 0% up through 80%.</p

    Selected Papers from the 5th International Electronic Conference on Sensors and Applications

    Get PDF
    This Special Issue comprises selected papers from the proceedings of the 5th International Electronic Conference on Sensors and Applications, held on 15–30 November 2018, on sciforum.net, an online platform for hosting scholarly e-conferences and discussion groups. In this 5th edition of the electronic conference, contributors were invited to provide papers and presentations from the field of sensors and applications at large, resulting in a wide variety of excellent submissions and topic areas. Papers which attracted the most interest on the web or that provided a particularly innovative contribution were selected for publication in this collection. These peer-reviewed papers are published with the aim of rapid and wide dissemination of research results, developments, and applications. We hope this conference series will grow rapidly in the future and become recognized as a new way and venue by which to (electronically) present new developments related to the field of sensors and their applications

    Wireless Sensor Networks

    Get PDF
    The aim of this book is to present few important issues of WSNs, from the application, design and technology points of view. The book highlights power efficient design issues related to wireless sensor networks, the existing WSN applications, and discusses the research efforts being undertaken in this field which put the reader in good pace to be able to understand more advanced research and make a contribution in this field for themselves. It is believed that this book serves as a comprehensive reference for graduate and undergraduate senior students who seek to learn latest development in wireless sensor networks

    Telemedicine

    Get PDF
    Telemedicine is a rapidly evolving field as new technologies are implemented for example for the development of wireless sensors, quality data transmission. Using the Internet applications such as counseling, clinical consultation support and home care monitoring and management are more and more realized, which improves access to high level medical care in underserved areas. The 23 chapters of this book present manifold examples of telemedicine treating both theoretical and practical foundations and application scenarios
    corecore