30 research outputs found

    The time of arrival statistics for cellular communication using multiple concentric annular rings of uniformly distributed scatterers

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    Abstract: Mobile communication has become popular over the last couple of decades. The channel between the base station and the mobile device depends of the enviroment in which the mobile device is placed. The time of arrival statistics of the signal arriving from the base station to the mobile device depends on the channel. The time of arrival statistics is an important parameter as it assists in determining the maximum width of the pulse that should be transmitted over the channel. Geometrical channel model is one of the widely used channel modeling techniques for determining the time of arrival statistics of the signals. In this paper we approximate the gaussian distribution of statterers around the mobile device by concentric annular rings of uniformly distributed scatterers to evaluate the time of arival statistics. We subsequently compare the satistics obtained by both the methods for validation of the results

    A novel frequency pattern enhancement technique based on capacitively coupled microstrip line feed

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    Abstract: A novel parallel-coupled microstrip feed line is proposed. The feed relies on the capacitance contribution arising from the capacitances occurring at adjacent split sections in order to lower the high intrinsic input impedance common to microstrip patch antennas. It is expected that the capacitance contribution will enhance the frequency pattern of the microstrip passive and thus overcome the narrow bandwidth tendency of the traditional patch. The novel feed has demonstrated enhanced impedance bandwidth, and the results have been validated theoretically, numerically and by measurement

    Spatial array of microwave sensors for IoT-based wireless connectivity

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    Abstract: Spatial array of microwave sensors for IoT-based wireless connectivity is presented. The traditional challenges of poor input impedance matching associated with small antenna is analytically characterized using the many available formulae based on a novel 2 脳 2 excitation network. Alternative microwave sensor solution designed at originally known low data throughput IEEE 802.11x standard, was previously investigated to support multi-channel bandwidth capacity, now examined for robust link budget to provide complementary leverage for IoT-based applications

    A triple-band microstrip passive based on quasi hybrid-ring coupler feeding

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    Abstract: We present a triple-band microstrip passive device using a quasi-hybrid-ring coupler feeding. The proposed hybridring feeder is based on the rat-race coupling mechanism using a balanced mode arrangement. The input excitation energy is split into two superimposed excitation electromagnetic waves travelling in opposite direction though with equal amplitude but with 1800 phase difference. The proposed feeder caused excitation resonance at modes TM11, TM02, and TM20 leading to triple bands. The findings have been validated using available numerical method and by measurement

    Smart homes : a domestic demand response and demand side energy management system for future smart grids

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    Abstract: Smart homes or the homes of the future will be equipped with advanced technologies for user comfort and entertainment. Intelligent systems will be available to ensure this comfort and reliability. With these technological advancements comes further energy management. The concept of domestic energy efficiency is a concern at present and will be, in the future. So how do we optimize homes and users as to how they conserve energy? Domestic user鈥檚 energy usage represents a large amount of total electricity demand. Typical home energy systems utilize a rudimentary form of energy efficiency and management. In this paper we look at a Demand Response and Demand side management system model to curb this situation. The demand response system is achieved by the utility turning on/off smart power plugs wirelessly throughout the home based on peak and off peak periods via communication through its smart grid. To help consumers shift their loads during these times, appliance power sources that can act autonomously based on wired or wireless signals received from the utility via its smart grid is required. Users in response to this, connect their appliances to these plugs by generating their own hierarchy system by prioritizing their appliance usage. Whereas the demand side management system allows users to manually configure dates and times for the turning on/off of the smart power plugs wirelessly through the user鈥檚 smart user interface. Therefore, an energy efficient future smart home that can save the user on monthly expenditure and save on energy simultaneously

    Modeling of a novel microstrip ring resonator for wireless applications

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    Abstract: In this paper, we present the modeling of the microstrip ring resonator (MRR) for wireless applications. The proposed MRR is designed to operate at 5.8 GHz using a combination of two sub-wavelength (位/4) bent MRRs together with two (位/8) arms to form a half ring of 位/2 in length. The combined structure is excited by an end-coupled transmission line in such a way as to center couple the two half rings. The entire structure is modeled numerically using an equivalent circuit that was derived, and hence characterized with the aid of the 2D equivalent circuit modeler. The effects of the various gap capacitances on the reflection coefficients, insertion loss, resonant frequency and bandwidth are investigated

    Parasitic effect on reduced latency of SoC-based big data

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    Abstract: Big data technology sustainability is contingent on the availability of interconnections of large scale, ultra-high-speed, densely integrated big data heterogeneous server platforms. For highly densified servers to be attainable, semiconductors technologies upon which these servers are predicated must further be miniaturized. It is recently not uncommon to implement bandgap reduction engineering of SiGe HBT in a bid to attain highly densified integrated circuit for large scale servers. Unfortunately, the parasitic effects become significant, in particular as these integrated circuits are targeted for high frequency of operations due to the interconnections links between the chip and the transceivers. Insertion loss |S21| becomes considerable, and both the signal level as well as noise figure depreciate substantially as a result. In this work therefore, we investigate the effect of parasitic effect on the roundtrip latency of system-on-chip (SoC)

    A novel microstrip feed based on the theory of small reflection

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    Abstract: A six-element microstrip patch antenna based on the theory of small reflection is investigated. The radiators are excited by a novel transmission line. The maxim and minim energy on the proposed transmission line are determined based on voltage allocation on a short-circuited microstrip line. Each radiator, made of a square microstrip patch, is designed to resonate at 5.8 GHz target frequency, with each of them carefully positioned at the maxim in a series-fed array arrangement, in order to catch optimal radiation on excitation of the line. The results obtained are impressive, with an impedance bandwidth of about 6.90%, an aperture size of 1.6位 脳 2.1位 and a gain of about 14.2 dBi. The feed demonstrates a compact size advantage, in particular when compared with the conventional series feed network

    Dielectric loading effect on periodic microstrip structure

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    Abstract: Digit-like periodic structures have demonstrated overtly multiple resonances that almost disqualify them as good candidates for microwave circuits, since it is rather difficult to identify their resonance at the dominant mode practically. In this work, an alternative solution to mitigate these spurious resonances is investigated. The dielectric loading effect is examined to determine its efficacy and extent. The results have been validated numerically using the commercially available finite integration technique solver. The findings indicate that the proposed alternative solution is promising. A wide impedance bandwidth or dual-band is achievable, depending on the location of the loading relative to the periodic structure and the feed system

    Detection and clustering of an Neutral Section faults using machine learning techniques for SMART railways

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    Abstract: Fault detection and diagnosis plays an important role particularly in railways were abnormal events are detected and a detailed root causes analysis is performed to prevent similar occurrence. The current method used to detect immediate and long-term faults is through foot inspections and inspection trolleys fitted with cameras proving to be inefficient and time consuming when analyzing the data. This paper examines the smart fault detection system on the overhead wires by applying machine learning techniques for accurate assessment of the neutral section before and after failure thereby grouping the events into fault bins. Modern computational intelligence has enabled the fault diagnostic and fault detection to be accurate from the data generated from the sensors. The interaction between the pantograph and contact wire will be monitored using accelerometers and non-contact infrared thermometer sensors were should there be a deviation from the normal signal spectrum it will be detected. The measured data from onsite will be conveyed to ThingSpeak for cloud computation thereby providing notifications in real-time which allows the end user to visualize, analyze and act on data online. A prototype has been built and tested which shows that the system works reasonably with data collected from sensors
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