118 research outputs found
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Design considerations of MIMO antennas for mobile phones
YesThe paper presents a new modeling and design concept of antennas using polar-
ization diversity of 2 £ 2 and 3 £ 3 Multiple Input Multiple Outputs (MIMO) system that is proposed for future mobile handsets. The channel capacity is investigated and discussed over
Raleigh fading channel and compared to a linear/planner antenna array MIMO channel. The capacity is also discussed over three types of power azimuth spectrums. The results are compared to the constraints capacity limits in which the maximum capacity observed
Choosing threshold levels for electromagnetic hazards
The concept of electromagnetic hazards is today frequently taken to refer to direct effects on biological tissue. However, several other effects are possible and have been the subject of a substantial amount of research in earlier decades. One of these is the hazard of ignition of flammable gas/vapor mixtures due to sparks resulting from radiofrequency currents flowing in metallic structures. Although the physics of the mechanism linking power from a radio transmitter to ignition of a flammable mixture is relatively straightforward, compared with bioelectromagnetic effects, there are many uncertainties and poorly-understood steps in the process, leading to considerable difficulties for committees tasked with setting safety limits. The author has experience of such committees, notably that concerned with British Standard 6656, and the way in which these difficulties were addressed may give useful insights for the regulation of other hazards
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Bandwidth Enhancement of Balanced Folded Loop Antenna Design for Mobile Handsets Using Genetic Algorithms
YesIn this paper, a simple folded loop antenna (FLA) for handsets with relatively wide-
band impedance, designed and optimized using genetic algorithms (GA). The FLA dimensions
were optimized and evaluated using GA in collaboration with NEC-2 source code. Configuration of optimal FLA with excellent VSWR covering entirely the required GSM1800 frequency bands was found within the maximum generation. A prototype antenna was tested to verify and validate the GA-optimized antenna structure. The measured data have shown good agreement with predicted ones. Moreover, the capabilities of GA are shown as an e±cient optimisation tool for
selecting globally optimal parameters to be used in simulations with an electromagnetic antenna design code, seeking convergence to designated specifications
Design of controlled RF switch for beam steering antenna array
YesA printed dipole antenna integrated with a duplex RF switch used for mobile base
station antenna beam steering is presented. A coplanar waveguide to coplanar strip transition was adopted to feed the printed dipole. A novel RF switch circuit, used to control the RF signal fed to the dipole antenna and placed directly before the dipole, was proposed. Simulated and
measured data for the CWP-to-CPS balun as well as the measured performance of the RF switch are shown. It has demonstrated the switch capability to control the beam in the design of beam steering antenna array for mobile base station applications
Evaluating the REF2014 Results in Art and Design
In the UK, periodic assessment of research in universities has taken place since 1986. The most recent took place during 2014 with the results being published at the end of the year. This evaluation is concerned with art and design though all disciplines were included in the assessment. The method used for assessing research quality is outlined and the results summarised. The lessons drawn from the evaluation by REF2014 are detailed. A number of issues are identified and discussed. These include the staff selected for submission, the method of evaluation, and a cost-benefit analysis of the process
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