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Antenna efficiency in graphene-based THz photoconductive antennas
2014 22nd Iranian Conference on Electrical Engineering (ICEE), 2014A dipole-like antenna made of graphene strips and integrated with a THz photonic mixer is studied numerically. The input impedance and the radiation properties of such graphene-based antenna are investigated through full-wave numerical simulations. Full-wave simulations show that the graphene-based antennas can provide higher input impedance along with
M. Zolfagharloo-Koohi, M. Neshat
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Antenna efficiency of handheld phones
IEE Seminar Electromagnetic Assessment and Antenna Design Relating to Health Implications of Mobile Phones, 1999Measurements in an anechoic room of three-dimensional radiation patterns for 42 test persons using a handheld phone with two antennas are investigated in order to find the body loss. The measured efficiency range from 0.9 dB to 17 dB. From the measurements is was possible to separate the absorption and the loss due to mis-match of the antenna.
Pedersen, Gert Frølund +2 more
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Spectrum Efficiency in Distributed Antenna Systems
2011 IEEE Global Telecommunications Conference - GLOBECOM 2011, 2011The distributed antenna system (DAS) is a promising system to provide high data rate for future wireless communications, since it can reduce the radio transmission distance. This paper aims to investigate the average spectrum efficiency and the cell edge spectrum efficiency in the downlink transmission of the DAS.
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A study of the antenna radiation efficiency for electrically small antennas
2013 IEEE Antennas and Propagation Society International Symposium (APSURSI), 2013Antenna radiation efficiency for electrically small antennas has been discussed in this paper. The radiated field is expressed in terms of spherical harmonic TE and TM modes and radiated and dissipated powers are described by this modal excitation coefficients.
Keisuke Fujita, Hiroshi Shirai
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On energy efficient antenna deployment of distributed antenna systems
2015 5th International Conference on Information Science and Technology (ICIST), 2015Distributed antenna systems (DAS) have been shown to be an efficient scheme to improve coverage and performance of wireless communications system. In this paper, we investigate the energy efficiency of a single-cell DAS. Given the coverage area and user distribution, Firstly we develop a general model for joint optimization of the number and location ...
Yabing Kang +4 more
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On the radiation efficiency of homogeneous antennas
2014 International Symposium on Antennas and Propagation Conference Proceedings, 2014Radiation efficiency of homogeneous antennas has been discussed in this paper. The radiated and dissipated powers are expressed in terms of the radiating and nonradiating currents. It has been found that the maximum radiation efficiency can be accomplished by the homogeneous spherical antenna which circumscribes arbitrary antenna shape.
Keisuke Fujita, Hiroshi Shirai
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Beam Efficiency Limitations of Large Antennas
IEEE Transactions on Military Electronics, 1964The beam efficiency of an antenna may be defined as the ratio of the power radiated within the main beam to the total power radiated. The beam efficiency is derived for ideal rectangular and circular apertures, as a function of the edge-to-center amplitude ratio. Random phase errors are assumed to exist across the aperture.
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Effect of antenna Q to the radiation efficiency of tunable antennas
The 8th European Conference on Antennas and Propagation (EuCAP 2014), 2014Narrowband tunable antennas have gained interest as an alternative to wideband antennas in mobile applications. However, one of the key problems of tunable antenna systems are the increased losses and thus the reduced efficiency of the antenna systems.
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Wideband antenna efficiency measurements
2010 International Workshop on Antenna Technology (iWAT), 2010Over the past 10 years or so, many broadband and ultra-wideband antennas have been developed for broadband high data rate mobile communications. It is realized how to make efficient and accurate measurements for such antennas could be a challenging issue. In this paper, we examine the antenna efficiency measurement techniques which have been used up to
Y. Huang +4 more
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Efficient HF submarine antennas
2008 IEEE Antennas and Propagation Society International Symposium, 2008For submarine applications, it is desirable to have broadband, efficient, extremely short HF antennas that can cover the whole band without the use of a complex internal/external tuning circuitry. A short monopole antenna is currently used except that it has the following disadvantages: it is not efficient and uses complex external tuning circuitry ...
F. Plonski, C.M. Gyenes
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