Results 251 to 260 of about 185,245 (299)
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Electronics and Power, 1984
Antenna systems are a key element in all satellite communication systems, and improvements in performance over the past 20 years have contributed to the increased efficiency of modern systems. Satellite antenna capability is still continuing to evolve, making this an exciting and promising field for the 1990s and beyond.
D.J. Brain, A.W. Rudge
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Antenna systems are a key element in all satellite communication systems, and improvements in performance over the past 20 years have contributed to the increased efficiency of modern systems. Satellite antenna capability is still continuing to evolve, making this an exciting and promising field for the 1990s and beyond.
D.J. Brain, A.W. Rudge
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Holographic antenna efficiency
IEEE Antennas and Propagation Society International Symposium. Digest. Held in conjunction with: USNC/CNC/URSI North American Radio Sci. Meeting (Cat. No.03CH37450), 2004The holographic antenna's efficiency is formulated to determine the holographic antenna dimensions and feed patterns that generate optimal performance. This efficiency comprises three main contributing sources of loss, namely, the spillover, taper, and, termination efficiencies.
S.R. Thingvold +3 more
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Antenna selection schemes for energy efficiency in distributed antenna systems
2012 IEEE International Conference on Communications (ICC), 2012In this paper two schemes of distributed antenna selection, Pathloss-based Antenna Selection (P-AS) and Energy-efficient Antenna Selection (E-AS), are studied for the purpose of improving energy efficiency in Distributed Antenna Systems (DAS). Path loss information is exploited in P-AS, whilst the energy consumption of antenna nodes is taken into ...
Hong Li +2 more
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Efficient Kernel Calculation of Cylindrical Antennas
IEEE Transactions on Antennas and Propagation, 1995This paper presents a technique for evaluating analytically and without limitation the singular part of the kernel integral of cylindrical wires due to uniform current distribution. This approach uses the static Green's function expression in cylindrical coordinates.
Park, Seong-Ook Park, SeongOok +1 more
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An LTE-Band Dual-Antenna Design with an Enhanced Antenna Efficiency
IEICE Transactions on Communications, 2009A neutralization line is internally added to a 770MHz LTE-band miniature dual-antenna system to improve its antenna efficiency. The odd-mode antenna impedance simulations indicate that the position of the neutralization line along the radiating structure determines the operation frequency.
Jinyong Kim +3 more
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AIP Conference Proceedings, 2006
The fundamental limits of the power efficiency of an antenna are explored. The antenna is confined in a sphere and all of the currents are assumed to run in a material with a conductivity that is a function of the radial coordinate. The analysis is based on the expansion of the electromagnetic fields in terms of vector spherical harmonics.
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The fundamental limits of the power efficiency of an antenna are explored. The antenna is confined in a sphere and all of the currents are assumed to run in a material with a conductivity that is a function of the radial coordinate. The analysis is based on the expansion of the electromagnetic fields in terms of vector spherical harmonics.
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On the spectral efficiency of CDMA with multiple antennas
Proceedings 2001 IEEE Information Theory Workshop (Cat. No.01EX494), 2002We consider the impact of transmit diversity on the capacity of synchronous, randomly-spread code-division multiple-access, in the presence of frequency-flat fading. For large user populations, we characterize the spectral efficiency (capacity per chip) of two systems that use different spreading sequences on each antenna: a theoretically optimal ...
Pallav Sudarshan, Brian L. Hughes
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Aperture efficiencies of impulse radiating antennas
Ultra- Wideband Short-Pulse Electromagnetics 4 (IEEE Cat. No.98EX112), 2002A concept of aperture efficiency is introduced for the purpose of comparing and optimizing the performance of impulse radiating antennas (IRAs). The aperture efficiencies of popular lens and reflector IRAs are computed as the ratios of peak radiated power densities on boresight compared with that produced by an ideal IRA with an aperture of equal area ...
C. Jerald Buchenauer +2 more
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Pecuniary Efficiency of Distributed Antenna Systems
IEEE Communications Letters, 2015In this letter, the gross expenditure, revenue, and profit of a distributed antenna system (DAS) are modeled and investigated. Using stochastic geometry framework, we evaluate the communications pecuniary efficiency (PE) that is defined as a ratio of average achievable bits per expenditure.
Jingon Joung, Hieu Duy Nguyen, Sumei Sun
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A Multifeed Antenna for High-Efficiency On-Antenna Power Combining
IEEE Transactions on Antennas and Propagation, 2017This paper presents a multifeed antenna structure that synthesizes the desired far-field radiation characteristics with on-antenna power combining and increases the total radiated power of a wireless transmitter. The driving signals at the multiple antenna feeds are scaled properly in amplitude and phase, so that they collectively synthesize the ...
Taiyun Chi +3 more
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