Results 321 to 330 of about 1,449,714 (389)

Radio Channel Fundamentals and Antennas

2014
In this chapter, we begin by discussing the fundamentals of the radio channel. Typical Radio Transmitter and Receiver block diagrams are reviewed, together with the components of a wireless communications system. Then, we turn to addressing the phenomenon of wave propagation, in particular, Multi-Path Propagation, Free-Space, and Path Loss.
Héctor J. De Los Santos, Christian Sturm, Juan Pontes   +2 more
openaire   +1 more source

Arecibo radio antenna

IEEE Antennas and Propagation Society Newsletter, 1976
Describes the special features, technology, applications and design of the Arecibo radio antenna.
openaire   +1 more source

Reconfigurable Antennas for Cognitive Radio

2016
With the development of the cognitive radio, that is a system (transceiver) aware of its own operational capabilities and needs which aims at a more efficient use of radio resources (e.g., more universal solution for the co-existence of multiple radio standards, but also limitation of electromagnetic radiations), the antennas with reconfiguration ...
Trong Duc Nguyen, Yvan Duroc, Tan-Phu Vuong   +2 more
openaire   +3 more sources

Radio Astronomy Antennas by the Thousands

Experimental Astronomy, 2004
Large number of microwave antennas of size and surface accuracy appropriate for the Square Kilometre Array (SKA) have not been manufactured previously. To minimize total cost, the design needs to be much more carefully considered and optimized than would be affordable for a small number of antennas.
openaire   +1 more source

Radio Frequency Identification

Industrial Communication Systems, 2018
This technical guidance note is aimed at those using or contemplating using RFID technology. It gives a brief summary of the technology and its usage before looking at how the Data Protection Act 1998 (" the Act ") applies to its use. 1.
Elise Marie Moran
semanticscholar   +1 more source

On geometry of radio antenna placements

1998
A smooth planar curve \(x(t)\) is said to have unique differences if all the vectors \(x(t)- x(t')\) that correspond to different pairs \((t,t')\), \(t\neq t'\), are different. In this note it is proved that if a smooth planar curve has unique differences, then it is a convex curve.
Kosheleva, Olga, Kreinovich, Vladik, Finkelstein, Andrei M., Chan, Steve   +3 more
openaire   +1 more source

Reconfigurable antennas for cognitive radio

2011 IEEE-APS Topical Conference on Antennas and Propagation in Wireless Communications, 2011
The paper reviews the requirements for antennas for use in cognitive radio systems, and presents a summary of some recent developments and future trends in this area.
P. Gardner, P. S. Hall, M.R. Hamid, F. Ghanem   +3 more
openaire   +1 more source

Wideband antennas for radio astronomy

2006 First European Conference on Antennas and Propagation, 2006
The global radio astronomy community has for the last several years embarked on an exciting project known as Square Kilometer Array (SKA). This project is a radio telescope operational from 0.1GHz to 25GHz, with a square kilometer of overall collecting area, providing an increase in sensitivity of two orders of magnitude.
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Wideband Antenna for Portable Radio

2008 International Workshop on Antenna Technology: Small Antennas and Novel Metamaterials, 2008
Narrow frequency bandwidth antenna is a typical shortcoming for most of the communication devices. Thus, a single radiating element which able to have resonant frequencies covering from 780MHz till 3000MHz with at least VSWR of 2.5:1 is critically needed especially for a mission critical two-way portable radio.
BoonPing Koh, SooLiam Ooi, KokHui Tan
openaire   +1 more source

An integrated antenna for cognitive radios

Proceedings of the 2012 IEEE International Symposium on Antennas and Propagation, 2012
An integrated antenna utilizing uniplanar nature of coplanar wave guide with wide and narrow band characteristics for category-A cognitive radios is presented. The space between two tapering which forms the ultra-wideband antenna (UWBA), where the surface current is minimum, is effectively used for the integration of a narrow band antenna (NBA).
Gijo Augustin, Tayeb A. Denidni
openaire   +1 more source