Results 211 to 220 of about 14,576 (267)

Introduction to radio and radio antennas

IEEE Spectrum, 1971
Electromagnetic wave propagation is a simple and beautiful phenomenon, but its rigorous mathematical derivation from Maxwell's equations is formidable. This article makes many of the concepts visible and plausible using only mathematics available to college freshmen and taught today in most high schools.
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Trees performing as radio antennas

IEEE Transactions on Antennas and Propagation, 1975
Radio transmission and reception experiments conducted in a tropical jungle are described. The performance of conventional whip antennas is compared with the performance of trees utilized as antennas in conjunction with hybrid electromagnetic antenna couplers (HEMAC's). The trees were found to outperform the whip in some cases by up to 20 dB.
K. Ikrath, W. Kennebeck, R. Hoverter
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Arecibo radio antenna

IEEE Antennas and Propagation Society Newsletter, 1976
Describes the special features, technology, applications and design of the Arecibo radio antenna.
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Radio-frequency transparent dipole antennas

2015 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, 2015
We present the concept of wideband radio-transparent dual-polarized dipole antennas, based on suppressing the scattering of dielectric or conducting rods with suitably designed cloaks. The antennas presented here show low scattering cross-sections at all angles for plane wave incidence, as demonstrated in a conventional reflector-based setup.
Jason C. Soric, Andrea Alu
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Printed Circuit Radio Link Antenna

6th European Microwave Conference, 1976, 1976
A printed circuit antenna which substitutes a paraboloid antenna in radio link applications at 1.8 GHz has been developed. The antenna is a novel traveling wave antenna, a so called grid antenna. It consists of a ground plane close to which is a printed sheet with several pairs of meander lines. The lines are fed in parallel from a coaxial line causing
Martti Tiuri, Johan Henriksson, Stefan Tallqvist   +2 more
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Antennas for Radio Astronomy

2009 Applied Electromagnetics Conference (AEMC), 2009
Radio Astronomy has made very significant contributions to human knowledge by discovering such exotic phenomena as quasars, pulsars, active galactic nuclei, superluminal motion and cosmic microwave background. These have been possible by the ever increasing sensitivity and angular resolution of the radio telescopes over the last six decades.
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Directional antennas and radio networks

2009 IEEE International Conference on Microwaves, Communications, Antennas and Electronics Systems, 2009
Spectrum management (SM) is a well known important issue [1]. Demand for RF spectrum already exceeds supply [2]. The advent of cognitive radio functionality and other SM advances, while important, have actually been constrained by an almost exclusive focus on omni-directional antennas, with scant attention paid to the spectrum deconfliction benefits ...
Newton Love, Leo H. Jones, Steven Stegmann   +2 more
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Packset radio antenna measurements

IRE International Convention Record, 2005
Packset radio antennas in the HF and VHF ranges have traditionally presented severe matching problems due to the dependence of antenna parameters on position, surroundings and operator. The advent of high power (20-40W) packsets tunable over the entire HF and VHF range have made better antenna matching desirable. A novel antenna measurement test set is
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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
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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
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