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Topic: Fractal antennas


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In the News (Sat 12 Dec 09)

  
  UCLA Engineering: UCLA Engineer Spring 2003
Antennas for the next generation of cell phones and other wireless communications devices may bear a striking resemblance to the Santa Monica mountain range, the California coastline, or even the tree in your backyard.
Fractals, or fractional dimensions, are mathematical models originally used to measure jagged contours such as coastlines.
Much of the early research on internal antennas was conducted in Rahmat-Samii's UCLA antenna laboratory in the early 1990s, and the university is one of the leading research institutions exploring fractals for antenna design.
www.engineer.ucla.edu /magazine/fractals.html   (909 words)

  
 Fractal Summary
Fractal structures can be found in the leaves of a tree, in the course of a river, in the shape of a broccoli, in our arterial system, and on the surface of a virus.
A fractal is a geometric figure, often characterized as being self-similar; that is, irregular, fractured, fragmented, or loosely connected in appearance.
Fractals and their properties were first brought to the attention of the world by the work of Benoit Mandelbrot in the 1970s.
www.bookrags.com /Fractal   (6563 words)

  
 Fractal Antennas Offer Benefits - Size can be shrunk from two to four times
A fractal element antenna, or FEA, is one that has been shaped in a fractal fashion, either through bending or shaping a volume, or introducing holes.
In order for an antenna to work equally well at all frequencies, it must satisfy two criteria: it must be symmetrical about a point, and it must be self-similar, having the same basic appearance at every scale: that is, it has to be fractal.
Fractal antennas have existed for a long time, although they were not consciously designed as such.
www.luminet.net /~wenonah/cfa/fractal.htm   (813 words)

  
 Fractal technology takes antenna design to new dimensions (February 2002) - Features - Wireless Web   (Site not responding. Last check: 2007-10-11)
Moreover, an antenna of arbitrary dimensions is not appropriate for a specific frequency because the antenna's size must fulfil a minimum relationship with the wavelength.
An antenna is said to be small when its larger dimension is less than two times the radius of the radian sphere in which the antenna is enclosed.
This antenna design can be physically interpreted as being the Hilbert monopole of a 1-D wire antenna, and the space it fills is closer to a surface than a line.
wireless.iop.org /articles/feature/3/2/6   (791 words)

  
 Fractal antenna - Wikipedia, the free encyclopedia
A fractal antenna is an antenna that uses a self-similar design to maximize the length, or increase the perimeter (on inside sections or the outer structure), of material that can receive or transmit electromagnetic signals within a given total surface area.
For this reason, fractal antennas are very compact, are multiband or wideband, and have useful applications in cellular telephone and microwave communications.
Fractal antenna response differs markedly from traditional antenna designs, in that it is capable of operating optimally at many different frequencies simultaneously.
en.wikipedia.org /wiki/Fractal_antenna   (395 words)

  
 Fractal Antenna Systems, Inc.
Usually fractals are described as being 'self-similar', or 'self-symmetric'.
Fractal antennas are the most successful hardware implementation of fractal geometry.
We have resisted publishing fractal antenna taxonomy as this fails to contribute to the true science of fractal antennas, and is worthless in exploring practical novelty from an inventive sense.
www.fractenna.com /nca_faq.html   (3124 words)

  
 Antenna Theory
This is the third edition of Antenna Theory: Analysis and Design which is designed to meet the needs of electrical engineering and physics students at thesenior undergraduate and beginning graduate levels, and those of practicing engineers as well.
Because there are so many methods of analysis and design and a plethora of antenna structures, applications are made to some of the most basic and practical configurations, such as linear dipoles; loops; arrays; broadband, and frequency independent antennas; aperture antennas; horn antennas; microstrip antennas; and reflector antennas.
A chapter on antenna measurements introduces state-of-the-art methods used in the measurements of the most basic antenna characteristics (pattern, gain, directivity, radiation efficiency, impedance, current and polarization) and updates progress made in antenna instrumentation, antenna range design, and scale modeling.
www.eas.asu.edu /~balanis/Antenna.html   (1510 words)

  
 Welcome to Worldradio Online!
When Nathan "Chip" Cohen, N1IR, built the first fractal antenna, his mind was not on the future of telecommunications antennas.
The fractal's pattern, repeating on many size scales, acted to self-load the antenna.
His first antenna was a dipole up six feet; his best DX a VE2.
www.wr6wr.com /newSite/articles/features/olderfeatures/fractals.html   (370 words)

  
 RFID Journal - Fractal Shares RFID Design Facility   (Site not responding. Last check: 2007-10-11)
Fractal says these companies will be able to develop a new range of smaller, custom-designed tags that operate in broad frequency bands.
Fractals themselves are geometric structures that repeat a "motif" shape over a variety of scales.
Fractal antennas/tags use these complex designs to increase the amount of antenna foil or trace material that can be squeezed into any design area.
www.rfidjournal.com /article/articleprint/365/-1/1   (473 words)

  
 Printed Plane-Filling Fractal Antennas for UHF Band
The dependence of the resonant frequency on the shape and size of the antennas are studied, and the current distributions along the antennas at resonant frequency are compared.
The antenna is fed at half of the total length by a delta-gap voltage source.
Peano and Wunderlich 2 antennas have similar current distribution because their main shapes are similar (the curve at four corners and center are the same).
maxwell.uwaterloo.ca /~x9chen/xuan_APS2004_v2.htm   (978 words)

  
 Uses of Fractals
The reason his paintings "look good" is that their fractal dimension is close to that of nature's, especially in the later paintings.
Antenna arrays, another approach, consist of thousands of small antennas which are either placed randomly or regularly spaced.
For a antenna to work equally well at all frequencies, it must be symmetrical around a point and it must be self-similar, both of which fractals can provide.
www.jracademy.com /~jtucek/math/uses.html   (396 words)

  
 ANTENAS FRACTAIS FRACTAL ANTENNAS - FRACTAL SHAPE ANTENNAS (FSA) - FRACTAL ELEMENT ANTENNAS (FEA)
Antennas seem simple enough, but the theory behind them, based on Maxwell's equations of electromagnetism, is almost impenetrable.
On the Behavior of the Sierpinski Multiband Fractal Antenna
Fractal Antenna Systems, Inc. has a broad ranging position of pending patents, both in the US and internationally, and can assure swift and definitive protection with each issuance.
www.wirelessbrasil.org /wirelessbr/secoes/sec_fractal/sec_fractal.html   (2457 words)

  
 Wireless Developer Network
Fractals are geometric structures that repeat a 'motif' shape over a variety of scales.
Fractal Antenna Systems, Inc., is privately held and based in Massachusetts at Telecom City.
It holds 6 patents on fractal antennas and related technology and has an expanding proprietary, patent pending position on fractal element antennae and related technologies.
www.wirelessdevnet.com /news/2003/mar/25/news7.html   (407 words)

  
 Fractal Antenna Systems: The World's Smallest Wideband and Multiband Antennas
Fractal Antenna Systems: The World's Smallest Wideband and Multiband Antennas
Fractal Antenna Systems, Inc., designs and manufactures the most compact and powerful antennas in the world.
Used in the most demanding commercial, military and government applications, Fractal Antenna’s products deliver unprecedented frequency coverage, versatility, and performance in form factors that are a fraction of the size of traditional antennas.
www.fractenna.com   (111 words)

  
 FRACTAL-ELEMENT ANTENNAS   (Site not responding. Last check: 2007-10-11)
However, it has only been in the last few years that fractal antennas have been extended to a more generalized design approach.
Used as miniature antennae, fractals have much to offer in terms of size and cost savings, as well as reliability.
We describe 'antenna-less' (that is, hidden) uses of fractal antennae in hand-held environments as well as some surprising uses for other needs.
www.ecs.umass.edu /conference97/abstracts/cohen.html   (118 words)

  
 MICROWAVE LABORATORY HOME PAGE   (Site not responding. Last check: 2007-10-11)
Microstrip antennas are highly preferred due to their advantages such as light weight and conformal nature.
Fractal geometries are recently introduced into the realm of antenna engineering, due to their ability to introduce multiband characteristics in antennas, purportedly due to their self-similar nature.
In addition, fractals offer a possibility of reducing antenna size, without compromising on the regular or ordered nature of geometry.
ece.iisc.ernet.in /~kjvinoy/mwl-res.htm   (1014 words)

  
 BU Bridge News - 11 Dec. 1998 - 7 Jan. 1999
When Nathan Cohen first submitted a paper documenting his fractal antenna research to a scholarly journal, the editors thought it was a practical joke.
The operability of antennas in fractal shapes has continued to be their best argument.
The University is already a hotbed for the study of fractal mathematics and fractal physics, he points out.
www.bu.edu /bridge/archive/1998/12-11/features3.html   (757 words)

  
 Microwave Lab. Projects   (Site not responding. Last check: 2007-10-11)
Fractals are fragmented geometries outside the realm of Euclidean geometry, with several common mathematical features.
During last ten years, several fractal geometries have been investigated, primarily due to their potential in realizing multi-band, or small sized, or better efficiency antennas.
The objectives are: to identify fractal geometries (and their variants) with angular distribution that show wideband antenna characteristics (similar to spirals typically used); to conduct extensive numerical simulations of antennas using these geometries for parametric studies, and to design, fabricate and test candidate prototype antenna designs.
ece.iisc.ernet.in /~kjvinoy/projects.htm   (655 words)

  
 David Mann Audio FAQ -- FM Excellence   (Site not responding. Last check: 2007-10-11)
(Ideal antenna dimensions are determined by the speed of light and the frequency of the station.) The main deficiency of the simple antenna in urban areas is non-directionality.
Most of the do-it-yourself antenna installation books were written in the 1950's and will tout the advantages of the flat "twinlead" wire.
Although a large outside antenna is certainly the best choice and usually successful, there are some areas, particularly in downtown urban areas or deep fringe rural areas, where no antenna will prove completely satisfactory.
www.davidmannaudio.com /faq/faq5.html   (1362 words)

  
 ScienceDaily: Fractal-shaped Tiles Developed For New Broadband Antenna Class
While fractal concepts have been used previously in antenna design, Werner and his research team are the first to introduce a design approach for broadband phased array antenna systems that combines aspects of tiling theory with fractal geometry.
Fractals Help UCLA Researchers Design Antennas For New Wireless Devices (October 22, 2002) -- Antennas for the next generation of cellphones and other wireless communications devices may bear a striking resemblance to the Santa Monica Mountains or possibly the California...
Fractal -- A fractal is a geometric object which is rough or irregular on all scales of length, and therefore appears to be 'broken up' in a radical way.
www.sciencedaily.com /releases/2003/10/031020054315.htm   (1702 words)

  
 FRACTUS :: Optimised Antennas for Wireless Devices   (Site not responding. Last check: 2007-10-11)
Barcelona, 6 September 2006 -- Fractus, the pioneer developer of fractal antenna technology, has been chosen to lead a technical session on the multi-...
Barcelona 16 March 2006 -- Fractus, the fractal antenna technology pioneer, is pleased to announce that it has received a new grant from the Spanish...
Fractus’ antennas key factor in making handset range 25% slimmer Barcelona, 7 March 2006 -- Fractus, the fractal antenna technology pioneer, has a...
www.fractus.com /news.php   (1589 words)

  
 Fractal antennas
The Koch dipoles can be appreciated as a series of curves and bends, these fractal dipole antennas are no longer having the same impedance as a common dipole antenna.
By transforming the input impedance to 95 ohms for the 3rd iteration Koch square curve, an extremely wideband match was achieved from 5GHz to 20GHz.
This is a parallel feed stacked fractal antenna using the square Sierpinski and diamond Sierpinski carpet.
members.fortunecity.com /scienziatopazzo/fractalantennas.htm   (223 words)

  
 Fractal-based antennas aid warship communications: News from Fractus
As a result, the size and performance of these antennas are critical in satisfying the needs of communications for warships, which lead the way to multiservice functionality.
The search for new antenna technologies led Fractus to explore beyond the reach of conventional geometry, to the field of mathematics known as fractals.
The quality of the antennas can also be improved, resulting in an increase in communications capacity and quality of service.
www.electronicstalk.com /news/fac/fac100.html   (393 words)

  
 Fractal - Wikipedia, the free encyclopedia
However, not all self-similar objects are fractals — for example, the real line (a straight Euclidean line) is formally self-similar but fails to have other fractal characteristics.
Escape-time fractals — These are defined by a recurrence relation at each point in a space (such as the complex plane).
Fractal patterns have been found in the paintings of American artist Jackson Pollock.
en.wikipedia.org /wiki/Fractal   (2121 words)

  
 Research Projects - Modified Minkowski Fractal Antenna   (Site not responding. Last check: 2007-10-11)
Corresponding single fractal and two element parasitic array antennas were fabricated and analysed.
Updates: The research paper on "Compact loop antennas and arrays" has been accepted at the International Conference on Antenna Technology ICAT-05 to be held at ISRO, Ahmedabad in Feb 05.
Presentation on "Use of Fractal Antennas in Amateur Radio" won the Best Presentation award in Hamfest India 2004 held at Mumbai in Dec 04.
home.iitk.ac.in /~abhiag/Project_Research.html   (225 words)

  
 Antenna : Manufacturers: Antennas
Fractal Antenna Systems - Solution to your OEM needs and can meet your design or vended antenna requirements for antennas from 400MHz to 10 GHz.
Fractus Antennas - Fractal Antennas are a new generation of multiband antennas for wireless communications.
Isotron Antennas - Isotron antennas are low-profile HF antennas.
www.dxzone.com /catalog/Manufacturers/Antennas   (2421 words)

  
 Fractal's patents pending - Boston Business Journal:
Fractal Antenna Systems Inc. Monday announced that it expects to receive a patent relating to fractal antennas and fractal resonators.
The Malden-based company -- which uses fractal geometry to make antennas that are smaller and broad- and multiband -- received a notice of allowance for the patent from the U.S. Patent and Trademark office.
Fractal Antenna Systems is a privately held company founded in 1995.
www.bizjournals.com /boston/stories/2002/05/06/daily5.html   (362 words)

  
 Doug Werner -- List Of Publications
The Modeling and Measurement of HF Antenna Skywave Radiation Patterns in Irregular Terrain.
Proceedings of the Fourth International Symposium on Antennas and EM Theory, Co-sponsored by the IEEE Antennas and Propagation Society, Xi’an, China, pp.
The Analysis of a Center-Fed Helical Microstrip Antenna Mounted on a Dielectric-Coated Circular Cylinder Using the Reciprocity Theorem.
www.engr.psu.edu /ee/faculty/werner/werner2.html   (2783 words)

  
 Antennas for All Applications- Third Edition - By John D. Kraus and Ronald J. Marhefka
Antennas for All Applications- Third Edition - By John D. Kraus and Ronald J. Marhefka
Become fluent in its language and comfortable in its culture.
End-Fire Antennas: The Helical Beam Antenna and the Yagi-Uda Array, Parts I and II
www.antennas3.com   (299 words)

  
 BAI Course 037: Antennas & Propagation for Wireless Communications
The course provides an understanding of basic antenna property definitions, antenna design fundamentals and considerations, numerous antenna types and RF propagation fundamentals.
Topics covered include antenna fundamentals, basic antenna types, elementary antennas, electrically small antennas, microstrip patch antennas, low profile antennas, aperture antennas, antenna arrays, propagation channel characteristics, and an overview of different antennas used in today’s wireless communication markets.
The course is well suited for design engineers and program mangers who require an understanding of antenna principles and design concepts.
www.besserassociates.com /outlinesOnly.asp?CTID=37   (638 words)

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