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Fractal Antennas For Ham Radio

fractal

Presented by Jack Hill – W4KH – w4kh@nanniandjack.com

Fractal Geometry is a particularly difficult concept for many people to grasp… Many of you may have heard of “Mandelbrot Sets”, so named for, to quote Wikipedia: “Benoît B. Mandelbrot (20 November 1924 – 14 October 2010) a Polish-born, French and American mathematician, noted for developing a “theory of roughness” in nature and the field of fractal geometry to help prove it, which included coining the word “fractal”. He later discovered the Mandelbrot set of intricate, never-ending fractal shapes, named in his honor.

I invite the reader to “Google” Mandelbrot and become more familiar with his work and how he came to rely on graphic images to foster his understanding of math concepts…

For the really curious, make sure you have a good version of Java (https://www.java.com) and then Google for “online fractal generator” and make your own!

When it comes to Fractal antennas, the field is in its infancy, although cellular telephones have made prolific use of these small, broadband, and efficient antennas. Because of the complexity of building an antenna using repeating patterns whose angles, leg dimensions, and overall pattern must be precisely executed for optimum performance, fractal antennas have not yet made significant inroads into HF operation, especially the lower frequencies (longer wavelengths). That said, one example of a “simple” fractal antenna is the log-periodic, whose elements are scaled from back to front in a manner that allows continuous transmit and receive coverage for a wide slice of spectrum, for example from 7.0 MHz to 30 MHz. Take particular note of the first URL presented, as M0WWA from the UK has designed and build a 28 MHz (ten meter) fractal antenna with pretty good results.

I have put together some URLs that will get your curiosity up and let you explore. Follow other pages in the URLs and links to other pages… if these are not enough, remember Google is your friend!

M0WWA Fractal Antenna Designs

http://www.m0wwa.co.uk/page/M0WWA_fractal_antenna.html

Wikipedia – Fractal Antenna

http://en.wikipedia.org/wiki/Fractal_antenna

Fractal antenna engineering – theory and design

http://www.personal.psu.edu/users/r/l/rlh45/journals/APS MAG Oct 1999.pdf

Fractal Geometry Panorama

http://classes.yale.edu/fractals/panorama/ManuFractals/FractalAntennas/FractalAntennas.html

Fractal Antennas

http://www.qsl.net/kb7qhc/antenna/fractal/

Fractal Antennas: Hype or Hope?

http://www.kb6nu.com/fractal-antennas-hype-or-hope/

Fractal Antenna for ham radio bands : resource detail

http://www.dxzone.com/dx26559/fractal-antenna-for-ham-radio-bands.html

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