Antennas, fractals and determination - profile of "Chip" Cohen, N1IR

When Nathan "Chip" Cohen, N1IR, built the first fractal antenna, his mind was not on the future of telecommunications antennas. In 1988, Chip had a 'no antenna clause' at his Boston apartment. To assure good 2 Meter repeater connections, he used an intricate fractal shape. The fractal's pattern, repeating on many size scales, acted to self-load the antenna. It provided a good 50 ohm match and could hit repeaters well into New Hampshire. But alas, his neighbor recognized the bizarre structure as an antenna, and its days were numbered. 

But Chip wasn't one to give up. Starting as a young 11 year-old novice, WN1HBX, Chip pushed ahead. His first antenna was a dipole up six feet; his best DX a VE2. However, in a couple of short years of odd jobs and yard work, he had managed to pay for a Swan 500 and a Yagi. At 14, Chip had DXCC and was the youngest Extra, as WA1JHQ in New England. 

As Chip started his college career, he was drawn more and more to antennas and their applications. After a bachelor's degree in physics, he received his degree in astrophysics from Cornell University. Working with antennas like the Very Large Array and Arecibo, he conducted a number of breakthrough radio astronomy projects and was the only graduate student at the time to actually do work for SETI (the search for extraterrestrial intelligence), completing his Ph.D under SETI pioneer Frank Drake, and later becoming one of the inspirations for the character of Ellie Arroway in the movie Contact. 

In the last decade, Chip has continued his SETI and antenna work. And as a professor at Boston University, Chip trains the next generation of engineers. In 1995, he achieved a lifelong goal of #1 DXCC Honor Roll. His fractal antenna work extends a flair for invention. In July, Chip was recognized for his ability by being named a finalist in the Discover Magazine Awards for Innovation for fractal antennas. 

Fractal antennas pose a few surprises. First, they have a tendency to be very broadband or multiband. Second, they can shrink the size down without coils or capacitors and are very efficient. Several simple designs have been published in 73, DX Magazine and Communications Quarterly. Chip promises yet smaller Yagis, rhombics, helices, and many other antennas using fractal design. he recently reported the replacement of spring 'rubber duckies' with far more efficient 'conformal cylinders' which house fractal designs. Small, high performance internal antennas also become viable with fractals. 

Forging ahead, N1IR's thoughts are never far from antennas and Amateur Radio, and he looks forward to a future inspired by them.

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