An Amazing Adventure Into the Real World of Fractal Antennas
It’s not every day that I get an invitation from a well-known scientist to come to his facility, along with one of my RCA Young Achievers. So of course, 17-year-old Austin Schaller, KD0FAA, and I accepted the invitation to visit Fractal Antenna Systems, Inc. in Waltham, Massachusetts. Young Austin, featured in Hams With Class in April WRO, had spoken about his fascination with fractal antennas at the 2009 Dayton Youth Forum, and again at the RCA Technical Symposium in November of 2011. Dr. Nathan ”Cohen, W1YW, founder and technical visionary of Fractal Antenna Systems, Image A, heard about Austin and his presentations, and contacted me with the invitation for an extraordinary adventure at his facility. Accompanying us on our tour were Austin grandfather and mentor, Frank De Vall, W0BIW; Stan Reubenstein, WA6RNU, Radio Club of America (RCA) President Emeritus; along with Chipfriends and associates: Bruce Blain, K1BG; and Fred Hopengarten, K1VR. The hospitality and graciousness of our host was unsurpassed. The electrical engineers in the lab — Obinna Okorro and Dan Earle — and Project Manager Jane Winter, went out of their way to make sure we got the most out of our visit. Dr. Cohen was so generous with his time and sharing his experience and knowledge, that the day at Fractal was not only extremely informative and interesting, but one of the most enjoyable field trips Iever been on. Of particular interest to me was how Chip took Austin under his wing. The two bonded and Chip included Austin in the hands on demonstrations we were fortunate enough to be shown throughout the day. Dr. Cohen was . Wizard’ personified. As a teacher, I was totally impressed with the learning experience he and his team gave us. It was such a privilege. Heres a brief description of some of the demonstrations that so intrigued us: •The M12 is one of the first fractal antennas. Ita simple bent wire that starts with a square and is bent into a fractal, giving full bandwidth and great SWR. We observed it worked on multiple bands with no tuner, no extra components and no matching. With a very small size —one-eighth wave square —and dipole equivalent gain, polarization and power pattern, we were able to confirm the antennas gain and efficiency. •The UACM is a three-dimensional fractal antenna that makes a discone into a stealthy, tiny diamond shape with a very wide bandwidth at a much shorter height. •The Dissimulation Tube Antenna is a portable and electrically-small antenna that works from high-frequencies to WiFi and is built into a collapsible tube as a mast. •The UWPE is a flat, very wideband fractal dipole antenna. With the Fractal Metamaterial Monopole demonstration, our host explained that we were observing textbooks being rewritten that day. This is a wideband, higher-gain vertical antenna enabled by slipping on a collar of fractal metamaterials. •The Invisibility Cloak was a demonstration that Austin especially anticipated. As RCA members, we were given the first public demonstration of this three-dimensional invisibility cloak, making a long metal pipe invisible to a wide microwave passband. Fractals are used to curl the radio waves around the pipe and converge on the other side, rendering the pipe invisible. Chip explained that ability to do this over a wide range of wavelengths is unique to the fractal technology. Will it be possible to cloak at visible light? These demonstrations say yes —in the next decade.” I asked Austin for his reactions to our incredible experience and to the opportunities he has had, and will continue to get through his amateur radio background. Heres what he said: students —regardless of age or grade level —should be encouraged to explore scientific phenomena in the world around them, conduct research, experiment, and to present their findings to the scientific community, to their classmates, through science fairs, and so on. November 19, 2011, I had the privilege of presenting to the Radio Club of America Technical Symposium about one of my passions, Antennas.’ Much to my surprise, Dr. Nathan Cohen, the inventor of the fractal antenna technology, himself, saw my YouTube video of the RCA presentation and kindly invited Carole and myself to visit his facility for a private tour. Dr. Cohens extensive collection of fractal antenna designs was a fascinating opportunity. Unusual geometries were etched onto flexible substrates, three-dimensional helices, and a multitude of other designs. As part of the tour, Dr. Cohen showed us live measurements of how some of the antennas performed, along with frequently misled experiments that caused many to conclude that fractal antennas don’t work. The data, however, was indisputable, demonstrating the wideband and multi-resonant qualities that they exhibit. the most interesting demonstration that Dr. Cohen showed us was the Invisibility Cloak,’ which involves the use of fractal arrays printed on a flexible substrate. The end cloaking technique allows objects to become invisible from a microwave perspective. Nathan Cohen has undoubtedly spent a lot of time and effort in discovering more about the nature of fractal antennas —and it was a unique experience to have visited his company.” WlYW Dedication to Young People It became obvious early on in the tour that Chip was passionate about providing knowledge and opportunities for young people. He was quick to point out the influence of ham radio on his career choices, and technical pursuits. He sums up his interest and devotion to youth this way: do what we are born to do: Experiment. Young hams have the unique chance to make and use electronics and communication techniques without the encumbrance of needing a Ph.D., or fancy equipment. the case of fractal antennas, ham radio started the ball rolling, using aluminum foil, bent wire, and a thirst to have some fun and learn new things. The acquired of doing’ is essential for making better engineers, scientists, and hi-tech business people in a wireless world; where the United States must stay at the forefront.” Great Appreciation Thanks to the wonderful opportunities within the ham community, both Austin and I had the experience of a lifetime. I continue to be so honored to work with young hams and to be able to participate in incredible situations that come about with the myriad of talented and devoted hams like Chip Cohen.