The US patent office has granted the ‘source’ patent on cloaks and deflector shields under patent number 9,847,583 . The inventor is Chip W1YW, who also is the inventor of fractal antenna technology. Fractal antennas were developed on the ham bands back 30 years ago. Fractal antenna technology is now a widely accepted and studied applied science by researchers across the globe, and is in wide use commercially. The new patent uses close-packed arrays of little fractal antennas to produce an evanescent surface wave that deflects around objects, including people, rockets, antennas, satellites, and so on. A good introduction to the invisibility cloak is in the attached video: Most people look at surface waves as a problem. W1YW saw them as a solution, and used the fractal antenna technology to make the surface waves very intense and controllable. The acknowledgement that the fractal antenna-based cloak technology is an important enhancement of the radio art was recently made apparent by Dr. Eli Brookner, a radar expert, at his presentation at the 2017 Radio Club of America Symposium. W1YW has demo’ed invisibility cloaks at both Hamvention and Boxboro conventions. It took 5 years to get the patent, which itself was ‘cloaked’ and was not public until issuance. Here’s a recent shot of W1YW (a ham for 52 years) with a giant Christmas ornament (he uses the Sputnik model as a radar phantom). Chip is an active DX’er and contester and uses fractal antennas at his home station in Massachusetts. 73 and HNY de John WØPV
Thanks John, This is extracted from a press release, that appeared in quite a few places, including the Microwave Journal: http://www.microwavejournal.com/art...tent-illuminates-applications-of-invisibility These things take forever in the patent office. Actually 5 years is a SHORT time to wait. As with many of my inventions, I do not discuss them until the patent issues. Fractal antennas were invented 30 years ago, almost to the day. Man, time flies...an amazing roller coaster ride. Ham radio experimentation can lead to some pretty cool innovations! Let's keep that spirit alive in 2018. 73 and HNY, Chip W1YW
Very interesting, thanks for posting it. I wonder if the the ability to propagate the evanscent wave and relaunch the space wave requires fractals, or if it can be done with other antenna shapes albeit using larger dimensions and/or more restricted bandwidth? In the video clearly the amount of power coming back toward the source antenna is low which would be akin to energy coming back from a radar pulse. I wonder what the effectiveness is of the cloaking is at various incident angles of radiation. The patent teaches that the effect can be scaled into infrared, even UV by appropriate dimensions of fractals which leads to the thought of a visible light cloak, or a defense against directed-energy weapons such as infrared lasers.
Certainly there are surface waves propagated with other shapes. But they are Hi Q and low transfer power. IOW the radiative transfer is less efficient, and narrow band. Radar guys have known this for decades. That's why they always looked at the effect (with other shapes) as a problem, not something to be enhanced and made a new solution. Here's the system in a nutshell (this stuff actually was written up in the Microwave Journal as the cover article in January 2015): BACKSCATTER: the incoming wave reflects off a boundary condition at the object. Its reflection is out of phase and phase-cancels with the incoming wave . Bye bye backscatter. SIDESCATTER: There is none--that's what happens with evanescent waves...they die quickly normal to the surface. So there is nothing (to speak of) as sidescatter in the far field. FRONT SCATTER: The surface waves propagate to the antipodal point (on the other side) and for reasons still being explored, interpret this as a discontinuity. Frankly, I am not really interested in understanding that as BASIC science, but using it as APPLIED science. Certainly we know that surface waves radiate at discontinuities to become traveling waves You wouldn't believe the crazy schemes I have been asked on visible light cloaks. The bottom line is that camouflage probably works better. Yes on the second. If you use this, the incoming wave is 'diffused' and the momentum needs a new classification--its not an elastic or inelastic scattering. I always was struck by the fact that little momentum gets imparted to the object. And little bounce back. Weird. Merry Xmas to all, W1YW
[/QUOTE] Photos of Chip show that he is youthening! Now, that is the technology I want. Congratulations to Chip on his accomplishments! 73, Howie, K2EIR
