Chip W1YW --inventor of the invisibility cloak (USP 8,253,639)--presenting at BOXBORO on Aug 25---LIVE Cloak demo! (and more:-)(left foto K1VR)
***SEE BELOW FOR HUMAN CLOAK LINK**
GREAT TO CU AT DAYTON! (see below)
UPDATED 15 June 2013
"The journey is important but there's nothing quite like knowing you've arrived!"
"So many antennas, So little time :-) "
Hello All de Chip !
I am happy that you dropped by my 'Zed bio. In a little under two years it's gone from 5,000 to 83,000+ views--one of the most popular 'hit's on the 'Zed right now. I will update with fun stuff periodically.
Chances are you've heard or worked me and are curious about my fractal antennas (see Carole Perry's(WB2MGP) cool World Radio story on
Yep, you'll find some info here, but also the story behind it. Most non-hams look at fractal antennas as a 'ham success story'. I am one of many hams who have seen Part 97 as an 'enhancement of the radio art'. We all want you to see the wonderful opportunity that ham radio offers and encourage you to be open to experimentation--and have some fun! Hamming and fractals have led to a new evolution of the antenna art (below are a few examples): it all started OTA!
"If W1YW can build antennas that radiate a signal and can sell those antennas . . . then more power to him."-- Dan KB6NU
Thanks for you well wishes Dan! WE ARE QRO!! Your 'parody' piece in the club newsletters a while back has produced a huge blessing of business for us! It really got people curious! As you mention, 'In the end, his company will live and die by how well,(sic)his antennas work and how much they cost when compared to antennas from other companies.' That is quite accurate. I just wanted you to know that we are doing very well and thank you for your kind concern and free publicity! PLEASE WRITE ANOTHER 'FRACTAL'PIECE:-)!
Now Dan, chances are that if you’ve been in a hospital; a university; a commercial building; a government building; an airport; a plane; a car; a train; an athletic event; a big box store; a concert; a worship service; a doctor’s office; and gee whiz! so MANY other places, you’ve probably run across at least one of my FRACTAL ANTENNAS. Now in the 18th year of business, and 25 years of fractal antennas:-)! Started with HAM-GENUITY:-)
Just for fun,Dan, here's 6 of my (many) production antennas--on parade! Tell your friends OM! Hav'em drop me a line:-)
Vy Best 73 OM!
We make'em; we sell'em--we LOVE them! American innovation with HEART!
Hey---what's IN those (tiny) radomes:-)?? Bet its something SPECIAL!
FRACTAL WHITE: Flying high with fractals!
FRACTAL GOLD: Fractal antennas fresh off the assembly Line! WALTHAM MA
From ceiling to floor--ship'em out the door:-)!
Note that I am using highlighting on bits that relate to questions I frequently get. Also, I have been asked to provide more (cool) fractal antenna pictures, which I will layer in as time permits.
MARCH OF THE FRACTALS antennas shown on this bio US patents 6,445,352; 6,985,122; 7,126,537; 7,256,751; 6,452,533 and pat pending (c) Fractal Antenna Systems,Inc.
Starting with the bottom line: I am asked by lots of non-hams: "DO YOU STILL DO THAT( (ham radio thingy)? " The answer is YES! I am not apologizing. Ham radio isn't a passing fancy tied into a hormonal rush. It's an experience that flowers in layers of friendship; learning; experimentation; and fun, with the deep route of benefiting others--in emergencies; in new technology. Not trying to be gushy, but feel free to use THAT line to shut up the naysayers!
Update 15 June 2013.(I1KH courtesy;now SK)
Copper vest (20 db Attenuation);copper-cloak--return to 0 dB attenuation at high end of passband (about 20% BW)!
What goodies lie inside the radomes:-0?
NATHAN COHEN, Fractals, 20, 227 (2012).
Human Cloaking Video
Peter about to disappear (from microwaves)
Recent copy discovery (note SKIN TONE ) Original-- and fractal deconvolution/skin tone correction (c) Nathan Cohen
Its not a coincidence that, in two last years, I have been readily available OTA, as time permits. I have given many thousands the opportunity--most unwittingly-- the chance to hear and work FRACTAL ANTENNAS. If you've been on CW, especially, you may have heard me working pileups. Only on occasion do I mention the antenna setup(s) (which do change for experimentation): its not an advertisement nor ego trip:-) One cool result of this is my fantastic progress on DXCC Challenge in one year--going from 898 to 2000+. About 2/3 of that is from new Q's on bands from 10M down to 160M. All of those have been with **HF/MF** fractal antennas invisible in the trees. I get dozens of emails asking about my setup. I've decided that I need to savor the results myself for a while, and won't be publishing the details until I am well over 2000 confirmed. I will confirm that I am using collinear fractal antennas that are electrically long, generally in inverted V arrangements. They are not physically long. Essentially they look like dipoles with traps--but they are neither.They have gain and low launch angles. They are not very high up. I do not find dipoles of any value given this option. And beams --well, these are beams as they have gain. They are not 'lawn chairs in the sky' with aluminium tubing.
A recent crew of interns at Team Fractal
Some recent talks 2011 to 2013 (and always updating 'adds'): I will bow out for a while after the late Fall-- too much (good) stuff happening! Returning on the lecture circuit in the Spring:-)
On September 9, 2011 I spoke at the QCWA Convention --- title: " Marconi Lives!: Hi Tech from History (Metamaterials and Fractals)".
On September 21, 2011I spoke on Antennas and Fractal Plasmonics at the Antenna Systems 2011 Conference in Nashville . Met several hams at conference. Had great time!
On November 3, 2011 I gave an invited colloquium on fractal antennas--Advanced Antenna Performance and Development Using Applied Fractals--for the IEEE Communications Society in Boston. Enthusiastic and exciting response. Many hams present!
On January 5, 2012, I gave an invited talk at the American Mathematical Society Joint Mathematics Meetings in Boston: Nuggets on the Tortuous Path--on fractal antennas and fractal metamaterials. One hundred fifty people came forward to see the demo. Way cool!
On August 25, 2012, I was an invited speaker at New England Ham Convention--'BOXBORO'. Title: 'CLOAKING AND THE INVISIBLE HAM' .
On October 13,2012, I gave a presentation at Pacificon--'CLOAKING AND THE INVISIBLE HAM'. Lotsa support! Friendly W6's! Where was my buddy KB6NU;-)?
On October 25, 2012,I gave a invited talk on 'You Can Do That?:Twenty Five Years of Fractal Antennas' for the Boston Chapters IEEE-Antenna & Propagation; IEEE-Microwave Theory & Techniques; and IEEE-Aerospace & Electronic Systems and Electron Devices Societies. Ooooh! Invisibility Cloak Demoes:-)! The world's top expert in radar said it was "an impressive.first". !!!!!!!!!!!!
On November 16, 2012,I gave an invited talk on 'Marconi, Metamaterials, Microwaves, and Invisibility Cloaks' for the Radio Club of America. Ooooh! Invisibility Cloak Demoes:-)!
On November 20,2012 I gave a demo of fractals and invisibility cloaks at the Yale University Math Department. Boolah Boolah!
On February 23, 2013 my fractal work, including cloak stuff,was featured in a TED talk at Yale University. Eat your heart out Harvard!
On March 21, 2013 I gave a talk on 'Practical Fractals and the Tortuous Path' at the Innovation Seminar at Brown University. Giggedy!
On May 18, 2013, I spoke at the Dayton Hamvention at the Youth Forum on invisibility cloaking--with demo!;-0.
In November, 2013, I will be an invited speaker and keynote at the International Conference on Fractals and Wavelets. More info later:-)
In December, 2013, I will be an invited speaker at the Antenna Systems 2013 Conference in Ls Vegas:-) More later:-)
For the folks that want to hear a talk exclusively on HF/MF ham fractal antennas--I am not planning this until after I complete DXCC Challenge at the 2000 level. BTW, I will consider such a talk if kindly asked.but I have no great drive to do so: keep in mind I've been doing this for 25 years and gave dozens of HF ham/fractal antenna talks in the 90's.
I want to savor and enjoy my efforts for myself now, for a while. It's become amusing when competitors use the ham forums to 'diss me and the technology--often while I am--literally-- running DX pileups with my fractal antennas! Go look at the DX Cluster and see for yourself:-) I get spotted all the time: JA; Europe; SA, UA;all spotting 'W1YW'.
BTW, Here's the breakdown(circa April 2013)on DXCC Challenge countries worked by me since Oct 2010 with FRACTAL ANTENNAS. I am also including the number from 1998-2000 for the fractal quad Yagi on 10m. I am NOT including the countries worked pre-fractal, but you can see that a vast majority of countries for DXCC challenge were worked by fractal antennas:
BAND COUNTRIES WORKED(fractal) DXCC Challenge confirmed(1968-present)
160 56(100hrs op) 47
80 109 147
40 173 210
30 207 243
20 201 302
17 219 252
15 224 270
12 182 208
10 310 299 (deletes)
Decide for yourself whether fractal antennas work well at MF/HF.
My DXCC Challenge confirmed has gone from under 1000 in Sept 2010 to 2000+ (projected) in Aug 2013.
Of course, the old articles on previous fractal antenna HF designs are out there, so kindly make some effort to dig them out if you are interested.
The following is long-ish, so a heads up: feel free to skim at your taste.
GENERAL BIO: WHERE I CAME FROM
The shot on my qsl was taken at the WAVE in Arizona. I get many queries on it.900,000 people have sought it out on photonet, for example. I used a Canon 20D (now also use a 5D). If you look hard you can see a 'Y' and a 'W'. That's one of the insights into life: if you look hard enough you will find relationships that are subtle and obvious at the same time. I've had success with my own personal vision in making sense of this wide world by photography and--of course--ham radio. But I'd say ham radio is absolutely the very best teacher of human behavior one could possibly encounter. Excellent training ground!
When I need to hunker down and look deep inside myself, the WAVE does it for me.
I AM a geometer,after all! From my 2010 and 2004 visits.
WN1HBX 1966(add a few years) <::::::::::::>2006 W1YW on my 40th ham-versary
I started out as a young squirt at age 11. Amusingly, as I grow older you can see a trend: the phonemes in my phonetics get shorter and shorter! And my callsign gets more old-timey as I get yet more seasoned:-) Maybe by the 50th I will be down to a 1 x 1 call ;-)
What does it all mean:-)? Well, here's some looking back.
First, I have a deep dark secret: I had an Elmer. He was a famous ham for the time, but inactive now. If you are an OT DX'er, you know K1IMP. Buddy of W9WNV. Yep. Herb was it. That was Milton MA--my kid QTH-- an interesting 'hotbed for ham'. As mentioned there was K1IMP. But there were also, among many others, K1SCQ and W1JNV. K1SCQ is now W1ZK and you should look him up on the web for Ralph's very interesting and courageous story (the events and details of which I remember well). RETURN THE USS PUEBLO!
W1 JAPAN NORWAY VICTORIA was, along with a handful of others such as W1JFG and W1FH , the B-I-G gun DXers in MA. Al, W1JNV, was 'illegally' loud--he had a home brew amp (4-1000-A, tuned by max burn on a flouresecent bulb: Thanks K1LWI for info~!) capable of at least 3KW. Size of a filing cabinet. An amazing character. He was also hard to escape--when he zero beat'ed his RX with his Hallicrafter xmtter, the milliwatt of power would still be 40 over 9 some 5 miles away. He was fun, crafty, cranky, but also a great teacher, and through his DX tutelage I learned much about dealing with a rough and tumble world-- from 'Uncle Al'. Anyway, that Milton origin saw DXCC HR for myself, W1WN (who grew up in Milton (see below)), W1ZK, and W1JNV. A DX cluster, in the original sense!
BTW, if you are geometry fan, you should know that Bucky Fuller grew up in Milton, in fact, up the street from my house. Of course my house was part of an apple orchard back then, that Bucky apparently wandered into frequently. Synchronicity? I seem to be a verb!
The photo below is from WA1JHQ --my Milton station in 1968. How's that for a teenage ham! To me the photo has much symbolism, as it could have been taken yesterday: that means we, as hams, really haven't seen much change in over 40 years on HF. That is both good and bad. So I pose for you the following question: do you see a shot from 1968--0r 2011? Think about it:-) Also, note the fractals in the picture:-) There are two kinds.
Is it 1968, or 2011? Sky aluminum at WA1JHQ
I lived ham radio as a 'tween and teen. And yes; I messed with antennas quite a bit. I got DXCC. I won an ARRL Public Service Award for helping with the 1972 Managua Earthquake. Ham radio kept me out of trouble (that was a drug-saturated era, mind you). I worked at Harvard with W1JFO and W1FPR on OMEGA (VLF). Then the idyllic routine ended. And then there was the the REAL world:
After a bachelor's in physics at Brandeis (with prior short stints at W0IO and W2UC), becoming N1IR, and completing a Ph.D. at Cornell, I had several careers, including a 16 year stint as a college professor, 15 of those at Boston University, from which I retired in 2002. I have been affiliated with many of the major research universities, in one way or another. Generically, I am an 'applied physicist' but radio astronomy has been my main gig (note: my science works have to do with imaging or sensors, for the most part). Basically radio astronomers are antenna guys (and gals) that like to map noise, not listen to it:-) I spent years of my life at the big dishes, including: Greenbank; VLA; OVRO; Haystack; and Arecibo. These days I might best be called a 'technologist' (inventor doesn't really describe it, although I have 41 patents; 28 U.S. patents), and am doing work outside the scope of this forum on a variety of fascinating future technologies. It's a passion that takes up much of my time, with driven effort, combined with an American work ethic built around business and making the world a better place.
An example of what I've done: Below is a pix of 'applied antenna theory'. Twenty years ago,I used my knowledge of making better antenna arrays to invent a method of deconvolution (deblurring) in real-time (20+ frames per second). One of many problems I was constantly reminded that 'couldn't be solved'. Here is a before and after shot of an ultrasound image (utrasound probes are arrays, similar to antennas) where it was applied. This technique is now an integral part of modern ultrasound scans. Interestingly, in working with the 'docs' I was quite surprised to learn that mostly minor 'birth defects' are common in utero, but are usually fixed as the fetus grows--by itself. So it is spooky to see all sorts of 'birth defects' with sharper ultrasound---that's why docs usually don't talk detail on ultrasounds until the third trimester of pregnancy. IOW, you don't want to know.The bottom image is about a factor of 2 1/2 times better resolution. The grating lobes have also been removed, too.
I still am doing medical technology stuff BTW:USING ANTENNAS AND USING FRACTALS. One of my latest patent filings uses RF to target-heat cancer tumors: the blood vessels of tumors have fractal networks, and this makes them unique enough from other tissue that you can find the RF resonances and do RF heating, with minimal absorption by normal tissues.
Funny where antennas will take you!
In my coveted but limited free time, over the course of almost 50 years, are other meaningful professional (and occasional) distractions: I am/have been a guitar 'shredder'; sciencewriter (2 best-selling science trade books); options trader; Master (Free)Mason (since 1991)(God--the ultimate GEOMETER! Almost ALL of creation being FRACTAL. Think about it.); record producer; photographer (couple examples below); and songwriter. My solo project as a recording artist --Americana--now amounts to 5 albums with a million plus hits on MySpace. It is uncanny how strong the link is between ham radio and audio. In 1985 I applied psychoacoustics to the TX and RX chain in ham radio--one of the first uses of 'enhanced SSB': now that a close knit group has grown around ESSB, it is re-emerging for me as part of my audio knowledge and background.
Twang Got Live: 2008 Like Ansel Adams, I long for the high places. Preferably with a rig! (C) 2002 Nathan Cohen
Ah, the fractal desert. Monument Valley & Kanab from a rig-side view (c)Nathan Cohen
I've been told that I look like a 'Renaissance Man' with so much happening! Truth be told, I put a lot of stuff on hold for more than a decade, in part to concentrate on defense related work and concentrate on family. In my later years, it's time to open the floodgates of what I've done:-). There's a LOT of water behind that dam! I still do some gov't work on occasion, but do not do classified work anymore, by my own choice. And my son is now a senior in college. Time to remind others where all those years of hard work really went! The invisibility cloak is just one of many breakthroughs and world-line events I will let out in the next few years. I am fully aware that we all have a short time here and I am making the best of my God given gifts.
What about YOU? What are you waiting for?:-)
Below is the cover of one of my books--sold very well in the late 1980's. A spinoff of my Cornell thesis on gravitational lenses. A 25th anniversary second addition is coming out in 2014. I am now editing another book, that I started 30 years ago and was 30 years ahead of its time. Where did the time go?! Also, another astronomy book is in the works,out in Fall 2013/ Winter 2014. I am catching up with a treasure trove of material that got put aside and now is in various editing stages.Other MS's are on the subjects of innovation, and one on the American university system.
This is a popular science book that spun off from my Ph.D. thesis. NEW EDITION IN 2013!
Ham wise, I am a DX'er. I know non-dxers look at DXing as silly, but it doesn't feel that way. It feels like a hunt. It is immensely satisfying and fun. You are in competition with yourself. At your pace. It's more than an excuse to learn some obscure geographic facts. I am also amused that I am DX to, say, JH1's, for example.
In 1995 I achieved a (nearly) 30 year goal by attaining #1 Honor Roll DXCC. 8BDXCC and DX Challenge also as W1YW. Now at 353/354 confirmed/worked. I am 1983/2095 on DXCC Challenge and expect to hit 2000 confirmed in late 2013. A substantial number of my DXCC Challenge cards were done TOWER-less, and most with fractal antennas in the last two years. I also just achieved 8BDXCC -squared.
Some hard-earned plaques(8BDXCC and #1HR DXCC) as N1IR --previous callsign ,and some recent plaques(TAPR AND DXCC CHALLENGE) as W1YW
With my son in college, I am now more solidly back on the air. I am, when possible, found a few hours on weekends and post-dinner running Q's to Europe, contest style, usually on 30M, 20M, 17M,12M, or 40M. I am 80% CW, with SSB and some RTTY.If I hear someone friendly on AM, I do that too!
Yep. I am now on 160m. More later;-)
Incidentally fellow DX'er W1WN was my best buddy some 40 years ago, and he openly admits I hooked him on DX (Hi Dave!). Dave has an awesome station BTW and if you want to see the creme de la creme take a look at his understated bio! We may have the unique distinction of being ham-pals as kids who then both attained #1 Honor Roll.
DX rules--here's my suggestions for the DX Game:
"LEAD WITH FRIENDLY"--W1YW
"SPIN THE KNOB"--W1YW
DX Message here: It's all about the HUNT! Everyone WINS!
My hamshack from Dec 2012: saved bits from the best of the 70s' to the 10's. The 7700 is now a 7800! Amps below at feet.
Rigs (Active): IC-7800; Command HF-1250, (Henry 2KD backup) as main QRO.Proprietary binaural signal processing on RX. Experimental 'enhanced SSB' psychoacoustic processing occassionally on TX.Various fractal antennas with various gains, directionality, and multi/wide bandedness, up and running subject to sunspots. Occasional mobile on the Caddy SRX (huge engine; 'Vett-like handling; sunroof the size of Rhode Island). One heck of a ground plane:-)
Some comments on the IC-7800 and amp combo. EXCELLENT receiver! I can't say enough about the low phase noise and noise floor. On TX, I, like others, are VERY CAUTIOUS with the power. I don't trust those PA transistors to take 200 watts, or even 150. I don't run them over 100 watts, when barefoot. Instead I let the amp do the work of the $$$$ xcvr modelwith a reputation for PA burnout. For 200 watts or less, for example on 30M, I run the exciter power low and go legal limit with the amp loafing (with a relay box in between). I conservatively runat about 1000 watts out max on other bands; Bird 43 in line. To run 150 watts out I crank the 7800 down to about <10 watts drive.
There's a reason the IC-7800 is the world's best rig: the receivers. I am always amused when some people say their rig hears better, yadayadayada. In fact, if you spend some time using and understanding the variable AGC AND the noise reduction(NR) you will hear WHY this is the world's best rig! Combining them let's you polish a matched filter which is unbelievable at reducing QRN, such as on 160M.
I have stored a backup of an IC-7700. I also now have a 6M amp. I will be exploring 6M QRP first-- then QRO.
Lotsa folks have heard the rumors about my 'custom sub' knob on the 7800. Yep; its real. The stock knob is too dinky for my tastes so I made one up, with finger dimple and fractal patterned finger grip. The knob part was done by a CAD file to a 3D printer. The finger dimple was made by K8FF (plug plug!): this knob assembly is not available on any stock rig. If you can THINK it you can MAKE it! Here's a pix:-)
Nowadays, non-ham wireless alternatives provide much of my knack to communicate: for example, sections of this bio were sent via Iphone from the top of a mountain in Austria--definitive 'shuss'! Others were/are written while 'Island Happy'; sort of like the Corona-beer commercial, only with a Buccaneer Pina Colada, or sitting by the fire and Grandfather's clock at home--and out in the desert under the stars in Utah. It's cool how common this versatility has become. Ah, wireless! Ain't it great? With or without callsign--its a special time to be alive.
BTW, clubbin' your thing? I belong to the IEEE; ARRL; TAPR; Clay Center ARC; QCWA; and RCA.
MY WORLD LINE
Family-wise I have been married for 23 years--one XYL I might add-- and have a son who is also an inventor and scholar, and is a senior at Vanderbilt University as a Cornelius Vanderbilt Scholar; Eagle Scout; and so on. He's so bright I call him 'son' ;-) He has a 3.85 GPA. Sigh; his is a generation that ham radio has little appeal, given other wireless options. We do manage to text, and I have him using CW shorthand. 'Being a family' and raising a son are the reasons I was mostly off the air for a decade. It was a sacrifice-- considering what a great young man he is, it was well worth it! Here's a recent photo of me with my son--
Son and the Source-- July 2012
I have hit a (YOUNG) 58 and can only say--yeh! I'm in better shape than when I was 40. For example, I ski like a dream and am pictured on the home page of a major ski resort (which tickles me pink). I also have a passion for mountain biking and desert hiking (but warn that it's only for those who understand how to deal with the delirium of dehydration). Time has thrown me a few 'scares' in recent years (losing my hearing was a recent one)but I am very much back up on my feet and vigilant about maintaining good health. How about you? I urge those of us hams who are underexercised and overweight to get out and enjoy yourself in the great outdoors. Take a rig along--but by all means get active!
W1YW powder-hounding at 54 in Brettonwoods NH--and a recent head shot (official geek executive hair!)
FRACTAL ANTENNAS: THAT HAM CONNECTION,
Since 1988, I have experimented with fractal antennas and find that I am the pioneer, source-inventor,and expert in an exciting field that is now an integral part of the antenna art. I have seen some unsavory and false depictions regarding my efforts in this regard, so here is some real information, which I expect conveys some of what it was like to be part of this. Keep in mind that fractal antennas have had several hundred scientific papers and dozens of patents since 2003, by hundreds of researchers world wide, so this is now a well established field, although most hams are unaware of it, and many, unfortunately, are not open to the latest antenna developments. Let me concentrate on mentioning the ham aspects, historically, because it actually started with ham radio, and that's how non-hams see it--as a positive spinoff of amateur radio.
You've probably heard of the antenna company 'Fractal Antenna Systems', ( http://www.fractenna.com) which was started in 1995 by myself and my dad, Hy (WN1ZWT, now SK in 2000). Here he is below (Hy) holding a torn-square fractal antenna in the ham shack/lab in 1995 or 1997. That's an antenna made from area copper etch on PCB--not a wire antenna.Company is now in a large facility not far from the old Polaroid plant off Route 128 in MA. I've had a very gratifying ride with real impact on the lives of others with this technology. And although the firm does not sell ham antennas ( the employees STILL need to be convinced), it started with my ham radio work, father and son hams. Hams 'done dude it'.
Incidentally, Hy taught radio in the AAF and was chummy with Artie Collins. But he still wouldn't buy me a KWM2 as a kid:-) Yep; I have one now:-) Really not very good compared to the IC-7700!
Please be aware that only a small fraction of fractal antennas are 'wire antennas'. I mention a specific one (MI2 and FQY)here only because it is easy for anyone to make for their own experimentation.
My dad Hy, (now SK) in shack basement in 1990's,and FRACTAL facility in 2011 with full anechoic chambers, lab, and manu
HMMMM --- HOW ABOUT AN EXAMPLE / HISTORY ?
Lots of hams ask if I am the "fractal antenna guy". Yes, I am the fractal antenna guy. Since 1988, starting in my dinky Boston apartment, and eventually migrating to the changing table and then basement of a real QTH: I am the inventor
START HERE: First fractal antenna built and tested--and cut down by landlord Winter 1987/1988
of fractal element antennas, again, from my ham radio fun.
Fractal shapes are common in nature because they allow for optimized processes. And if you wonder why a fractal should make an antenna (lightning is fractal and an RF source BTW), I suggest you turn it the other way around--and ask what shape(s) RF currents make to dissipate charge (that is, radiate). Here's one of my favorite demo's from Youtube--where RF MAKES a fractal antenna:
Below is a limited excerpt from the PBS fractals show where some of it is recounted (shown under fair use for educational purposes). Note that Benoit asked me to appear, and the segment was filmed in Spring 2008:
Being of modest means and buying my equipment from the MIT Flea market, progress on fractal antennas took me several years. For example, I made initial gain and pattern measurements with two Drake TR22C's and a precision attenuator. I later bought a cruddy old network analyzer. and, of course, there was MFJ stuff. To satisfy quite a few queries on some ham history: Here I am (pixs a bit below), in October 1994, in the early years of development, testing some early fractal antennas with my son--then 2. Notice the bag of cookies! This proves that those who experiment with FRACTAL ANTENNAS HAVE NOT LOST THEIR COOKIES :-)! These were chocolate chip BTW. Son is now a head above me and 21 .
Wanna see the first article -cover on fractal antennas? If I get enough interest, I may make the article available. The ARRL has been extended the option of free electronic reproduction rights to the article, but has not responded to the offer, which will expire soon. The article was held (for republication) for many years by me due to the emphasis on military work I was involved in. Now, the efforts are successfully commercial and fractal antenna research is done globally. And the state of the art is at least a decade ahead of what's in the journals. Here's the cover, from Summer 1995. This is the article that started it all:
The element you see me holding from 1994 (with my son holding the cookies)is essentially a fractal loop MI2 which, with slightly smaller bandwidth than dipole, is basically equivalent. But ITS ABOUT 1/4 the size of a dipole!No matching or coils or caps. What makes that cool is it's only about an 1/8 wave on a side, so its very tiny.
Because this is a simple antenna to build and illustrates many aspects of interest to hams, I am only focusing on this one design here.
Here's the current amplitudes. Two current max that phase together to give high polarization integrity and dipole equivalent gain--in 1/4 the size of a 1/2 wave dipole! In other words, you could fit nearly 4 of these fractal loops INSIDE a quad loop.Ooooh! Pretty:-)!
Not magic--it's physics.The big deal on the TWO CURRENT MAXIMA is that they are sufficiently separated to interfere constructively and render a small amount of gain.Thus the gain and bandwidth, because of two current maxima, is HIGHER than an 1/8 wave conventional loop. There (1/8th loop, not fractal one)you have one current maxima , a funky pattern, no polarization integrity, and so on. The fractal has essentially given you an electrically long structure in a subwavelength size. Obviously if you continue to shrink to an antenna that is VERY ELECTRICALLY SMALL you end up with a transmission line and feeble radiation. Even in the very first fractal antenna papers I cautioned against that. No one involved with the invention of fractal antennas has ever claimed huge performance on a grain of rice sized antenna. That is pseudoscience. Don't look at me! ;-> I worked hard for my Ph.D. and ain't no one taking it away:-)
A MI2 fractal loop modeled with Jerry Burke's NEC4. Footprint about 1/8 by 1/8 wave.
Would you like to see the gain? Below is a pic of a MI2 being prepped for measurement in my range (this one is at microwaves) and the accompanying gain,which peaks at about 2.5 dBi. The bandwidth, as shown , would be equivalent to the entire 20M band. So, yes, you CAN make a small, high performance 20m fractal loop. I've done it.
Of course, if you can a LOOP you can make a beam--a fractal quad Yagi!
The pix to the right (below)is a 10M/12M version of the Fractal Quad Yagi (FQY)(which uses two fractal MI2 loops)up at my QTH from 1998-2001--about 4 1/2 feet on a side; 5.5 dBi with 25 dB F/B and (despite rumors to the contrary) easily made bent wire loop(s) with cpvc spreaders. Essentially I leveraged our knowledge of how to support quads, with the electrical advantages (and there are many: hundreds of researchers worldwide have corroborated this in the last 8 years, for example) of fractals, for this antenna.The performance is very much what you get with a 2 el cubical quad, which is 4+ times greater in its volume. Want to drool on the fractal quad NEC sim? It's even further to the right as an azimuthal plot. Notice 5.41 dBi (free space), great polarization integrity, and excellent F/B. This is a really tiny antenna with excellent performance.
Note: pixs (c) 1994, 1995, 1998,2009, 2012Fractal Antenna Systems,Inc. or as noted.Used by permission
Fractal antennas, jr op, and me in Oct 1994 My Fractal QUAD: RIP 1998-2001 Gainfully employed!(includes ohmic losses)
I worked 310 countries with that antenna, came 4th world wide in the 2000 10M Contest (low power single op)--and it sustained icestorms and wind. No matching; SWR better than 2:1 over almost a MHz at 10M. Only vandalism ended its ruling the airwaves:-0 NOW-- THIS fractal antenna is just one fractal design that I have come up with and used in ham radio. Its been published; it's been proven. My company sells (and has commercial customers with) a version of the element even today (in fact, just got a partial deliverable of 200 out the door as I write this). Still waiting to see something that performs better in that tiny volume: about an 1/8 by 1/8 x 1/8 wave. If so--WHERE IS IT :-)? Been waiting almost 14 years to see a better, smaller, Yagi antenna. This is far smaller than a spider, hex or Moxon, for example. Show us a practical ham antenna that is just two bent loops of wire--with no matching; no elaborate supports; and so on, that exceeds this performance in this size :-)
Wanna see an azimuth plot of a FQY? Below is a RANGE MEASURED azimuth plot in free space on a calibrated range at 1200 MHz (see the photo mentioned above for a look at the element; this is a quad made from that element). Peak gain about 6 dBi with quite good measured F/B. If you aren't getting the right F/B you have either got the sizes wrong (slightly) or gone for a dB or so more forward gain. Alternatively you should play with the element spacing. I recommend #6 wire, no insulation for HF versions. Also, note that if your element resonance is to low, you can short out one of the inner stubs (that is replace it) to cut some inductance.
There is much ado about efficiency in ham antennas. So, are you ready? THE FRACTAL LOOP ELEMENT IS OVER 95% EFFICIENT, with copper losses of about 0.2dB. So please: those who harp on 'fractal bending only introduces loss', go try flying a kite (for 160m:-)) And please identify yourself honestly--we know you are a competitor! So much for the benefit of making more than one current max in a small area! Fractal antennas are a lot more than bending; most aren't even wire antennas; ohmic loss only becomes an issue when sizes are much less than 1/20th a wave in size. GO SHOW US SOMETHING BETTER FRIENDS!:-) If you don't want the world's smallest and best performing small HF antenna, without components or matching, then try something else:-)
Here's a summary for this 'fractal quad yagi':
ANYONE ELSE USE IT--- ANOTHER EXAMPLE?
Many of you have asked me about F3DD's 20M fractal quad , which is up and running in 2012. I confirm he is getting better results than a conventional quad, and this is expected at his 10m height: a conventional quad droops lower to the ground so the lower section radiationhas a higher launch angle .Essentially shrinking the quad with the fractal HAS NO COMPROMISE OR DOWNSIDE: great bandwidth; no matching; minimal loss; high gain; great F/B; no components. Note that he is driving BOTH elements (it is a driven array), out of phase (as driven)by 135 degrees. the delay lag between elements ( 1/8 wave)puts a phase delay of 180 propagating . In this configuration, the 20m fractal quad is heavily 'supergaining', which should have a dramatic decrease in BW, which he is not seeing. I will be running experiments here, as needed to assist him in his understanding of the results.There is nothing erroneous nor 'new physics' involved. Kindly leave him alone and let him enjoy his efforts please. Thank You!
I'm not the only one to use this design--ON THE AIR :-) Here's a comment from a fellow fractal antenna experimenter KF7BS--who is a fellow ham, but otherwise not affiliated in any way. Gary Schweitzer had the cover story on this antenna in 73 Magazine in 1999. Gary's article contains more than sufficient info to build the antenna for your sole experimental purposes:-)In response to my recent query on his recollection (TU Gary!), back in the last Sunspot cycle, Gary found:
"I first put it up for testing on my deck railing about 6 feet off the ground. As I was testing I heard a station from Australia calling CQ, so I answered him. He came back with a 5-7 report. I switched to the vertical I had on the roof at the time and he barely heard me. When I raised the antenna to 45 feet, I decided this was the best antenna I had ever used. Keep in mind this was on the upslope of the sunspot cycle so 10 Meters was in good shape, but in a 1 year period, I had worked over 185 countries and in several 10-10 QSO parties, I was the guy everybody was trying to contact instead of the other way around. All this with 100 watts as I've never owned an amplifier. In conclusion I would say this antenna performed beyond my best expectations both in characteristics and on air performance."
KF7BS captures cover with a fractal; a commercial (non-ham) FQY with 3 elements
By my count, about 155 people built fractal quads. There are quite a few being built now; fine with me!. If you wish to give it a try, I suggest you hit up Gary for a pdf or reprint, or hunt it down on the net. I am happy to debug in a pinch, if you get stuck, but in general I shy off from technical support unless it relates to a very recent article of mine.
There is a myth that this antenna is too small ('electrically small') to work. The answer: that's wrong. the Chiu- Harrington limit is much smaller than the size of this antenna. If Mozzie can build one onthe TV show WHITE COLLAR, so can you:-) This is a false myth lovingly placed and amber-watered religiously by my professional antenna competitors and those who have their own issues. Ahhh ! Ham radio! Occasionally we fail to purge the CB culture many of us started with. There's still time to reform !
High school kids commonly win science fairs with fractal antennas. If they can bend a wire and make it perform, then what's stopping you"-)? Take chances. Get dirty. Have fun.
I know there are occasional grumblings about my 'failure to disclose' any ham fractal antenna designs. I find this hurtful and a little bizarre: from 1995 to 2001 I published several in the ham magazines( Comm Quart; 73; DX Magazine)and actively discussed them on the internet and on the air. F3DD is an excellent example (http://www.f3dd.org)of someone who used my available info and did what ham's are supposed to do: EXPERIMENT AND HAVE FUN. My time is defined by action--right now there is huge commercial and DIY interest in fractal antennas, and only a modest amount with hams. There are probably over 100,000+ DIY fractal TV antennas that have been built in the last 5 years, for example.
Note that right down the street from me, AG1LE has a FQY up. Needs some tweaking on the element lengths, and I don't recommend a slant 45 feed, but frankly a nice job! He gets 2 dB gain over a fullsized vertical, while pointing off the the side, so he's losing at least 3 dB by not pointing properly: beams were meant to be turned:-). See his webpage for details.Can we stop the false silliness that this is hard to build? Mauri did it as an afternoon project. Here's the picture from his bio page:
(c) AG1LE--from his bio page
AG1LE's FQY with slant 45 feed (not recommended by me)
Hams ARE interested in fractal antennas, but the truth is few hams really like to build new things (I have great empathy and respect for those that do). I will continue to help those who make the effort.
FAULTY FRACTALS AND THE TORTUOUS PATH
Innovators have to pass a time-depleting gauntlet called the 'tortuous path'. Many die before their innovations see wide use. I have been lucky in that I have seen THREE tortuous paths, while alive! It hasn't been pretty, but to create and watch tech adoption of your baby is about as satisfying as anything you can imagine. Right now, I am one happy ham!
Of course there are those who actually LIKE placing others in harm's way in innovation, and there are a few of these, quite vocal, who are hams. The effect of such cannot be ignored: It is a myth that ignoring such comments lessens their impact: See, for example,
This makes for an interesting section in an upcoming book I am completing on innovation, which shows that merely presenting the facts and letting reason prevail is a poor and ineffectual means of letting the innovation take its course. In fact, that is the best possible way to let it die, have the pioneer get dissed and flattened, and for others to gain credit and financial gain later on. There are hundreds of such examples; in radio there are Tesla for wireless; Farnsworth for television, and so on.
Here's a tiny taste of that tortuous path.
First, I am always amused when I hear the lame explanations on how fractal antennas 'don't work'. My favorite is the bogus explanation that 'fractal antennas are nothing more than radiating coax'. Yes, I know that's just ridiculous, but it was all the buzz at Dayton, based on a comment by a ham who lives here in my home town. This actually is attributed to a hammy Harvard University physics Ph.D.! I guess Harvard Phys gives lessons in silliness. Needless to say, that grad ham is actually not DOING physics anymore .So here's my challenge to my Harvard Phys colleague: you put your Ph.D. on the table and I'll put on mine. Then we'll take that fractal antenna you are talking about and measure it choked (actually all my antennas are measured choked). If it works, you send a letter to Harvard and give up your Ph.D., and visa versa for me at Cornell if it doesn't work. Do you have the intestinal fortitude to back up your asssertion? I do:-) Go for it! Or, as they say, shut it up and shut it down:-)
Here's a second example (you can track down yourself) that's a little more transparent: AE5CC
Many hams enjoy antenna modeling, and that’s why I used to give out—15 years ago now—files for this MI2 and many other fractal antennas. I have stopped doing this, because there is so much error with some of those using and diagnosing these modeling simulations that I just don’t have the time to sleuth why each odd case is done wrong, and telling you how to fix it. I am very sympathetic, in contrast, to those who actually BUILD antennas. You’re a ham—build something!
A recent and well publicized case of a faulty modeling attempt is by Lloyd Van Warren, AE5CC. ‘Van’ has modeled an MI2 (and up to MI4) antenna using various software pieces, with NEC. He finds that the MI2 antenna is down 10 dB from a dipole, and is slightly bigger than the actual MI2 antenna. Van, you are off by 10 dB buddy!
Perhaps someone who knows Van cans set him straight: there have been numerous verifications of the performance of the Minkowski fractal. It is dipole equivalent gain. The results have been modeled, published, and well known for 17 years. Van's results appear to be off an order of magnitude or more from the reality, for example MI2. Van, your results and your conclusions are grossly in error.Kindly spend some time debugging.
Here's what your power pattern/gain SHOULD look like with NEC, done properly:
The results (gain):
ACTUAL MI2: +1.7 dBi or better ;-)
AE5CC MODEL: -8 dBi or worse :-(
Here's what I sent, cordially, to Van a while back---
I dropped the following info off to my colleague AE5CC:HereHereThanks for checking out my MI2 fractal antenna, a patented design (USP’s 6452553 and 7256751). I appreciate that you enjoy simulation, but I do want to make sure you are aware of the gross error your simulations show on this and other fractal antennas. I also want to encourage you to build antennas in addition to simulating them, as hardware is the ultimate goal of antenna analyses, and measurement is an independent guide to the accuracy, or lack of it, of simulations.
For example,the MI2 (second iteration) modeled in NEC4, reveals a 97% efficiency and dipole equivalent gain. Recently an open house with members of the Radio Club of America showed this to: K1VR; WB2MGP; K1BG; WA6RNU; W0BIW; KD0FAA; and several others. In addition, the visitors were treated to actual chamber measurements of a wire-bent MI2 at 175 MHz, Its gain was indisitinguishable (within 0.2dB) from an ETS calibrated dipole of 1.7 dBi. This fractal antenna is thus unity gain to a dipole and not down 10 dB as you report in your blog. I trust you will take these facts and correct your assertions publicly available on the web.
To aid fellow hams I will place a public copy of this info on my bio page
Wishing you the best and happy hamming!
NOTE: As of June 15, 2012 AE5CC has acknowledged the discrepancy between verified results of dipole gain for the MI2, vs AE5CC modelling of -10 dBd. They have not been corrected on his blog however--more than a year later.
Here's a pix of that MI2 I built EASILY in 5 minutes from bending wire. It's 9 1/4 inches on a side, which makes it resonant at 175 MHz with unity dipole gain. TINY!!! A squeeze above 1/8 wave by 1/8 wave.
Now, Van seems rather 'focussed' on making this for 160m.I have no idea why. I am already using small, efficient fractal antennas on 160m. This is not a design for 160m, and I didn't recommend that for 160m:-)Maybe he should ask the competitor that recommended it;-)?
AND TODAY--- OTA WITH
Today I am also using a variety of (very different and very different looking) HF fractal antennas (here's a portion of one design example pix below), but have no interest in seeing them vandalized. All I want to do is have some fun and keep them hidden; small, high performance; and so on. I certainly am having the time of my life DXing and Q'ing--and I ain't using a G5RV or aluminum beam! I am always testing and switching around fractal designs, weather and health permitting.
To give a sense of size and performance, imagine a 1M dipole that is full bandwidth on both 10M and 12M with virtuallly the same directivity as a dipole. Form factor 2 inch diameter. Weight less than 1 lb. There's that Part 97 experimentation and 'enhancement' bit!
At the moment I have fractal antennas for a rotating basis, for 80M -70CM. All are multiband; they are all hidden in trees. My observation, so far, is that I 'get out' best to worst in the following order for HF: 30M; 17M; 40M;20M; 12M; 15M; 10M;80M;160M. The antenna experimentation continues. When I get something more permanent I will do scaled down versions of the antennas, at UHF,and measure their calibrated power patterns in an anechoic chamber.
I am still trying to understand the intrigue of 160M. I have a 160M fractal I put up occasionally and am experimenting. The launch angle issue is a fascinating one to work out. However, the QRN on 160M really does a number on my hearing. After a few minutes listening on 160M my ears literally ring. I do appreciate the many friendly and technically savvy OM's that hang on 160, BTW. As mentioned, I have about 100 hours on 160m over two 'DX Seasons': 56 worked/45 confirmed.
section of one of my HF antennas, 2012; Here is a section before it gets weatherized and raised; raised barely visible
Most hams are happy to know that smaller antennas are possible---but then take some used wire and throw up a dipole. Hey! I think think that's great! Any way of operating these days is a plus, as most US hams have not been OTA in years, if ever. And, of course, a vast majority of US hams have never been near the HF bands. ANY antenna is a springboard to a new world. Dive in! Join us!
MORE FUN WITH FRACTALS
In mid-2007, after 12 years, the US patent office finally acknowledged, through patent award, that I am the pioneer in the use of fractals in tuned circuits ('resonators'), IOW, fractal resonators . This topic is now a hotbed for researchers in electronics, who have also (re)discovered the value in using fractals, particularly in small, sharp, multiband filters at microwave. Thus I have had the humbling distinction of giving rise to at least two modern technologies from my Part 97 tinkering:-) Below is a cover of a book on the subject and one of my fractal filters, a field I founded more than 20 years ago. 'Time will tell'! Indeed:-)!
I have been acknowledged via patent as the 'source' inventor of fractal filters. Folks are slowly catching up:-) USP 7256751
Lately I've gotten some notoriety for inventing the first wideband invisibility cloak (it uses fractal resonators). But sorry--I really am not interested in Harry Potter! Take a look at the video links below:
In October, 2009, my firm announced a new antenna technology that marries fractals with metamaterials. Makes for some really cool antennas that haven't been produced in other ways. Just uses layers of fractal circuit boards and a more conventional antenna as an exciter/probe. Take a look at the video link at the top of the bio.
So, just to make it clear, I am also the 'source' inventor of the invisibility cloak. Stay tuned for more 'invention' info on this in the next few months. Some folks believe it was invented by researchers in England and at Duke University. The patent office has not acknowledged that and that claim cannot be made
There's still a lot of innovation coming out of the Old Man--the HAM :-)!
USP 7,256,751 and pat.pending
Cross section of fractal resonators/metamaterials, juxtaposed as part of the first wideband invisibility cloak. Note analogy. Note restoration by cloak at right
The trick is for us, as hams, to keep it up, and not fall back on past efforts. Take chances. Try something new. Make mistakes. (To paraphrase Miss Frizzel:-) Use this all as an incentive to learn--and ENHANCE THE RADIO ART:-)
SUMMING UP: A PEP TALK for Y-O-U
If I could pass along one life-lesson to readers of this summary, I want to emphasize that 'sticking to it' is a major virtue that is little celebrated these days. In a chaotic, rough and tumble world, "press on regardless" is often the only separator of eventual success versus existential and then continual failure. As hams, we learn this lesson well: many of our achievements are cumulative--think DXCC and other awards for example. That's actually fairly rare: America is all too often about the BIG payoff or the abject failure. Oddly, failure seldom has to do with whether something 'works' or not, but rather some outside agenda that is people-driven. An up or out view of failure is nonsense. If you have something, then you fail only if you believe the Sirens of Titan. There's plenty out there! For example, some people are unhappy with others efforts and do malicious things: witness VE1BLL's (I do not know this person) identity theft of my call for a 'blogspot' website--along with comments I did not make. The sirens whistle loudly, but listening is nonsense: save your ears(and I know something about saving your ears) for the pileups.Life is not ephemera and wasn't made for amateurs (as opposed to radio amateurs hi hi). You leave only footprints, so get on with it :-). In summary, I want to encourage you to "suck the marrow out of life" (H.D. Thoreau) and hope that my example will encourage you to enjoy ham radio--and be the very best you can be.
73 to ALL
aka the Source
Last modified: 2013-06-18 00:46:39, 140390 bytes cached
This user has no active logs
Does this page contain inappropriate content? If so, Report this page...