Taking a quick look at a Fractal Antenna

[@andrewmcneil]

What do you think of fractal antennas?

[@JamesGraingerJC]

Extremely curious!

[@urgtuiop5455]

Its snake oil. Paste over the detail in each triangular pane with silver conductive ink and see if there's any significant change at all.

[@andrewmcneil]

@@urgtuiop5455 I agree but they do have a die hard fanbase

[@jafinch78]

"Fractal Antennas" are like "Metamaterials" designs literally where very specific design requirements have to be defined and the designs made to meet those requirements. The range of shapes alone can be overwhelming and at least is to me. They're great for reducing the size of antennas and have really enabled wireless communications to get so small without bonkers sized antennas. They're more-so a thing in the cell phone world frequencies on up, though does seem like there are some VHF and UHF capabilities that are successful, albeit not marketed anywhere I've seen. Kind of reminds me of a situation where stating traces are voodoo and no good and dead bug or breadboard or something other designs are better. There are definitely design considerations that need to be made to be effective. Might even be the designs have to be used to be effective in the situations requirements where size and weight are the limiting factors. However, well thought out and designed traces, stripline and or microstrip can create a whole nother world of potential. Similar with fractal antennas and metamaterials. They're insanely amazing IMO. One design that gets me amazed seeing, is the design where is like a sleeve that is a roll of fractal antennas on a sheet that goes over a traditional single straight wire element, say like an old fashioned car antenna. Last I knew there was a video on YT with the before and after effect shown on a VNA. Amazing change in band capabilities performance.

[@quadcorei8085gen2]

Well if it is not tuned well you can scan it, scale it, print it on a PCB with toner transfer and have a tuned one in a few iterations. would be nice to see the radiation pattern.

[@jafinch78]

Thanks for the detailed assessment. Very particular little buggers from what I've seen. Reminds me of the worlds of designs like I noted in the comment replies below. Love how you noted requires more a mathematician versus and RF Engineer. Probably is like a closed circle of subject matter experts that may be more open about what they're doing than most know, though most get lost in the complexity and very specific design situations. Definitely a design frontier, with some interesting decades back observations and applications somewhat I guess if thought of like I do from the thinking like a fractal antenna is a metamaterial in 2D more so, even though there are 3D fractal antennas that I think are a metamaterial from my observations.

[@MrJeffschefke]

I feel like im miss reading something here, a 1.2 SWR is like 1% loss isnt it? Is this a different scaling or something then im expecting?

[@andrewmcneil]

Its return loss its not the same as VSWR

[@gammaleader96]

@@andrewmcneil I'm with @MrJeffschefke, I understand return loss (normally in dB? for a logmag diagram), SWR etc. but I'm not totally sure how your setup is scaled so I don't think I understand the absolute values of your measurements (the relative shape is clear of course) Maybe you could do a short video on your setup and how you calibrate it, etc. I think I'm not alone at enjoying a testgear video. :) Otherwise a very interesting antenna design, I always thought this kind of "regular" fractal design is more of a theoretical thing but it seems to be used after all.

[@andrewmcneil]

@@gammaleader96 Will do

[@Masirah1]

Thanks, consider me on the same group of audiences.

[@kevinrtres]

@@andrewmcneilThanks, I was wondering about it myself.

[@TheElectronicDilettante]

So as I’m trying further my knowledge of Radio and related topics, I’ve been trying read everything I can find on the subject. As I was just reading an antenna design book I came across this passage that made the use of fractal antennae make sense. “As we decrease the wavelength (increase frequency), we decrease the model size in the same proportion. To build wide-band antennas, we need structures that can be their own scale models. One approach is to remove any characteristic length by specifying the antenna only in terms of angles.” -V. H. Rumsey, Frequency independent antennas, 1957 IRE National Convention Record, pt. 1, pp. 114-118.

[@Sonex1542]

I really enjoy the fact that you actually measure the antennas you have on thos channel. What good would it do to just flash them on the screen without putting them on the analyzer.

[@andrewmcneil]

I think this is the reason why they won’t send them to me to review!😁

[@seavil1]

From my understanding Electro Culture society likes to use fractal antennas for receiving energy from the atmosphere and charging the soil to produce a much faster and bigger yield in their crops. Just lookup Electro culture and you will see what it is about. I believe if you can get into this field, you might find many knew things in the antenna world and even help the culture improve on their antennas. A lot of fractal designs were first seen in cathedrals. Some say cathedrals were a huge receiving station for energy to heal people or the society around the cathedral. There is so much to look at and research about. I hope you find this interesting; I would like your insight in this field.

[@Phil659]

"Electro culture" is garbage. Plants dont grow with electricity.

[@TheTemporalAnomaly]

It will have a quarter wave resonance dictated by the height from feedpoint to the top of the triangle, that is assuming there is no groundplane under the copper. I am guessing it will show a wide band resonance around 1200mhz, just based on my estimate of size against your fingers. Ebay is full of these shady products, there are nearly as many of these as there are fake RF transistors. Great channel, seen a good few of your videos. Chris, UK.

[@catalinalb1722]

Hello Andrew, thanks for measuring it! I have it too laying somewhere... For a log time I was wondering if a PCB Fractal Antenna Minkowski style could be made for 13.56 MHz (NFC) as a Loop. Dimensions around 20x20cm. What do you think?

[@jchowdyovi]

13.56 Mhz is an interesting choice for a home hobbiest. ;)

[@andrewmcneil]

Please tell us why 13.56 sounds interesting

[@Jack-j9r9p]

Hi. I'm interested in designing & building a Minkowski fractal loop antenna for 14 & 28 MHz. Jack

[@Superkuh2]

There's no use for fractal antennas, they just look pretty. A simple meanderline would do better well. Any space filling curve would. But this isn't even a meanderline type fractal antenna; all those little triangle gaps are just within a normal planar monopole conductive outline; they slightly increase the electrical length, that's all. "Fractal" antenna usually just means "scam".

[@jafinch78]

Like in this situation, where I do definitely agree, or in general? Are fractal antennas not used in cell phones all over the place successfully? Seems to me in generally stating "fractal antenna" or even "metamaterial" is a scam, is false. Again, I do agree for most being sold some generic product, is most likely maybe. The "fractal antenna" and "metamaterial" designs need a more detailed and subject matter expert understanding like I find analogous to dead bug, breadboard and PCB trace design to microstrip and or stripline designs. RF systems wouldn't be so good now days without the transition to PCB trace design and then for the higher frequency systems microstrip and or stripline designs. Similar speaking situation. Junk if not well planned design and for specific implementations. Maybe even can say like a different situation where like RF versus Optical designs for the transition from below to above the microwave range, albeit not really so far different in design carrier current and free air coupling methods.

[@chip-s5f]

Fractal antennas are used in jets, university housing, medical devices, stadiums, hand held devices, and lots more. They arent pretty because you never see them as they are inside devices or covered in radomes.

[@Superkuh2]

To respond to both of you, note that I did not say fractal antenna don't work. I said they have absolutely no benefit when compared to simple space filling curves or random equivalent metallizations. They're equivalent. The 'fractal' bit is entirely to attract RF engineer's interest. The performance is the same as non-fractal patterns of the same scale.

[@jeffschroeder4805]

Is there any way to fine tune the effectiveness for various frequencies" You don't have an easy way to shorten the antenna or modify the ground plane.

[@andrewmcneil]

There is no easy when it comes to fractal antennas. I think to truly understand them you have to be into mathematics more than RF engineering

[@railgap]

Someone found a way to build an antenna with worse response than a discone! That's an achievement, of sorts. XD

[@bradthelad3000]

Does anyone know is there such a thing as a fractal antenna for 5g LTE..I would love to have a series of flat antennas on the inside of my top floor window to suck in mobile internet. Appreciate any thoughts. I only ask about fractal antenna as its flat and would be easily mounted on a window pane..thx

[@Dr_Wrong]

Try a Fractal Rusty Nail!

[@andrewmcneil]

😂😂

[@TuttleScott]

that's not a fractal antenna, its just an antenna that looks like a famous fractal geometry.

[@andreamitchell4758]

it's actually the tri force of power

[@tedmead465]

Experimental Ground plane with a Fractal design of radiator

[@Dr_Wrong]

This. This is exactly why I can't figure out wtf antennas physically do!