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Evolved antenna

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Re: Evolved antenna

#21

Post by aequitas »

kirubakaran wrote: post #11
aequitas wrote: post #7

Reminds me of an old article about evolutionary circuit design. The computer was tasked with creating a osscilator using physical hardware. It created a really complex and unconventional design that no-one understood, but it worked, only not work outside of the lab. As it turned out the algorithm had designed it in a way that it used the radio noise from the computer it was running on as a source. It had effectively…

That is super fascinating. Do you happen to have a link?

It was in a magazine I read in my youht 20 years or so back. I'll try to find it online if it's there.

Re: Evolved antenna

#22

Post by jarfil »

joe_the_user wrote: post #16
aequitas wrote: post #7

Reminds me of an old article about evolutionary circuit design. The computer was tasked with creating a osscilator using physical hardware. It created a really complex and unconventional design that no-one understood, but it worked, only not work outside of the lab. As it turned out the algorithm had designed it in a way that it used the radio noise from the computer it was running on as a source. It had effectively…

Seems like an entertaining story but for that to work, the computer would have to have physical access to either each version of the circuit it designed or have the radiation-conditions in the lab programmed into its fitness functions. Neither of these conditions seem at all likely. Any evolutionary circuit design would involve the evolution of properties as modeled by some equations (as the antenna design process do…

An FPGA is a physical circuit that can be reconfigured via software on the fly, it should be possible to run an evolutive algorithm by running every iteration on actual hardware... so it should also be possible for the algorithm to optimize for amplifying some local interference.

Re: Evolved antenna

#23

Post by [deleted] »

tomatotomato37 wrote: post #20
elil17 wrote: post #2

They say this is only used rarely. I’m curious why people wouldn’t design every antenna this way

Talking less about antennas but more about the overall concept, most evolutionary algorithms don't take manufactoring into account at all, so they tend to be a pain to actually build.

[deleted]

Re: Evolved antenna

#24

Post by aequitas »

scrooched_moose wrote: post #17
aequitas wrote: post #7

Reminds me of an old article about evolutionary circuit design. The computer was tasked with creating a osscilator using physical hardware. It created a really complex and unconventional design that no-one understood, but it worked, only not work outside of the lab. As it turned out the algorithm had designed it in a way that it used the radio noise from the computer it was running on as a source. It had effectively…

Was it Creatures From Primordial Silicon? http://www.netscrap.com/netscrap_detail.cfm?scrap_id=73 They used a FPGA for voice detection. It was fascinating they didn't understand how it worked, and it wasn't a universal design because it depended on manufacturing variation.

I read it in a Dutch magazine, but it could very well have been based on the article you're referring to. It was a lot shorter, but 1998 seems the right time.

Re: Evolved antenna

#25

Post by guelo »

dbcurtis wrote: post #6

Interesting to see this antenna here. I heard the creator speak at a local IEEE event a few years ago. Quite remarkable. Nobody would intuit an antenna design like that. Great demonstration of the power of GA. Antenna optimization software has changed antenna design completely. Before wide-spread computer simulation, there was an awful lot of antenna range cut-and-try. Antennas are much better now. Learning to drive…

Are the software radiation simulations accurate? Are they based on solving complex physics formulas?

Re: Evolved antenna

#26

Post by gooseyard »

aequitas wrote: post #7

Reminds me of an old article about evolutionary circuit design. The computer was tasked with creating a osscilator using physical hardware. It created a really complex and unconventional design that no-one understood, but it worked, only not work outside of the lab. As it turned out the algorithm had designed it in a way that it used the radio noise from the computer it was running on as a source. It had effectively…

maybe this?

https://www.damninteresting.com/on-the-origin-of-circuits/

ive re-read that piece dozens of times, the implications are fascinating.

Re: Evolved antenna

#27

Post by sevensor »

gooseyard wrote: post #26
aequitas wrote: post #7

Reminds me of an old article about evolutionary circuit design. The computer was tasked with creating a osscilator using physical hardware. It created a really complex and unconventional design that no-one understood, but it worked, only not work outside of the lab. As it turned out the algorithm had designed it in a way that it used the radio noise from the computer it was running on as a source. It had effectively…

maybe this? https://www.damninteresting.com/on-the-origin-of-circuits/ ive re-read that piece dozens of times, the implications are fascinating.

There's a reason that conventional design uses models that abstract away the particulars -- in this case the evolved solution isn't robust to process variation in the FPGA. It's really easy for optimization to exploit irrelevant details to give you designs that aren't very useful. I'm no skeptic when it comes to EAs -- I did my dissertation using them, and I've subsequently written one of my own -- but you have to have realistic expectations for them. They get a lot less magical when you look at them up close.

Re: Evolved antenna

#29

Post by dbcurtis »

guelo wrote: post #25
dbcurtis wrote: post #6

Interesting to see this antenna here. I heard the creator speak at a local IEEE event a few years ago. Quite remarkable. Nobody would intuit an antenna design like that. Great demonstration of the power of GA. Antenna optimization software has changed antenna design completely. Before wide-spread computer simulation, there was an awful lot of antenna range cut-and-try. Antennas are much better now. Learning to drive…

Are the software radiation simulations accurate? Are they based on solving complex physics formulas?

Well..... for some definition of accurate.

For large antennas with thin structures, the typical solver is "Method of Moments". NEC2 was developed by the government and is public domain. It is quite popular, and does some things well but it is also easy to stumble into modeling bugs/deficiencies, and isn't much use above high UHF. But is very useful if you know how not to step in the bugs, and is free. NEC4 falls under ITAR, the last I heard. So it isn't particularly hard to get a license, but you have to clear ITAR.

Microwave structures are more often done with a finite-element model, as I understand it.

Both rely on numerical approximations to Maxwell's equations. At least for MoM, each element cheats the boundary conditions a bit in order to make the problem tractable. With a fine enough grid, you get a good enough answer.

Another friend that has started two antenna companies is an NEC4 guru. I asked him: "How can I tell if my model has a small enough grid?" Him: "Keep reducing the mesh until the answer stops changing. When it stops, you had enough elements in the previous try." Antenna modelling is a bit of an art, I'm not expert, just hack a few as a hobby.

Re: Evolved antenna

#30

Post by auslander »

And then there is phased arrays, a computer-controlled array of antennas which creates a beam of radio waves that can be electronically steered to point in different directions without moving the antennas.

Pure math (matrix of delays per element). Go crazy :)

https://en.wikipedia.org/wiki/Phased_array

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