[HN Gopher] Automated Antenna Design with Evolutionary Algorithm...
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Automated Antenna Design with Evolutionary Algorithms [pdf] (2006)
Author : austinallegro
Score : 52 points
Date : 2025-04-23 14:14 UTC (8 hours ago)
(HTM) web link (ntrs.nasa.gov)
(TXT) w3m dump (ntrs.nasa.gov)
| qoez wrote:
| This has to have been done in more modern times in simulation of
| the EM field for a better design instead of practically
| nativeit wrote:
| There are a few software options available, I think, from
| simple little Java runtime executables to enterprise suites[1]
| costing 5-6 figures to license.
|
| 1. https://www.keysight.com/us/en/products/software/pathwave-
| de...
| deerstalker wrote:
| Very cool. Evolutionary Algorithms have kinda been out of the
| mainstream for a long time. They are good when you can do a lot
| of "black-box" function evaluations but kinda suck when your
| computational budget is limited. I wonder if coupling them with
| ML techniques could bring them back.
| bob1029 wrote:
| > I wonder if coupling them with ML techniques could bring them
| back.
|
| EAs are effectively ML techniques. It's all a game of search.
|
| The biggest problem I have seen with these algorithms is that
| they are wildly irrespective of the underlying hardware that
| they will inevitably run on top of. Koza, et. al., were
| effectively playing around in abstraction Narnia when you
| consider how impractical their designs were (are) to execute on
| hardware.
|
| An L1-resident hill climber running on a single Zen4+ thread
| would absolutely smoke every single technique from the 90s
| combined, simply because it can explore so much more of the
| search space per unit time. A small tweak to this actually
| shows up on human timescales and so you can make meaningful
| iterations. Being made to wait days/weeks each time you want to
| see how your idea plays out will quickly curtail the space of
| ideas.
| munksbeer wrote:
| > A small tweak to this actually shows up on human timescales
| and so you can make meaningful iterations.
|
| Please could you explain what you meant by this part? I'm
| trying and failing to understand it.
| bob1029 wrote:
| An L1-resident algorithm can outperform one that needs to
| talk to DRAM each iteration by 100x or more. In terms of
| wall clock time, this can mean the difference between
| minutes and days.
|
| Would you be willing to try a fleeting idea if it took 2
| days to test? How about if we could bring that down to 15
| minutes?
| henning wrote:
| The main use of evolutionary algorithms in machine learning
| currently is architecture search for neural networks. There's
| also work on pipeline design, finding the right way to string
| things together.
|
| Neural networks already take a long time to train so throwing
| out gradient descent entirely for tuning weights doesn't scale
| great.
|
| Genetic programming can solve classic control problems with a
| few instructions when they can solve it, so that's cool.
| nickpsecurity wrote:
| They're not in the press a lot. They're probably still in
| production behind the scenes. I was reading about using them
| for scheduling not long ago. Btw, a toy one I wrote to show how
| they work got best results with tournament selection with
| significant mutations (closer to 20%).
|
| There's a lot of problems where you're searching among many
| possibilities in a space that has lots of pieces in each
| solution. If you can encode the solution and fitness, a GA can
| give you an answer if you play with the knows enough. You also
| might not need to be an expert in that domain, like writing
| heuristics. If you know some, they might still help.
| antegamisou wrote:
| Much more robust than almost all modern ML algorithms which
| let's be real, aren't exactly applicable to anything outside
| recommendation systems and 2D image processing.
| potatoman22 wrote:
| I can't tell if this is a joke
| antegamisou wrote:
| Genetic algorithms' weaknesses largely boil down to getting
| stuck in local extrema and premature convergence, which can
| be resolved by trying different values for parameters like
| probability of mutation, trying different genetic
| operators, offspring/parent ratio etc.
|
| Meanwhile you have a whole separate discipline [1] for
| potential weaknesses on machine learning algorithms. Of
| course they may win when it comes to interdisciplinary
| ubiquity in CS, but any algorithm that relies on data
| assimilation and has little analytic formulation will
| suffer in robustness.
|
| [1]
| https://en.wikipedia.org/wiki/Adversarial_machine_learning
| janalsncm wrote:
| There is no reason I couldn't use the same adversarial
| attacks against an EA. It just doesn't have a Wikipedia
| page because EA isn't as common.
| buescher wrote:
| These designs fascinate people who haven't designed antennas. I
| don't doubt that throwing enough computational power at
| optimizing antennas will produce antennas optimized for something
| at the expense of something else but if you're a casual what you
| should notice is that these papers never mention the "something
| elses". You can get a paper out of just about any antenna design,
| btw. There's also a type of ham that will tune up a bedframe or
| whatever. So just getting something to radiate should not be
| confused with advancing the state of the art.
|
| These antennas found their way into the utterly savage
| "pathological antennas" chapter of Hansen and Collin's _Small
| Antenna Handbook_. See "random segment antennas". Hansen and
| Collin is the book to have on your shelf if you're doing any
| small antennas commercially and that chapter is the chapter to go
| to when you're asked "why don't you just".
| xraystyle wrote:
| This comment really sums it up well. Literally everything with
| antenna design is a trade-off. You can design an antenna to
| radiate very well at a given wavelength. The better it is at
| doing this, the worse it tends to be at every other wavelength.
| You can make an antenna that radiates to some degree across a
| wide array of wavelengths, but it's not actually going to work
| very well across any of them.
|
| Same thing with radiation patterns. You can make a directional
| antenna that has a huge amount of gain in one direction. The
| trade-off is that it's deaf and dumb in every other direction.
| (See a Yagi-Uda design, for instance.)
|
| Physics is immutable and when it comes to antenna design there
| really is no such thing as free lunch. Other than coming up
| with some wacky shapes I don't really think AI is going to be
| able to create any type of "magic" antenna that's somehow a
| perfect isotropic radiator with a low SWR across some huge
| range of wavelengths.
| buescher wrote:
| There's always a market for a better free lunch.
| quesera wrote:
| > _perfect isotropic radiator with a low SWR across some huge
| range of wavelengths_
|
| Fair analysis -- but of course, there are industries where a
| funky and expensive radiator optimized for a single frequency
| could be very worthwhile.
| jamesholden wrote:
| "Do not confuse inexperience with creativity"...
| osm3000 wrote:
| I just read it in the referenced book section from the parent
| comment. It shocked the imaginary bubble where my mind is a
| bit. I want to reflect more on it.
|
| Somehow, in the midset of all these LLM and diffusion models,
| the only thing that seems to catch attention is creativity.
| I've not thought of experience.
| buescher wrote:
| Experience makes creativity harder, but that's what mature
| creativity is. Did anyone tell you it wouldn't be work?
|
| The people who are most awed by LLMs are those people most
| used to having to be merely plausible, not correct.
| os2warpman wrote:
| Not only are they pathological, but when you order a example be
| built because CST confirmed that the design would kick ass and
| you put it in the chamber and actually measure it for real, you
| walk away wondering why you wasted so much time and money.
| buescher wrote:
| I wish I'd had a copy of the book referenced much earlier in
| my career too.
|
| As far as the twisted-paperclip antennas go, just imagine
| trying to verify each of those 3D bends was to spec. Or
| conversely, running a monte carlo on all the degrees of
| freedom in that design.
| plastic-enjoyer wrote:
| Antenna design feels like some occult arts
| greenbit wrote:
| It kind of is. If your SWR is 1.09, in _theory_ you could do
| better, but in practice, there 's generally nowhere to go but
| up.
| nativeit wrote:
| Any chance I could sell you a high-priced "cryogenically-
| treated" length of coax?
| meindnoch wrote:
| "It has become fashionable to design wire antennas with some
| type of optimizer program, almost independent of good physics
| or high-quality performance. The results sometimes have wire
| segments in all directions; see Figure 5.24 for an example. A
| long total wire length may achieve resonance in a small volume,
| but there are several disadvantages. If Z is the normal
| monopole direction, the X currents tend to cancel, as do the Y
| currents. However, in certain directions the cross- polarized
| field may not be negligible. Longer total wire length increases
| loss resistance, reduces efficiency, and increases reactance.
| And generally the bandwidth is narrow. Examples are Altshuler
| and Linden (2004), Choo et al. (2005), Altshuler (2005), and
| Best (2002, 2003). Use of fractals and meanderlines to fill
| space (Gonzalez-Arbesu et al., 2003; Best and Morrow, 2002)
| suffers from the same problems.
|
| "Do not confuse inexperience with creativity" (Linda Whittaker)
| is appropriate here."
| dumdedum123 wrote:
| Who? I can't find the source, and it seems everybody knows
| about it.
|
| EDIT: Oh, it's the book itself. But what is _their_ source?
| p_j_w wrote:
| Are you asking for Collins and Hansen's sources?
| supportengineer wrote:
| A long time dream of rocket scientists is single-stage-to-orbit.
| Ideally you'd have a vehicle that takes off and lands like a
| conventional jet plane at a regular airport. I've always thought
| that perhaps AI and evolutionary algorithms might be able to
| navigate a way through the various tradeoffs and design
| constraints that have stopped us so far.
| dumdedum123 wrote:
| As a rocket scientist I assure you it's been tried
| Zigurd wrote:
| As an avid observer of rocket design, I suppose that hasn't
| happened because SSTO may not have any good solutions. I
| further suppose that the design parameters are so constrained
| there is very little opportunity for a generative or
| evolutionary, or any other AI-driven design approach, to do
| more than optimize some components.
| timschmidt wrote:
| SpaceX's solution with Starship definitely demonstrates how
| difficult a problem it is. Raptor are the best engines humanity
| has, all the landing hardware is part of the launch tower to
| save weight, and those seem to be table stakes. Stoke aerospace
| has a fantastically genius solution with their regeneratively
| cooled heatshield / expander cycle aerospike engine. It
| literally turns the energy you're trying to burn off during re-
| entry into delta-v in the opposing direction while reducing
| weight and complexity.
| lormayna wrote:
| As somebody who almost fried his computer during the antenna
| design course to optimize a dipoles array with a (not optimized)
| genetic algorithm, I really like this content.
| babuloseo wrote:
| Do people not go on Wikipedia nowadays? This is literally on the
| frontpage of the wiki for this stuff:
| https://en.wikipedia.org/wiki/Genetic_algorithm
| JohnKemeny wrote:
| A good rule of thumb: never mock someone's enthusiasm or
| excitement about learning something, even if it's old news to
| you. Let people enjoy discovering things.
| JWLong wrote:
| I'm rediscovering it. I remember reading about this in some
| flashy, superlative Popular Science article, from the
| early/mid 2000s. So I was quite excited to click on the link
| and see that shape again.
|
| But also, something something lucky ten thousand.
|
| https://xkcd.com/1053/
| incognito124 wrote:
| Can someone share with me why antennas need to be designed in the
| first place? I thought it was one-shape-rules-all type of problem
| kavouras wrote:
| In my limited understanding, there are many factors
| differentiating between antennas, different antennas are better
| at emitting/receiving at different frequencies, and also
| there's directionality in the mix . For example a satellite
| dish and an FM radio antenna are both antennas, they're
| certainly not the same thing.
| drwu wrote:
| The requirements and constraints depend on the product. For
| example, the geometry of your product to accommodate the
| antenna is not always the same; the (internal and external)
| environment of the case is also different; there may be
| requirement of combining various frequency bands into one
| antenna; etc.
| buescher wrote:
| Right. Everything in the near field of the antenna is part of
| the antenna. Handheld products are an extreme example of
| this: remember "just avoid holding it in that way"? (after
| that, Apple built big test chambers and brought journalists
| in to see them)
|
| Where are the antennas on your phone today?
| eskibars wrote:
| There are many different types of antennas, each with different
| tradeoffs. Some examples of the tradeoffs are:
|
| - How well does it work at a specific frequency, if you're just
| trying to transmit/receive on one specific frequency
|
| - How well does it work on the frequency range(s) if you're
| working on more than a specific frequency
|
| - How well does it block frequencies that you don't want to
| send/receive
|
| - How well directional is it to trade off using lots of
| radiation to blast in many directions vs a higher focus beam
| using less energy or getting less interference from other
| directions
|
| - How much physical space do you have in each dimension?
|
| These are just a few examples, but for example you can provide
| a much "better" connection in almost every sense of the word if
| you can make your antenna directional (point between the source
| and destination) only on a specific frequency, and be huge, but
| most of the time you have some physical space constraints,
| multiple frequencies to deal with, and the potential that your
| signal could at least come from some degrees in each the x/y/z
| axes, and sometimes it needs to be omnidirectional.
|
| Again, these are just examples, but you end up with these types
| of design considerations that play into larger system design
| (can you put more transmitters up to encourage directionality,
| limit frequencies, etc).
|
| There are some well known "base" antenna types like dipole,
| yagi-uda, circular, and log periodic dipole array if you want
| to look them up by name and see some of the known tradeoffs and
| design choices, but virtually any wire can be an antenna and
| there are an unlimited number of shapes, nearly all of which
| don't have known radiation characteristics
| nativeit wrote:
| You can claim that you aren't a highly-skilled psycho-super-
| soldier developed to infiltrate comment sections to spin
| engineers into a frenzy, but I won't believe it.
| simne wrote:
| Could somebody share link to calculator of antenna parameters for
| arbitrary shape? Or may be some good book, where to read, how
| these things calculated?
|
| I've seen few books on this topic, but have some issues on
| translate them into program.
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