3D Printing Antennas With Dielectric Resin

[Machining and Microwaves] has long wanted to use a 3D printer to print RF components for antennas and microwave lenses. He heard that Rogers — the company known for making PCB substrates, among other things — had a dielectric resin available and asked them if he could try some. They agreed, with some stipulations, including that he had to visit their facility and show his designs in a video. Because of that, the video seems a little bit like a commercial, but we think he is genuinely excited about the possibility of the resin.

Since he was in their facility, he was able to interview several of the people behind the resin, and they had some interesting observations about keeping resin consistent during printing and how the moonbounce feed he wanted to print would work.

Some of the exotic RF test equipment was interesting to see, too. The microwave lenses look like some kind of modern art. According to the Roger’s website:

Radix Printable Dielectric materials are a ceramic-filled, UV-curable polymer designed for use with photopolymer 3D-printing processes like sterolithography (SLA) and digital light processing (DLP) printing. These materials and printing processes enable the use of high-resolution, scalable 3D-printing for complex RF dielectric components such as gradient index (GRIN) lenses or three-dimensional circuits. The 2.8Dk printable dielectric is designed to have low loss characteristics through millimeter wave (mmWave) frequencies and low moisture absorption for end-use applications.

It isn’t clear to us that you could use this resin in your own printers, but they did look pretty similar to what we have hanging around except, perhaps, for the continuous circulation of the resin pool. We figured the resin wasn’t inexpensive. In fact, we found a liter online for $1,863. We don’t know if that’s the suggested retail price or not, but we also suppose if you need this material, you won’t be that surprised at the cost.

If you don’t need microwave frequencies, you might be able to get by with some easier techniques. Or, you can even do something slightly more difficult but probably a lot cheaper.

14 thoughts on “3D Printing Antennas With Dielectric Resin

  1. Interesting.

    High performance plastics like PEEK and Ultem have similar dielectric constant and loss tangent as that magic goo, and are available in filaments for FDM. Tough temperature requirements though (360-400 C), and still not cheap ($250-$1000/kg)

    Polycarbonate though! That’s a contender. Dielectric constant of 2.27 and very low loss, and eminently printable on many printers.

    And I have some 10 GHz gear. Now I just need a design to print & test. Yeah, a zone plate is an obvious first try. Though at 10 Ghz it’s still going to be pretty big.

      1. Zetamix Epsilon is another option for a purpose-made filament now that Preperm 300/1200 has disappeared from public sale after the Avient takeover. Exciting times ahead. I’m making the FZP for 122 GHz and that’s big enough, 200 mm diameter, but I’m machining it on a giant vacuum chuck on my lathe rather than printing it. I think 24 GHz is the lowest frequency where an FZP is practical or sensible, but they can always be built using many sections of solid material. It’s a good option at 248 GHz where machining a sufficiently precise parabola and hyperbolic or laterally-displaced ellipse subreflector are pretty challenging, and spun dishes are way too inaccurate

    1. Marco, you read my mind! It needs to have extremely low dielectric loss, and perhaps a filler of Barium titanate or even Titanium dioxide suspended in a low loss-tangent photopolymer. That might be feasible for DIY in a Saturn or similar, but if the particles sediment out, it’s going to block the UV and mess things up. Definitely worth a try though. Failure is always an option…

      1. It doesn’t necessarily need to be low loss, depends on what you are making. Some complex meta-material you probably just want to modulate velocity factor, but for a zone plate you can simply use attenuation to make a “grey” scale zone plate. Phase and amplitude modulation both work for a non-binary zone plate.

  2. Thanks for posting this, Hackaday peeps! Apologies for the video being a bit of an advert. I was paid a fee for making the video, but had complete editorial control and I am a huge fan of this material. The price certainly puts it into the aerospace/academia domain rather than home printers, but I’m hopeful that new materials will arise that I could print in my Saturn. There are some other materials for FDM printers that do a similar job at lower precision. I hope to be doing some more explanatory vids about the lenses and the practical results, and about the filament versions to compare results at 5.7, 10, 24, 47 and 76 GHz. I’ll also be making some Fresnel Zone Plate antennas for 122 GHz soon.

    1. I enjoyed the video and learned a little bit about antennas. I don’t like sponsored videos about things we already know about (free to play video games anyone?) but this is something new to me and they seem to be on the cutting edge of their technology. Thanks for the video.

    2. Serious question. Could this method be used to create a crude version of the radar absorbent “stealth coatings/paint” used by military aircraft?

      I’m not purposing a person could turn their DJI into a stealth drone, or make their Civic invisible to police band traffic radar, but it might have applications in radio frequency labs where RF noise isolation was key and Faraday cages were not enough or not an option.

      I can see this having all kinds of applications in making compact antennas for mobile purposes across all radio bands. It would be interesting to see if the evolved antenna algorithm could be adapted to this material.

      evolved antenna: https://en.wikipedia.org/wiki/Evolved_antenna

        1. Apparently they can get sub millimeter resolution with this material. While I don’t think printing sheets of this stuff would be affordable outside the military it would make for excellent coating on ships. Especially if it could be painted with an RF transparent and environmentally resistant coating. Sea water is hell on everything. I can see micro crystals of salt filling all the pores and channels to set up weird asymmetric wave guides.

    3. I;m thinking this could make it possible to 3D print phased array RADAR antennas as shaped panels on the outer skin of aircraft. Cover the outside with a radio transparent smooth skin for aerodynamics and the antenna essentially uses zero interior space. They could be installed in multiple places around an airplane for global coverage. AWACS without the huge disc on top. Fighter plane tracking and targeting in every direction. They’d also be useful for weather observation planes, search and rescue too. Instead of a nose cone covering a flat phased array, make the nose cone the phased array.

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