The Incredible Shrinking Antenna: 3D Printing Reduces 100 Components to 1

One thing that 3D printing is particularly good at doing is making things smaller. I’m not just talking about high-resolution 3D printers capable of 3D printing on the nanoscale, although those have certainly done some remarkable things. I’m also referring to the technology’s ability to take large, complex assemblies and reduce them, in some cases, to a single small part.

Antennas can get significantly larger than what we’re used to seeing, e.g., the thin pieces of metal extending out from car hoods. Heavy-duty antennas, such as those used for aircraft and spacecraft, satellite communications, and military purposes can get quite large and heavy, thanks to the number of complex radio frequency (RF) components that are required to give them their power. The Ka-band 4×4 Monopulse Array, a high-bandwidth, directional tracking antenna array for aircraft, is a complicated piece of equipment composed of 100 parts. Or it was – by redesigning and 3D printing it, antenna manufacturer Optisys was able to reduce it to a single piece that fits in the palm of a hand.

“Companies in the commercial and military space are pressured for shorter lead-times, lighter weight and smaller antennas,” says Clinton Cathey, Optisys CEO. “By combining RF design simulation, mechanical engineering, and system optimization focused on AM, we provide metal 3D-printed antenna products at greatly reduced size, weight, lead-times, part count and cost—with as-good or better RF performance than conventionally manufactured systems. We’re creating structures that were simply not possible to produce in the past.”

The antenna array had to be completely redesigned to transform it into a single component. Once the redesign was complete, Optisys 3D printed it on a Concept Laser 3D printer.

“Concept Laser’s powder-bed fusion in particular is perfect for this application because of the fine resolution it provides for antennas functioning in the one to one-hundred Gigahertz [GHz] range of RF in which most of our potential customers operate,” says Cathey.

The reduction of size and number of parts wasn’t the only benefit that Optisys saw by 3D printing the antenna array. Conventional methods of manufacturing antennas such as the Monopulse Array can take eight months of development time on average, plus three to six more of build time. By using 3D printing, Optisys was able to reduce lead time to two months. In addition, production costs were reduced by 20-25% and non-recurring costs were reduced by 75%. Weight savings added up to 95%.

“Our unique offering is that we redesign everything from an additive manufacturing perspective,” says Optisys COO Robert Smith, M.E. “We take into account the entire system functionality, combine many parts into one, and reduce both development and manufacturing lead times to just a few weeks. The result is radically improved size and weight at lower costs.

In addition to what our test-piece project revealed, 3D printing offers a number of other advantages. When we design multiple antenna components into a single part, we reduce the overall insertion loss of the combined parts. And because our antennas are so much smaller this also lowers insertion loss dramatically despite the higher surface roughness of AM build, for similar or even better RF performance than conventional assemblies.”

Although Optisys is capable of 3D printing in various metal materials with their Concept Laser printer, they tend to go with aluminum for antennas, thanks to its surface conductivity and strength when exposed to shock and vibration. It’s also lightweight with strong corrosion resistance.

“3D-printed metal will have virtually the same properties as a solid piece of the same material for RF performance,” says Smith. “Structurally the products have been tested in rigorous vibration environments and they also have the same coefficient of thermal expansion (CTE) as wrought metals. This also gives them better stability over temperature than plastic RF components.”

According to Smith, additive manufacturing has a number of benefits in the long run, as well – it’s easier to add new features to an existing 3D design, as well as to assemble the finished parts. Unless, of course, you’re 3D printing something in a single part, in which case it requires no assembly at all. Less maintenance is required with fewer parts, too.

Optisys’ team has a combined 60 years of experience in satellite communications, RF design, Line-of-Sight communications and mechanical design. According to Cathey, the team has spent years developing their antenna-system optimization technology package. All designs are validated through simulation and tested to all aerospace frequencies. Optisys has several patents and is working on expanding their portfolio; they’re currently in discussions with several leading aerospace companies and academic institutions. Discuss in the 3D Printed Antenna forum at 3DPB.com.