GRAPEVINE, Tex.—Optisys LLC, a provider of sophisticated, 3D-printed metal micro-antenna products for high-performance aerospace and defense applications, recently completed a project that documents the significant advantages of employing additive manufacturing (AM) to produce such systems. Optisys redesigned a large, multi-part antenna assembly into a palm-sized, lighter, one-piece, 3D-printed metal antenna. The component was manufactured with a Concept Laser machine to provide optimum radio frequency (RF) performance.
Antennas are critical for conveying information—voice, video and/or data—across long distances. They are widely employed in commercial and military aircraft, spacecraft, satellite communications, unmanned aerial vehicles (UAVs), and by ground terminals and land-based troops. Yet the complex radio frequency (RF) components that make up an antenna system can be large and heavy—characteristics that can impact mobility and performance.
“Companies in the commercial and military space are pressured for shorter lead-times, lighter weight, and smaller antennas,” said Optisys CEOO Clinton Cathey, in a company release. “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 test-piece demonstrator project involved a complete redesign of a high-bandwidth, directional tracking antenna array for aircraft (known as a Ka-band 4×4 Monopulse Array). Optisys performed every aspect of the design work in-house and printed the component in a single piece on its Concept Laser machine.
“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,” said Cathey.
Manufacturing antenna systems via conventional methods, such as brazing and plunge EDM, is a complex, multi-stage process that can take an average of eight months of development time and three to six more of build time, said Optisys COO Robert Smith, M.E, in the release.
“Our unique offering is that we redesign everything from an additive manufacturing perspective,” said Smith. “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.”
Optisys conducted a profitability analysis on how its redesigned microwave antennae test piece compared to a legacy design that is traditionally manufactured. By optimizing its design for additive manufacturing, Optisys realized a number of benefits, including part count reduction from 100 discrete pieces to a 1 piece integrated assembly; weight savings of over 95 percent; and lead time reduction from 11 months to 2 months. The company is also reported to have reduced production costs by 20-to-25 percent and non-recurring costs by 75 percent.
“In addition to what our test-piece project revealed, 3D printing offers a number of other advantages,” said Smith. “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.”
Optisys can print in a variety of metals with its Concept Laser machine. However, for antenna products, the company prefers aluminum because of its surface conductivity, light weight, corrosion resistance, and strength under shock and vibration. “3D-printed metal will have virtually the same properties as a solid piece of the same material for RF performance,” said 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.”
Part consolidation through AM provides a number of downstream benefits as well, Smith said. “Reducing part count also reduces assembly and rework. It’s easy to add features to an existing AM design, easier to assemble the finished components, and, long-term, you have less testing, maintenance, and service when you have fewer parts.”
The Optisys (www.optisys.tech) team has a combined 60 years of aerospace experience in SATCOM (satellite communications), RF design, LOS (Line-of-Sight) communications, and Mechanical Design. “We’ve spent years on parameter and process development of our antenna-system optimization technology package,” said Cathey. “We validate our designs through simulation, test to all aerospace frequencies, and manufacture military-ruggedized production parts.”