Issue link: https://iconnect007.uberflip.com/i/1534120
56 DESIGN007 MAGAZINE I APRIL 2025 ing to do what the military has been doing for decades, when they were typically using PTFE materials. Oen, with these high-performance phased arrays, you weren't getting what you wanted with yields, but it was the only way to get the performance. e thermoset materials that were available at the time really couldn't achieve that type of performance. Around 2015, we started seeing a turn toward high-speed digital materials, and then it became a lot easier to build RF products. But there are still performance challenges. We always ask, "What do you need to achieve from the mate- rial?" Oen the response is, "We need it to be ultra low-loss." If you're looking for what you could have gotten with PTFE, you won't quite get that. While the Df specification for the latest thermosets is getting close, there are mechani- cal performance characteristics that just don't match up. For instance, with PTFE, you have very good adhesion to copper foils with mini- mal roughness. With thermosets, you just can't achieve the same level adhesion of copper. It's about trying to strike a balance. How do you know what will work? If I go to consumer goods, it's considered a high-end product where they will deal with drop tests. With a radio for first responders, the drop test is much higher. How do we deal with this type of issue? Oen, we start by focusing on electrical performance, but when we get to mechanical performance for different types of applications, we see that there are limits to what we can do. We have to do a lot more engineering work. Even in the defense industry, there's a lot more volume using high-performance thermosets. Added to that are the commercial OEMs look- ing closer at the cost. What's the manufactur- ability? at's our focus. PTFE isn't going away. ere are some very special things about PTFE; it is still best for high-power—high- power antennas, RF power amplifiers, high- power couplers, etc. But the thermoset will lead the way from a volume perspective if that isn't already happening. How do we start bet- tering some of the performance characteristics from a mechanical standpoint so that these thermosets can do some of the things that maybe you're still reserving for PTFE now? Is thermoset the most popular type of RF material in use today, by volume? Yes. It's thermoset from a volume standpoint, and honestly, it probably always has been. Where PTFE definitely is still playing, and where it's hard to get past, is in high power. PTFE can run at very high temperatures. I have customers with continuous operating temperatures above 200°C. You won't do that with thermoset materials that can also achieve very low insertion loss. ere's always a space for PTFE. PTFE can still be difficult to manufacture, can't it? It's squishy and hard to handle. Yes, but it's come a long way. PTFE doesn't scare people as much anymore. But honestly, younger engineers coming into the indus- try have more willingness to implement new Brent Mayfield " ...younger engineers coming into the industry have more willingness to implement new ideas. "