Microwave Product Digest: Millimeter wave frequencies will be used for cellular communications for the first time in 5G. What challenges and opportunities does this present for the microwave industry?
Ted Heil: Millimeter wave wasn’t uncharted territory to the RF and microwave industry before 5G development began. Applications above 26 GHz have been well-known for some time, including some mid-to-high volume commercial applications such as E Band and Ka Band point-to-point radios, automotive radar and others.
That said, there are significant technical and economic challenges to realizing a ubiquitous mobile network on millimeter wave frequencies. One challenge is the deployment of the enormous number of connection points that will be required due to the limited range of low power millimeter wave nodes. Although we have heard several options for “on the pole” solutions, site acquisition will be a big hurdle that still requires a viable resolution. Other technical impediments include building penetration and the logistics of getting millimeter wave signals in and out of solid or even glass structures. In spite of these challenges, there are a lot of intellectual resources and a lot of investment dedicated to solving these problems, so there’s a high degree of confidence that solutions will evolve.
As for radio hardware, we know that highly integrated CMOS solutions are the only viable way to meet the volume and price point requirements for access points and subscriber devices. This is a “big investment” game and will be most likely limited to companies already in the CMOS space or highly capitalized startups with something new to offer in terms of RFIC topology. For smaller companies, there will be a growing ecosystem around solutions for the R&D behind 5G because system designers will need components to evaluate prototypes and test and measurement solutions for R&D testing and production testing.
MPD: What RF and microwave technologies do you feel will have the greatest impact in our industry overall between now and 2020?
TH: I think one of the most significant areas of development will be in packaging technologies that get signals in and out of chipsets in a repeatable, reliable manner at millimeter wave frequencies. The industry needs a way to integrate multichip solutions without losing control of RF performance at high frequencies. The only cost-effective solutions are through automated surface mount assembly processes, and these high-band signals are extremely sensitive to parasitics and unexpected board-level effects. What we hope to see in the next few years, and this is an area Mini-Circuits is actively pursuing, are packaging technologies that provide easy, reliable integration of multichip assemblies at millimeter wave frequencies. This is a technology that will fill a great need in the marketplace, and we believe once it’s developed, it will have a powerful impact on the RF and microwave industry, extending well beyond 5G alone.
Additionally, in FDD applications, cost-effective, high-selectivity filtering in the millimeter wave bands still presents a challenge. Today the only high-selectivity filters available at these frequencies are waveguides, which are large in size and expensive. As 5G develops toward commercialization, there will be a growing need in the market for technologies that drive these filters down in both size and cost. Mini-Circuits is currently working on developing LTCC filters that meet the requirements for filtering in these systems in terms of selectivity, repeatability, size and cost.
MPD: After years of hype and little to show for it, IoT networks are actually being deployed in a variety of applications. Do you believe IoT is a major opportunity for the RF and microwave industry? If so why, and if not why not?
TH: To many of us, the IoT remains an enigma rife with buzzwords and as yet unspecified “potential.” What we do know is that the trend toward a new ecosystem of connected devices on a mass scale will bring a whole new class of players into the RF and microwave space. Unlike companies that come from an RF pedigree, these are customers who are not traditionally versed in RF and microwave engineering. They tend to be very smart people from application software backgrounds who now need a wireless connection for their product. That presents a lot of challenges for RF and microwave solution providers. Our sales and applications channels now have a lot of new customers outside the traditional niche to identify and reach out to, and it puts pressure on us to present our products in an easier-to-use, plug-and-play manner. Of course, at the same time it also presents a whole new world of opportunity.
MPD: If your company sells into the defense industry: We believe that the defense industry will retain its crucial importance to the RF and microwave industry regardless of overall DoD budget constraints. Do you agree with this statement? Either way, please explain your reasoning.
TH: I think the indisputable answer is yes. RF and microwave have been synonymous with the defense and aerospace electronics industry since the founding of the defense and aerospace electronics industry. All defense systems require some RF/microwave element, whether it be in communications, sensing, countermeasures or surveillance. Defense applications are all in some way aimed at communication among geographically divergent elements, detecting foreign objects, evading detection or obtaining information on an adversary. In wartime and in peacetime, these are the core elements of the defense theater, and you can’t do any of them without RF/microwave technology.
Today, there’s more demand on these systems because the battlefield has expanded and so have national borders in the conventional sense. Whereas 70 years ago, battles played out between forces on land, at sea and in the air, today warfare is conducted with technology – missiles, UAVs, Radar and Lidar – over a much broader field which extends around the planet and increasingly into space. So even though there are still a lot of questions about the defense budget over the next few years, RF and microwave will always have an inextricable role in defense applications, and the defense sector will remain a crucial segment of the market for RF and microwave products.