John Cowles, GM of RF and Microwave Business Unit, Analog Devices
MPD: 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?
The emergence of the millimeter wave 5G frequencies at 28 and 39 GHz for cellular communications is very exciting for the community, but it does present significant economic and performance challenges. The need to manage multiple independently-steered beams is driving innovative architectural partitioning between digital and analog beamforming, trading off flexibility, cost and power dissipation. Digital beamforming is the most flexible approach, but requires a full transceiver per element and significant digital processing, which places challenges on size and power. Analog beamforming greatly reduces the number of transceivers, but makes multiple beam management less flexible.
As we move towards the front-end, the critical question for the industry becomes: can the transmit/receive module be monolithically incorporated into the beam-former or transceivers, or will they need to be in a different technology? We’ll have a better idea of how to solve for this once link budgets, cost and size trade-offs are better understood. Finally, the antenna technology is also generating excitement through the prospect of co-designing them with the front end to facilitate array level calibration and digital correction schemes. Overall, we see 5G elevating the capabilities of the industry to address future needs in communications and other emerging millimeter wave applications.
MPD: What RF and microwave technologies do you feel will have the greatest impact in our industry overall between now and 2020?
For a long time, the RF and microwave space was dominated by simple function GaAs HBT and pHEMT MMICs. The emergence of SiGe and fine-line CMOS quickly displaced many of these functions in the cellular range needing higher levels of integration, while GaAs MMICs retained the most challenging, front-end sockets and those at higher frequencies. We fully expect these trends to continue, particularly the growing importance of highly integrated CMOS solutions in higher volume applications that require mixed signal and digital back-ends.
In addition to the shifts above, we are already witnessing GaN and SOI technologies enabling new levels of performance that have not been possible in the past. GaN has extended the window for solid-state MMIC power amplifiers out beyond 100W and for modules into the kW range, challenging TWTs and hybrids. Similarly, SOI has surpassed the performance of other RF switch technologies in a smaller footprint and has demonstrated impressive RF and microwave transceiver dynamic range. Ultimately, having this capability and expertise across a whole palette of semiconductor and co-packaging technologies is essential to providing optimal solutions to the complex problems facing the industry.
MPD: 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.
We absolutely agree. The DoD’s need to replenish munitions expended in the Middle East conflicts and their drive to upgrade the technical capabilities of existing electronics platforms is driving growth in the area of RF and microwave. We see activities such as the Defense Innovation Initiative and DARPA’s Electronics Resurgence Initiative are investing in technology advancements to ensure continued U.S. military dominance and the investments are expected to drive long-term growth in this area.
In addition, we’ve observed that communications, missile defense, smart munitions, electronic surveillance and countermeasure systems, and space-based electronics have all been identified as key areas of government investment —and all of these categories have significant RF and microwave content. More specifically, we expect electronics content areas such as phased array antenna technologies, advanced communications, and high efficiency solid state power amplifier products to grow significantly.