MPD: Please describe what you consider to be your company’s most significant technological improvements in 2023.
This year, RLC achieved power ratings on mechanical switch designs nearly twice our standard power curves. Many factors influence power handling, including larger RF conductors (cross-sectional areas), larger cavities, and specialized dielectric materials. These provisions have three significant constraints in common: removing the heat effectively, managing “hot spots,” and managing geometries to allow for the highest frequency operation. RLC recently delivered the following switch products, all of which operate into a 3.1 VSWR: the SP8T (1600 W CW), SP8T (2200 W CW), and the SP2T (1800 W CW).
Higher frequency always limits power handling, but we designed and delivered switches this year that conservatively operate with 1600 W CW up to 4 GHz, 500 W CW to 12.4 GHz, and more than 200 W at 18 GHz, representing the best in Industry higher frequency power handling. RLC also provides innovative high-power filter solutions across various topologies. One low-frequency tubular filter handles 1500 W CW at elevated temperatures with loss of just 0.13 dB. In another example, RLC delivered a 200-W “tubular” filter using the jacket of a 0.14-in. semi-rigid cable as the housing. Sectional pieces of precision-milled rod material were formulated the inductive/capacitive elements, and strategically placed thermally conductive materials transferred heat to the jacket housing, an example of how very-low-loss designs promote impressive power handling even with a very small scale.
MPD: Has Microwave Design Software improved in recent years, and if so, how is it helping your company achieve its goals?
Since the “Big Red book” in 1967 and other “cookbook” like publications and tables, followed by Touchstone, Microwave Office, and later into more modern programs such as HFSS and Solid Works, the tremendous power in the hands of the RF engineering community has had incredible impact to our Industry.
Production efficiencies and time to market have improved substantially. Accurate assessment of filter performance before cutting metal allows RLC to realize production electrical requirements on a “first run” basis, with and or very often without a minor tweak or two. Our customer gets the quick turnaround time we promised, and RLC can move to the next design more quickly as well.
High power handling is a mainstay across the RLC product lines. Back in the day, thermal analysis was far more empirical. Today, critical factors such as heat spreading, RF current/voltage analysis, and conductive/convection cooling effects are more easily analyzed. Higher power with higher confidence levels is the result; again, all stakeholders win here. In general, modern design tools allow RLC to present lower-risk, more competitive, and highly reliable solutions to our customer base.
MPD: What does the Department of Defense need most from the microwave industry?
DoD needs continued SWAP reduction at the component and system levels and higher levels of functionality in smaller packages with less power consumption. The RF and microwave community must support those objectives at every level, from the component to the assembly, subsystem, and system.
We also must enforce strict adherence to eliminating counterfeit parts from entering our products. Well-developed purchasing practices, company policies, and training of personnel are essential. Obsolescence management is a critical concern as well. Suppliers must strive to design for longevity in production where possible and support lower-quantity orders for sustainment requirements in the future to eliminate or prolong the need for redesign. Of course, quality and reliability must be embedded at every level to deliver a product that works every time. Most important, every person in our Industry must recognize and embrace their role in providing those in and out of uniform the best solutions possible.
MPD: An increasing number of applications rely on RF and microwave technology. What application is most likely to significantly contribute to the industry by the end of the decade?
Quantum computing will continue to contribute to the evolution of the Industry in the coming years. Regardless of the quantum approach used (trapped ion, semiconductor spin, or superconducting), all depend on RF energy to control and read the state of QBITS.
RLC has supplied catalog and custom lowpass, high-pass and band-pass filters for some time for the warmer and colder (10 mK) regions within various dilution refrigeration systems. In current versions of superconducting quantum platforms, the number of coaxial lines to control and read the state of the QBIT(S) increases linearly with the number of QBITS.
Existing and emerging 50, 100, and 1000 QBIT quantum computing platforms will include these types of filters as well as attenuators, IR filters, ferrite devices, HEMT microwave amplifiers and parametric amplifiers, much of which is (still) in coaxial packaging. While more dense integration is already required (RLC offers multiple filter paths in one blind-mate package, for example), reaching 10K QBIT systems and beyond will bring amazing innovation and, revolutionary levels of miniaturization and new ways of achieving the required microwave functionality. These changes, improvements, and innovations will require tremendous engagement in so many supporting industries, none of which is more important than our own.