The 2019 IEEE International Microwave Symposium has been upbeat as expected, with almost all exhibitors discussing millimeter-wave (mmWave) technologies and how they will be used in 5G wireless cellular systems and automotive radar systems. One of the unexpected messages from the show has been the strong markets represented in defense and aerospace systems, and how some of the military customers are also seeking mmWave solutions for military systems. Attendance for the technical sessions is strong, and the exhibition floor has been crowded with interested visitors.
Military specifiers are also seeking more RF/microwave power such as gallium-nitride-on-silicon-carbide (GaN-on-SiC) devices with high power density. Integra Technologies announced good news at the exhibition, in the form of a two-year contract for thermally enhanced GaN-on-SiC device technology from the U. S. Air Force.
GaN-on-silicon (GaN-on-Si) and silicon LDMOS high-power device technologies were also in evidence at the 2019 IMS, but it was Integra Technologies making news with the contract to accelerate the technology and the manufacturing readiness. GaN-on-SiC technology is well-suited for high-power, high-efficiency transistors and integrated circuits (ICs) for power-amplifier modules.
Specifically, Integra announced it was awarded a two-year contract by the U.S. Air Force to accelerate technology and manufacturing readiness of its patented, thermally enhanced GaN/SiC technology. The technology is ideal for high-efficiency, solid-state RF power applications including high-power radar systems requiring improved performance, increased range, and reduced operating costs. The company is leveraging its domestic R&D and manufacturing platform to optimize the GaN epitaxial wafer, device design, and package design.
“We are excited to work with the Air Force," said Suja Ramnath, President and CEO of Integra Technologies. “Through this effort, we have the opportunity to commercialize our leap-ahead GaN/SiC technology to meet the high-efficiency performance and production-readiness requirements of the U.S. Department of Defense.”
Material Issues
It’s been difficult to find any exhibitor who doesn’t have a new product to announce at the show. Visitors are walking away with a variety of product samples after attending demonstrations at the different booths.
For circuit designers in need of thermally stable material, Rogers Corp. introduced its TC350 Plus thermally enhanced low-loss laminates. The printed-circuit-board (PCB) materials are based on polytetrafluoroethylene (PTFE), high thermally conductive plastic, fillers, and woven glass reinforcement, combining for a dielectric constant of 3.5 at 10 GHz.
This rare combination of low loss and high thermal conductivity makes these materials a good fit for RF/microwave power amplifiers in which the most gain can be extracted. With a low thermal coefficient of dielectric constant of 42 ppm/°C at +140°C, the materials maintain consistent performance with temperature.
The new material features a low planar X/Y coefficient of thermal expansion of 10/9 ppm/°C and a low Z-axis CTE of 38 ppm/°C. The z-axis thermal conductivity is 1.24 WmK and the low loss tangent is 0.0017 at 10 GHz. The material is available in panels as large as 48 × 36 in. Providing high-reliability plated through holes (PTHs), the material generates very little heat through transmission-line losses.
