Workshop on June 11st, 2023
WSL: State-of-the-Art Millimeter-Wave GaN Transistor and MMIC Technologies and Future Perspective
Organizers: Farid Mejdjoub (CNRS – IEMN) / Keisuke Shinohara (Teledyne Scientific & Imaging)
Owing to superior electrical and thermal properties of GaN-on-SiC material systems, a tremendous progress has been made on GaN-based transistor and MMIC technologies. Advanced heterostructure material designs, epitaxial growth techniques, and transistor scaling processes enabled GaN MMICs to extend their applications from microwave to millimeter-wave frequencies (up to W-band). Next-generation RF systems require high efficiency and high linearity for more complex modulation schemes to support very high data rates. The traditional trade-off among efficiency, linearity, and power density imposes performance limitations on GaN MMICs, which become more pronounced at millimeter-wave frequencies. In this workshop, world-leading experts will discuss present status, challenges, and future perspective of millimeter-wave GaN transistor and MMIC technologies, covering emerging materials and devices, device modeling, thermal management, reliability, and circuit designs.
Connected Futures Summit on June 13th, 2023
SiGe Speaks to the Sky!
Speaker: Pascal Chevalier (STMicroelectronics)
Exhibiting very steep growth, the deployment of Low Earth Orbit (LEO) satellite constellations is accompanied by a significant volume of user terminals (UT). Designed to track the satellites using phased-array antennas, UTs are key components and require the use of technologies optimized to meet performance targets and ready for consumer-like volumes. This talk will discuss how Silicon Germanium (SiGe) BiCMOS, a long-standing technology at ST, addresses UT challenges thanks to its best-in-class performance in terms of noise figure, a key parameter as it directly links system performance with effective throughput. We will look at how ST’s SiGe BiCMOS technology is used in the RF Front-End of several hundred elements per antenna. In addition to looking at the technology serving current UT production (B9MW), we will see what is being developed for the next generation of user terminals (B55X).
Technical Session on June 15th, 2023
Th1G-4: Highly-Linear and Efficient mm-Wave GaN MMICs: Challenges in Model and Validation
Speaker: Jeong-sun Moon (HRL)
Realizing high-performance mm-Wave 5G and beyond communication systems will require transistors with higher linearity and efficiency than current technology options. While GaN HEMTs offer excellent power density, their limited linearity and efficiency compromise overall system performance; this requires substantial DC power consumption and power back-off to circumvent. Here, we will present the linearity and efficiency of graded-channel GaN HEMTs with the linearity figure-of-merit, OIP3/PDC, of 20 dB at 30 GHz, well beyond the 10 dB rule of thumb. For power amplifier applications, a twotone PAE of 62% was obtained experimentally at 30 GHz, which is a state-of-the-art result. We find that ~3 dB back-off from peak PAE is sufficient to achieve a carrier to third-order intermodulation (C/IM3) ratio of 30 dBc. Recent Ka-band and Wband MMICs with graded-channel GaN technology illustrate their potential for future linear and efficient mmW applications. We will talk about challenges associated with accurate linearity and efficiency modeling and validation at mmW MMICs.