Fuse2 Topic 2: Heterogeneously Integrated Arrays for Massively Scalable sub-THz Communications and Sensing

As the demand for wireless data keeps growing and new technologies like augmented reality (AR), virtual reality (VR), and self-driving cars become more common, the next generation of mobile networks must handle extremely high data speeds—up to Terabits per second—within the next ten years. Ensuring safe autonomous driving requires advanced radar systems with extremely high-resolution imaging capabilities. Military aviation also needs ultra-high data rate (>10 Gbps) airborne connectivity to support complex missions and share information in challenging environments. Developing these capabilities involves creating new wireless communication and sensing devices utilizing large available bandwidth and small wavelengths offered by sub-THz spectrum above 200 GHz. However, the severe path loss must be overcome using large transmitter and receiver arrays. Implementing large transmitter and receiver arrays above 200 GHz using the current semiconductor and packaging technologies presents significant thermal, electromagnetic, and mechanical challenges. To solve these issues, we propose scalable 240-GHz transmitter and receiver arrays based on new application-specific array architectures, innovative silicon-based beamformers, high-performance InP power amplifiers (PAs) and low noise amplifiers (LNAs), and advanced packaging technology. The proposed work is expected to serve as the basis for next-generation wireless connectivity and sensors to drive the integration of digital, physical, and human worlds, fostering growth and innovation across industries. The proposed program will educate the next generation of scientists and engineers through specialized training programs, equipping them with integrated circuit design, packaging, antenna design, and radar and communication systems skills. It will also provide them with synergistic collaboration opportunities to work on the co-design across different areas of engineering. The research outcomes will be utilized to develop short courses and certifications to teach critical manufacturing processes at Penn State University, targeting students from diverse backgrounds and working engineers who need advanced packaging and system integration skills.The proposed research will advance semiconductor and packaging technologies for next-generation wireless communications and sensing through new scalable sub-THz phased arrays using heterogeneous integration. The proposed array architecture shifts from traditional two-dimensional (2-D) half-wavelength pitch array designs to new application-specific architectures. This paradigm shift allows the horizontal integration of InP ICs, SiGe beamformer ICs, and antenna arrays to overcome thermal and integration challenges at frequencies above 200 GHz. A scalable Mills Cross Array, an aperiodic 2-D super array, and a scalable linear MIMO array will be developed using 4-channel heterogeneously integrated beamformer modules for sub-degree resolution automotive radar, 10-Gbps airborne connectivity, and near-Tb/s wireless base station, respectively. Compact, power-efficient beamformer transmitter and receiver ICs will be designed in GlobalFoundries' 9HP SiGe process, considering co-integration with InP front-end ICs. A new phase shifter architecture based on two parallel transmission lines periodically connected via digitally controlled switches will be explored for precise, calibration-free phase shifting at 240 GHz. 240-GHz InP PAs and LNAs will be designed using Teledyne’s InP 250-nm HBT process to obtain the highest possible performance and fit these in the linear half-wavelength pitch available within the package. Innovative Antenna-in-Package (AiP) substrate stack-ups, package materials including glass and polymer, interconnect/transition/antenna designs, and IC embedding will be explored for optimal electromagnetic and thermal performance. This project will be the first comprehensive study on materials, ICs, antenna-in-package, architectures, and system co-design for the heterogeneous integration of phased array modules above 200 GHz.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.