Ultra-Low-Noise Cryogenic HEMT Amplifiers for HEP Applications

Advancing quantum technologies requires cryogenic amplifiers with ultra-low noise and high efficiency to enable precise signal detection at extremely low temperatures. Current amplifiers do not meet the required efficiency and noise standards for the DOE’s targeted applications. This project aims to solve these limitations by developing a new amplifier that achieves both ultra-low noise and high efficiency, specifically tailored for the stringent requirements of quantum technology applications. The proposed project will develop cryogenic High Electron Mobility Transistor (HEMT) Low-Noise Amplifier (LNA) with ultra-low noise performance. Phase-1 established technical feasibility by achieving low noise levels, and Phase-2 will build upon these results. The approach involves iterative prototyping, transistor modeling, semiconductor material optimization, and close collaboration with DOE partners to ensure successful deployment. Phase-1 achieved several key milestones that form the foundation for the work proposed in Phase-2. Notable accomplishments include the development of wafer fabrication-ready InP HEMT LNA designs, covering the 2–4 GHz, 4–6 GHz, and 6–8 GHz frequency bands. The designs included three-stage LNAs, transistor modeling cells, and NIST-grade on-wafer calibration structures. These designs were optimized for noise temperature, gain, and stability, achieving simulated noise temperatures below 1 K, gains exceeding 35 dB, and excellent return losses. Phase-2 will focus on fabricating the wafer designs from Phase-1 and conducting rigorous testing under both room-temperature and cryogenic conditions. Specific tasks include optimizing the gate geometry, refining the epitaxial material composition, and conducting comprehensive cryogenic testing to validate performance. The cryogenic testing will be performed using an advanced cryostat system integrated with RF test capabilities, ensuring precise characterization of noise temperature and S-Parameters. This phase will also involve refining the custom process design kit (PDK) to support future InP HEMT LNA iterations and ensuring the amplifier's readiness for integration into quantum technology systems The successful development of this project’s cryogenic low noise amplifiers will have significant commercial and societal benefits. It will enable new capabilities in quantum sensing, secure communications, and advanced research instrumentation. The amplifier will contribute to the growth of quantum computing technologies, improve the efficiency of secure data transmission, and support advancements in energy research.