Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR
Characterizing RF and Quantum Systems Under Cryogenic Conditions
The electrical and RF performance of modern electronic devices can change significantly at extremely low temperatures. Conductivity, noise performance, losses, gain, and reliability are all temperature-dependent. Characterization under cryogenic conditions is therefore particularly important for components designed to operate at very low temperatures, including those used in quantum computing, radio astronomy, space applications, and highly sensitive sensor systems.
Fraunhofer FHR's cryogenic measurement platforms enable precise characterization of electronic and RF components at temperatures down to 1.5 K. The cryogenic laboratory features three specialized systems covering different levels of integration, from individual chips and wafers to printed circuit boards, RF components, and more complex systems. Depending on the platform, measurements can be performed from DC to 67 GHz.
Specialized Measurement Infrastructure Down to 1.5 K
The laboratory infrastructure includes a CRX-4K cryogenic probe station, an SHI-950-LT cryogen-free cryostat, and a 4 K probe station developed at Fraunhofer FHR. The CRX-4K supports on-wafer measurements from 4 to 300 K at frequencies up to 67 GHz. The SHI-950-LT covers a temperature range from 1.5 to 300 K and features a modular sample holder platform as well as connections for up to six RF cables.
Fraunhofer FHR's custom-developed 4 K probe station provides particularly flexible measurement capabilities. It features a 300 × 300 mm test area, eight individually configurable interfaces, and supports measurements from 4 to 300 K. In addition to S-parameter and impedance measurements, the platform can accommodate application-specific measurement configurations.
Precise Characterization of RF Electronics
The available measurement capabilities include S-parameter measurements for determining reflection and transmission characteristics as well as measurements of gain, impedance, bandwidth, and insertion loss. This enables amplifiers and filters to be systematically characterized for operation at cryogenic temperatures.
At temperatures as low as 1.5 K, thermal disturbances are significantly reduced, enabling the investigation of physical phenomena that may be obscured at higher temperatures. The resulting measurement data support component development and validation and help account for temperature-dependent changes in the design of future systems.
From Quantum Computing to Radio Astronomy
Applications range from qubit-control chips and microwave components to MMICs, low-noise amplifiers, mixers, oscillators, and receivers for radio telescopes. Fraunhofer FHR thus provides a flexible research and development infrastructure for the characterization and validation of advanced RF and quantum systems.