Under CopyrightHeinz, FelixFelixHeinzThome, FabianFabianThomeLeuther, ArnulfArnulfLeutherAmbacher, OliverOliverAmbacher2023-02-242023-02-242022https://publica.fraunhofer.de/handle/publica/437025https://doi.org/10.24406/h-43702510.1109/IMS37962.2022.986529410.24406/h-4370252-s2.0-85137998547This paper reports on a cryogenic noise temperature measurement system that is capable of performing measurements directly at the reference plane of a chip. The system uses the well known cold attenuator measurement principle. Wire-bonding a monolithic microwave integrated circuit attenuator to the device under test enables precise measurements at chip level. The overall noise measurement uncertainty in the Ku-band has been estimated to be ± 1.4 K in a 3 σ confidence interval. This estimated measurement uncertainty is able to compete with state-of-the-art coaxial measurement systems, although proper matching is harder to achieve in probing systems.enCryogenicshigh-electron-mobility transistors (HEMTs)low-noise amplifiers (LNAs)metamorphic HEMTs (mHEMTs)monolithic microwave integrated circuits (MMICs)noisenoise measurementnoise modelingconference paper