On-wafer Characterisation of Noise Parameters of GaN HEMTs between 77 K and 400 K

In this paper, we study the effect of temperature changes on the noise performance of GaN high electron mobility transistors (HEMTs) covering a wide temperature range (77 K to 400 K) and frequency range (2 GHz to 30 GHz). The measurement system consists of a temperature-controlled manual probe station and a vector network analyser (VNA) which has a built-in active source tuner and a sensitive noise receiver. We investigated the relationship between temperature changes and key noise metrics such as minimum noise figure and optimal noise impedance. Additionally, we compared the measurement system with different calibration planes. The work will not only provide insights into the noise mechanism of GaN HEMTs but also benchmark a different noise measurement method for new research challenges and applications.