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We report wafer characterization of the S-parameters and microwave noise temperature of discrete GaAs and GaN HEMTs over a temperature range of 20 - 300 K. The measured noise temperature (T50) exhibits a dependence on physical temperature that is inconsistent with a constant drain temperature, with Td for the GaAs and GaN devices changing from ~ 2000 K and ~2800 K at room temperature to ~ 700 K and ~ 1800 K at cryogenic temperatures, respectively. The observed temperature dependence is qualitatively consistent with that predicted from a theory of drain noise based on real-space transfer of electrons from the channel to the barrier.
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Theory of drain noise in high electron mobility transistors based on real-space transfer
High electron mobility transistors are widely used as microwave amplifiers owing to their low microwave noise figure. Electronic noise in these devices is typically modeled by noise sources at the gate and drain. While consensus exists regarding the origin of the gate noise, that of drain noise is a topic of debate. Here, we report a theory of drain noise as a type of partition noise arising from real-space transfer of hot electrons from the channel to the barrier. The theory accounts for the magnitude and dependencies of the drain temperature and suggests strategies to realize devices with lower noise figure.
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- Award ID(s):
- 1911220
- PAR ID:
- 10363361
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- Journal of Applied Physics
- Volume:
- 131
- Issue:
- 8
- ISSN:
- 0021-8979
- Page Range / eLocation ID:
- Article No. 085111
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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