Electric noise : from devices to complex systems
This research field is decomposed in four main projects:
- The first one is related to the reliability and the robustness of microwave electronic devices. The low-frequency noise is very sensitive to any change in the device microscopic structure, and can detect a defect or the growing of a defect much before than other electrical parameters. Together with physical modelling, this approach allows us to assess the reliability in recently developed technologies (GaN, Diamond…) and to understand the origin of the observed shortcomings.
Low frequency noise measurement in a shielded room
- The second project concerns the noise properties of new devices from low-frequency to 40 GHz. Very-low noise applications are particularly studied, like amplifiers or noise reference sources. Investigations are also performed on sub-micron transistors and other nano-scale devices. These devices, because of the size reduction, feature generally a relatively high level of low frequency noise, which must be considered for high-frequency applications.
- Electrical or behavioural models are developed in order to understand complex phenomena like low-frequency noise up-conversion in oscillators for high spectral purity applications or to evaluate the robustness of RF amplifiers in the presence of blocking signals.
- The last project concerns the noise in complex systems. The noise characteristics of several devices must be individually determined in order to evaluate their impact on the overall system noise. Sampling phase detectors used in phase locking of low phase noise microwave oscillators and a noise-injection radiometer have been analyzed in this way.
High frequency noise measurement (1 – 40 GHz)