A simplified approach for the determination of the noise parameters of HEMT's at microwave and millimeter wave frequencies has already been presented for either on wafer and packaged devices tested at room temperature. Such methodology relies on the extraction of a noisy transistor model from measurements of the scattering parameters and the noise figure at the fixed source impedance of 50 Ω (namely, F50). The noise parameters of the device are then computed by model simulation and the results obtained are in very good agreement with those determined by the whole experimental procedure. In the present work, commercial pseudomorphic HEMTs have been characterized in the 233-313 K temperature range from 6 to 18 GHz to the aim of validating the use of a furtherly simplified procedure. We here predict the complete noise performance of such pHEMTs by means of a very reduced set of measurements, i.e. the scattering parameters vs. frequency at different temperatures and simply the F50 values vs. frequency at room temperature. The computed noise parameters vs. temperature are compared with those determined by application of the standard measurement procedure. The results show a good accuracy and consistency which allows the very simplified method to be employed when rapid noise testing vs. temperature is needed.
Determination of HEMTs noise parameters vs. temperature using two measurement methods
CADDEMI, Alina;
1997-01-01
Abstract
A simplified approach for the determination of the noise parameters of HEMT's at microwave and millimeter wave frequencies has already been presented for either on wafer and packaged devices tested at room temperature. Such methodology relies on the extraction of a noisy transistor model from measurements of the scattering parameters and the noise figure at the fixed source impedance of 50 Ω (namely, F50). The noise parameters of the device are then computed by model simulation and the results obtained are in very good agreement with those determined by the whole experimental procedure. In the present work, commercial pseudomorphic HEMTs have been characterized in the 233-313 K temperature range from 6 to 18 GHz to the aim of validating the use of a furtherly simplified procedure. We here predict the complete noise performance of such pHEMTs by means of a very reduced set of measurements, i.e. the scattering parameters vs. frequency at different temperatures and simply the F50 values vs. frequency at room temperature. The computed noise parameters vs. temperature are compared with those determined by application of the standard measurement procedure. The results show a good accuracy and consistency which allows the very simplified method to be employed when rapid noise testing vs. temperature is needed.Pubblicazioni consigliate
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