TEMPERATURE-DEPENDENT NOISY MODELS OF PSEUDOMORPHIC HEMTS

From a complete characterization in terms of noise and scattering parameters carried out at room temperature in the 8-16 GHz frequency range, the noisy small-signal model of a pseudomotphic HEMT series has been extracted. The transistor scattering parameters have been subsequently measured at lower temperatures (down to -50 degrees C) by placing the device text fixture in a thermocontrolled chamber. The model effectiveness has then been tested by determining the circuit element values at the different temperatures and by observing the model noise performance.