An Automated Measurement System for the Characterization of Electron Device Degradation under Nonlinear Dynamic Regime

A fully automated measurement setup is described, which is aimed at investigating the time dispersion (or ldquowalkoutrdquo) of microwave electron-device characteristics. The proposed setup has the original capability of characterizing device degradation under a nonlinear dynamic operation. Such information is invaluable when the success of a project is inherently related to the end-of-life performance of each system component (e.g., military and space applications). Some previous works underline the importance of such information, but they are not oriented to device characterization and, moreover, are focused on a particular application (e.g., power amplifier design). The commonly adopted measurement techniques, which are essentially focused on high-field static operations, are extremely useful to perform accelerated stress, but they cannot be adopted to obtain exhaustive information about the time dispersion of device characteristics under realistic operative conditions. Through the proposed system, the stress procedure can be carried out under static (DC) and nonlinear dynamic (RF) operations to give the maximum flexibility in gathering useful information on the device degradation in different operating regimes. In particular, the device under test (DUT) is fed in rf-stressing conditions by applying a large-amplitude excitation signal at moderately high frequency at either the input (forward mode) or output (reverse mode) port of the device. The system features, in fact, a symmetrical dual-channel architecture. The DUT can be either a bipolar- or a field-effect transistor, and the walkout of its characteristics can be observed both at the end of the stress test and in real-time during the test execution. A special-purpose control software automates the measured data acquisition. Several experiments that were performed using the proposed setup are discussed in the paper.