Instrument for measuring small-signal parameters of field-effect transistors

Conclusions

Investigations have shown that in developing equipment for measuring small-signal parameters of field-effect transistors it is advisable to design devices for measuring parameters of the transistors' equivalent circuits.

On the basis of the examination and study of equivalent-circuit parameters we designed and produced an instrument suitable for measuring six transistor parameters, namely, the internal low-frequency transductance S₀, the output dynamic resistance R₀, the source and drain resistances R_s and R_d respectively, and the capacitances C_gs and C_gd. This instrument is suitable for measuring parameters of transistors with all the basic types of structures and channels over wide limits of biases on their electrodes.

The measurement precision depends on the limits of the measured parameter and the precision of employed voltmeters and phase meter. A tentative estimate of this precision amounts to ±10% for limiting values of R₀≤10 kΩ; S₀≤0.5 mA/V; R_s and R_d≤10 Ω; C_gs≤1 pF, and C_gd≤0.2−0.3 pF. If the tested parameters have values larger than the above limiting ones, the instrument can be used for measuring them with greater precision.