The Four Quadrant Characteristic Field
H. E. Kaden · 1965
The measured transistor characteristics serve best at first to describe the technical behaviour of the transistor. We can obtain quantitative and qualitative statements concerning the amplification of a.c. voltages and currents from characteristics of this kind. For mathematical considerations characteristic values can be defined with the help of the characteristic curves. The measurement of characteristics for a.c. behaviour is not so simple for the transistor as for the electron tube because point by point plotting of “static characteristics” is not suitable for describing a.c. processes. Characteristics for dynamic transistor behaviour have to be plotted at constant crystal temperature (see temperature behaviour of the transistor). Each characteristic curve must therefore be dynamically measured from a working point of constant dissipation (oscillograph).