9.1 INTRODUCTION ●
The analysis thus far has been limited to a particular frequency. For the amplifier, it was
a frequency that normally permitted ignoring the effects of the capacitive elements,
reducing the analysis to one that included only resistive elements and sources of the independent
and controlled variety. We will now investigate the frequency effects introduced
by the larger capacitive elements of the network at low frequencies and the smaller capacitive
elements of the active device at high frequencies. Because the analysis will extend
through a wide frequency range, the logarithmic scale will be defined and used throughout
the analysis. In addition, because industry typically uses a decibel scale on its frequency
plots, the concept of the decibel is introduced in some detail. The similarities
between the frequency response analyses of both BJTs and FETs permit the coverage of
both in the same chapter.