ABSTRACT
This chapter covers the dc analysis for five commonly used amplifying devices. They are the solid-state bipolar junction transistor (BJT), the junction field-effect transistor (JFET), the enhancement type metal-oxide field-effect transistor (MOSFET), the depletion type MOSFET, and the vacuum tube triode. Before an amplifying device can perform as an amplifier, the device must be operated together with other electronic components such as resistors and capacitors to form an amplifying circuit. The amplifying circuit allows the amplifying device to be dc biased properly, i.e., a suitable amount of dc quiescent current and dc voltage so that the device operates in its active or linear region. Some dc bias techniques, including fixed-bias, voltage-divider bias, and self-bias are discussed in this chapter.
