Electrical Engineering ⇒ Topic : Fixed Bias Circuit

Fixed Bias Circuit

Figure (a) shows the fixed bias circuit

                Figure (a) Fixed bias circuit.

For DC analysis, the coupling capacitors are open circuit and the current through R_G is zero.Hence, R_G can be replaced by short-circuit equivalent and the fixed bias circuit is shown in Figure (b).

            Figure (b) Sinnplified fixed bias circuit.

V_GS is fixed in magnitude because V_GG is a fixed DC supply. Hence, the name fixed bias circuit.

The drain current for fixed bias can be calculated from equation,

Applying KVL to the output circuit,