What is the purpose of JFET biasing?

Question

What is the purpose of JFET biasing?

Answer 1

A JFET has to be biased for successful application and it is always operated with the gate-source p-n junction reverse biased. This reverse biasing of the gate-source junction with a negative gate voltage produces a depletion region along the p-n junction which extends into the n-channel of the gate and thus increases its resistance by restricting the channel width i.e. the channel resistance.

Note : The channel resistance can be controlled by varying the gate voltage, thereby controlling the amount of drain current.