Fixed Bias.

DC bias of a FET device requires setting of gate-source voltage V_GS to provide desired drain current I_D. For a JFET drain current is restricted by the saturation current IDS. As the FET has such high input impedance that no gate current flows and DC voltage of the gate set by the voltage divider or a fixed battery voltage is not affected or loaded by FET.

Fixed DC bias is obtained by using a battery V_QG. This battery ensures that the gate is negative always with respect to source and no current flows through the resistor R_G and gate terminal which is I_G =0. The battery gives a voltage V_GS to bias the N channel JFET, but no resulting current is drawn from battery V_GG. Resistor RG  is included to allow any AC signal applied through the capacitor C to develop across R_G. While any AC signal will develop across RG, the DC voltage drop across RG is equal to I_G R_G that is 0 volt.

The gate source voltage V_GS is then

V_GS = - v_G - v_s = - v_GG - 0 = - V_GG

The drain source current I_D is fixed by the gate-source voltage as determined by the equation.

This current causes a voltage drop across drain resistor R_D  and can be given as V_RD  = I_DR_D and the output voltage  

V_out = V_DD - I_D R_D

Email based Electronics Devices and circuits assignment help - homework help at Expertsmind

Are you searching Electronics Engineering assignment help expert for help with JFET - Fixed Bias questions?  JFET - Fixed Bias topic is not easier to learn without any external help?  We at www.expertsmind.com offers free lecture notes for Electronics Devices and circuits assignment help and Electronics Devices and circuits homework help. Live tutors are available 24x7 hours for helping students in their JFET - Fixed Bias related problems. We provide step by step JFET - Fixed Bias question's answers with 100% plagiarism free content. We prepare quality content and notes for JFET - Fixed Bias topic under Electronics Devices and circuits theory and study material. These are avail for subscribed users and they can get advantages anytime.

Why Expertsmind for assignment help

1. Higher degree holder and experienced experts network
2. Punctuality and responsibility of work
3. Quality solution with 100% plagiarism free answers
4. Time on Delivery
5. Privacy of information and details
6. Excellence in solving electronics engineering questions in excels and word format.
7. Best tutoring assistance 24x7 hours