N-channel jfet fixed bias with high gain = 200

jfet

schematic

simulate this circuit – Schematic created using CircuitLab

I would like to know if it is possible to produce an n-channel jfet connected in fixed bias configuration with a high gain of 200. If so, can you please give me a part number or a circuit diagram? The criteria are as follows:

Amplifier type:FET n-channel
Configuration: Common source fixed biasing
frequency range:100Hz-1MHz
Input signal:35mV,Rs=2kohm
midband gain:200

Best Answer

I would like to know if it is possible to produce an n-channel jfet connected in fixed bias configuration with a high gain of 200.

For your circuit, the product of the small-signal transconductance and drain impedance at the operating point set an upper bound on the voltage gain.

Using the numbers @Andy aka provides:

\$A_v < 20k\Omega \times 6.5 \frac{mA}{V} = 130\$

Since your drain resistor and load are in parallel with the small-signal drain impedance, your circuit gain must be less than this upper bound.

So, as a first step, you must select a transistor with maximum possible voltage gain quite larger than 200.