There is an amplifier circuit obtained between JFET and MOSFET. For the FET used in the circuit, \$I_{\text{DSS}} = 8\text{ mA}\$, \$V_{\text{GSoff}} = -3\text{ V}\$ and working point current is 1.42 mA.
Use MOSFET parameters as \$K_n = 1 \text{ mA/V}^ 2\$, \$V_{\text{TN}} = 1\text{ V}\$, \$g_m = 0.75\text{ mA/V}\$.
The voltage gain of the first floor in the circuit is calculated as 0.7, and the voltage gain of the second floor is calculated as -100.
R7 = 101(R8) and R8 + R9 = 4.462 kΩ.
I want to calculate the resistance values according to the parameters given in the question (in kΩ). I will use re model to solve this. However, the JFET is composed of a common drain. The resistance of R3 is confused. Books have common drain gain but no R3 resistance. What is the JFET's gain formula?