Given the feedback circuit below and assuming the voltage amplifier has gain Av, input resistance and output resistance Ro, answer the following questions: Rs a. Loop gain b. Closed loop gain c. Input resistance d. Output resistance Rin м x RE QV₂ Rout A) Sketch the feedback small signal model of this circuit. (Hint: You may convert the input VIN and source resistance R, to its Norton current equivalent if needed) B) Find the following in terms of the amplifier parameters and resistances Rs and RF:

a) Two feedback configurations are shown in Figures Q1.a(i) and Q1.a(ii). Derive the closed-loop gain Af in each case. V₁. V₁. A1 B1 Figure Q1.a(i) A₁ B₁ Figure Q1.a(ii) A₂ A₂ B₂ ܘܢ -V

Figure 6 shows a circuit where feedback is provided between the drain and gate of the transistor M1 Q6 Draw the small signal equivalent circuit of the open loop circuit obtained by breaking the loop at the gate of transistor M1 (suitable for the analysis in the mid band frequency range). Consider Cg as short circuit in the model and state any assumption. (a) (b) State the necessary conditions for the oscillation to occur in the circuit. Using the conditions from (b), derive an expression for the amplifier oscillation frequency fo. (c) Derive the necessary condition for the oscillation to occur in the circuit and state if you can conclude that the circuit will oscillate when considering the values of the inductances L2 = 8 LI = 2 mH; capacitors C = 2 nF; transconductance of the transistor gml = 1.4 mS; and resistors R1 = R2 = Rs : 10 k2. (d) %3D L2 L, R, Cg. C Vout Cp M1 R2 CG Rs Cs Vss = 0 V Figure 6

The hide word is “ obtain “