[20 minutes] 10.1 [15 points] A common-source amplifier is fed from a signal source having a resistance Raig = 100 k2 and has a load resistance RL 100 k2. The MOSFET has Cgs = 0.1 pF, Cgd=50fF, gm = 1 mA/V, and ro= 100 k2. The total capacitance between the output node and ground is C₁ = 0.1 pF. [3 points] (a) Find the midband gain.. [12 points] (b) Use the method of open-circuit time con- stants to obtain an estimate of the upper 3-dB frequency, JH. [30 minutes] 10.2 125 points] (a) Sketch the high-frequency equivalent circuit of [5 points] a common-emitter amplifier that is fed with a volt- age signal source Vsig having a resistance Reig and that is loaded with a resistance R. In addition to the internal capacitances of the BJT, C, and Cμ, there is a capacitance C between the output node and ground. [7 points] (b) If the transistor is biased at /c = 0.1 mA and has ẞ=100, V40 V, fr=500 MHz, and C 0.27 pF, find the values of gm. x, ro, and C. [13 points] (c) Use the method of open-circuit time-constants to obtain an estimate for the upper 3-dB frequency, JH, for the case Ruig = 25 kn, RL = 25 kn, and CL=0.5 pF. Also, find the midband gain. [25 minutes] 10.3 [20 points] (a) An NMOS common-source amplifier with [8 points] a simple PMOS current-source load has a total capacitance at the output node of C = 10 pF. If the resistance of the signal source is very small, find the de gain, the 3-dB frequency, and the gain- bandwidth product, provided that gm 1 mA/V and ro 20 ks for each of the two transistors. [12 points] (b) If, in the circuit in (a), a cascode transistor is added to both the amplifier and the current-source load, find the new values of the de gain, f3dB, and the gain-bandwidth product. Assume that all tran- sistors have the same gm and ro as in (a) and that the total capacitance at the output node remains unchanged. 10.4 Rig Figure 10.4.1 H For the cascode amplifier in Fig. 10.4.1 (with the de bias circuitry not shown), gm1 = 8m2 = 2.5 mA/V, rol = 102 = 20 k2, Cgs1=Cgs2 = 20 fF, Cgd1=Cgd2 =5fF, Cdb1 =Cdb2 = 5 IF, CL=5fF, and Raig 10 k2. Investigate two designs, one that results in a de gain of 60 dB and one that provides a de gain of 40 dB. For each case, find the required value of RL, the resulting 3-dB frequency fH, and the gain-bandwidth prod- uct. Comment on the tradeoff between gain and bandwidth. 10.5 Visit Rig Figure 10.5.1 ww RL CL 01 [40 minutes] [30 points] [35 minutes] [30 points]

Fig: 1