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(ii) For the common source amplifier shown in figure 1(b) determine the 3 dB frequency, given the following values for the components: RD = 10 kΩ, RL = 10 kΩ, R1 = 50 Ω, the MOSFET gate source capacitance, Cgs = 10 pF, the MOSFET gate drain capacitance, Cgd = 10 pF. Assume that the MOSFET drain current, ID = 0.2 mA and that the MOSFET is operating in the saturation region. Neglect the effect of channel length modulation. Figure 1(b) Answer: fc = 1 2π(Cgs + Ceq)R1 Ceq = 91.9 pF

(ii) For the common source amplifier shown in figure 1(b) determine the 3 dB frequency, given the following values for the components: RD = 10 kΩ, RL = 10 kΩ, R1 = 50 Ω, the MOSFET gate source capacitance, Cgs = 10 pF, the MOSFET gate drain capacitance, Cgd = 10 pF. Assume that the MOSFET drain current, ID = 0.2 mA and that the MOSFET is operating in the saturation region. Neglect the effect of channel length modulation. Figure 1(b) Answer: fc = 1 2π(Cgs + Ceq)R1 Ceq = 91.9 pF

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(ii) For the common source amplifier shown in figure 1(b) determine the 3 d B frequency, given the following values for the components: R D = 10 k Ω , R L = 10 k Ω , R 1 = 50 Ω , the MOSFET gate source capacitance, C g s = 10 p F , the MOSFET gate drain capacitance, C g d = 10 p F . Assume that the MOSFET drain current, I D = 0.2 m A and that the MOSFET is operating in the saturation region. Neglect the effect of channel length modulation. Figure 1(b) Answer:
f c = 1 2 π ( C g s + C e q ) R 1 C eq = 91.9 p F

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