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Suppose a signal source Vgen has a Thevenin-equivalent circuit resistance Rgen = 50k as shown below, and is connected through terminals 1 and 2 to a load resistance RL = 600 : Calculate the voltage loss LdB = 20log10(Vgen/VL) for this circuit. Conventionally, loss in dB is a positive number, which is why the source voltage is on top in the fraction.

Suppose a signal source Vgen has a Thevenin-equivalent circuit resistance Rgen = 50k as shown below, and is connected through terminals 1 and 2 to a load resistance RL = 600 : Calculate the voltage loss LdB = 20log10(Vgen/VL) for this circuit. Conventionally, loss in dB is a positive number, which is why the source voltage is on top in the fraction.

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Suppose a signal source Vgen has a Thevenin-equivalent circuit resistance Rgen = 50k as shown below, and is connected through terminals 1 and 2 to a load resistance RL = 600 : Calculate the voltage loss LdB = 20log10(Vgen/VL) for this circuit. Conventionally, loss in dB is a positive number, which is why the source voltage is on top in the fraction.

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Assume the source follower is connected as a buffer amplifier between terminals 1 and 2 of the first figure (instead of the wire shown connecting them originally). The capacitors are large enough to act as short circuits at the frequency of interest. Find a value for RG that makes the AC voltage at the gate vg = 0.8Vgen. Then calculate the buffer amplifier gain VL/vg = AV, using the formula AV = RL/ 1/gm+RL Finally, calculate the buffered lossLB = 20log10(Vgen/VL) with the buffer inserted in the circuit. The value of LB should be considerably smaller than the original L, showing that although source followers have a voltage gain less than 1 , they can prevent significant losses when impedances are mismatched as at the beginning of this problem.

Assume the source follower is connected as a buffer amplifier between terminals 1 and 2 of the first figure (instead of the wire shown connecting them originally). The capacitors are large enough to act as short circuits at the frequency of interest. Find a value for RG that makes the AC voltage at the gate vg = 0.8Vgen. Then calculate the buffer amplifier gain VL/vg = AV, using the formula AV = RL/ 1/gm+RL Finally, calculate the buffered lossLB = 20log10(Vgen/VL) with the buffer inserted in the circuit. The value of LB should be considerably smaller than the original L, showing that although source followers have a voltage gain less than 1 , they can prevent significant losses when impedances are mismatched as at the beginning of this problem.

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