107年 - 107 國立臺北大學_日間學士班曁進修學士班轉學生招生考試試題_電機工程學系、通訊工程學系日間學士班3年級：電子電路#147369

1. [10%] Explain (a) channel length modulation of a MOSFET and (b) early effect of a BJT.

2. [10%] Calculate the equivalent resistance \( R_{ab} \) in Fig. 1.

3. [10%] Apply Miller's Theorem and an amplifier gain to \( C_{gd} \), redraw the high-frequency model of a common source amplifier in Fig. 2.

4. [10%] Draw the small-signal mixed \( \pi \)-model of a common-base amplifier as shown in Fig. 3.

5. [10%] Compute the small-signal voltage gain \( (A{V} = V{out} / V{in}) \) of a common-source amplifier shown in Fig. 4, assuming transconductance of \( M{I} \) is \( g_{m} \).

6. [10%] Fig. 5 shows the circuits illustration of full-wave rectifier with four constant-voltage diodes \( (V{D,ON} = 0.7\mathrm{V}) \). Plot the \( V{in} / V{out} \) characteristics curve. (Hint: \( V{in} \) as \( x \)-axis and \( V_{out} \) as \( y \)-axis).

7. [10%] Compute the impedance \( Z_{1}(s) \) of the lossy tank in Fig. 6.

8. [10%] Compute the output voltage \( (V{\mathrm{out}}) \) of the amplifier shown in Fig. 7, assuming \( A0 = \infty \)

9. [10%] Find each location of poles \( (\omega{p1}, \omega{p2}) \), zeros \( (\omega{z1}, \omega{z2}) \), and 3-dB low-frequency \( \omega_{t} \) (rad/s) of the low-frequency response of \( L(s) = [s(s + 10)] / [(s + 100)(s + 25)] \)

10. [10%] Find the Thevenin equivalent circuit \( (V{TH}, R{TH}) \) of this circuit as shown in Fig. 8.