課程名稱︰電子學一
課程性質︰必修
課程教師︰吳肇欣
開課學院：電資學院
開課系所︰電機系
考試日期（年月日）︰2014/11/13
考試時限（分鐘）：110
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
1. Fig.1 shows the circuit model of a voltage amplifier loaded with a resistor
RL and a capacitor CL. The parameters are given as RS = 40 kΩ, Ri = 200kΩ,
AVo = 140, and Ro = 2kΩ.
(1)[7%] Find the minimum RL allowed to maintain a voltage gain no less than
40dB.
(2)[7%] Base on (1), what is the maximum CL allowed to keep a 3-dB frequency
higher than 20 kHz?
(3)[9%] The input voltage form is given by 0.1sin(10^4t) + 0.5sin(10^5t)[V].
With the minimum RL and the maximum CL, find the output voltage Vo.