。。。。。。Effects of bypass capacitor， coupling capacitors on the upper and lower frequency， by means of simulation can verify the influence The C1 consists of 10 μ F decreased to 1 μ F， the other parameters constant， can measure the lower limit frequency is 3 Hz， the upper limit frequency is 43MHz; the C2 will decrease from 10 μ F to 1 μ F， the other parameters constant， can measure the lower limit frequency is 35 Hz， the upper limit frequency is 56 MHz; will bypass capacitor C3 is composed of 47 μ F decreased to 1 μ F， the other parameters constant， can measure the lower limit frequency is 12 kHz， the upper limit frequency is 43 MH These results show that， in low frequency is mainly influenced by the bypass capacitor， with the teaching material is consistent with the concl1．2．4 输入电阻分析Analysis of the 4 input resistance利用Multisim 10软件根据图1更改为输入电阻测量电路，在放大器的输入回路接虚拟电压表和电流表，根据测量值可求出输入电阻。测量图和测量结果如图7所示。Using Multisim 10 software according to figure 1 to change the input resistance measurement circuit， the virtual voltmeter and ammeter in the input circuit of the amplifier， according to the measured values for input Measurement and measurement result as shown in figure 根据测量结果计算输入电阻为：Ri=Vi／Ii=9．154／1．693=5．406 969 9kΩ。According to the measurement of input resistance: Ri=Vi / Ii=154 / 693=406 969 9K1．2．5 输出电阻分析Analysis of 5 output resistance输出电阻RO的大小表征电路带负载能力的大小。输出电阻越小，带负载能力越强。用传统方法测量放大器的开路电压VO=512．871 mV和负载电阻上的电压VOL=271．613 mV，再利用RO=(VO-VOL)RL／VOL计算输出电阻RO=4．530 032 8 kΩ。而采用外加激励法测量输出电阻仿真电路图8所示。Load capacity size characterization circuit output resistance RO The output resistance is small， with a load capacity is The traditional method of measuring amplifier circuit voltage VO=871 mV and load resistance the voltage on VOL=613 mV， then RO= (VO-VOL) RL / VOL computing output resistance of RO=530 0328 K And the use of external excitation method to measure the output resistance simulation circuit shown in figure 旁路电容、耦合电容对上下限频率的影响，可以通过仿真的手段验证其影响程度。将C1由10μF减小到1μF，其他参数不变，可测得下限频率为63．3 Hz，上限频率为18．43MHz；同理将C2由10μF减小到1μF，其他参数不变，可测得下限频率为52．35 Hz、上限频率为17．56 MHz；将旁路电容C3由47μF减小到1μF，其他参数不变，可测得下限频率为2．12 kHz，上限频率为18．43 MHz。以上结果显示，低频特性主要受到旁路电容的影响，这跟教材中的结论是一致的。1．2．4 输入电阻分析 利用Multisim 10软件根据图1更改为输入电阻测量电路，在放大器的输入回路接虚拟电压表和电流表，根据测量值可求出输入电阻。测量图和测量结果如图7所示。 根据测量结果计算输入电阻为：Ri=Vi／Ii=9．154／1．693=5．406 969 9kΩ。1．2．5 输出电阻分析 输出电阻RO的大小表征电路带负载能力的大小。输出电阻越小，带负载能力越强。用传统方法测量放大器的开路电压VO=512．871 mV和负载电阻上的电压VOL=271．613 mV，再利用RO=(VO-VOL)RL／VOL计算输出电阻RO=4．530 032 8 kΩ。而采用外加激励法测量输出电阻仿真电路图8所示。
