27.7.1. Defining Lower Cutoff Frequency

Try these first

1. 1.

   What is the lower cutoff frequency?

   Hint

   Think about the implications of gain on frequency.

2. 2.

   Define a coupling capacitor.

   Hint

   Consider its role in amplifier circuits.

3. 3.

   What is the impact of increasing the emitter resistor?

   • Increase gain
   • Decrease gain
   • No effect

   Hint

   Think about the voltage gain formula discussed.

4. 4.

   True or False: Coupling capacitors can only be used with DC signals.

   • True
   • False

   Hint

   Review their purpose in amplifier circuits.

5. 5.

   Design an amplifier circuit with given specifications targeting a specific lower cutoff frequency. Discuss how you would select component values and justify your decisions regarding R_E and C values.

   Hint

   Use the formula for cutoff frequency to link R and C.

6. 6.

   You have an amplifier circuit where increasing R_E from 1kΩ to 10kΩ dramatically reduced gain. Provide a mathematical analysis of this scenario, including the implications of stability and what design considerations you recommend.

   Hint

   Reflect on how changes in R_E affect the gain as described in class.