40.1.4. Need for High Frequency Analysis

Try these first

1. 1.

   What are the two types of capacitance associated with BJTs?

   Hint

   Think about the terminal connections of the transistor.

2. 2.

   What does Miller's theorem help us achieve?

   Hint

   Recall the function of bridges in electrical terms.

3. 3.

   What is Miller's theorem used for?

   • To calculate resistance
   • To calculate equivalent capacitance
   • To measure voltage

   Hint

   Think about its role in simplifying circuit analysis.

4. 4.

   True or False: A higher gain in an amplifier results in increased input capacitance.

   • True
   • False

   Hint

   Reflect on how gain relates to capacitance.

5. 5.

   A CS amplifier has a gain of -5 and Cgd = 20 pF. Calculate the effective capacitance at the input.

   Hint

   Remember to take the gain into account, and consider the absolute value of capacitance.

6. 6.

   Analyze a CE amplifier circuit where Cπ = 10 pF and Cµ = 5 pF. Determine how these affect the frequency response.

   Hint

   Consider the influence of each capacitance as per the circuit model.