3.2. Barkhausen’s Criteria

Try these first

1. 1.

   What must the loop gain be to maintain oscillations?

   Hint

   Think about how gain can compensate for losses.

2. 2.

   What phase shifts are acceptable for oscillations?

   Hint

   Consider how signals reinforce or cancel one another.

3. 3.

   What is the minimum loop gain required for oscillations?

   • 0.5
   • 1
   • 2

   Hint

   Remember the criteria for sustaining oscillations.

4. 4.

   True or False: A phase shift of 270° will sustain an oscillator.

   • True
   • False

   Hint

   Consider the reinforcement or cancellation of signals.

5. 5.

   Design an oscillator circuit that meets Barkhausen's Criteria, including calculations for gain and phase.

   Hint

   Sketch the circuit and label the components while calculating the gains.

6. 6.

   Critically analyze a given oscillator circuit with specifications that fail Barkhausen's Criteria.

   Hint

   List all components and their contribution to the overall gain and phase.