Topic: Microwave Engineering
The modes in a reflex klystron
- A. Result from excessive oscillating frequencies of the cavity
- B. Correspond to different oscillating frequencies of the cavity
- C. Are caused by spurious frequency modulation
- D. All give much the same frequency but different transit times
Answer: D. All give much the same frequency but different transit times
Explanation: Different modes of oscillation in a reflex klystron correspond to the electron beam transit times equal to $(n + 3/4)$ cycles. While these modes produce slightly varying output powers and tuning ranges, they all basically sustain oscillation near the fundamental resonant frequency of the single cavity.