Topic: Microwave Engineering
To avoid difficulties with strapping at high frequencies, the type of cavity structure used in the magnetron is,
- A. Hole and Slot
- B. Slot only
- C. Vane
- D. Rising-Sun
Answer: D. Rising-Sun
Explanation: In standard magnetrons, strapping rings are used to ensure the device operates in the dominant $\pi$-mode. However, at high frequencies (like millimeter waves), strapping becomes physically difficult to manufacture and introduces losses. The Rising-Sun cavity structure uses alternating large and small cavities to achieve the mode separation required without needing strapping.