Question
Why do most two-element Yagis with normal spacing have a reflector instead of a director?
Answer Options
- A) Lower SWR
- B) Higher receiving directivity factor
- C) Greater front-to-side
- D) Higher gain
Correct Answer: D
Explanation
A two-element Yagi antenna can be built using a driven element (DE) plus either a reflector (RE) or a director (DI). The reflector is tuned to be slightly longer than the DE, and the director is tuned to be slightly shorter than the DE. Both create gain, but the reflector typically provides better overall forward gain with fewer elements.
Most two-element Yagis with normal spacing use a reflector instead of a director because a two-element DE-RE combination typically provides higher gain (or \frac{F}{B} ratio) than a two-element DE-DI combination. The reflector is a more effective parasitic element for a simple, single-element gain configuration.
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