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سؤال 499

What does the term “ground gain” mean?

  1. The change in signal strength caused by grounding the antenna
  2. The gain of the antenna with respect to a dipole at ground level
  3. To force net gain to 0 dB by grounding part of the antenna
  4. An increase in signal strength from ground reflections in the environment of the antennaپاسخ درست

توضیح

Energy leaving the antenna downward is reflected by the ground and, at low elevation angles, arrives in phase with the direct wave, adding to it. That reinforcement can raise low-angle signal strength by several decibels over what the same antenna would produce in free space, and it is what the term describes.

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شروع تمرین
سؤال 499: What does the term “ground gain” mean? · FCC Amateur Extra Class (Element 4) · Questena