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سؤال 532

How much does the gain of an ideal parabolic reflector antenna increase when the operating frequency is doubled?

  1. 2 dB
  2. 3 dB
  3. 4 dB
  4. 6 dBپاسخ درست

توضیح

The gain of a parabolic reflector is proportional to the square of the dish diameter expressed in wavelengths, so at a fixed physical diameter doubling the frequency halves the wavelength and quadruples the gain. A power ratio of four is 6 dB.

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شروع تمرین
سؤال 532: How much does the gain of an ideal parabolic reflector… · FCC Amateur Extra Class (Element 4) · Questena