H12-311_V3.0 · Question #170
The two commonly used units to describe antenna gain are dBi and dBd, and the conversion relationship between them is: dBi=dBd+2.14.
The correct answer is B. False. Option B is correct because the standard conversion factor between dBi and dBd is 2.15, not 2.14. The correct relationship is dBi = dBd + 2.15, which derives from the theoretical gain of a half-wave dipole antenna over an isotropic radiator, calculated as 10 * log10(1.64) =…
Question
The two commonly used units to describe antenna gain are dBi and dBd, and the conversion relationship between them is: dBi=dBd+2.14.
Options
- ATrue
- BFalse
How the community answered
(48 responses)- A27% (13)
- B73% (35)
Explanation
Option B is correct because the standard conversion factor between dBi and dBd is 2.15, not 2.14. The correct relationship is dBi = dBd + 2.15, which derives from the theoretical gain of a half-wave dipole antenna over an isotropic radiator, calculated as 10 * log10(1.64) = 2.1488 dBi, which rounds to 2.15. Option A is wrong because while the formula structure is correct and dBi and dBd are indeed the two common antenna gain units, the constant 2.14 is a rounded figure that goes in the wrong direction -- the precise value rounds to 2.15, not down to 2.14.
Memory tip: Associate the "5" in 2.15 with the "5" in a half-wave dipole (half = 0.5), reminding you the correct offset is 2.15 and not 2.14.
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