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Mugless
Australia
11 Posts |
 Posted - 06/20/2020 : 20:11:07
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Hi Everyone,
Please explain the definition GQ 390 uses for dBm.
I assume the equation of dBm is:
dBm = 10 * Log10 (P_reading) / (P_reference)
If this is correct, please confirm that P_reference = 100,000 mW/m2, or 10 mW/cm2, since 0 dBm corresponds to that number:
Thanks,
Doug |
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| Reply #1
EmfDev
2250 Posts |
Posted - 06/22/2020 : 09:50:32
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| The RF power reference is 1mW. It is converted to density with other parameters including gain. |
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| Reply #2
Mugless
Australia
11 Posts |
Posted - 06/22/2020 : 16:00:28
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Thanks,
So the conversion to 1 mW to power density involves a factor of 100,000 that takes into account other parameters including gain.
Is that the gain of the built-in antenna?
What are the other parameters?
Is the 100,000 factor derived from calibration of the GQ 390 against standard, reference equipment? If so, the fact that it is such a neat, round number is odd, if not even suspicious!! |
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| Reply #3
EmfDev
2250 Posts |
Posted - 06/23/2020 : 10:03:17
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| 0dBm converts to 1mW but in power density becomes 10mW/cm2. 10mW/cm2 converts to 10^5 mW/m2. |
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Topic |
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What is dBm?
