How to convert dBm to W/m²?  

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Moderator
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10/09/2010 9:11 pm  

The formula to convert dBm to W/m² is:

S
[W/m²] = (10^(p[dBm]-G[dBi]) / 1000) * ((4 * Pi) / (Lambda[m]²))

Remarks:
G = Antennagain
Lambda = Wavelength
Pi = 3,1415

Example:
Say your have a reading of -40dBm at 950MHz with a HyperLOG 7025 antenna (which offers a gain of 4,9dBi at 950MHz). The result is:
0,000.004.08W/m² or 4,08µW/m²

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javholgu
(@javholgu)
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Joined: 8 years ago
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05/08/2011 9:08 am  

Hello,
I am Javier. I am interested on citing the source of this formula (page 63 of manual) in an article and would like to ask if you know a solid reference to use. Also I would appreciate if you could share a mistaken formula and its reliable source to convert dBm to W/square meter where frequency is not considered.
I would appreciate your valuable feedback
Regards,
Javier


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Moderator
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05/08/2011 9:24 am  

This is standard math and physics.
The formula clearly shows that its IMPOSSIBLE to convert dBm to W/m² WITHOUT adding the frequency.

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Twitch
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20/06/2016 8:27 am  

I have a hyperlog 6080 what is the antennae gain and where do I find the lambda number for the formula?


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Twitch
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20/06/2016 8:31 am  

Where do you get the dBi number?


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Twitch
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20/06/2016 8:33 am  

where do you get the dBi number?


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Twitch
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20/06/2016 8:53 am  

The W/m2 numbers, I don't understand why the , comes before a decimal point. For example 0,00.004.08W/m2 what does the comma and decimal point mean in comparison with american numbers.


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Moderator
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20/06/2016 9:13 am  

This are the international physical ISO standards used by most of the world. The US simply do it "wrong".
Have a look at https://en.wikipedia.org/wiki/Decimal_mark

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nayam
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28/08/2019 9:47 am  

Where I Will get dBm number? 


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