How to convert dBm ...

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# How to convert dBm to W/m²? (@moderator)
Joined: 12 years ago
Posts: 1045
Topic starter

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

Snip (@javholgu)
New Member
Joined: 11 years ago
Posts: 1

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 (@moderator)
Joined: 12 years ago
Posts: 1045
Topic starter

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

Snip (@twitch)
Active Member
Joined: 7 years ago
Posts: 8

I have a hyperlog 6080 what is the antennae gain and where do I find the lambda number for the formula? (@twitch)
Active Member
Joined: 7 years ago
Posts: 8

Where do you get the dBi number? (@twitch)
Active Member
Joined: 7 years ago
Posts: 8

where do you get the dBi number? (@twitch)
Active Member
Joined: 7 years ago
Posts: 8

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. (@moderator)
Joined: 12 years ago
Posts: 1045
Topic starter

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

Snip (@nayam)
New Member
Joined: 3 years ago
Posts: 1

Where I Will get dBm number?

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