Understanding dBi and dBm: WLAN Antenna Gain & Router/Network Card Signal Strength Units

Hello! I'm just getting started in radio networks and I have a few important questions for me.


In WLAN antennas, apart from the internal impedance and the radiation account, there is one more parameter that I do not understand. This is the "dBi" gain What is this unit and how is it measured? the more "dbi" the antenna has the better??

In routers and network cards I see the unit 'dBm' what is this unit??

PLEASE give me some clarification

I can't seem to get an answer. It seems to me that for WLAN fitters these parameters should be known! Doesn't anyone know what they mean?? I'll have to look on other websites....

dBi is the unit of measurement for antenna gain.
Antenna gain expressed in dBi indicates how many decibels the signal level is greater than the hypothetical isotropic antenna (antenna gain). For example, an antenna with a gain of 8 dBi transmits a signal 100.8 = 6.31 times stronger than an isotropic antenna."

"dBm is a unit of measure of power related to 1 mW.
Power expressed in dBm tells how many decibels this power is greater (or less) than the power of 1 mW. 1 mW corresponds to 0 dBm, 10 mW -> 10 dBm, 0.1 mW -> -10 dBm.

For example, 100mW converted to dBm is:

10 * log10(100mW/1mW) = 10 * log10(100) = 10 * 2 = 20dBm

I guess it's exhaustive, I found it in the 20th century on the internet

Quote:

For example, an antenna with a gain of 8 dBi transmits a signal 100.8 = 6.31 times stronger than an isotropic antenna."

dBi is just for isotropic antennas and dBd for dipoles, and just 6.31 is more for a dipole I guess or something

dbi and this is the logarithm of the output power to the input power,
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