DB to DBI Calculator

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DBi and dBd are units of power gain, both are relative values, but the reference is not the same. The reference reference for dBi is an omnidirectional antenna; the reference reference for dBd is a dipole.

It is generally believed that dBi and dBd represent the same gain, and the value expressed in dBi is 2.15 larger than the value expressed in dBd. (ie dBi=dBd+2.15). G(dBi)=10lgGi G(dBd)=10lgGd

DBm is a value that evaluates the absolute value of power, and the calculation formula is: 10lgP (power value/1mw).

DB to DBI Calculator

1. Db to dbi calculator

1.1 If the transmit power P is 1mw, it is 0dBm after converting to dBm.

1.2 For 40W power, the converted value in dBm should be:

10lg(40W/1mw)=10lg(40000)=10lg4+10lg10+10lg1000=46dBm.

1.3 For an antenna with a gain of 16dBd, when its gain is converted into dBi, it is 18.15dBi (generally ignoring the decimal place, it is 18dBi).

1.4 0dBd=2.15dBi.

1.5 GSM900 antenna gain can be 13dBd (15dBi), GSM1800 antenna gain can be 15dBd (17dBi).

2. Db to dbi calculator extended information:

2.1 Take power as an example:

Signal power is X = 100000W = 10^5

The reference power is Y=1W

The value of dB: Lx(dB) = 10lg(10^5W/1W) dB= 10lg(10^5) dB= 50 dB

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I have the following additions.

  1. The notation shall be “dB” or deci-Bell - with a captiol B(ell), not Db
  2. dBm means that power is referenced to 1 mW in an impedenace (with antennas normally 50 ohm)
  3. dBi means a power referenced to an isotrope antenna
  4. dBd means a power rerefenced to an dipole antenna.
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Thank you for sharing, with your additions, I have a correct understanding.

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