Calculated Current

Calculated current is the current determined from the calibration. This document describes how you should calculate the calculated current correctly.

Given calibration information

Frequency (MHz)	Current (mA)	Forward Power (dBm)
201,973	137	35,1

Question: What is the calculated current if the forward power is 35,4 dBm at the same frequency?

Answer: 141,8144768 mA

The calculation

First you calculate the dB difference in power.

$35,4-35,1=0,3dB$

• Note: the unit is dB not dBm

Calculate the calibrated current to dBmA so we can add the value.

$20*log10(137)\approx 42,73441134$ dBmA

So after the addition of the power difference the new value is 43,03441134 dBmA.

Calculate this back to mA:

$10^{\frac {43,03441134}{20}}\approx 141,8144768$ mA

Power expressed in milliWatt in dB values.

• 1 mW = 0 dBm

• 2 mW = 3 dBm

• 100 mW = 20 dBm

• 1 W = 30 dBm

• 100 W = 50 dBm

Decibel