About dBm to mW Conversion

What is dBm and mW?

dBm (decibel-milliwatts) and mW (milliwatts) are both units used to measure power, particularly in the context of radio, microwave, and fiber-optic communication systems.

• dBm (decibel-milliwatts): A power ratio in decibels (dB) of the measured power referenced to one milliwatt (mW). It is used to conveniently express both very large and very small power levels in a logarithmic scale.
• mW (milliwatts): A linear unit of power equal to one-thousandth of a watt. It is commonly used to express absolute power levels in radio frequency (RF) and optical systems.

Formula for dBm to mW Conversion

The formula to convert dBm to mW is:

\[P_{mW} = 10^{\frac{P_{dBm}}{10}}\]

Where:

• \(P_{mW}\) is the power in milliwatts
• \(P_{dBm}\) is the power in decibel-milliwatts

Calculation Steps

1. Identify the power level in dBm.
2. Divide the dBm value by 10.
3. Calculate 10 raised to the power of this result.
4. The result is the equivalent power in mW.

Example

Let's convert 20 dBm to mW:

1. Given: \(P_{dBm} = 20\)
2. Apply the formula: \(P_{mW} = 10^{\frac{20}{10}}\)
3. Calculate: \(P_{mW} = 10^2 = 100\)

Visual representation:

Therefore, 20 dBm is equivalent to 100 mW.