For independent power quantities that can be summed, convert each dBm value to milliwatts, add the powers and convert the result back to dBm.
How it works in practice
Coherent RF combining also depends on phase and network behavior, so simple power summation is not a complete combiner model. Be clear about whether you are adding measured average powers or coherent signal amplitudes. Network loss must also be considered.
Example and interpretation
Two independent 10 mW powers sum to 20 mW, approximately 13.01 dBm, not 20 dBm.
Checks before use
- Convert each reading to linear power
- Check whether power summation applies
- Add linear values
- Convert back
Important limit
Do not use this arithmetic to ignore coherent phase cancellation.
Related Centron RF product
SMA 2 W 6 GHz fixed attenuator. Use calculated levels to define a requirement, then compare it with the exact product’s current bandwidth, input power, impedance and available attenuation options. Calculations assume stated conditions and do not replace a component datasheet.
Further reading
Keysight: Fundamentals of RF and Microwave Power Measurements. This background reference explains general principles; the selected Centron RF model’s datasheet governs its own ratings.
Related guides
Educational guide. Numerical examples use the stated assumptions and are not test results for a supplied unit.