How Many Watts Remain After RF Attenuation?

Finned N-type RF dummy load on a laboratory bench with CentronRF watermark

For an ideal matched path, output power equals input power multiplied by 10 raised to −A/10, where A is attenuation in dB.

How it works in practice

This is a power-ratio calculation. Actual loss may differ from nominal attenuation, and mismatch can affect delivered power. Use measured frequency-specific attenuation when precision matters. The attenuator still experiences the full input stress at its upstream port.

Example and interpretation

A 2 W input through 20 dB attenuation gives approximately 0.02 W, or 20 mW, at the output.

Checks before use

  • Identify input power
  • Use actual attenuation where available
  • Calculate output
  • Check input and output limits

Important limit

Small output power does not imply small attenuator dissipation.

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.