Attenuation in dB represents a power ratio. Approximately 3 dB halves power, 6 dB quarters it and 10 dB leaves one tenth.
How it works in practice
The exact half-power value is about 3.0103 dB. Use exact formulas where small differences matter. Voltage ratios differ because power is proportional to voltage squared only under compatible impedance conditions. State whether a ratio is power or voltage.
Example and interpretation
A 1 W input becomes about 0.501 W after exactly 3 dB loss, not exactly 0.500 W.
Checks before use
- Identify power versus voltage
- Use the correct logarithmic factor
- Calculate the ratio
- Round appropriately
Important limit
Do not apply a ten-log power formula directly to a voltage ratio.
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.