For a passive load under the usual definition, reflection coefficient magnitude is (VSWR − 1)/(VSWR + 1). It describes reflected-wave amplitude relative to incident amplitude.
How it works in practice
Reflected power fraction is the square of that magnitude. These relations assume a defined reference impedance and suitable transmission-line conditions. They do not describe thermal power handling or every active-device situation. Use measured values at the relevant frequency.
Example and interpretation
For VSWR 1.5, magnitude is 0.2 and reflected power fraction is 0.04, or 4%.
Checks before use
- Use the measured VSWR
- Calculate magnitude
- Square it for power fraction
- State the reference impedance
Important limit
Do not treat reflection coefficient magnitude as the reflected-power percentage directly.
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.

