SWR Calculator

Formula

The formula to calculate the Standing Wave Ratio (SWR) is:

\[ \text{SWR} = \frac{1 + \sqrt{\frac{\text{Pr}}{\text{Pf}}}}{1 - \sqrt{\frac{\text{Pr}}{\text{Pf}}}} \]

Where:

\( \text{SWR} \) is the Standing Wave Ratio
\( \text{Pr} \) is the reflected power
\( \text{Pf} \) is the forward power

Example Calculation

Let's consider an example:

Reflected Power (Pr): 5 W
Forward Power (Pf): 100 W

Using the formula to calculate the SWR:

\[ \text{SWR} = \frac{1 + \sqrt{\frac{5}{100}}}{1 - \sqrt{\frac{5}{100}}} = \frac{1 + \sqrt{0.05}}{1 - \sqrt{0.05}} \approx \frac{1 + 0.224}{1 - 0.224} \approx \frac{1.224}{0.776} \approx 1.58 \]

This demonstrates that with a reflected power of 5 W and a forward power of 100 W, the SWR is approximately 1.58. ✅