This tool converts Reflection Coefficient (sometimes referred to as Gamma) **Γ **to Voltage Standing Wave Ratio or **VSWR**.

VSWR to Reflection Coefficient Γ** **

## Formula

**VSWR = (1+|Γ|)/(1-|Γ|)**

the absolute value of the reflection coefficient,**|Γ|** **< 1**

## Background

**VSWR** is sometimes called standing-wave ratio is a measure of the impedance match between a feedline’s characteristic impedance and the attached load. The load can be an antenna or any RF module such as a filter or amplifier. The greater the degree of mismatch the less efficient the design and implementation.

VSWR is often expressed as a ratio to 1. For example, if the VSWR is **1.9** then it is written as **1.9:1**.

Within the context of antennas **a good value of VSWR is 1.5 or lower**. In an ideal situation the load is perfectly matched to the feedline characteristic impedance and **Γ=0**. In this case, no signal energy is reflected and all of it is transmitted forward.

If the reflection coefficient is **Γ = 1**, the denominator in the equation above goes to 0 and VSWR is ∞. This is the worst possible match as all the power is reflected back.