This tool finds the percent (**%**) of power that’s reflected back for a specified value of Voltage Standing Wave Ratio (**VSWR**).

**Calculator**

Enter the VSWR. The % reverse power and the reflection coefficient (**Γ**) will be calculated.

**Formula**

** Γ = (VSWR – 1)/(VSWR + 1)**

**Reverse Power _{%}** =

**100*|Γ|**

^{2}VSWR is a number greater than 1.

It is often expressed as a ratio. For instance a VSWR of 2 is written as 2:1.

**What does a VSWR of 1.5 mean?**

Using the calculator above, for a VSWR of **1.5**, the reflected power is **4%**. The balance of power (**96%**) is transmitted forward. In most applications, this is considered a good value.

It’s not unusual however, to encounter higher values of VSWR. For instance the Local Oscillator port of the ADE mixer has a VSWR as high as **4**.

One technique to improving the mismatch is to add an attenuator pad (typically 3 dB) between the signal source and LO port of the mixer. Here is a more detailed post on how to improve VSWR.

As the VSWR increases, so also does the percentage of reflected power.

An ideal value of VSWR is **1** where none of the power is reflected and all of it is transmitted forward. This is the most efficient scenario.