Adding attenuation improves the VSWR.

If you have a load with a bad VSWR, it is possible to improve the matching by an attenuator. This calculator can calculate the improved VSWR when attenuation is inserted between the source and load. The following variables can be changed in this tool:

-  Load VSWR

-  Inserted attenuation

The return loss, improved return loss and final VSWR are calculated.

 Windows RF Calculator