====== Standing wave ratio ======

**Standing wave ratio** (**SWR**) describes the standing-wave pattern associated with impedance mismatch along a transmission line. It is often measured when evaluating an amateur radio antenna system.

===== Interpretation =====

A low SWR indicates a good match at the measurement point. It does not by itself show that the antenna radiates efficiently. A dummy load can present a good match while intentionally converting most transmitted energy into heat.

The measurement point, operating frequency and feed-line configuration matter when interpreting a result. Include these details with the instrument and test conditions in any published measurement.

===== See also =====

  * [[antenna|Antenna]]
  * [[transmission_line|Transmission line]]
  * [[radio_experiment|Radio experiment]]