How to describe how good an antenna is? Measuring SWR

Measuring SWR

Measuring SWR

Standing Wave Ratio

The standing wave ratio is normally measured by inserting a device in the feeder cable of the antenna. How much power reflected back from the antenna compared to the power transmitted forward is measured.

Such a device is called a directional coupler.

Directional couplers

Directional couplers or SWR meters for frequencies lower than 150 MHz are relatively cheap and quite accurate. For frequencies above 400 MHz exact meters are expensive.

The most wellknown universal instrument is a BIRD-wattmeter.

Such a device is called a directional coupler.