Beverage antenna

The Beverage antenna, a very early type of wave antenna or traveling wave antenna, is a long-wire receiving antenna mainly used in the low frequency and medium frequency radio bands, invented by H.H. Beverage in 1921. It is used by amateur radio operators, shortwave listeners, longwave radio DXers, and for military applications.

A Beverage antenna consists of a horizontal wire from one-half to several wavelengths long (tens to hundreds of meters / yards for shortwaves; up to several kilometres / miles for longwaves) suspended above the ground, with the feedline to the receiver attached to one end, and the other end of the wire terminated through a resistor to ground. The antenna has a unidirectional radiation pattern with the main lobe of the pattern at a shallow angle into the sky off the resistor-terminated end, making it ideal for reception of long distance skywave (skip) transmissions from stations over the horizon which reflect off the ionosphere. However the antenna must be built so the wire points in the direction of the transmitter(s) to be received.

The advantages of Beverage antennas are their excellent directivity, wider bandwidth than conventional resonant antennas, and the ability to clearly receive distant and overseas transmitters. Their disadvantages are very long physical size, requiring considerable land area, and because of the length, being unfeasible to rotate to different reception directions. As a work-around, antenna installations often use multiple Beverage antennas to provide wide azimuth coverage.

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