As the length of a single linear antenna increases, a characteristic deterioration in directivity appears showing so called side lobes. If several antennas are used in parallel, however, directivity is improved due to the increase in antenna surface area. The field of single radiators is additive in the directions in which the oscillations are in phase, while they are canceled out in other directions by interference.

Nowadays antenna arrays are found at almost all mobile radio base stations, and radio and television broadcasting stations. Their advantages result from their ability to achieve increased gain and improved directivity. It is possible to select or mask targeted reception areas. The necessary transmission power is also reduced due to the corresponding increase in antenna gain.

Download
English version	[270 kB]
German version	[270 kB]
After downloading please unpack all files of the zipped packages and start the executable.

The program "TwoAerials" allows to study the effect of distance and phase shift of two coupled antennas. For downloading the program click on the little floppy disk symbols at right.