TEM horn circular array for wide band pattern notch reconfigurable antenna system

This paper presents a wideband circular antenna array with a reconfigurable radiation pattern. The array consists of eight TEM horn antennas. The antenna array exhibits an omni-directional azimuthal radiation pattern when all eight ports are excited with signals of the same magnitude and phase. The antenna array is fed through eight reconfigurable bandstop filters and a power splitter. This enables it to provide an omnidirectional azimuthal pattern along with a single directional pattern null in a given spatial direction and at a certain frequency. Both the special direction and the frequency can be altered. The antenna works from 0.8GHz to 3.0GHz. The array will be useful in combating interference in wideband communication systems or spectrum search in cognitive radio systems.