Beamforming for circular and semicircular array antennas for low-cost wireless LAN data communications systems

An investigation into beam synthesis for small circular and semicircular arrays is presented. Array antennas of this type are likely to become a core component in future wireless LAN systems architecture. They offer additional spatial diversity as a means for combating multipath interference, necessary for high speed data communications, and user mobility. Beams are synthesised using cophasal and adaptive algorithms. Beamwidths of 19° and –20 dB sidelobe levels are attainable from an array of three wavelengths diameter. A semicircular array of this type can maintain a gain of approximately 10 dBi over a look direction angular range of ±50°.