Optimum Design of Low-Cost Dual-Mode Beam- Steerable Arrays for Customer-Premises Equipment Applications

Two novel designs of dual-mode beam-steerable array antennas are proposed for customer-

premises equipment applications. To obtain the optimal distribution of excitations for the arrays, the gain

and front-back ratio of the array systems are optimized by using the method of maximum power transmission

efficiency. The first design operates at 2.45 GHz and uses four folded monopoles of height<1/10 wavelength

and a sleeve of height of 1/4 wavelength underneath the monopoles. The peak gain and the front-to-back ratio

are 6.7 dBi and 7.8 dB respectively. The second design operates at 830MHz and uses four Yagi monopoles as

elements with a common reflector and four directors. The peak gain and the front-to-back ratio for the second

design are 6.0 dBi and 16.8 dB respectively. The proposed antennas have advantages including: low cost

and compact size; dual-mode operation including the modes of omnidirectional radiation and directional

radiation; and in the mode of directional radiation, the beam can be electronically steered to achieve the full

coverage of the azimuthal plane. It achieves higher gain than the traditional electronically steerable passive

array radiator antenna.