Dual-band conical-scanning Yagi-Uda antenna

A dual-band conical-scanning Yagi-Uda antenna is presented. The proposed antenna is composed of dual-band director elements, dual-band driven elements, and planar reflectors which the alignment of each element is not on the same plane of the dual-band driven elements. The PIN diodes are used in order to change position of driven elements and directors. The patterns can be switched in four directions that main beams are in the zenith angle of 30°. It is shown that the dual-band antenna for 1 and 2 GHz operation achieves an impedance bandwidth of 8.5% and 12.5%, respectively. The front-to-back ratio of conical beams is higher than 8 dB. The antenna gain is around 6 dBi.