Adaptive WiMAX subscriber antenna for 2.6 GHZ and 3.45 GHZ

In this paper, development and realization of an adaptive antenna for WiMAX system are presented. Realization consists of two versions of low-cost multisector antennas for 2.6 GHz and 3.45 GHz frequency bands. Both antennas consist of four sectors radiators. The prototype antenna is designed to provide the highest possible gain for required antenna-size limitations. The radiation beam is electronically steerable to provide reception/transmission diversity. Each sector radiator includes two circular microstrip patches stacked vertically. The microstrip patches are punched out of metal sheet and use air as the dielectric. A solid-state microwave switch is used to select one of the four sectors. Such a structure assures 360deg horizontal signal coverage with about 10-12 dBi of gain. The antenna design and measured characteristics are presented.