Switched-beam slot sector antenna for WLAN applications

A small sector antenna using a switched-beam slot antenna is proposed. The switched-beam slot antenna has a main beam which is tilted to the direction along the slot plane, and its beam direction is inverted by changing the phase of the slot element excitation. We present a four-sector structure whose planar size of 10/spl times/10 mm/sup 2/ at 25 GHz and is suited to the antenna for a small card terminal. For the future, we are planning to fabricate and measure the four-slot structure and investigate the main beam control in the vertical plane for further performance improvement.