PLANAR ANTENNA WITH CONTROLLABLE BEAM DIRECTION APPLICABLE TO RFID TAG

摘要

PURPOSE: A planar antenna applied to an RFID tag controlling a beam direction is provided to improve beam tilt and circular polarization of the antenna by variously controlling the number and arrangement of the subs connected to a radiant unit. CONSTITUTION: An insulation layer(110) is made of a dielectric substance with a preset dielectric constant. An upper feed patch(120) is formed on the insulation layer. A lower feed patch is formed from the upper feed patch to the inward direction of the insulation layer with a preset interval. A ring shaped radiant unit(140) is formed on the insulation layer to overlap with the upper feed patch partially. A stub(150) is arranged to face the center of a circle formed by the radiant unit or the outside. A ground plate is positioned in the lower part of the insulation layer.