Patent ID: 7518513

Claim:
A conveyor system for processing items on which radio frequency identification tags are disposed, said system comprising: a frame; a conveyor that is disposed movably on the frame and that conveys items through a path of travel, each item having at least one respective radio frequency identification tag disposed thereon; an antenna disposed on the frame with respect to the path of travel so that the antenna radiates radio frequency signals into a first area through which the items pass, wherein the antenna comprises a substrate and a plurality of patch elements disposed on the substrate in respective positions that are sequential with respect to a direction transverse to the path of travel, wherein electric current at each said patch element drives radiation of the radio frequency signals and defines a rotating electric current pattern, and wherein respective rotational directions of the electric current pattern at two said patch elements are opposite to each other; and a radio frequency transmitter that drives the antenna to emit the radio frequency signals into the first area.