A conveyor system for processing items on which radio frequency identification tags are disposed includes a frame and a conveyor that is disposed moveably 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. A first antenna is disposed proximate the path of travel so that the first antenna radiates radio frequency signals into a first area that is proximate the conveyor and through which the items pass and receives responses to the radio frequency signals from the respective radio frequency identification tags. A second antenna is proximate the first antenna and the path of travel so that the second antenna radiates radio frequency signals into the first area. At least one radio frequency receiver receives signals from the first antenna corresponding to the responses received by the antennas from the respective radio frequency identification tags and outputs first signals corresponding to the responses. A processor receives the first signals and is programmed to associate a first signal with a first item when the processor receives the first signal while at least a portion of the first item is within a predetermined second area that includes at least part of the first area. The second antenna radiates radio frequency signals that interfere with reception of and response to the radio frequency signals from the first antenna by a respective radio frequency identification tag in the presence of radio frequency signals from the first antenna and the second antenna. The second antenna is disposed with respect to the first antenna and the conveyor so that the second antenna radiates radio frequency signals into a third area that is proximate to but generally excludes the second area.