A conveyor system for processing items on which radio frequency identification tags are disposed includes a frame, 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, a second antenna, a radio frequency receiver, a processor, and radiation absorbing material disposed between the first and second antennas and the path of travel, so that the absorbing material shields a portion of the radiation that would otherwise radiate into an area through which the items pass.