A critical factor in increasing the widespread adoption of Radio Frequency Identification (RFID) technology for different supply chain applications is the ability to achieve a high level of read accuracy. The read accuracy is dependent on the size of the region that receives sufficient power from the reader. While most current research considers the powering region of a reader to be determined only by its read range, in reality read accuracy can be complicated by such issues as polarizations and the relative orientations of reader antennas and tags. In particular, when tag positions are not fixed, the specific placement of reader antennas and their interaction with the polarization and the orientation of the tags can have a significant effect on the success of the interrogation processes. This research uses Friis' equation for both the forward link and the backward link to explicitly consider orientations and polarizations while addressing the problem of optimizing the locations of a set of reader antennas at a scanning portal. The objective is to maximize the size of the powering region satisfying a particular read accuracy requirement. This research develops different methodologies and provides results for obtaining the best antenna locations to address different scenarios in supply chain applications. It addresses the case where items are static within a read portal, as well as when they might be moving on some type of material handling equipment. Various scenarios are considered for the tag orientations, including item-level applications where any orientation might be possible and case-level and pallet-level scenarios where the number of possible tag orientations might be limited
