Synthesized-beam RFID readers may be used to locate RFID tags. In one embodiment, a tag's response rates on different beams can be used, along with the target locations of those beams, to estimate the tag's location. The estimated tag location is within a region where beams with nonzero tag response rates overlap, and the distances of the estimated tag location from any two different beam target locations may correspond to a ratio of tag response rates on the two different beams. In another embodiment, a tag's response rates on different beam pairs configured to cooperatively power RFID tags can be used, along with the target locations of those beam pairs, to estimate the tag's location.