An antenna structure capable of determining the direction of a radiofrequency identification (RFID) tag includes a wide-angle antenna disposed within an attenuator that has regions of low attenuation. The attenuator may include a metal plate with holes. In this case, the antenna only detects RFID tags that are aligned with a hole, and hence the direction of the RFID tag is detected. Multiple holes of different sizes can be provided. In this case, if the RFID tag is moving, the direction and speed of movement can be determined from the duration of received RFID signals. For example, a long period of RFID tag signal reception indicates that the tag passed in front of a large hole in the attenuator. The present invention is particularly well suited for use with conveyor belts and in applications where RFID tags move along known paths.