| 摘要 |
An RF base station system includes an RF signal generator coupled to an RF emitter (106, 122), such as an antenna and an RF-reflective surface or field shaper (108) arranged to reflect RF signals emanating from the RF emitter to increase the effective tag reading volume of the base station system. In an illustrative embodiment, a plurality of reflective surfaces may be arranged to form the walls of a tunnel-like enclosure (108) to confine RF energy from the RF emitter (106, 122) to a tag-reading volume within the enclosure. In addition to confining the RF energy, the geometry of the reflective surfaces, the carrier frequency of the RF signal, and placement of the RF emitter (106, 122) may be chosen so that the probability is increased that the RF field strength within the enclosure (108), or a portion thereof, meets an RF tag's reading threshold requirement. In particular, the enclosure geometry, the carrier frequency of the RF signal, and placement of the RF emitter (106, 122) may be chosen so that multiple RF propagation modes are established within the cavity formed by the enclosure.
|
