초록 ▼

The present invention features an improved radio frequency identification (RFID) reader which operates with a low power consumption and which may tolerate a wide fluctuation in input voltages. The RFID reader is housed so that the influence of its physical surroundings, especially metallic objects,

The present invention features an improved radio frequency identification (RFID) reader which operates with a low power consumption and which may tolerate a wide fluctuation in input voltages. The RFID reader is housed so that the influence of its physical surroundings, especially metallic objects, on system performance is minimized. A pre-compensation metal plate is used to stabilize the self-resonant frequency of the reader, even in the presence of large metal masses. The pre-compensation plate may be formed from aluminum or another non-ferrous material or, for long-range RFID readers, from ferrite or another similar, high magnetically permeable material. In addition, the RFID reader features improved sensitivity so that the effective operating distance is maximized. Also, the operating frequency is dynamically controlled in discrete steps of 10 Hz or less so that the effects of component parameter drift, temperature change, or other external factors are minimized. The RFID reader also automatically adapts itself to the requirements of an external access control system to which it is attached.

대표청구항 ▼

[ What is claimed is:] [1.]1. A reader for use in radio frequency identification (RFID) applications, comprising:a) a housing for mounting an RFID device on an external mounting surface;b) an antenna disposed within said housing;c) RF generation means for generating an RF signal at a predetermined f

[ What is claimed is:] [1.]1. A reader for use in radio frequency identification (RFID) applications, comprising:a) a housing for mounting an RFID device on an external mounting surface;b) an antenna disposed within said housing;c) RF generation means for generating an RF signal at a predetermined frequency disposed in said housing, said RF generation means being operatively connected to said antenna for cooperatively generating an RF field external to said housing;d) digital signal processing means disposed in said housing for interpreting variations in said RF field caused by a transponder external to said housing interacting with said RF field; ande) a pre-compensation plate disposed in said housing proximate said antenna for substantially eliminating changes to said RF field caused by influences of metal at or near said external surface.