Patent ID: 6177872
Filing Date: 2001-01-23
Classification: G06K,G08B

Abstract:
An RFID tag comprising:an RFID circuit,an antenna, anda series connected transmission line impedance transforming circuit connected between the RFID circuit and the antenna to match the impedance of the RFID circuitry to the impedance of the antenna, wherein the impedance transforming circuit includes a first transmission line connected to the RFID circuit, the first transmission line transforming the relatively high impedance of the RFID circuit into an impedance that is a substantially pure resistance and that has a reflection coefficient whose magnitude is substantially the same as the reflection coefficient of the source, and one or more series-connected transmission line(s) connected to the first transmission line, said one or more series-connected transmission line(s) transforming the relatively low valued substantially pure resistivity looking into the first transmission line into an impedance which matches the impedance of the load.