Rifid tags and methods of designing rfid tags
AssigneeMicron Technology, Inc.
InventorJohn R. Tuttle
Life of this patent
Estimating the term…
Abstract
RFID tags and methods of designing RFID tags. At least some of the illustrative embodiments are RFID tags comprising a tag antenna, a matching circuit coupled to the tag antenna, a shorting device coupled to the tag antenna and the matching circuit (wherein the shorting device is configured to selectively couple the tag antenna to common), and a tag circuit coupled to the matching circuit and the shorting device (the tag circuit configured to control the shorting device). In one or more such embodiments, a difference between a reflection coefficient of the tag antenna when the shorting device is conductive and a reflection coefficient of the tag antenna when shorting device is non-conductive is greater than or equal to approximately 0.8.
Claims21
A radio frequency identification (RFID) tag comprising:
- a tag antenna;
- a matching circuit coupled to the tag antenna;
- a shorting device coupled to the tag antenna and the matching circuit, wherein conductivity of the shorting device affects a reflection coefficient of the tag antenna;
- and
- a tag circuit coupled to the matching circuit and the shorting device, the tag circuit configured to control the shorting device;
- wherein a difference between a reflection coefficient of the tag antenna when the shorting device is conductive and a reflection coefficient of the tag antenna when the shorting device is non-conductive is greater than or equal to approximately 0.8.
A radio frequency identification (RFID) tag comprising:
- a tag antenna;
- a matching circuit coupled to the tag antenna;
- a tag circuit coupled to the tag antenna through the matching circuit;
- and
- a switch configured to selectively couple the tag antenna to a common potential;
- wherein an impedance of the antenna is more than approximately four (4) times a conducting impedance of the switch.
A method comprising:
- designing an antenna for a radio frequency transceiver, wherein physical characteristics of the antenna are selected independent of effects of the physical characteristic on impedance of the antenna;
- and then
- designing an impedance matching circuit having approximately the same impedance as the antenna;
- and
- selecting a shorting device with a conductive impedance, the shorting device selected based on the impedance of the antenna.
Dependencies are inferred from the claim text.