RF tagging system including RF tags with variable frequency resonant circuits
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Aug 29, 1995
Grant Date -
N/A
app pub date -
Feb 16, 1994
filing date -
Feb 16, 1994
priority date (Note) -
In Force
status (Latency Note)
Importance
Abstract
An RF tagging system which provides a large number of potential identification codes without increasing the physical size of RF tags used therein includes a plurality of RF tags (20, 90, 140, 230, 250) and an external reader (200). Each RF tag includes at least one resonant circuit (22, 92, 142, 231, 251) which is resonant at any one of a plurality of different frequencies, a receiver (34, 102, 152,244, 264) for receiving an interrogation signal, and a control (36,104,154,246, 266) responsive to receipt of an interrogation signal for causing its at least one resonant circuit to be resonant at selected ones of the different frequencies in a predetermined time sequence corresponding to a predetermined identification code. The external reader includes a detector (216, 218, 220, 222) for detecting the selected resonant frequencies of the RF tags and a decoder (226) for decoding the time sequence of the selected resonant frequencies for recovering the predetermined identification code.
First Claim
Other Claims data not available
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
- 409 Citation Count
- G08B Class
- 98.84 % this patent is cited more than
- 30 Age