SWITCHED CAPACITANCE METHOD FOR THE DETECTION OF, AND SUBSEQUENT COMMUNICATION WITH A WIRELESS TRANSPONDER DEVICE USING A SINGLE ANTENNA
First Claim
Patent Images
1. A reader for an RFID system comprising:
- a reader antenna;
a driver circuit adapted to provide current to the reader antenna; and
a tuning circuit situated between the driver circuit and the reader antenna, the tuning circuit adapted to condition current provided from the driver circuit to the reader antenna, the tuning circuit comprising control circuitry configured to switch the reader between a detection mode and a transaction mode, wherein the reader antenna is used to transmit detection signals in the detection mode and transaction signals in the transaction mode.
1 Assignment
0 Petitions
Accused Products
Abstract
A transponder detector is provided with capabilities for detecting the presence and type of a transponder in its read range while operating at low power and also using a common antenna for detecting and executing data transactions with transponders.
-
Citations
25 Claims
-
1. A reader for an RFID system comprising:
-
a reader antenna; a driver circuit adapted to provide current to the reader antenna; and a tuning circuit situated between the driver circuit and the reader antenna, the tuning circuit adapted to condition current provided from the driver circuit to the reader antenna, the tuning circuit comprising control circuitry configured to switch the reader between a detection mode and a transaction mode, wherein the reader antenna is used to transmit detection signals in the detection mode and transaction signals in the transaction mode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
-
16. A method of operating an RFID reader, the RFID reader comprising an antenna, driver circuitry, and a tuning circuit situated between the antenna and driver circuitry, comprising:
-
transmitting a detection signal from the antenna, the detection signal being generated by the tuning circuit; switching the reader from a detection mode to a transaction mode; and transmitting a transaction signal from the antenna, wherein the detection signal is used to detect the existence of an RFID transponder within communication range of the antenna and wherein the transaction signal is used to share transaction data with the RFID transponder. - View Dependent Claims (17, 18, 19, 20, 21)
-
-
22. An RFID reader, comprising:
-
an antenna; and a tuning circuit operable to cause the antenna to transmit detection signals at two or more different carrier frequencies and transaction signals at two or more different carrier frequencies, wherein the detection signals are transmitted by the antenna when the reader is in a detection mode, wherein the transaction signals are transmitted by the antenna when the reader is in a transaction mode, and wherein the tuning circuit limits operation of the reader in the transaction mode to instances where a transponder operating at one of the two or more different carrier frequencies is detected within an operating range of the antenna. - View Dependent Claims (23, 24, 25)
-
Specification