Near field RFID probe with tunning
First Claim
1. A radio-frequency identification (“
- RFID”
) probe comprising;
a probe tip comprising a resonant coil configured to communicate with an RFID compatible device at a predetermined resonant frequency, the resonant coil including a plurality of strands in a crisscross spiral form that are connected in parallel;
a plurality of switch capacitor networks each comprising a capacitor and an RF switch, wherein switching the RF switch on and off in the plurality of switch capacitor networks charges or does not charge the capacitor in the plurality of switch capacitor networks thereby switching one or more of the associated of the plurality of switch capacitor networks on and off, which changes the capacitance of the resonant coil, thereby changing a resonant frequency of the resonant coil; and
a probe control module configured to adjust the resonant frequency of the resonant coil to maintain the predetermined resonant frequency by switching the switch capacitor networks responsive to detecting that the resonant frequency of the resonant coil has deviated from the predetermined resonant frequency.
1 Assignment
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Accused Products
Abstract
A near field radio-frequency identification (“RFID”) probe includes a probe tip comprising a resonant coil configured to communicate with an RFID compatible device at a predetermined resonant frequency. The near field RFID probe further includes a plurality of switch capacitor networks each comprising a capacitor and an RF switch, wherein switching the plurality of switch capacitor networks changes the capacitance of the resonant coil, thereby changing the resonant frequency of the resonant coil. The near field RFID probe further includes a probe control module configured to adjust the resonant frequency of the resonant coil to maintain the predetermined resonant frequency by switching the switch capacitor networks responsive to detecting that the resonant frequency of the resonant coil has deviated from the predetermined resonant frequency.
48 Citations
18 Claims
-
1. A radio-frequency identification (“
- RFID”
) probe comprising;a probe tip comprising a resonant coil configured to communicate with an RFID compatible device at a predetermined resonant frequency, the resonant coil including a plurality of strands in a crisscross spiral form that are connected in parallel; a plurality of switch capacitor networks each comprising a capacitor and an RF switch, wherein switching the RF switch on and off in the plurality of switch capacitor networks charges or does not charge the capacitor in the plurality of switch capacitor networks thereby switching one or more of the associated of the plurality of switch capacitor networks on and off, which changes the capacitance of the resonant coil, thereby changing a resonant frequency of the resonant coil; and a probe control module configured to adjust the resonant frequency of the resonant coil to maintain the predetermined resonant frequency by switching the switch capacitor networks responsive to detecting that the resonant frequency of the resonant coil has deviated from the predetermined resonant frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- RFID”
- 11. A tunable resonant coil comprising a plurality of switch capacitor networks, each comprising a capacitor and an RF switch, wherein switching the RF switch on and off of each of the plurality of switch capacitor networks charges of or does not charge the capacitor in each of the plurality of switch capacitor networks, which changes a capacitance of the resonant coil, thereby changing a resonant frequency of the resonant coil, responsive to receiving a control signal indicating that the resonant frequency of the resonant coil has deviated from a predetermined resonant frequency wherein the tunable resonant coil is disposed on an inside surface of a substrate, and wherein the substrate comprises a slotted ground plane on an exposed surface.
Specification