Conveying information to an interrogator using resonant and parasitic radio frequency circuits
First Claim
Patent Images
1. A method of conveying information to an interrogator, comprising:
- the interrogator sensing the presence of a resonant radio frequency circuit that is tuned to a first resonant frequency; and
responsive to a parasitic radio frequency circuit being brought to within a parasitic coupling distance of the resonant radio frequency circuit, the interrogator sensing a shift in the resonant frequency of the resonant radio frequency circuit, wherein the first shift in the resonant frequency conveys a first information element to the interrogator.
1 Assignment
0 Petitions
Accused Products
Abstract
A method of conveying information to an interrogator includes the interrogator sensing the presence of a resonant radio frequency circuit that is tuned to a first resonant frequency. Responsive to a parasitic radio frequency circuit being brought to within a parasitic coupling distance of the resonant radio frequency circuit, the interrogator senses a shift in the resonant frequency of the resonant radio frequency circuit, wherein the shift in the resonant frequency conveys information to the interrogator
-
Citations
41 Claims
-
1. A method of conveying information to an interrogator, comprising:
-
the interrogator sensing the presence of a resonant radio frequency circuit that is tuned to a first resonant frequency; and
responsive to a parasitic radio frequency circuit being brought to within a parasitic coupling distance of the resonant radio frequency circuit, the interrogator sensing a shift in the resonant frequency of the resonant radio frequency circuit, wherein the first shift in the resonant frequency conveys a first information element to the interrogator. - View Dependent Claims (2, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
5. The method of claim 5, further comprising the interrogator signaling to the parasitic radio frequency circuit to change the capacitance coupled to the resonant radio frequency circuit.
-
14. An interrogator comprising:
-
a field generating device for coupling to a resonant radio frequency circuit;
a signal generator coupled to the field generating device; and
a measuring device for determining that the signal generator has tuned the field generating device to the resonant frequency of the resonant radio frequency circuit, wherein the measuring device additionally determines that the resonant frequency of the resonant radio frequency circuit has changed from a first to a second frequency. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21)
-
-
22. A method comprising:
-
an interrogator detecting a resonant radio frequency circuit that is tuned to a first resonant frequency;
a user coupling a parasitic radio frequency circuit with the first resonant radio frequency circuit to form a coupled circuit, the coupled circuit resonating at a second frequency; and
the interrogator initiating a process based on detecting the presence of the first and the second resonant frequency. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31)
-
-
32. A system, comprising:
-
an interrogator;
at least one handheld card that includes a resonant radio frequency circuit;
at least one handheld card that includes a parasitic radio frequency circuit;
wherein the interrogator causes a first process to occur in response to detecting the presence of the resonant radio frequency circuit, and wherein the interrogator causes a second process to occur in response to detecting that the parasitic radio frequency circuit is within a coupling range of the resonant radio frequency circuit. - View Dependent Claims (33)
-
-
34. A system, comprising:
-
means for detecting the presence of a resonant radio frequency circuit; and
means for detecting that a parasitic radio frequency circuit is within a parasitic coupling range of the resonant radio frequency circuit. - View Dependent Claims (35, 36, 37, 38, 39)
-
-
40. A parasitic radio frequency circuit, comprising:
-
an inductor that receives a modulated power signal from a magnetic field;
a low pass filter that removes signaling information from the modulated power signal; and
a switch that controls the connection between at least two reactive elements based on the signaling information. - View Dependent Claims (41)
-
Specification