Radio Frequency Identification Device Systems
1 Assignment
0 Petitions
Accused Products
Abstract
A passive transponder (10) includes a resonator circuit (16) to receive a powering signal thereby to provide electrical energy to the transponder (10) by inductive coupling. The resonator circuit (16) is switchable between a high Q factor mode in which an induced voltage in the resonator circuit (16) decays slowly, and a low Q factor mode in which an induced voltage in the resonator circuit (16) decays more quickly. The transponder (10) includes a power storing arrangement (24) to store at least a portion of the electrical energy obtained from the powering signal.
37 Citations
32 Claims
-
1-16. -16. (canceled)
-
17. A passive transponder which includes a resonator circuit to receive a powering signal thereby to provide electrical energy to the transponder by inductive coupling, the resonator circuit being switchable between a high Q factor mode in which an induced voltage in the resonator circuit decays slowly, and a low Q factor mode in which an induced voltage in the resonator circuit decays more quickly, and the transponder including a power storing arrangement to store at least a portion of the electrical energy obtained from the powering signal, said resonator circuit having a transponder antenna coil for inductively coupling to an interrogator antenna from which a series of radio frequency signals are transmitted or transmittable, the series of radio frequency signals comprising a leading powering signal and a trailing modulated data signal and said power storing arrangement being operable to store at least part of the electrical energy which is induced by inductive coupling of the transponder antenna coil during transmission of the leading powering signal, the transponder further including:
-
a demodulating arrangement for demodulation of the trailing modulated data signal; and a Q factor controller for changing the Q factor of the resonator circuit between said high Q factor mode, in which mode the transponder antenna coil is configured to receive the powering signal, and said low Q factor mode, in which mode the resonator circuit is configured to receive the modulated data signal. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
-
-
25. A method of operating a passive transponder, the method including:
-
receiving a powering signal by a resonator circuit of the transponder, the resonator circuit including an antenna coil and having a high Q factor mode and at least a portion of electrical energy received by the resonator circuit being stored onboard by the transponder, receiving said powering signal by said resonator circuit of the transponder including receiving a leading powering signal from an interrogator for powering the transponder, at least part of the electrical energy which is induced by inductive coupling of the transponder antenna coil during transmission of the leading powering signal being stored; lowering the Q factor of the resonator circuit, including switching the resonator circuit of the transponder to a low Q factor mode; receiving from said interrogator, a trailing modulated data signal by the resonator circuit of the transponder during a time period when the resonator circuit has the lowered Q factor; and demodulating the trailing modulated data signal. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32)
-
Specification