Near field RF communicators having refined energy sharing characterisitics utilizing improved shunt current control
First Claim
1. A near field communications (NFC) device, comprising:
- a rectifier configured to rectify an induced power to provide a rectified power;
a voltage-controlled impedance configured to adjust an induced current flowing through the voltage-controlled impedance, in response to a control signal, to regulate the rectified power;
a regulator controller configured to provide the control signal based on a feedback signal; and
a feedback device configured to multiply the control signal by a reference voltage to generate the feedback signal.
5 Assignments
0 Petitions
Accused Products
Abstract
A near field RF communicator has an inductive coupler (223) to enable inductive coupling with a magnetic field of an RF signal; a rectifier (213,214,215,216) to rectify an AC voltage derived from an RF signal inductively coupled to the inductive coupler (223); and a regulator (209,210,211,220,221,900) to regulate a voltage derived from an RF signal inductively coupled to the inductive coupler, the regulator having a voltage-controlled impedance (210, 211) and a regulator controller (209) to provide a control voltage for the voltage controlled impedance and to vary the control voltage in dependence upon a current flowing through the voltage controlled impedance (210, 211). To prevent the voltage regulator from drawing excess current and energy from an RF field in which the communicator is present the voltage regulator is controlled to provide a chosen impedance characteristic.
29 Citations
20 Claims
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1. A near field communications (NFC) device, comprising:
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a rectifier configured to rectify an induced power to provide a rectified power; a voltage-controlled impedance configured to adjust an induced current flowing through the voltage-controlled impedance, in response to a control signal, to regulate the rectified power; a regulator controller configured to provide the control signal based on a feedback signal; and a feedback device configured to multiply the control signal by a reference voltage to generate the feedback signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A near field communications (NFC) device, comprising:
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a rectifier configured to rectify an induced power and to provide a rectified voltage and a rectified current; a first voltage-controlled impedance module coupled to the rectifier; and a second voltage-controlled impedance module coupled to the first voltage-controlled impedance module, the first voltage-controlled impedance module being configured to substantially maintain a proportionality between the rectified voltage and a voltage input to the second voltage-controlled impedance module, the second voltage-controlled impedance module being configured to produce a demodulation signal substantially proportional to the rectified current. - View Dependent Claims (16, 17, 18)
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15. A near field communications (NFC) device, comprising:
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a rectifier configured to rectify an induced voltage and an induced current to provide a rectified voltage and a rectified current; a voltage-controlled impedance configured to adjust the induced current in response to a control signal to regulate the rectified voltage; a regulator controller configured to generate the control signal using a feedback signal; a feedback module configured to adjust the control signal in response to a scaling signal to generate the feedback signal; and a voltage adder configured to generate the scaling signal based on a sum of a modulated signal and a reference signal. - View Dependent Claims (19, 20)
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Specification