Near field RF communicators having refined energy sharing characteristics utilizing improved shunt current control

摘要

A near field RF communicator has an inductive coupler to enable inductive coupling with a magnetic field of an RF signal; a rectifier to rectify an AC voltage derived from an RF signal inductively coupled to the inductive coupler; and a regulator to regulate a voltage derived from an RF signal inductively coupled to the inductive coupler, the regulator having a voltage-controlled impedance and a regulator controller 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. 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.

主权项

1. A regulator, comprising;
a variable impedance configured to shunt an alternating current in response to a control voltage to regulate a rectified voltage; an amplifier configured to generate the control voltage in response to the rectified voltage and a feedback voltage; and a voltage scaler configured to measure the shunted alternating current and to scale the control voltage to provide the feedback voltage such that the rectified voltage is proportional to the shunted alternating current.