DE-TUNING IN WIRELESS POWER RECEPTION

摘要

Exemplary embodiments are directed to wireless power transfer. A receiver (820) with a receive antenna (L2) couples with near field radiation in a coupling mode region. The receiver generates an RF signal at a resonant frequency responsive to the near field radiation. A de-tuning circuit (860) generates a variable impedance responsive to a control signal to modify the RF signal to a smaller amplitude or to a different resonant frequency. A rectifier (840) converts the modified RF signal to a DC signal. A comparator (850) creates a feedback loop by generating the control signal responsive to comparing the DC signal to a reference voltage (Vref). The de- tuning circuit may operate in digital mode or in linear mode with the feedback. An impedance element (Rl) may be coupled to the de- tuning circuit to generate a voltage proportional to a current through the de-tuning circuit. The proportional voltage is rectified to a receive signal (1430) with information sent from a transmitter.