A device for receiving a data signal transmitted via load modulation has a transmitter portion that transmits a primary signal along a signal path to an antenna for wireless transmission of the primary signal. A sensor senses current or voltage variations of the primary signal in the signal path, and a signal extraction unit extracts the data signal based on the sensed current or voltage variations.

An apparatus for detecting an operating characteristic mismatch at an output of an amplifier by using a replica circuit is presented. In one exemplary case, a detected voltage difference at the output of the two circuits is used to drive a tuning control loop to minimize an impedance mismatch at the output of the amplifier. In another exemplary case, the replica circuit is used to detect a fault in operation in a corresponding main circuit. A method for detecting a load mismatch in a main RF circuit using the replica circuit is also presented.

An electromagnetic modulation device may include a receiver configured to receive electromagnetic signals, a digital-to-analog converter configured to continuously generate a modulation signal, a mixer coupled to the receiver and the digital-to-analog converter and configured to encode the electromagnetic signals received by the receiver with the modulation signal generated by the digital-to-analog converter upon receipt of the electromagnetic signals by the receiver, and a transmitter coupled to the mixer and configured to transmit the encoded electromagnetic signals generated by the mixer.

An electromagnetic modulation device may include a receiver configured to receive electromagnetic signals, a digital-to-analog converter configured to continuously generate a modulation signal, a mixer coupled to the receiver and the digital-to-analog converter and configured to encode the electromagnetic signals received by the receiver with the modulation signal generated by the digital-to-analog converter upon receipt of the electromagnetic signals by the receiver, and a transmitter coupled to the mixer and configured to transmit the encoded electromagnetic signals generated by the mixer.