Asynchronous trigger modulation for RFID systems

We present a scheme for using asynchronous trigger modulation in radio frequency integrated circuits (RFICs), which allows more robust backscatter modulation without increasing tag power consumption. Since the implementation does not require load modulation transitions that correspond to regular clock intervals of synchronous logic, a whole new class of waveforms in RFID is also possible, including a family of perfect pulses that provide extra sensitivity for long-range tags.