High Dynamic Range electronics or HDR-electronics includes circuits for processing analog signals with a dynamic range beyond the range of ADC -converters at RF-frequencies. With HDR-front-ends we can receive weak RF-signals as low as nano-Volts, and generate real RF-power, in the same time-slot, in the same frequency-range, and on the same antenna.
Examples are: long-range RFID-readers, single-antenna EAS-detectionsystems, deactivators and inductive metal position-sensors. Dynamic range is 140 dB or more, which in theory can be handled only by a high-speed ADC of 24 bits resolution.
In HDR-electronics, part of the signal-processing where high bandwidth and resolution are required, is done with pure analog components. Ultra-low signal events are finally limited by thermal noise, which can be reduced with impedance-level.
The power-electronics involved (supplies, transmitters, generators) should be very clean, with low amplitude- and low phase-noise. This is an extra challenge not found in the designs of many NFC-frontends.
Other sources of interference are prevented by proper EMC-design, and various canceling techniques. After the analog processing in converters and filters the signals can be limited in bandwidth to feed relatively slow ADC’s.