An exemplary embodiment of the present disclosure provides a backscattering RFID system comprising: a combined oscillator and reflection amplifier circuit comprising a first tunnel diode having an anode and a cathode; and a biasing circuit in communication with the anode and configured to bias the first tunnel diode in a negative differential resistance region; wherein the combined oscillator and reflection amplifier circuit is configured to modulate a RF interrogation signal to produce a backscatter signal.