Long range and low powered RFID tags with tunnel diode

In this paper, we present a 5.8 GHz RFID tag equipped with a high gain, low power reflection amplifier based on a tunnel diode. Experimental results show that the realized prototype achieves gains above 40 dB and requires only 29 μW of biasing power. The tag detects very low RF signals (<; -90 dBm) and provides read ranges up to 2 km. Long communication ranges and Manchester encoding are achieved by biasing on and off the tunnel diode.