Memory-less and Backscatter-less Tunnel Diode Harmonic Signatures for RFID

TL;DR

This paper investigates the natural harmonic signatures generated by tunnel diodes without external signals, enabling potential RFID tag identification without backscatter or memory, thus simplifying RFID systems.

Contribution

It introduces a novel method of using inherent harmonic signatures from biasing tunnel diodes for RFID tag identification without backscatter or memory.

Findings

Harmonics are generated naturally from tunnel diodes in their negative differential resistance region.

Each diode board exhibits unique harmonic signatures for identification.

Harmonic signatures can be used for backscatter-less RFID applications.

Abstract

Tunnel diodes have traditionally been researched for extending backscatter read-ranges for ultra-high-frequency (UHF) radio-frequency identification (RFID) tags as reflection amplifiers. This paper explores the natural harmonics that arise from biasing these diodes within their negative differential resistance regions and with no interrogating signal from a transmitting source, such as an RFID reader, to injection-lock these diodes. These harmonics are characterized for five tunnel diode boards, made with the same components and with each board's fundamental frequencies measuring at above -15 dBm at a biasing voltage of 200 mV when measured over-the-cable. The occurrence of these harmonics creates unique harmonic signatures for each board and demonstrates possible harmonic RFID applications that can help RFID readers discover and even identify RFID tags with backscatter-less and memory-less IDs generated by tunnel diodes.