A New and Simple Approach on Multi-Resonator Circuit Based Chipless RFID Tags for IoT Applications

In this paper, a novel multi-resonator circuit as a chipless RFID tag is proposed for internet of things (IoT) applications. For this purpose, a simple geometrical transition between a dual-mode square loop resonator (DMSLR) and an open loop resonator (OLR) is introduced by means of a small patch. Two frequency codes can be obtained from a DMSLR, since it has two resonance frequencies. On the other hand, while an OLR is utilized, only one frequency code can be obtained. Thus, totally 3 frequency codes can be achieved from one resonator in a very simple way and 3$^{N}$ codes can be achieved by using N resonators. For demonstration, two circuits including 4 resonators were fabricated and tested.