Long read range and flexible UHF RFID tag antenna made of high conductivity graphene‐based film

Abstract

An antenna made of a graphene-based film with organic polyimide precursor of high conductivity 1.1 × 10 6 S m −1 and thickness 30 μm, operating in the ultrahigh frequency (UHF) band for radio frequency identification applications is presented in this article. The antenna is optimized to have a conjugate match to the impedance of the chip by tuning the design parameters. Tags are fabricated and tested using the designed antenna, which are shown to have realized gain above −1.5 dBi and radiation efficiency beyond 90% in the whole UHF band from 860 to 960 MHz. The read range of proposed tag is greater than 12.3 m over the entire UHF band with a maximum value of 14 m at 920 MHz. In addition, the flexibility of the tags is demonstrated. After 2000 cycles of bending and stretching, the read range only decreases by 4.5 m comparing to the initial state at 915 MHz. K E Y W O R D Sflexible, graphene-based film, high conductivity, long read range, UHF RFID

A Dual-Band Conformal Antenna Based on Highly Conductive Graphene-Assembled Films for 5G WLAN Applications

“…Nevertheless, the metal mesh conductive sheet is too expensive and prone to oxidation [14], the conductive ink normally has low conductivity which is not suitable for antenna design [15][16][17], and the carbon nanotube also has a relatively high sheet resistance, resulting from junction resistance and is not possible to produce large-area film [18]. Recently, graphene-assembled films with the advantages of high conductivity, good bending resistance and good chemical stability have been considered as a promising alternative conductive material for antenna [19][20][21], sensor [22][23][24] and other RF applications [25,26], which show great potential in overcoming the challenges of conformal antenna design [27][28][29]. It is worth noting that most of these flexible antennas are single-band and their bending angle is greatly limited.…”

Wearable near‐field communication bracelet based on highly conductive graphene‐assembled films

“…and excellent conductivity of 10 6 S/m along with better mechanical stability and flexibility than traditional metal-based films. 21,22 In this paper, we designed a flexible HCGAF NFC tag antenna with size of 80 mm × 50 mm according to the international standard communication protocol ISO/IEC 14443 on polyethylene terephthalate (PET) substrate, by using a simple one-step laser engraving method. The flexible NFC tag antennas which are designed to operate around 13.56 MHz showed a 10 dB bandwidth from 12.5 to 15 MHz.…”

“…Reported in our previous works, HCGAFs exhibited relatively low sheet resistance of 36 mΩ/sq. and excellent conductivity of ~10 6 S/m along with better mechanical stability and flexibility than traditional metal‐based films 21,22 …”

Circular multi‐usage RFID tag antenna with coding ability for chipless application

“…Many radio frequency identification (RFID) tag antennas for ultra‐high frequency (UHF) band have been designed in the previous work 1‐5 . With these designs, some of the tag antennas can be mounted on metallic surfaces directly, 6,7 other reported designs can work on the human body, organs, blood bag and water‐filled containers 8‐11 .…”