Graphene-Flakes Printed Wideband Elliptical Dipole Antenna for Low Cost Wireless Communications Applications

TL;DR

This paper introduces a low-cost, wideband elliptical dipole antenna made from screen-printed graphene flakes, demonstrating promising RF performance and flexibility for wearable wireless communication devices.

Contribution

It presents a novel graphene-flakes based screenprinting process for wideband antennas with high efficiency and mechanical durability for low-cost wireless applications.

Findings

Antenna operates from 2 GHz to 5 GHz with 60% efficiency.

Maximum gain of 2.3 dBi at 4.8 GHz.

Graphene antenna adds only 3.1 dB loss compared to silver ink antenna.

Abstract

This letter presents the design, manufacturing and operational performance of a graphene-flakes based screenprinted wideband elliptical dipole antenna operating from 2 GHz up to 5 GHz for low cost wireless communications applications. To investigate radio frequency (RF) conductivity of the printed graphene, a coplanar waveguide (CPW) test structure was designed, fabricated and tested in the frequency range from 1 GHz to 20 GHz. Antenna and CPW were screen-printed on Kapton substrates using a graphene paste formulated with a graphene to binder ratio of 1:2. A combination of thermal treatment and subsequent compression rolling is utilized to further decrease the sheet resistance for printed graphene structures, ultimately reaching 4 Ohm/sq. at 10 {\mu}m thicknesses. For the graphene-flakes printed antenna an antenna efficiency of 60% is obtained. The measured maximum antenna gain is 2.3 dBi at 4.8 GHz. Thus the graphene-flakes printed antenna adds a total loss of only 3.1 dB to an RF link when compared to the same structure screen-printed for reference with a commercial silver ink. This shows that the electrical performance of screen-printed graphene flakes, which also does not degrade after repeated bending, is suitable for realizing low-cost wearable RF wireless communication devices.