  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.
