  We report measurement of the radio-frequency (RF) transport electromagnetic
properties of chemical vapour deposition (CVD) graphene over the DC to 110 MHz
frequency range at room temperature. Graphene on Si/SiO2 substrate was mounted
in a shielded four terminal-pair (4TP) adaptor which enabled direct connection
to a calibrated precision impedance analyser for measurements. Good agreement
is observed for the DC four-probe resistance and the 4TP resistance at 40 Hz,
both yielding R ~ 104 {\Omega}. In general the apparent graphene channel
electromagnetic properties are found to be strongly influenced by the substrate
parasitic capacitance and resistance, particularly for high-frequencies f > 1
MHz. A phenomenological lumped-parameter equivalent circuit model is presented
which matches the frequency response of the graphene 4TP impedance device over
approximately seven decades of the frequency range of the applied transport
alternating current. Based on this model, it is shown for the first time, that
the intrinsic graphene channel resistance of the 4TP device is
frequency-independent (i.e. dissipationless) with RG ~ 105 {\Omega} or sheet
resistance of approximately 182 {\Omega} / sq. The parasitic substrate
impedance of the device is found shunt RG with RP ~ 2.2 {\Omega} in series with
CP ~ 600 pF. These results suggest that our new RF 4TP method is in good
agreement with the conventional DC four-probe method for measuring the
intrinsic sheet resistance of single-atom thick materials and could potentially
open up new applications in RF electronics, AC quantum Hall effect metrology
and sensors based on graphene 4TP devices operating over broad range of
frequencies.
