QWED - Software for Electromagnetic Design

Measured parametre	Surface resistance R of graphene layer
Range of measured surface resistance R	0.1 Ω to 10000 Ω
Accuracy of measurement of the surface resistance of a graphene layer of thickness h	± 5%
Operational frequency	13 GHz
Dimensions of dielectric substrate	Lateral dimensions 10 mm x 10 mm, thickness <0.5 mm. Upon a special request it is possible to extend the lateral dimensions of the substrates.
Additional equipment needed to perform measurement	Vector Network Analyser
Measurement procedure	Resonant frequency and Q - factor of the empty resonator and the resonator with the graphene layer deposited on the dielectric substrate are measured. Dedicated software application (supplied with the resonator) is used to calculate the surface resistance R of the graphene layer. The electric conductivity of the graphene layer of thickness h is calculated using the following formula: σ = 1/(Rh)* The accuracy of calculation of the electric conductivity is proportional to the accuracy of the measurement of the thickness of the deposited graphene layer.
Recent publications about the measurement method	J. Krupka and W. Strupinski, Measurements of the sheet resistance and conductivity of thin epitaxial graphene and SiC films, Applied Physics Letters, vol. 96, 2010. J. Krupka, W. Strupinski, and N. Kwietniewski, Microwave conductivity of very thin graphene and metal films, Journal of Nanoscience and Nanotechnology, Vol. 11, 1-5, 2011.