i am currently working on shielding efficiency of nanocomposites and i just want to know what would be the most applicable method for EMI SE measurement in the mentioned frequency range for thin films of shielding material.
there is IEEE standard 299.1-2013 - IEEE Standard Method for Measuring the Shielding Effectiveness of Enclosures and Boxes Having all Dimensions between 0.1 m and 2 m.
several methods there are to measure the shielding effectiveness of the materials in the range of frequency from 600 MHz to 4 GHz. For your material, a good method is to use a system of nested reverberation chambers. The procedure is shown in Standard IEC 61000-4-21. However, you can see the attached works as well.
You could also use an anechoic chamber as well, if you have large samples of the material; you can use a fixture for coaxial cable or waveguide, etc., it depends on the material type.