A novel equivalent refractive index model of high transparency metallic mesh was proposed to calculate its shielding effectiveness accurately. Based on Ulrich’s empirical method

LZ’s equivalent reactance model and Kohin’s equivalent film method

the model accurately established the relation among mesh equivalent refractive index

structural parameters and dielectric boundary refractive indexes so that it is easy to calculate the mesh shielding effectiveness under various incident angles and to prevent the invalidation of Chen’s formulas about oblique incidence on high transparency. To identify the new model’s validity

two kinds of metallic meshes in period of 160 μm

line width of 5.5 μm and period of 320 μm

line width of 4.5 μm were fabricated using UV-lithography

and the shielding effectiveness were measured by microwave network analyzer at 12~18 GHz. Experiment and analysis show that the new model’s theoretical calculation error is less than 2 dB

more accurately than 4 dB of Ulrich’s model and 8 dB of Chen’s and LZ’s models.