Shielding efficiency waveguide measurements at 400 MHz

A knowledge of shielding efficiency of plane materials like shielding panels, special paints, windows foils etc. is demanded for construction of shielded boxes, enclosures and for other applications. A waveguide measurement unit was specially designed and manufactured to measure the high level of shielding efficiency of thin conductive materials in the frequency band of 400 MHz. A dynamic range of measurement up to 100 dB was reached. The shielding efficiency of various materials was measured and compared to measurements in free space. The waveguide unit development brought several advantages which had to be addressed. The main problems were caused by reflections of the inserted material under test with high attenuation of the relatively short waveguide. Waveguide, broadband transitions design, attenuators arrangements and the material under test attachment were designed using both simulations and experiments.