Building Material Attenuations at 5 GHz and at mmWave Frequencies 30 GHz and 90 GHz

Millimeter wave (mmWave) communication systems will be usedwidely, both indoors and out. Many systems will use directional antennas to overcome attenuation due to free space and obstructions. For specification of link parameters, the attenuation of common materials is of value, and this is the subject of this paper. Measurements were conducted at three frequencies to estimate the attenuation of several common building materials. Frequencies were 5 GHz, and two mmWave frequencies, 30 and 90 GHz. Materials were those found in a typical office building: glass, plasterboard, dropped-ceiling tile, and solid wooden fire doors. We also calculated the attenuation for each material for these frequencies using the commercial ray-tracing tool Wireless InSiteOR, and generally found very good agreement. Most materials exhibit moderate (few dB) attenuation, with the wooden fire doors yielding the largest loss, over 30 dB at 90 GHz. Remarks on the wide range of attenuations on mmWave signals are provided.