Measurements of Reflection and Penetration Loss of Construction Materials at 28 GHz and 38 GHz

This paper presents measurements of penetration losses and reflection coefficients for common construction materials at 28 GHz and 38 GHz. Using a signal generator, a CW at 0 dBm was transmitted by 20 dBi horn antenna and received by a similar antenna. The materials tested were thin and thick polystyrene, thin and thick pressed wood, thin wood, window glass, a wooden door and a brick wall. As expected, polystyrene have neglected penetration loss, independently of its thickness and frequency. Brick wall presents high penetration loss, 58 dB at 28 GHz and 63 dB at 38 GHz. A strong relation between thickness and penetration loss was observed in pressed wood. Reflection coefficients were measured in an indoor meeting room. Incidence angle was varying from 15 degrees to 45 degrees with steps of 5 degrees. Reflection coefficients of polystyrene are close to 0. Glass window presented the largest reflection coefficient, of 0.65 at 38 GHz at incidence angle of 45 degrees.