Scattering effect based on measurements of reflection coefficients at 60 GHz in an underground mine gallery

This paper presents reflection coefficient measurements in order to analyze the scattering effect of rough walls and floor on mm-Wave propagation at 60 GHz in an underground mine. A 60 GHz frequency domain measurement system with directional antennas is considered. Reflection coefficients are obtained by individual reflected signals and line of sight (LOS) signals with a particular reflective angle then compared with theoretical models. Results suggest a distinguishable reflection and scattering characteristics between mine wall and floor. In specular directions, the path loss difference between the LOS and the reflected signal lies between 11 dB to 18 dB. In both surfaces, strong reflections on specular directions and scattering on non specular directions have been observed. Moreover, wall surface of the mine produces more scattering with strong reflections than floor surface. These reflection coefficient parameters are useful to estimate multipath signal strength in channel modelling for propagation prediction in underground mine.