Reflection and transmission properties of reinforced concrete walls

The proliferation of communication systems used in and around man-made structures has resulted in a growing need to determine the reflection and transmission properties of various commonly used building materials at radio frequencies typically used in businesses and residential environments. This paper gives examples of calculated reflection and transmission coefficients for a reinforced concrete wall over a frequency range of 100-6000 MHz. The reflection and transmission coefficients were calculated using a finite-difference time domain solution of Maxwell´s equations. In general, the results show that the reinforced concrete structures severely attenuate signals with wavelengths that are much larger than the re-bar lattice, and the transmitted signal has a complex structure with resonances and nulls that strongly depend upon the geometry of the reinforcing structure and the concrete wall thickness.