Measurement and Analysis of Reflection Attenuation of Change Signals Traversing Concrete Barriers Within the 400-1400 MHz Range

The electromagnetic wave attenuation characteristics of two common construction materials, specifically C30/37 concrete and aerated-concrete, namely C30/37 concrete and aerated concrete, have been investigated due to their importance in rubble-penetrating radar-based life-sign detection. This paper presents the results from radar experiments using free-space vector network analyzer measurements within the 400 - 1400 ${\bf{400}}-{\bf{1400}}$ MHz frequency range, aimed at monitoring periodic arm movements behind wall blockages made of these materials. To ensure data validity, tests were carried out with two different antenna types: the Vivaldi tapered slot antenna and the double-ridged horn antenna. The reflection data collected at a fixed sensor position were processed by eliminating the static background and averaging the results. The received power levels and frequency variations of the resultant change data were evaluated and compared in relation to the electromagnetic absorption characteristics of the examined concrete samples.