A. S. Bagdasaryan - Dr. Sci. (Eng.), professor, senior research fellow at IRE named after V. A. Kotelnikov RAS. Е-mail: bagdassarian@mail.ru
S. O. Nikolaeva - Post-graduate student, Voronezh State Technical University. E-mail: niks@mail.ru
V. D. Repnikov - Dr. Sci. (Phys.-Math.), professor, head of the department «Applied mathematics»

The paper deals with the energy potential distribution over radio channel components in surface acoustic wave (SAW) ? based radio frequency identification (RFID) systems. The principle of operation of SAW-based RFID systems involves reading of the radio channel information in a coded form of an acoustic RFID tag. The type of RFID tag is based on a piezoelectric crystal. The energy potential contained in the RFID system (~115 dBm) allows for the passive RFID tag information reading at a range of 10-15 meters. This result is true when finding RFID-tag in open space. While in operation including man-made impact case RFID-tag can be affected by semiconducting medium in the form of meteorological precipitation (snow, rain, dust, mud, mudflows alluviums, etc.) as well as in avalanche and landslide protection systems including ore, coal and coal dust in mining and mines. With this provision the reading quality and range can be significantly reduced at the expense of electromagnetic wave absorption by semiconducting media. In this paper calculation data are presented with reading range reduction in RFID-systems under the influence on different semiconducting media tag depending on radio channel`s characteristics and acoustic loss in RFID-tags. It is shown that the reading range is not practically affected by the presence of snow cover on the tag. So even in case of hard-packed wet snow there is range reduction by only 2 %. The presence of mudflow alluviums on tag lead to 3-4 times range reduction. The greatest reading range reduction will take place if tag is under the layer of ore-bearing rock and black coal. According to performed calculations energy potential distribution characteristic curve is plotted in RFID-system between radio channel structural components on 860 MGz-frequency. It is shown that depending on system purpose energy potential can be redistributed between its components.