Um Estudo das Reflexões de Sinais de RF em Sistemas RFID de UHF

A study of the behavior of RF signals for RFID communication systems operating in UHF is presented, including experimental and model results. A generalization of the Dielectric Canyon propagation model is presented, involving reflections in the ground and/or other objects. The model results are compared with measurements made with a RFID reader and also with a spectrum analyser. This comparison explains the "blind" spots where tags are not activated, even at close distances. This study is important for applications in environments where tags are close to the ground, such as in agriculture.