Analysis of RF-Interferences in WLAN and Bluetooth Environments

The Surface Acoustic Waves (SAW) technology allows the realization of RF interrogated sensors for extreme environmental conditions (temperatures up to +400°C). The SAW tags transmit data using CW radar technology, which operates in this case in the 2.45 GHz ISM band. The main interference in the 2.45 GHz band is produced by wireless systems like IEEE 802.11 WLAN and IEEE 802.15 Bluetooth. The influence of these disturbances on physical parameters of the SAW measurement results were explored in theory and practice. Based on these measurement results coexistence strategies were developed and implemented as Matlab code. A statistical evaluation of each strategy was made. Good results were achieved for FSCW reader unit measured data whereas for FMCW reader unit measured data it was difficult to find a solution because of the extensive disturbance pattern in the measured data.