Wireless sensor system based on SAW coded passive devices for multiple access

This work reports on a wireless sensor system based on coded direct sequence spread spectrum differential delay line surface acoustic wave devices. Spread spectrum techniques were used to interrogate prototype sensor devices with embedded quasi-orthogonal coding, thus allowing multiple device access by the system implemented. A base station unit incorporating analog and reconfigurable digital circuitry has been designed and constructed to interrogate the sensor devices. Sensor and system operation were experimentally verified. The system was validated for temperature sensing.