Implementation of On-Off Passive Wireless Surface Acoustic Wave Sensor Using Coding and Switching Techniques

摘要

Methods and systems for passive wireless surface acoustic wave devices for orthogonal frequency coded devices to implement ON-OFF sensors reusing orthogonal frequency code and distinguishing between ON and OFF states using additional PN sequence and on/off switches producing multi-level coding as well as external stimuli for switching and identification of a closure system. An embodiment adds a level of diversity by adding a dibit to each surface acoustic wave devices, thus providing four different possible coding states. The PN on-off coding can be with the dibit for coding in a multi-tag system.