Progress of matching network for passive remote hybrid sensor based on SAW resonator

The matching network is an important section of the passive remote SAWR (surface acoustic wave resonator) hybrid sensor. There were two disadvantages for the classical method to design the matching network: The one was that the matching network reduces the Q factor of match point. The other was the strong mismatch occurs when the impedance of sensing element shifted from the well-matched point. S. Klett et al proposed the well-matched matching network, and improved the Q of match point. This paper researched the low-mismatched matching network deeply.