| 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. The design method of LMMN (low-mismatched matching network) includes several steps. The first step is matching the SAWR impedance to equivalent serial RLC or parallel GLC resonant circuits. Then, cascading/shunting a reactive sensing element changes the resonant frequency, and keeps the well-matched status of match point. Four types of LMMN are presented. For the constructions based on single SAWR, the mismatch below 1.02 described with SWR (standing wave ratio) and the high Q values are obtained. In addition, two of four have excellent linearity, and another two have higher sensibility. Such characteristics are kept in constructions based on double-SAWRs. In this paper, the low-mismatched design methods of matching networks for passive remote SAWR hybrid sensors are proposed. The several characteristics including the continuing low mismatch, the high Q, the linearity, and the sensibility are obtained. They are for both single and double SAW resonators constructions. |