| 摘要 |
The invention relates to a surface acoustic wave (SAW) resonator used for a gas sensor. The SAW resonator used for the gas sensor comprises a piezoelectric substrate (32), a first inter-digital transducer (34), a second inter-digital transducer (35), a first short circuit grating reflector (33), a second short circuit grating reflector (36) and a metal film (37), wherein the first inter-digital transducer (34) and the second inter-digital transducer (35) are arranged on the surface of the piezoelectric substrate (32), the first short circuit grating reflector (33) and the second short circuit grating reflector (36) are respectively adjacent to the outer sides of the first inter-digital transducer (34) and the second inter-digital transducer (35), and the metal film (37) is arranged between the two inter-digital transducers. The first inter-digital transducer (34), the second inter-digital transducer (35), the first short circuit grating reflector (33), the second short circuit grating reflector (36) and the metal film (37) are respectively in a double-layer electrode structure with thick aluminum and thin gold, the thickness of the aluminum is 1%-1.3% lambda, and the thickness of the gold is 0.15%-0.25% lambda, wherein the lambda indicates sound wave length. Due to the fact that the aluminum/gold double-layer electrode mode is adopted, and the distance between the inter-digital transducers and the reflectors and the width of the metal film are adjusted, the SAW resonator can have the characteristics of single resonant mode, low loss and high Q valve. |
