A SAW Delay-line oscillator as a high-resolution temperature sensor

Abstract A new highly linear temperature sensor with a large resolution using a LiNbO3 SAW delay-line oscillator is presented. The large temperature dependence of the propagation velocity of a surface acoustic wave in a yz LiNbO3 crystal (⋍ −90 ppm/°C) is used in an electroacoustic delay line in the feedback path of an oscillator. The oscillation frequency is inversely proportional to the signal delay. Measurements of this sensor show very linear frequency-versus-temperature characteristics.