Research Of Characteristics On Surface Acoustic Wave Temperature Sensor

Surface acoustic wave sensors are tiny physical model is a branch of the sensor. Because it's the most numerous advantages and broad application prospect, caused the developed countries around the world, science and industry of great interest, as nearly 10 years of research hotspot. Extensive research has SAW sensors, and widely used in various fields of physics and chemistry, including in particular the concentration of gas detection surface acoustic wave of gas sensors, the detection of the nature of liquid surface acoustic wave sensors measuring angular velocity, the liquid surface acoustic wave velocity sensor, and the pressure sensor, torque sensor, humidity sensors and biosensor etc. Surface acoustic wave temperature sensor is the basic principle in piezoelectric materials, surface, SAW forks refers to the transducer resonators, oscillators, or appropriate design or resonators, oscillators, SAW that the measurement on the subtle. When tested object in piezoelectric substrate, piezoelectric and physical properties of the surface will cause the propagation characteristics of SAW. As surface acoustic wave components in wireless communication and high-performance sensor technology application more widely to surface acoustic wave components, and also puts forward a higher request: response frequency, wider bandwidth, smaller size and lower insertion loss, even achieve wireless transmission, wireless passive sensor. Accordingly, making more and more complicated devices, with better performance and the prediction model is put forward more and more requirements.Surface acoustic wave temperature sensor based on the theory of surface wave theory of piezoelectric harmony. Surface acoustic wave is a kind of solid shallow surface elastic wave propagation, piezoelectric crystal surface acoustic wave components is the main material, the surface acoustic wave components in production process, fully consider the various piezoelectric crystals, dielectric, piezoelectric flexible and iron electrical properties, such as selecting suitable piezoelectric crystal substrate materials, it is making surface acoustic wave temperature sensor is the key. Due to the change of environment or various physical, chemical and biomass of the effect caused by the surface acoustic wave components or parts of the wave of change, the structure size is resonant frequency echo delay. For surface acoustic wave temperature sensor when the temperature change of the center frequency, resonator along drift. So the frequency excursion measurable external conditions, used to measure the many parameters, thus measuring temperature changes. Surface acoustic wave (SAW) sensor mainly through the surface acoustic wave delay line and various physical quantity of resonator induction. This paper designs the surface acoustic wave temperature sensor, the main application linear delay to reflect gate fork transducer. Through to delay type surface acoustic wave temperature sensor design research, completed the surface acoustic wave temperature sensor design manufacture, and on the basis of analyzing the surface acoustic wave components in stress, humidity sensor volume test the feasibility of the application.Surface acoustic wave components design mainly around the surface acoustic wave components is an important component of the transducer designed to fork out. Fork refers to the transducer is widely applied in surface acoustic wave incentive and spread. It will have a direct impact on the performance of surface acoustic wave components. In the transmission of voice signal input signal will become transducer and the piezoelectric crystal surface, output will receive the transducer signal output signal into a sound. In practical applications, surface acoustic wave components of external electrical properties such as: pulse response characteristics, and frequency response characteristics, and the circuit parameters, such as the input and output impedance will affect the transmission properties of devices SAW. To make the mechanism and transducer fork to develop, must meet the requirements analysis SAW - IDT features simple and meets the requirement of the model and method. SAW devices adopted production of large scale integrated circuit technology, the plane manufacturing process is clean, coating, photolithography, etching, frequency correction, testing, packaging, etc. This thesis mainly USES is single electrode fork, fork refers to transducer rely mainly on the preparation of transducer means to realize, photolithography lithography will directly influence the accuracy or surface acoustic wave sensors pieces frequency is the main factor. Photolithography precision is higher resolution of the photo resist, fork refers to the bar transducer refers to the wavelength of surface acoustic wave (SAW size, and the wavelength and velocity of common decision SAW frequency. Single electrode fork to structure, fork transducer finger set wide wavelength 1/4 SAW.Surface acoustic wave (SAW) refers to the design of the transducer fork, has been widely adopted impulse response model of the delta function of sampling method and frequency response parity decomposition of the discrete Fourier transform method. The basic idea is to desired frequency response function (f) Fourier inverse transform, impulse response H (f). According to the sampling theorem on a certain rate of h (t), or phase homogeneous sampling window function with W (f), limited long truncated W (t n ).h(tn). The design process of simulation model: function model, the COM theory model, impulse model and P matrix model .This paper introduces the mathematical model used in the design and application of design theory of COM model were analyzed. At the same time the paper surface acoustic wave sensors sensitive characteristics were analyzed, including surface acoustic wave sensors fork to type, surface acoustic wave sensors selection, surface acoustic wave sensors connected matching, etc. According to the above the surface acoustic wave sensors characteristics of research and analysis, this paper based on the temperature on the surface acoustic wave sensors, the effect of making the two delay type surface acoustic wave temperature sensor, further research and test surface acoustic wave sensors. This paper designs made room temperature (20°c) work for the 73.69 MHz frequency comb delay-surface acoustic wave temperature sensor and working frequency for 73.01 MHz smoke refers to delay-surface acoustic wave temperature sensor. And through the comb delay type of film deposition velocity and substrate temperature sensor SAW that affect perturbation theory and SAW the relation between frequency. MatLab software and applications based on COM mathematical model for simulation experiment results are given. Purpose is based on surface acoustic wave temperature sensor design analysis, fundamentally studied surface acoustic wave frequency characteristics of the temperature sensor. On the surface acoustic wave sensors design research consideration on the increase, so as to improve the frequency of SAW surface acoustic wave temperature sensor sensitivity. Through the surface acoustic wave theory research of temperature sensor, the temperature sensor surface acoustic wave, in order to promote surface acoustic wave sensor technology research and development of new devices and control system of the new generation used a new road.