共查询到17条相似文献,搜索用时 187 毫秒
1.
无源无线声表面波谐振器传感信号是一个低信噪比、瞬态衰减信号,并叠加有激励信号和信道噪声.本文利用信号统计特性,显著地提高信噪比,获取谐振频率所在区间,让激励频率在该区间内取值,使之逼近谐振频率,从而达到检测谐振频率的目的. 相似文献
2.
本文介绍了一种采用声表面波谐振器作为传感器的虚拟仪器系统.该仪器系统采用虚拟仪器技术取代部分传统仪器,引入数字信号处理方法和反馈控制,通过无线激励查询传感信号,提取信号特征并显示测量结果.系统提高了测量精度和测量距离,可进行多种参数的测量,能够自动捕捉被测参量并跟踪其变化. 相似文献
3.
4.
随着传感技术的不断发展,出现了越来越多以传感器为基础的无线传感检测系统.这些传感系统需要对采集到的数据进行数据分析.因此,传感器的数据分析对于无线传感系统的精确检测起到至关重要的作用.首先对设计的声表面波(surface acoustic wave,SAW)微压力传感器进行实际测量,利用最小二乘法建立数学模型,对测得的... 相似文献
5.
6.
双声路声表面波传感器测量系统研究 总被引:1,自引:0,他引:1
环境温度对声表面波传感器影响较大,常采用双声路结构补偿环境温度的影响,本文结合声表面波器件结构,设计了一种新的测量系统。它由交替工作的延迟线振荡器、混频电路和数字信号处理电路组成。延迟线振荡器输出信号经滤波后与109MHz的本机晶体振荡器输出信号相混频,通过低通滤波取其差频,并经整形后由数字信号处理电路处理。应用标准信号源验证了测量系统的准确性,频率跟踪特性误差在50Hz以内。测量系统显示直观,精度高,是双声路声表面波传感器理想的测量系统。 相似文献
7.
介绍一种基于声表面波(SAW)的温度传感系统,该系统针对目前电力变电站测温点多、无法实时监控的情况,提出高精度、低成本的解决方案。 相似文献
8.
针对高压开关柜电缆室空间狭小,电磁干扰复杂的应用环境以及传统温度监测系统的弊端,提出了一种基于无源无线声表面波(SAW)传感技术与ZigBee协议组网的温度监测系统方案。结合热传导、热膨胀以及固体力学理论运用COMSOL软件对电缆室进行有限元分析,获得了温度分布以及热应变情况,为监测位置选定提供了依据;该系统采用声表面温度传感器代替传统的温度传感器提取温度信息,能够实现电气隔离;采用星型拓扑结构构建ZigBee无线网络实现温度数据收发,可以灵活配置。通过模拟实验平台搭建验证了该系统测温可行性。 相似文献
9.
10.
介绍了一种无线数传集成加速度传感系统。在讨论了测量加速度传感器及信号采集变换电路之后,给出了该系统测量数据无线传输的原理和设计方法。该系统克服了有线传输测量加速度传感系统的局限性,测量使用极为方便。 相似文献
11.
电磁脉冲信号的详细衍变过程,特别是其陡峭前沿的变化信息,有助于深入理解电磁脉冲信号产生及传播过程,它对于我国国防和自然科学的发展都有着极其重要的科学和实践意义。本文提出一种基于三路并行低速模数转换器(TPL)的模拟信号压缩感知技术,通过对传感器输出的电磁脉冲信号进行欠采样(信号的采样频率低于奈奎斯特采样定理的要求),得到并恢复被测电磁脉冲信号的高速采集波形。基于TPL压缩感知技术的应用,可以降低被测电磁脉冲信号陡峭前沿对后端电子ADC采样速率的要求。本文针对TPL实现过程中稀疏字典、观测矩阵的建立方法,以及信号的重构方法进行了深入地研究,创新性地提出基于KSVD的原子数自适应字典构建方法。在此基础上,通过仿真和实验测试了TPL系统对电磁脉冲信号的压缩感知采集效果,以此验证了该方法的可行性。 相似文献
12.
为消除干涉幅值对分布光纤振动传感系统在相位解调时的影响,提出了一种基于改进型相位生成载波(PGC)调制解调
技术的 Michelson 干涉仪型光纤振动传感解调系统。 其首先对 Michelson 干涉仪光纤振动传感系统的参考光纤上施加一定幅值
和频率的高频载波信号,完成对待测振动信号的高频调制。 而后通过零次谐波、一次谐波载频信号和低通滤波器还原出含有待
测振动信号的正弦项和余弦项。 最后通过对正弦项和余弦项的适当变换并相除解调出不含有干涉幅值的待测信号项。 通过仿
真与实验分析,提出的改进型 PGC 解调方案可以有效消除干涉幅值对解调输出信号产生的失真影响。 相似文献
13.
It is demonstrated that the sensitivity of sensors based on two-port surface acoustic waves (SAW) resonators increases by
a factor of Q (Q-loaded quality factor of the resonator) if the output signal of these sensors is represented in the phase
format instead of the conventional frequency format. Practical possibility of use of the SAW gas sensor with phase format
of transmitted signal as output signal is demonstrated using procedure of the determination of the water contents in gaseous
nitrogen with 386 MHz ST-quartz SAW resonator as an example. It is found that the SAW power affects the sensor response owing
to the influence of the SAW intensity on the equilibrium amount of water molecules adsorbed on the resonator surface. Extremely
high sensor sensitivity was obtained when using phase format of reflected signal as a sensor output. Using such a format of
sensor output we have reliably measured the change of temperature of ST-quartz SAW sensor substrate as small as 0.01∘C. 相似文献
14.
15.
This paper presents a novel surface acoustic wave sensor for civil structural health monitoring. The sensing chip packaged in a shell is composed of two SAW delay line dice. One is utilized to sense the pressure induced by a gauge, and the other is used to sense the surrounding temperature for temperature compensation. Each SAW delay line die consists of an inter-digital transducer and two open grating reflectors. The SAW devices are analyzed by using coupling of modes model. Then, the devices in different parameters are fabricated on a 128°Y-X cut LiNbO3 substrate by lift-off technique. Finally, a network analyzer is utilized to test the devices. Large signal-to-noise ratio, low loss and clear sharp peaks of the reflection coefficients S11 in frequency and time domain can be observed. The experimental results matched well with the theoretical analysis by the finite element software COMSOL. The IDT finger pairs number, electrodes number of per reflector and acoustic aperture effect the reflection coefficient S11 is discussed in detail. 相似文献
16.
Beom-Keun Yoo Yong-Wook Park Chong-Yun Kang Seok-Jin Yoon Jin-Sang Kim 《Journal of Electroceramics》2006,17(2-4):1013-1017
This paper presents properties of saw acoustic wave (SAW) gas sensors to detect volatile gases such as acetone, methanol,
and ethanol by measuring phase shift. A dual-delay-line saw sensors with a center frequency of 100 MHz were fabricated on
128∘ Y-Z LiNbO3 piezoelectric substrate. In order to improve sensitivity of SAW sensors, a thin titanium (Ti) film as mass sensitive layer
was deposited using e-beam evaporation on the surface of the SAW sensors. In our investigation the response time and sensitivity
of SAW sensors were measured. The response time and sensitivity of SAW sensor with thin Ti film were strongly improved because
of changing electrical and mechanical properties in the mass sensitive layer. As a result, high sensitivity and fast response
time could be achieved by deposition of thin Ti film as mass sensitive layer on the surface of SAW sensor. It can be applied
for high performance electronic nose system by assembling an array of different sensors. 相似文献