Abstract: A detection system and a wind driven generator. The detection system includes: a plurality of passive wireless sensors respectively provided at the corresponding positions to be detected, which are used for obtaining detection signals of the positions to be detected; and a leaky coaxial cable provided along the position to be detected, wherein the leaky coaxial cable can emit electromagnetic waves to drive the plurality of passive wireless sensors, and can receive the detection signal sent by the passive wireless sensors. The detection system can save installation space, as well as reduce maintenance costs since there is no need to replace a battery regularly, and when conducting multi-point measurements, costs are reduced and the number of passive wireless sensors that the system can configure is increased.

Abstract: A method and apparatus for placing quartz SAW (Surface Acoustic Wave) devices together with a clock/oscillator have been disclosed. Mounting on a single lead frame both a SAW device and an integrated circuit (IC).

Abstract: A SAW-based micro-sensor apparatus for simultaneously monitoring acceleration/vibration and temperature utilizing a sensing element configured as a SAW device (e.g., SAW resonator or SAW delay line). The SAW device can be located in different locations on a substrate with respect to a thin piezoelectric diaphragm comprising an inertial mass. The temperature-compensated acceleration/vibration can be measured utilizing a frequency difference between an acceleration sensitive SAW resonator (e.g., SAW-g) and a temperature sensitive SAW resonator (e.g., SAW-T). The temperature can be measured utilizing a frequency shift provided by the SAW-T and a temperature reference SAW resonator (e.g., SAW-R). Similarly, the phase response of different reflectors of the SAW delay line can be utilized to differentially measure the acceleration/vibration and temperature.

Abstract: A contactless SAW based torque and temperature sensor comprising a first (2) and second (3) SAW resonator provided on a substrate made of Y+34° cut of quartz. The first SAW resonator (2) has its principle axis inclined at +45° to the X-axis of the substrate, which, in use is either aligned with the longitudinal axis of the device who torque is to be measured or is perpendicular thereto, and the second SAW (3) has its principle axis inclined at ?45° to the X-axis of the substrate. A third SAW (4) has its principle axis inclined at an angle of 30 degrees to the X-axis of the substrate. Each said SAW resonator (2,3,4) is formed by laying a film of aluminum on the substrate having a thickness (h) and the SAW resonators have an average operating wavelength ? where the ratio h/? is in the range 0.021 to 0.032.

Abstract: A temperature measurement system is characterized by at least one passive surface acoustic wave (SAW) temperature sensor. The sensor includes at least one piezoelectric substrate having an interdigital SAW transducer disposed upon the piezoelectric substrate for conversion of an RF signal into an acoustic wave and vice versa. At least three additional SAW elements are also disposed on the substrates in a manner such that they define two acoustic propagation paths that are non-parallel relative to the crystal axes of the substrates, and such that the temperature coefficients of delay in the two tracks differ. The SAW elements receive a signal from the SAW transducer and produce response signals. The response signals combine to produce a signal with a power spectral density such that the integrated power within each of two specified portions of the spectrum provides an indicator of the temperature.