A piezoelectric transducer operating in the thickness vibration mode is represented as a six terminal network. The mesh equations, electro-mechanical impedance matrix and equivalent circuit valid for any general conditions of loading and frequency are obtained. All properties of the transducer can thus be determined once the impedance of the loads and the energy sources are specified. Part II. Abstrac t The electrical driving point impedance and admittance of a piezoelectric transducer operating in the thickness vibration mode are derived for all conditions of loading and frequency. Universal curves of these quantities are included for particular cases of importance.
This paper presents a wireless ultrasound sensing system that uses frequency conversion to convert the ultrasound signal to a microwave signal and transmit it directly without digitization. Constructed from a few passive microwave components, the sensor is able to sense, modulate, and transmit the full waveform of ultrasound signals wirelessly without requiring any local power source. The principle of operation of the unpowered wireless ultrasound sensor is described first, and this is followed by a detailed description of the implementation of the sensor and the sensor interrogation unit using commercially available antennas and microwave components. Validation of the sensing system using an ultrasound pitch-catch system and the power analysis model of the system are also presented.
This paper presents a wireless ultrasound sensor that uses frequency conversion to convert the ultrasound signal to a microwave signal and transmit it directly without digitization. Constructed from a few passive microwave components, the sensor is able to sense, modulate, and transmit the full waveform of ultrasound signals wirelessly without requiring any local power source. The principle of operation of the unpowered wireless ultrasound sensor is described first. Implementation of the sensor and the sensor interrogation unit using commercially-available antennas and microwave components is described in detail. Validation of the sensing system using an ultrasound pitch-catch system and the power analysis model of the system are also presented.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.