Matching of series and parallel resonance frequencies for ultrasonic piezoelectric transducers

Getman, I. P.; Lopatin, S.S.

doi:10.1109/isaf.2000.942419

Cited by 6 publications

(7 citation statements)

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“…A knowledge of such impedance characteristics is important for, structural health monitoring [10,11] and for electrical circuit modelling [6,8] of the piezoelectric devices. In the case of high power applications, knowledge of the impedance characteristics is important so that maximum transmission performance can be achieved [5,[12][13][14]. In the other words, at resonant frequencies, piezoelectric elements convert the input electrical energy into mechanical energy most efficiently, and so it is necessary to accurately extract these frequencies and excite the system appropriately.…”

Section: Introductionmentioning

confidence: 99%

Power converters design and analysis for high power piezoelectric ultrasonic transducers

Ghasemi

Zare

2014

2014 16th European Conference on Power Electronics and Applications

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High power piezoelectric ultrasonic transducers have been widely exploited in a variety of applications. The critical behaviour of a piezoelectric device is encapsulated in its resonant frequencies because of its maximum transmission performance at these frequencies. Therefore power electronic converters should be tuned at those resonant frequencies to transfer electrical power to mechanical power efficiently. However, structural and environmental changes cause variations in the device resonant frequencies which can degrade the system performance. Hence, estimating the device resonant frequencies within the incorporated setup can significantly improve the system performance. This paper proposes an efficient resonant frequency estimation approach to maintain the performance of high power ultrasonic applications using the employed power converter. Experimental validations indicate the effectiveness of the proposed method.

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Section: Introductionmentioning

confidence: 99%

Power converters design and analysis for high power piezoelectric ultrasonic transducers

Ghasemi

Zare

2014

2014 16th European Conference on Power Electronics and Applications

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“…The force induced by the impinging acoustic signal is represented by the voltage v a (t) in the mechanical branch while the parallel capacitance C p represents the dielectric nature of the piezoelectric material. According to such an equivalent circuit, the piezoelectric acoustic device, under voltage readout, displays the highest receiving response at the parallel resonance f p [29], defined as: A sinusoidal excitation voltage vexc(t) with peak amplitude Aexc = 1 V and frequency fexc within the bandwidth 5.3-5.6 kHz, provided by the lock-in amplifier (HF2LI, Zurich Instruments: Zurich, Switzerland), was applied to a speaker (FRWS5, Visaton: Haan, Germany) with a flat response in the frequency region of interest placed at 6.5 cm above the diaphragm, as shown in Figure 11c.…”

Section: Resultsmentioning

confidence: 99%

“…The velocity of the diaphragm causing the emitted acoustic signal is represented in electrical formalism by the current i a (t). According to such an equivalent circuit, the piezoelectric acoustic device, under voltage excitation, exhibits the highest transmitting output at the series resonance f s [29] defined as:…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, the frequency response of the device is characterized by two resonances which differ in value named the series resonant frequency f s and parallel resonant frequency f p [28]. According to such an equivalent circuit, a piezoelectric acoustic transducer, under voltage excitation, exhibits the highest transmitting output at the series resonance, while, under voltage readout, it displays the highest receiving sensitivity at the parallel resonance, shifted to a higher frequency [29]. However, when only a single piezoelectric element is used as a transceiver for both transmitting and receiving acoustic signals at resonance, a dynamic frequency tuning would be desirable to obtain the maximum transmitting-receiving effectiveness [30].…”

Section: Introductionmentioning

confidence: 99%

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Piezoelectric MEMS Acoustic Transducer with Electrically-Tunable Resonant Frequency

et al. 2022

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The paper presents a technique to obtain an electrically-tunable matching between the series and parallel resonant frequencies of a piezoelectric MEMS acoustic transducer to increase the effectiveness of acoustic emission/detection in voltage-mode driving and sensing. The piezoelectric MEMS transducer has been fabricated using the PiezoMUMPs technology, and it operates in a plate flexural mode exploiting a 6 × 6 mm doped silicon diaphragm with an aluminum nitride (AlN) piezoelectric layer deposited on top. The piezoelectric layer can be actuated by means of electrodes placed at the edges of the diaphragm above the AlN film. By applying an adjustable bias voltage Vb between two properly-connected electrodes and the doped silicon, the d31 mode in the AlN film has been exploited to electrically induce a planar static compressive or tensile stress in the diaphragm, depending on the sign of Vb, thus shifting its resonant frequency. The working principle has been first validated through an eigenfrequency analysis with an electrically induced prestress by means of 3D finite element modelling in COMSOL Multiphysics®. The first flexural mode of the unstressed diaphragm results at around 5.1 kHz. Then, the piezoelectric MEMS transducer has been experimentally tested in both receiver and transmitter modes. Experimental results have shown that the resonance can be electrically tuned in the range Vb = ±8 V with estimated tuning sensitivities of 8.7 ± 0.5 Hz/V and 7.8 ± 0.9 Hz/V in transmitter and receiver modes, respectively. A matching of the series and parallel resonant frequencies has been experimentally demonstrated in voltage-mode driving and sensing by applying Vb = 0 in transmission and Vb = −1.9 V in receiving, respectively, thereby obtaining the optimal acoustic emission and detection effectiveness at the same operating frequency.

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“…This principle requires very low impedance materials that are not available in pure form or single phase. Therefore, dispersed microsphere with air inclusion, aerogel, or plastic foam is used for this purpose [7]- [13]. The problem of air dispersion is the nonuniformity in its distribution, which causes scattering of waves.…”

Section: Introductionmentioning

confidence: 99%

New type of matching layer for air-coupled ultrasonic transducers

Toda¹

2002

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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This paper presents a new concept in the design of an impedance matching structure for air coupled ultrasonic transducers. A reflective layer structure is inserted between the transducer and propagation medium with a small air space. Adjusting the air space and the reflectivity of the inserted structure causes the transducer impedance to match with the impedance of the propagation medium. Two such structures were investigated as a reflector: a polymer thin film and a thick plate with many holes. Wave impedance theory was applied to these reflecting structures, and the impedance of a thin film layer at the incident surface was calculated using boundary conditions. Impedance of holed plate is calculated in a similar fashion. It was found that the calculated impedance of these structures approximately matched the impedance of the PZT air transducer (40 KHz). The acoustic pressure output was maximized by adjusting the position of the matching structure. A theoretical gain of up to 10 dB in the acoustic pressure was predicted under ideal circumstances, and the experimental observations showed a gain of 9.5 dB in the acoustic pressure for a 12 m polyethylene film placed at a distance of 0.1 mm from the transducer's surface. The increase was 9.8 dB for a polyvinylidene fluoride (PVDF) film and 9.7 dB for a 1.5 mm printed circuit board with many holes at a distance of 25 m from the transducer's surface.

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Matching of series and parallel resonance frequencies for ultrasonic piezoelectric transducers

Cited by 6 publications

References 0 publications

Power converters design and analysis for high power piezoelectric ultrasonic transducers

Power converters design and analysis for high power piezoelectric ultrasonic transducers

Piezoelectric MEMS Acoustic Transducer with Electrically-Tunable Resonant Frequency

New type of matching layer for air-coupled ultrasonic transducers

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