RU188744U1 - Dual element electroacoustic transducer for parametric generation of acoustic signals - Google Patents

Abstract

The utility model is used for parametric generation of acoustic signals. The essence of the utility model is that a two-element electro-acoustic transducer for parametric generation of acoustic signals contains two electrical oscillators, the outputs of which are through a linear adder, a pulse modulator controlled by a pulse generator, and a power amplifier connected to the piezoelectric transducer input, the piezoelectric element of which has a flat surface round shape, while the second piezoelectric transducer is connected to the output of the power amplifier Only with a piezoelectric element having a flat ring-shaped surface, the first piezoelectric transducer being located inside the second one. EFFECT: increased amplitude of the sound pressure, a component of the polyharmonic signal of the resulting ultrasonic calibration field in the hydroacoustic basin. 3 hp f-ly, 3 ill.

Description

The invention relates to measuring parametric radiators that are used as a source of sound vibrations in a hydroacoustic basin.

The level of technology

Testing and periodic testing of the characteristics of hydroacoustic equipment includes the time-consuming process of measuring the parameters of hydroacoustic antennas, whose operating frequencies range from several hundred hertz to several hundred kilohertz. When measuring the parameters of antennas in the reception mode in a wide frequency range, it is necessary to overcome technical difficulties, in particular, a set of standard narrow-band interference emitters is needed, whose dimensions and weight become too large. So far, in hydroacoustic measurements, piezoelectric transducers with a piezoelement in the form of spherical (cylindrical) shells and plates are used as interference sound emitters in water. Sound pressure measuring emitters must meet specific operational requirements: 1) high stability of operation over time under different climatic conditions (atmospheric pressure, temperature, humidity); 2) a large dynamic range of the amplitudes of the calibration sound pressure; 3) a wide range of operating frequencies; 4) directivity characteristic of the measuring radiator should contain the minimum number of additional petals in the formed calibration acoustic field (see Klyukin II, Kolesnikov AE Acoustic measurements in shipbuilding. - L .: Shipbuilding, 1966, pp.5 -14) . At present, in the measurement practice, the application of small-sized devices operating on the principles of nonlinear acoustics and forming sharply directed radiation in a wide frequency band, measuring parametric emitters, is promising. Measuring parametric radiators have advantages in comparison with standard interference emitters: wide frequency band and smooth frequency tuning in the working range, small weight and size parameters of piezoelectric transducers for pump waves, frequency independent angular width of the main lobe and the absence of a side field in the directivity characteristic (HN) of a parametric radiator in the range of operating signals of operating frequencies.

Known cavitating pulse parametric source (US Pat. No. 3964013 “Cavitating parametric underwater acoustic source”, William L. Konrad, Int.Cl H04B 11/00, G01S 9/66, publ. 15.06.1976), used in sonar devices, which in the mode of radiation, it has a high spatial selectivity on the low-frequency component of the spectrum generated in the aquatic environment - a differential frequency wave containing two electrical oscillators, the outputs of which through a double balanced modulator, a pulse modulator controlled by a pulse generator, and The terminals are connected to the input of a piezoelectric transducer, which is equipped with shielding elements, hydro, electrical and noise insulation.

The disadvantages of the analogue are the low reliability and stability of the operation of the piezoelectric transducer of a parametric source, as well as the lack of noise immunity. The reasons for the drawbacks are: intense acoustic radiation generating powerful interference, which leads to a decrease in the signal-to-interference ratio at the receiver input; hydrodynamic perturbations generated by cavitation phenomena, gradually damaging the surface of the device's piezoelectric transducer, reducing its service life; deformation of the piezoelectric elements due to functioning under conditions of high mechanical and electrical loads, leading to a shift in the resonant frequency of the piezoelectric transducer and a decrease in the frequency range of generation of the differential frequency wave due to the appearance of a non-linear dependence of the deformation of the piezoelectric element on the electric field applied to it.

Signs that coincide with the claimed object: two generators of electrical oscillations, power amplifier, piezoelectric transducer, equipped with screening elements, hydro, electrical and noise insulation.

Known parametric measuring emitter for hydroacoustic pools (Novikov B. K., Rudenko O. V., Timoshenko V. I. Nonlinear hydro-acoustics. - L .: Shipbuilding, 1981. - 264 p.), Containing two generators of electrical oscillations, the outputs of which through a linear adder, a pulse modulator controlled by a pulse generator, as well as a power amplifier and a notch filter are connected to the input of a piezoelectric transducer equipped with screening elements, hydro, electrical and noise insulation, and the radiating aperture of One is a section of a convex piezoelectric plate.

The disadvantages of the analogue include the limited range of operating frequencies of the calibration signals in the low-frequency region, the reduced conversion rate of the generated difference signal from the ultrasonic pump signals, and the lack of specific acoustic power of the pump signals in the aquatic environment. The reasons are: the convex spherical shape of the radiating surface; using only the spectral components of the difference frequency, while in the nonlinear aquatic environment, high-frequency spectral components are also formed.

Signs that coincide with the claimed object: two generators of electrical oscillations, a linear adder, a pulse modulator, a pulse generator, a power amplifier, a notch filter, a piezoelectric transducer equipped with elements of screening, hydro, electrical and noise insulation.

Known acoustic parametric emitter (US Pat. No. 4320474 “Saturation limited parametric sonar source”, Huckabay et al, MKI H04B 1/02, publ. 03.03.1982), adopted as the closest analogue, containing two electrical oscillators, the outputs of which through linear adder, a pulse modulator controlled by a pulse generator, as well as a power amplifier, from the output of which a powerful electrical signal is fed to the inputs of two identical piezoelectric transducers, piezoelements-plates of which have flat round surfaces for the sake of catfish (d / 2) each, which apertures are located in one plane, with their phase-geometric centers offset by a distance 2d from each other and provided with screening elements, hydraulic, electrical and sound insulation.

The disadvantages of the closest analogue are the low reliability and stability of the functioning of piezoelectric transducers of a parametric source, the low efficiency of generating calibration sound pressure fluctuations in a small range of operating signals of the difference frequency. The reasons are the transverse spatial separation of the centers of the apertures of two piezoelectric transducers with flat disk piezoelectric plates; the inability to change the mutual arrangement of two identical piezoelectric transducers with a flat disk piezoelectric plate; limiting the fatigue-strength properties of piezoceramics of the efficiency of conversion of electrical energy into acoustic.

Signs that coincide with the claimed object: an oscillator of electrical oscillations, a power amplifier, a piezoelectric transducer, equipped with screening elements, hydro, electrical and noise insulation.

Disclosure of the essence of the utility model

The task of the claimed utility model is the creation of a two-element electroacoustic transducer for parametric generation of acoustic signals, with enhanced operational capabilities, consisting in the ability to generate in a non-linear water environment calibration sound waves in a wide range of variations in the working amplitudes of their sound pressure.

The technical result of the utility model is to increase the amplitude of the sound pressure of the polyharmonic signal component of the resulting ultrasonic calibration field in the hydroacoustic pool due to phased addition of acoustic power of biharmonic pump signals in a given non-linear water environment, which improves the reliability of measurement results by reducing the level of masking noise.

, выходы которых через линейный сумматор, импульсный модулятор, управляемый импульсным генератором, а также усилитель мощности, выход которого соединен со входом пьезоэлектрического преобразователя, пьезоэлемент которого имеет плоскую поверхность круглой формы, дополнительно введен подключенный к выходу усилителя мощности второй пьезоэлектрический преобразователь, пьезоэлемент которого имеет плоскую поверхность кольцеобразной формы, причем первый преобразователь расположен внутри второго.The technical result is achieved by the fact that in a parametric measuring emitter containing two generators of electrical oscillations with frequencies

whose outputs through a linear adder, a pulse modulator controlled by a pulse generator, and a power amplifier, the output of which is connected to the input of a piezoelectric transducer, the piezoelectric element of which has a flat circular surface, is additionally connected to the output of the power amplifier of a second piezoelectric transducer, the piezoelectric element of which has a flat the surface is annular, with the first transducer located inside the second.

It is advisable to design the piezoelectric transducers so that the internal diameter of the annular flat surface of the second transducer piezoelectric element coincides with the diameter of the circular flat surface of the piezoelectric element of the first transducer, and the external diameter of the second transducer's annular flat surface is determined by the condition of equality of the squares of the radiating surfaces of the transducer, ie.

, где:

where:

- внешний диаметр кольцеобразной плоской поверхности второго преобразователя;

- outer diameter of the annular flat surface of the second transducer;

- внутренний диаметр кольцеобразной плоской поверхности второго преобразователя.

- internal diameter of the annular flat surface of the second transducer.

Rationally in a two-element electroacoustic transducer for parametric generation of ultrasound, the first and second piezoelectric transducers are placed in a supporting structure of a cylindrical shape, made with the possibility of providing adjustment, i.e. adjusting the alignment in space of the acoustic axes and the radiating surfaces of the piezoelectric elements of both piezoelectric transducers.

Rationally in a two-element electroacoustic transducer for parametric generation of ultrasound to provide the first and second piezoelectric transducers with elements of shielding, hydro, electrical and noise insulation.

FIG. 1 shows a block diagram of a two-element electroacoustic transducer for parametric generation of ultrasound with a schematic representation of the design of piezoelectric transducers.

FIG. 2 shows the experimental results of measuring the axial distributions of the amplitudes of the sound pressure for the difference frequency signal

и

. FIG. 3 presents the experimental results of measuring the magnitudes of changes in the amplitude of sound pressure for the signals of the difference frequency

and

.

которой совпадает с диаметром плоского пьезоэлемента первого пьезоэлектрического преобразователя, а внешний диаметр

определяется условием равенства излучающих площадей

пьезоэлементов обоих пьезоэлектрических преобразователей, т.е.

и несущую конструкцию цилиндрической формы 9, которая может в одном из вариантов реализации устройства объединять в единое целое пьезоэлектрические преобразователи 7 и 8. Несущая конструкция 9 цилиндрической формы обеспечивает возможность юстировки, т.е. точной регулировки совмещения в пространстве как акустических осей, так и излучающих поверхностей пьезоэлементов обоих пьезоэлектрических преобразователей 7, 8. Пьезоэлементы возбуждаются электрическими сигналами с частотами

находящимися в их полосе пропускания. Принцип построения несущих конструкций, обеспечивающих юстировку акустической системы, и способы прецизионного изменения расстояния между преобразователями известны и применяются в методах ультразвуковой интерферометрии (см. Специальный физический практикум, ч.1 3-е изд., М., Изд-во Моск. ун-та,1977, с.309-317, Ультразвук. Маленькая энциклопедия. Глав. ред. И.П.Голямина. – М.: «Сов. Энциклопедия»,1979. С.151-153).A two-element electroacoustic transducer for parametric ultrasound generation contains the first 1 and second 3 electrical oscillators, the outputs of which through a linear adder 2, a pulse modulator 4 controlled by a pulse generator 5, and the power amplifier 6 are connected to the inputs of the first piezoelectric transducer 7, the piezoelectric element of which has a flat the surface is circular in shape, and the second piezoelectric transducer 8, the piezoelectric element of which has a flat ring-shaped surface, vn morning diameter

which coincides with the diameter of the flat piezoelectric element of the first piezoelectric transducer, and the outer diameter

determined by the condition of equality of the radiating areas

piezoelectric elements of both piezoelectric transducers, i.e.

and a supporting structure of a cylindrical form 9, which in one of the embodiments of the device can integrate piezoelectric transducers 7 and 8 into a single unit. The supporting structure 9 of a cylindrical form allows adjustment, i.e. fine adjustment of the alignment in space of both the acoustic axes and the radiating surfaces of the piezoelectric elements of both piezoelectric transducers 7, 8. The piezoelectric elements are excited by electrical signals with frequencies

in their bandwidth. The principle of construction of supporting structures that ensure the alignment of the acoustic system, and the methods of precision variation of the distance between the transducers are known and used in the methods of ultrasonic interferometry (see Special Physical Practice, part 1, 3rd ed., Moscow, Moscow University Press Ta, 1977, pp.309-317, Ultrasound. The Little Encyclopedia. The chief editor of IP Golyamin. - M .: Sov. Encyclopedia, 1979. P.151-153).

поступающие через линейный сумматор 2 на вход импульсного модулятора 4, управляемого импульсным генератором 5. С выхода импульсного модулятора 4 радиоимпульс с бигармоническим заполнением (биения электрических колебаний близких частот

находящихся в полосе пропускания пьезоэлектрических преобразователей 7, 8, (см. Ультразвук. Маленькая энциклопедия. Глав. ред. И.П.Голямина. – М.: «Сов. Энциклопедия»,1979. С.51-52) через усилитель мощности 6 поступает на входы пьезоэлектрических преобразователей 7, 8, пьезоэлементы которых имеют плоскую поверхность круглой формы и плоскую поверхность кольцевой формы соответственно. Внутренний диаметр

кольца совпадает с диаметром плоского пьезоэлемента первого пьезоэлектрического преобразователя 7, а внешний диаметр

определяется условием равенства излучающих площадей

пьезоэлементов обоих пьезоэлектрических преобразователей 7 и 8, т.е.

, оба пьезоэлектрических преобразователя 7 и 8 снабжены элементами экранировки, гидро-, электро- и шумоизоляции. Пьезоэлементы пьезоэлектрических преобразователей 7 и 8 колеблются на основной толщиной моде в режиме одностороннего излучения и излучают мощные сигналы бигармонической накачки с близкими частотами

находящимися в их полосах пропускания, которые формируют в водной среде характеристики направленности для акустических волн бигармонической накачки, имеющую круговую симметрию относительно оси, проходящей через их центры и перпендикулярно к середине плоских поверхностей. В силу пьезоэлектрических свойств пьезоэлементы пьезоэлектрических преобразователей 7, 8 будут изменять свои полуволновые толщины с частотами, равными частотам приложенных электрических сигналов, т.е. будут совершать колебания. Все точки поверхностей пьезоэлементов колеблются синфазно и с одинаковой амплитудой. Эти колебания передаются в водную среду и распространяются в виде сгущений и разряжений продольной волны. Водная среда обладает нелинейностью своих упругих свойств, что приводит к появлению эффектов как самовоздействия, так и взаимодействия при распространении импульса интенсивной ультразвуковой волны (см. Мюир Т.Дж. Нелинейная акустика и ее роль в геофизике морских осадков//Акустика морских осадков/ Пер. с англ.; Под ред. Ю. Ю. Житковского. – М.: Мир, 1977. – с. 227 – 273). Воздействие нелинейного изменения упругих свойств воды на характеристики мощного импульсного сигнала накачки в области распространения проявляется в параметрической генерации градуировочных ультразвуковых сигналов как разностной

, так и суммарной

частот, вторых гармоник волн накачки

, что справедливо для акустических полей, формируемых обоими пьезоэлектрическими преобразователями 7, 8. Заявляемая полезная модель реализует способ суперпозиции амплитуд звуковых давлений сформированных градуировочных ультразвуковых сигналов, проявляющийся при совпадении для них как волновых фронтов, так и фаз колебаний.Dual-element electroacoustic transducer for parametric generation of ultrasound works as follows. Generators 1, 3 produce electrical signals with frequencies

coming through a linear adder 2 to the input of a pulse modulator 4 controlled by a pulse generator 5. From the output of a pulse modulator 4 radio pulses with biharmonic filling (beats of electrical oscillations of near frequencies

located in the passband of the piezoelectric transducers 7, 8, (see Ultrasound. Small encyclopedia. The main. Ed. And. P. Golyamin. - M .: Sov. Encyclopedia, 1979. P.51-52) through the power amplifier 6 enters the inputs of piezoelectric transducers 7, 8, the piezoelectric elements of which have a flat surface of circular shape and a flat surface of circular shape, respectively. Inner diameter

the ring coincides with the diameter of the flat piezoelectric element of the first piezoelectric transducer 7, and the outer diameter

determined by the condition of equality of the radiating areas

piezoelectric elements of both piezoelectric transducers 7 and 8, i.e.

, both piezoelectric transducers 7 and 8 are equipped with shielding elements, hydro, electrical and noise insulation. The piezoelectric elements of the piezoelectric transducers 7 and 8 oscillate at the fundamental thickness of the mode in the one-sided emission mode and emit powerful signals of biharmonic pumping with similar frequencies

located in their transmission bands, which form in the aquatic environment the directivity characteristics for acoustic waves of biharmonic pumping, which have circular symmetry about an axis passing through their centers and perpendicular to the middle of flat surfaces. Due to the piezoelectric properties, the piezoelectric elements of the piezoelectric transducers 7, 8 will change their half-wave thickness with frequencies equal to the frequencies of the applied electrical signals, i.e. will hesitate. All points of the surface of the piezoelectric elements oscillate in phase and with the same amplitude. These vibrations are transmitted to the aquatic environment and spread in the form of condensations and discharges of the longitudinal wave. The aquatic environment has a non-linearity of its elastic properties, which leads to the appearance of both self-action and interaction effects during the propagation of a pulse of an intense ultrasonic wave (see Muir TJ. Non-linear acoustics and its role in marine precipitation geophysics) / Acoustics of marine sediments / Trans. from English; Ed. by Yu. Zhitkovsky. - M .: Mir, 1977. - pp. 227-273). The effect of a nonlinear change in the elastic properties of water on the characteristics of a high-power pulsed pump signal in the propagation region is manifested in the parametric generation of calibration ultrasonic signals as a difference signal

and total

frequencies, second harmonics of pump waves

that is true for acoustic fields formed by both piezoelectric transducers 7, 8. The claimed utility model implements a method of superposing sound pressure amplitudes of the generated calibration ultrasonic signals, which appears when both wave fronts and oscillation phases coincide.

Examples of implementation

=50 кГц использовались сигналы накачки с частотами

1035 кГц,

1085 кГц, эксперименты проводились также для волн разностных частот 25 кГц, 75 кГц.The stated principle of the construction of a two-element electroacoustic transducer for parametric ultrasound generation was implemented in the design of a mock-up of a composite emitter including piezoelectric piston transducers, piezoplates which, in accordance with the utility model, are a flat disk placed concentrically inside a flat ring (12 mm disc diameter, for an outer ring 24 mm, internal 13 mm, central resonant frequency of 1.06 MHz.). For nonlinear generation of differential frequency wave

= 50 kHz pump signals with frequencies were used

1035 kHz,

1085 kHz, experiments were also carried out for waves of difference frequencies of 25 kHz, 75 kHz.

50 кГц в области коллинеарного распространения и нелинейного взаимодействия мощных сигналов накачки с частотами

1085 кГц,

1035 кГц на акустической оси предлагаемого двухэлементного электроакустического преобразователя для параметрической генерации ультразвука (кривая 3), а также при раздельном функционировании его составных частей: второго пьезоэлектрического преобразователя 8, пьезоэлемент которого имеет плоскую поверхность кольцевой формы (кривая 1), первого пьезоэлектрического преобразователя 7, пьезоэлемент которого имеет плоскую поверхность круглой формы (кривая 2). Как следует из сопоставления графиков, предлагаемый рабочий режим полезной модели приводит в дальней зоне к увеличению амплитуды звукового градуировочного сигнала на (4 – 5) дБ.FIG. 2 presents the experimental results of measuring the axial distributions of the amplitudes of the sound pressure for the signal of the difference frequency

50 kHz in the field of collinear propagation and nonlinear interaction of high-power pump signals with frequencies

1085 kHz,

1035 kHz on the acoustic axis of the proposed two-element electroacoustic transducer for parametric generation of ultrasound (curve 3), as well as with separate functioning of its components: the second piezoelectric transducer 8, the piezoelectric element of which has a flat ring-shaped surface (curve 1), the first piezoelectric transducer 7, the piezoelectric element which has a flat surface of a round shape (curve 2). As follows from the comparison of the graphs, the proposed operating mode of the utility model leads in the far-field zone to an increase in the amplitude of the sound calibration signal by (4–5) dB.

25 кГц и

50 кГц в дальней зоне макета составного излучателя за счет введения расфазировки сформированных градуировочных ультразвуковых сигналов. Расфазировка осуществляется путем продольного перемещения друг относительно друга плоского диска (пьезоэлектрический преобразователь 7), размещенного концентрически внутри плоского кольца (пьезоэлектрический преобразователь 8), и эквивалентна введению фазового сдвига между бигармоническими сигналами накачки, излучаемыми указанными элементами макета. Как следует из фиг. 3, для каждого градуировочного сигнала разностной частоты наблюдаются периодические области максимумов и минимумов, период изменений равен периоду биений. Высокочастотный сигнал, имеющийся на записях (фиг. 3) имеет место вследствие электрической наводки и недостаточной фильтрации. Таким образом, путем продольного перемещения составных элементов можно осуществлять точную настройку устройства, т.е. регулировать эффективность нелинейной генерации градуировочных ультразвуковых сигналов. В полезной модели предусмотрено отсутствие расфазировки между бигармоническими сигналами накачки за счет того, что несущая конструкция цилиндрической формы выполнена с возможностью совмещения в пространстве как акустических осей, так и излучающих поверхностей пьезоэлементов обоих пьезоэлектрических преобразователей 7,8.FIG. 3 presents the experimental results of measuring the magnitudes of changes in the amplitude of sound pressure for the signals of the difference frequency

25 kHz and

50 kHz in the far-field zone of the composite emitter layout due to the introduction of skewing of the formed calibration ultrasonic signals. Phasing is carried out by longitudinal displacement of a flat disk relative to each other (piezoelectric transducer 7) placed concentrically inside a flat ring (piezoelectric transducer 8), and is equivalent to introducing a phase shift between the biharmonic pump signals emitted by the indicated layout elements. As follows from FIG. 3, for each calibration signal of the difference frequency, periodic regions of maxima and minima are observed, the period of changes is equal to the period of beats. The high-frequency signal present on the records (Fig. 3) occurs due to electrical interference and insufficient filtering. Thus, by longitudinal movement of the components, it is possible to fine-tune the device, i.e. to regulate the efficiency of non-linear generation of calibration ultrasonic signals. The utility model provides for the absence of skew between the biharmonic pump signals due to the fact that the supporting structure of a cylindrical shape is made with the possibility of combining in space both the acoustic axes and the radiating surfaces of the piezoelectric elements of both piezoelectric transducers 7.8.

The analysis of the experimental results presented above allows us to draw the following conclusions: the inventive two-element electroacoustic transducer for parametric ultrasound generation satisfies at least the following specific operational requirements: a large dynamic range of amplitudes of the calibration sound pressure, a wide range of operating frequencies, the directivity characteristic of the measuring emitter contains the minimum number of additional lobes in the formed calibration acus tic field. It should be noted that the spatial distributions of sound pressure amplitudes for acoustic fields of difference frequency signals generated by an electroacoustic transducer for parametric ultrasound generation, optimally meet another operational requirement for a formed calibration field: monotonicity and uniformity of changes in sound pressure amplitudes in both the longitudinal and transverse directions water volume hydroacoustic pool, which allows you to place graduated space The landmarks are close enough to the device. On this basis, it can be assumed that the practical use of the proposed electroacoustic transducer for parametric generation of ultrasound as a measuring instrument in hydroacoustic pools of limited sizes in addition to the above advantages will reduce the weight and size parameters of hydroacoustic pools.

It should be emphasized that an increase in the amplitude of the sound pressure of the components of the calibration signal of the resulting ultrasonic field in the measurement volume of the sonar basin leads to an increase in the reliability of the measurement results. It should be noted that in acoustic measurements, in addition to the useful signal, the receiving channel is affected by signals that create difficulties in carrying out measurements, since they distort or mask the useful signal. So, as a rule, during acoustic measurements, the signal level (measured together with interference) should be 10–15 dB higher than the interference level (measured without a signal), and it is most difficult to eliminate reverberation interference, i.e. noise generated by a scattered useful signal. However, the claimed two-element electroacoustic converter for parametric generation allows, in this case as well, to gain by increasing the directivity and the absence of lateral radiation.

The claimed utility model can be widely used in the field of acoustic measurements, in particular, in measuring sound pressure emitters, which under hydroacoustic basin conditions can be used as a source of sound vibrations with high amplitude of sound pressure, which allows to increase the reliability of measurement results and reduce their difficulty receiving by reducing the level of masking noise.

Claims (4)

1. A two-element electroacoustic transducer for parametric generation of acoustic signals containing two electrical oscillators, the outputs of which are connected via a linear adder, a pulse modulator controlled by a pulse generator, and a power amplifier connected to the input of a piezoelectric transducer, the piezoelectric element of which has a flat surface of a circular shape, distinguished by that the output of the power amplifier is connected to the second piezoelectric transducer with a piezoelectric element having n a glossy ring-shaped surface, with the first piezoelectric transducer located inside the second. 2. Two-element electroacoustic transducer for parametric generation of acoustic signals according to claim 1, characterized in that the inner diameter of the flat surface of the annular shape of the piezoelectric element of the second piezoelectric transducer is equal to the diameter of the flat surface of the piezoelectric element of the first piezoelectric transducer, and the outer diameter of the flat surface of the annular shape of the piezoelement element Converter is determined by the condition of equality of the areas their surfaces of the first and second piezoelectric transducers. 3. Two-element electroacoustic transducer for parametric generation of acoustic signals according to claim 1, characterized in that the first and second piezoelectric transducers are located inside the supporting structure of a cylindrical shape, made with the possibility of adjusting the alignment in space of both acoustic axes and piezoelectric transducers of both piezoelectric transducers . 4. A two-element electroacoustic transducer for parametric generation of acoustic signals under item 1, characterized in that the first and second piezoelectric transducers are equipped with screening elements for hydro, electrical and noise insulation.

Images