RU2101855C1 - Controlled acoustic electronic device - Google Patents

Abstract

FIELD: radio electronics. SUBSTANCE: device is based on sound duct made of polydomain monocrystal of ferroelastic- ferroelectric, isomorphous gadolinium molybdate with electrically controlled spatial position of flat domain boundary. Device has also information acoustic channel, as well as test-and-measuring acoustic channel inserted in negative feedback circuit for spatial position of flat domain boundary. Piezoelectric transducers of longitudinal oscillation mode are used as volume acoustic wave transducers of test-and-measuring acoustic channel. They are positioned on the side of sound duct face edges perpendicular to plane of flat domain boundary and arranged in working region of flat domain boundary displacement with full overlapping of it. One of the above-indicated volume acoustic wave transducers is made of two sections with acoustically antiphase similar-aperture sections. Acoustic contact of each transducer of test-and-measuring channel is made with use of immersion layer. Amplitude- phase detector with comparison element and setting is used as control signal forming unit. This type of design of test-and-measuring channel including the sensor of spatial position of flat domain boundary in sound duct and of control signal forming unit provides for high-accuracy control of information parameter value, particularly value of delay time in controlled ultrasonic delay line in extended control range. EFFECT: high-accuracy control of information parameter value within wide range. 2 wdgv

Description

 The invention relates to the field of radio electronics, in particular acoustoelectronics, and can be used as an adjustable acoustoelectronic device for temporal or phase signal selection, for example, as an adjustable ultrasonic delay line, in various electronic systems for processing signal information.

 Known are acoustoelectronic devices for temporal and phase signal selection, in particular adjustable ultrasonic delay lines (RLS), containing a piezocrystalline sound guide made of a polydomain single crystal ferroelastic-signal-electric, isomorphic to gadolinium molybdate, in the form of a Z-slice plate containing at least two heterogeneous domains separated by a flat domain wall (PDG), the main input and output transducers of volumetric acoustic waves (OAV) located in the acoustic ontact with the sound duct and located on its one or both opposite working end faces, perpendicular to the Z-faces of the sound duct, and forming, together with the PDG, an acoustic information channel, control electrodes located on two opposite Z-faces of the sound duct in the working area of the PDG movement and connected to the output adjustable source of constant voltage.

 The main disadvantage of such adjustable acoustoelectronic devices is the low accuracy of the regulation of the information parameter (in particular, the signal delay time in the RAVZ OAV), due to the low reproducibility of the intermediate adjustment characteristic of the device: "a change in the value of the control signal at the output of an adjustable voltage source, a change in the location of the domain wall in the sound duct" associated with the presence of deviations in the stoichiometric composition of a single-crystal material in a duct, in the degree of its defectiveness, unipolarity, etc., leading to an almost unpredictable change in the real values of the coercive fields of a single crystal and, as a result, to a violation of the unambiguity and reproducibility of the control characteristic of the device: "the magnitude of the control electric voltage signal is the value of the adjustable time delay of the signal."

Closest to the invention in technical essence is another known adjustable acoustoelectronic device that performs the functions of an adjustable phase or time shift, in particular, and functions of an OAWS, selected as a prototype device, containing a piezoelectric crystal sound duct made of a polydomain single crystal ferroelastic ferroelectric, isomorphic molybdate gadolinium, in the form of a Z-slice plate containing at least two heteropolar domains separated by a flat domain wall d (PDG), the main input and output transducers of volumetric acoustic waves (OAV), which are in acoustic contact with the sound duct and located on its one or two opposite working end faces, perpendicular to the Z-faces of the sound duct, and forming together with the PDG information acoustic channel, control electrodes located on two opposite Z-faces of the sound duct and the working area of the PDG movement and connected to the output of an adjustable voltage source, the input of which is through the ph the control signal is connected to the output transducer of the OAB control and measuring acoustic channel, and the input transducer of the latter is connected to the generator of the reference sinusoidal signal [2]
In this known adjustable acoustoelectronic device, the development of a given value of a controlled informative parameter (phase shift, time delay) is carried out using negative feedback on the position of the PDG in the sound duct, due to which it is characterized by a fairly high accuracy of regulation. However, this takes place only for a very narrow range of regulation of the informative parameter, in particular, limited to tenths of a percent for RAVL OAV. There are several reasons for this. First of all, the topology of this adjustable acoustoelectronic device limits the maximum potential range of regulation of the information signal delay time to a value not exceeding 3% of its nominal value (see, for example, [1]). In addition, the topology used, which fundamentally limits the domain of spatial displacement of PDG due to the necessity of placing the converters of this channel on different sides of it (see [2]), further narrows (several times) the control range. Finally, an additional narrowing of the achievable control range in the known device is also associated with the need to implement an unambiguous dependence of the output signal of the control and measuring channel relative to the magnitude of the bias displacement. As a result, the acceptable accuracy of regulation of the delay time in the prototype device is achievable only in the regulation range not exceeding several tenths of a percent.

 The technical result to which the claimed invention is directed is to provide high accuracy of regulation of the value of the informative parameter, guaranteed by the use of a negative feedback circuit on the position of the gas generator, in a wide range of its regulation, in particular, to ensure high accuracy of regulation of the delay time in the RAVZ OAV in the range of its regulation up to tens and hundreds of percent of the nominal value. The implementation of this, based on the use of the negative feedback loop on the position of the PDG in the sound duct of the device, involves providing conditions for expanding the range of the spatial position of the PDG controlled by the negative feedback circuit.

 The essence of the invention lies in the fact that in a controlled acoustoelectronic device containing a piezoelectric sound duct made of a multidomain single crystal ferroelastic ferroelectric, isomorphic to gadolinium molybdate, in the form of a Z-slice plate containing at least two heteropolar domains separated by a flat domain wall ), the main input and output transducers of volumetric acoustic waves (OAV), which are in acoustic contact with the sound duct and located on its one or two opposite working end faces, perpendicular to the Z-faces of the sound duct, and forming, together with the PDG, an acoustic information channel, according to the invention, additional input and output transducers of OAV are introduced into it, which are also in acoustic contact with the sound duct, located in the working area of the PDG with its complete overlap on the side of two opposite end faces of the sound duct, orthogonal to the above faces and working end faces, and forming a control and the acoustic channel, the reference sinusoidal signal generator, the output of which is connected to the output additional transducer OAB, and a control signal generating unit connected between the input of the regulated constant voltage source and the output additional transducer OAV, while piezoelectric transducers are used as OAV transducers of the control and measuring acoustic channel transducers of the longitudinal vibration mode, located on the side of the end faces of the sound duct, perp and are located in the working area of the PDG movement with its complete overlap, while one of the transducers of the control and measuring acoustic channel is made two-section with acoustically antiphase sections of the same aperture, the acoustic contact of each of the transducers of the control and measuring acoustic channel is made using an immersion layer and, as the control signal generating unit, an amplitude-phase detector with a comparison element with a setup is used .

In FIG. 1, a, b schematically shows an adjustable acoustoelectronic device (two variants of its structural embodiment are shown from the side of the Z-face); in FIG. 2 a typical dependence of the amplitude A _{1 of the} signal at the output of the PDG spatial position sensor in the sound duct and the signal A ₂ at the output of the amplitude-phase detector of the control signal generating unit (Fig. 2a), as well as the geometry of the control and measuring acoustic channel for two different x coordinates - and x + spatial position of the PDG in the working area of its movement through the sound duct of FIG. 2, b, c.

двух соседних секций двухсекционного преобразователя 9). Преобразователи 9 и 10 расположены со стороны торцовых граней 13, 14, ортогональных плоскости ПДГ 4, и размещены в рабочей области перемещения ПДГ 4 с полным ее перекрытием. В качестве блока 21 формирования сигнала управления использован амплитудно-фазовый детектор 21", электрически последовательно соединенный с элементом сравнения 21' с уставкой ("уставка").The adjustable acoustoelectronic device contains a sound pipe 1 made of a polydomain single crystal of a ferroelastic ferroelectric, isomorphic to gadolinium molybdate, for example, terbium or gadolinium molybdate, in the form of a Z-slice plate (drawing plane in Fig. 1, a, b) containing at least two bipolar domains 2 and 3, separated by a flat domain wall (PDG) 4, as well as the main input 5 and output 6 piezoelectric transducers of volumetric acoustic waves (OAV), which are in acoustic contact with sound duct 1 and is located ies on its one working end face 7 (Fig. 1, a) or on two opposite working end faces 7 and 8 (Fig. 1, b), perpendicular to the Z-faces of sound duct 1; additional input 9 and output 10 OAB transducers that are in acoustic contact with the sound duct 1 through immersion layers 11 and 12, respectively, and placed on the side of its two opposite end faces 13 and 14, orthogonal to one or both working end faces (face 7 in FIG. . 1, a; faces 7 and 8 in Fig. 1, b); control electrodes 15 and 16 located on two opposite Z-faces 13, 14 of the sound duct 1 in the working area of the PDG movement 4, connected to the output terminals 17 and 18, respectively, of an adjustable constant voltage source 19, the input of which 20 through the signal generating unit 21 the control is connected (terminal 22) to the output auxiliary converter 10, and the output additional converter 9 is connected (terminal 23) to the generator 24 of the reference sinusoidal signal. The main transducers OAV 5 and 6 together with the PDG form an information acoustic channel, and the electrical leads 25 and 26 of the transducers 5 and 6 are respectively the input and output of the entire device. In the case of placing transducers 5 and 6 on one end face 7 (see Fig. 1, a), as these transducers, it is preferable to use OAV piezoelectric transducers of the shear vibrational mode or the longitudinal and shear vibrational modes (for transducers 5 and 6 or 6 and 5, respectively ) If transducers 5 and 6 are placed on two opposite end faces 7 and 8 (see Fig. 1, b), it is advisable to use piezoelectric transducers of only different vibration modes (shear and longitudinal for transducers 5 and 6, respectively, or vice versa). Additional transducers OAV 9 and 10 together with PDG 4 form a control and measuring acoustic channel of the device. In this case, OAV piezoelectric transducers of the longitudinal oscillation mode were used as transducers 9 and 10, and, moreover, one of them (transducer 9 in Fig. 1, a, b) is made two-section with acoustically antiphase sections of the same aperture (in the particular case shown in Fig. .1, a, b, this is realized due to the electrically antiphase connection of the corresponding electrodes 9 ₁ , 9 ₂ and

two adjacent sections of a two-section converter 9). The transducers 9 and 10 are located on the side of the end faces 13, 14, orthogonal to the plane of the PDG 4, and placed in the working area of the movement of the PDG 4 with its complete overlap. An amplitude-phase detector 21 "is used as a control signal generating unit 21, which is electrically connected in series with a comparison element 21 'with a set point (" set point ").

 It should be noted that sound duct 1 can contain more than two bipolar domains separated by corresponding domain boundaries additional to PDG 4, however, the latter can only be located outside the working area of PDG 4 movement outside the aperture of the acoustic control and measuring channel (9 4 10) . In addition, we note that when placing the input 5 and output 6 converters on the side of one working end face 7 (see Fig. 1, a), the opposite face 8 is expedient to be made non-parallel to the first and provide it with a sound-absorbing coating 27 to reduce the level of false signals ( ULS). Note also that the specific circuitry of block 21 may differ from that shown in FIG. 1a, b (in particular, the comparison element 21 'can be made integrated into the circuit of the amplitude-phase detector 21 "). Finally, we note that the spectrum of acceptable materials for the implementation of immersion layers 11 and 12 is very diverse, although in practice most In cases, epoxy resins are usually used (without hardeners) Additionally, we note that the feedback circuit may also contain reinforced elements (not shown in Fig. 1, a, b), which serve to reduce the control error.

 Adjustable acoustoelectronic device operates as follows.

 When an input RF signal (informational) is applied to the electrical terminal 25 of the input transducer 5, the latter excites volumetric acoustic waves (longitudinal L or shear S, depending on the type of transducer 5), propagating in the sound duct 1 in the direction of the PDG 4. Upon reaching the PDG 4, the OAV interacts with it: partially reflected from the PDG and partially refracted on it, and also partially transform its mode composition, i.e., the L-mode waves are converted to S-mode waves or vice versa. OAW interacting with PDG 4 propagate further in the direction of the output transducer 6, on which they are converted into an electric radio-frequency output information signal, taken from the electric terminal 26 of the output transducer 6. In this case, the output electric signal is delayed relative to the input for a time determined by the length of the acoustic information channel (Converter 5 PDG 4 - Converter 6) and the speed of propagation of OAV in it (taking into account their possible differences in various sections of this acoustic channel). Thus, in particular, in the embodiment of the device shown in FIG. 1a, the formation of the output signal is carried out using the reflection effect emitted by the OAV converter 5 from the PDG 4, and in the constructive embodiment of the device shown in FIG. 1b, using the effect of the passage of OAV through PDG with the conversion of vibration modes on it.

Since it is known [3] that the most effective (in the energy sense) reflection of OAV from PDG with their normal incidence on PDG for shear (S) OVA, as well as for OAV reflected from PDG with the conversion of vibration modes (L to S or S to L ), then in the first constructive embodiment of the device (Fig. 1, a) the transducers 5 and 6 are either both of the shear vibration modes S (with a plane of displacements parallel to the Z-faces of the sound duct 1), or one of the transducers 5, 6 of the shear vibration modes S, and another longitudinal oscillation mode L. The time delay t of the output signal relates The input for the two indicated cases is determined by the relations, respectively:
t = (x ₁ + x ₂ ) / v _S and t = (x ₁ / v _L + x ₂ / v _S ) or t = (x ₁ / v _S + x ₂ / v _L ), (1)
where v _S and v _{L are the} velocities of the SAS of S- and L-modes of oscillations, respectively;
x ₁ and x _{2 are the} distances from the PDG from the input and from the PDG to the output converters, respectively.

Given that for this constructive version of the device (see Fig. 1, a) x ₁ ≃ x ₂ , relations (1) are converted to:
t = 2x ₁ / v _S and t = x ₁ (1 // v _L + 1 / v _S ) (1 *)
In the second constructive embodiment of the device (see Fig. 1, b) one transducer (5 or 6) of the shear mode of oscillation, and the other longitudinal, so the time delay t of the output information signal relative to the input is determined by the relations:
t = (x ₁ / V _L + x ₂ / V _S ) and t = (x ₁ / V _L + x ₂ / V _S ) or t = (x ₂ / v _L + x ₁ / v _S ), (2 )
where all the designations are identical to those specified above with the only addition that now (Fig. 1, b) the values of x ₁ and x ₂ are interconnected by the ratio: x ₁ + x ₂ = l, where l is the length of the sound duct 1. With this in mind, the ratio (2) are converted to:
t = l / v _S + x ₁ (1 // v _L + 1 / v _S ) or t = l / v _L + x ₁ (1 // v _S + 1 / v _L ) (2 *)
In the ratios (1 *) and (2 *), the quantities l, v _S, and v _L are fixed for the selected sizes of the sound duct, its material, and the direction of propagation of the OAB in it. Thus, the time delay t of the output information signal relative to the input in the inventive device is uniquely related to the location of the PDG 4 in the sound pipe, determined in particular by the distance x ₁ from the input transducer 5 to the PDG 4 along the acoustic information channel.

Как следует из соотношений (1**) и (2**), для первого конструктивного варианта устройства (фиг. 1, а) диапазон регулирования Δt определяемый величиной Δx₁ ограничен сверху лишь длиной звукопровода и может в несколько раз превышать номинальное значение временной задержки, т. е. может достигать сотен процентов. Для второго конструктивного варианта устройства (фиг. 1, б) из соотношений (1^**) и (2**) следует, что максимально возможный диапазон регулирования Δt_max ограничен относительной величиной разности скоростей V_L и V_S ОАВ (V_L-V_S)/V_L,S, которая для кристаллов, изоморфных молибдату гадолиния, составляет ≃14% в связи с чем максимальный реально достижимый диапазон регулирования составляет (10-12)% Отметим, что конкретная величина диапазона регулирования в заявляемом устройстве формируется соответствующим выбором размеров рабочей области перемещения ПДГ 4, которая, в свою очередь, определяется протяженностью управляющих электродов 15, 16 в направлении информационного акустического канала.In the presence of an adjustable source 19 at the output terminals 17 and 18, and therefore at the control electrodes 15 and 16, of a constant electric voltage, creating an electric field E in the area of the sound duct 1 under the electrodes 15, 16, exceeding the corresponding coercive value E ₀ in magnitude the force of the ferroelectric properties of the material of the sound duct 1 takes place its peripolarization, which, due to the ferroelastic nature of the material of the sound duct 1, is carried out by lateral displacement of the PDG 4 along the sound duct 1. This depends ing on the sign applied to the electrodes 15, 16 of the electric napryazheniyaprivodit to increase or decrease the distance x ₁ between the input transducer 5 and PDH 4 by an amount Δx ₁ and, consequently, a corresponding change in the time delay Δt values of t in the device:

As follows from the ratios (1 **) and (2 **), for the first constructive version of the device (Fig. 1, a) the control range Δt determined by the value Δx _{1 is} limited from above only by the length of the sound duct and can several times exceed the nominal value of the time delay , i.e., it can reach hundreds of percent. For the second constructive variant of the device (Fig. 1, b), from the relations (1 ^** ) and (2 **) it follows that the maximum possible control range Δt _{max is} limited by the relative value of the difference in speeds V _L and V _S ОАВ (V _L -V _S ) / V _{L, S} , which is ,14% for crystals isomorphic to gadolinium molybdate, and therefore the maximum achievable regulation range is (10-12)%. Note that the specific regulation range in the inventive device is formed by the appropriate choice of sizes working area moving PDG 4, which, in turn, is determined by the length of the control electrodes 15, 16 in the direction of the acoustic information channel.

The development of a given value of the change in the time delay Δt ^{* of the} information signal in the adjustable acoustoelectronic device is also carried out using the negative feedback circuit for changing the spatial position x PDG 4 in the sound pipe 1, which is uniquely associated with the corresponding values Δx ₁ and Δx ₂ In particular:
Δx = Δx ₁ = Δx ₂ for the embodiment in FIG. 1, a (3)
Δx = Δx ₁ = l-Δx ₂ for the embodiment in FIG. 1, b (4)
The feedback circuit is formed by a control and measuring circuit (24, 23, 9, 10, 22, 21, 20, 19, 18), in which a generator 24 of a reference sinusoidal signal of a fixed frequency together with an acoustic control and measuring channel (23, 9, 10 , 22) plays the role of the PDG 4 spatial position sensor in the working area of its movement: the control signal generating device 21 plays the role of the signal converter from the sensor (amplitude-phase detector 21 ") and the comparison element 21 ': the adjustable constant voltage source 19 will play the role The described feedback circuit performs automatic correction of the magnitude and sign of the constant electric voltage at the output terminals 17, 18 of the source 19, applied to the control electrodes 15, 16, which ensures the implementation of the required magnitude Δx of the offset of the PDG 4 to obtain a given value of the time delay t of the information signal .

 A characteristic feature of the functioning of the claimed device, due to the specifics of its design (its significant differences) in comparison with the prototype device, is the implementation of the process of generating a control signal supplied to the input 20 of an adjustable source 19.

) электрический выходной сигнал контрольно-измерительного канала, выделяемый на клемме 22, характеризуется кроме амплитудной модуляции в функции пространственного положения ПДГ 4 в рабочей области ее перемещения (см. фиг. 2, а пунктирная кривая) еще и противоположностью фазы (фазовой манипуляцией) для координат пространственного положения ПДГ 4 х≤ х₀ и х ≥ х₀, т. е. слева и справа от координаты х₀ центра рабочей области перемещения ПДГ 4 (см. фиг. 2, а, б, в). В результате детектирования такого сигнала амплитудно-фазовым детектором (АФД) 21" на выходе последнего имеет место постоянное электрическое напряжение, величина А₂ и знак которого однозначно связаны с координатой х пространственного положения ПДГ 4 в рабочей области ее перемещения (см. фиг.2, а сплошная кривая). Благодаря выбору одинаковой апертуры двух акустических противофазных секций (9₁, 9₂) и (

) преобразователя 9 электрический сигнал на выходе 20 АФД 21" для координаты х х₀ ПДГ 4 оказывается равным нулю и отличается знаком для областей координат ПДГ 4 x <х₀ n x > х₀. В результате, сигнал на выходе АФД 21" оказывается симметризированным по амплитуде и противоположным по знаку для координат ПДГ 4, равноудаленных от координаты х₀ центра рабочей области ее перемещения, что гарантирует воспроизводимость регулировочной характеристики устройства в целом. Последующее сравнение этого сигнала с уставкой, осуществляемое элементом сравнения 21', определяет на выходе 20 блока 21 необходимые величину и знак управляющего сигнала для регулируемого источника 19, постоянное электрическое напряжение соответствующей полярности с выходных клемм 17, 18 которого подается на управляющие электроды 15, 16 и обеспечивает требуемое смещение ПДГ 4 для реализации заданной величины временной задержки информационного сигнала устройства (см. фиг. 1, а, б).It is carried out as follows. Connected to the fixed-frequency reference sinusoidal signal generator 24, the input piezoelectric transducer 9 excites a volumetric acoustic wave (OAV), which, having passed through the immersion layer 11, propagates through the sound duct 1 in the entire working region of the PDG 4 movement in the direction parallel to the plane of the latter. After passing the sound pipe 1 and passing the second immersion layer 12, this OAB is converted by the output piezoelectric transducer 10 into an electrical signal, allocated at terminal 22. This signal carries information about the position of the PDG 4 in the working area of its movement. Indeed, its amplitude A ₁ turns out to be a parabolic function of the coordinate x of the position of the PDG 4 in the working area of its movement along the sound pipe 1, limited by the coordinates of the beginning x _n and end x _to this area, and the minimum value of A ₁ takes place at the coordinate x _{0 of the} PLG 4 corresponding to the middle of the indicated working area of its movement (see Fig. 2, and the dashed curve). Referring to FIG. 2, and the dashed curve is a typical experimental dependence of A ₁ on x, the nature of which is partially explained in FIG. 2, b, c, where the geometry of the control and measuring acoustic channel of the device is shown schematically (transducer 9 immersion layer 11 sound duct 1 - immersion layer 12 transducer 10) for two different coordinates x- and x + PDG 4. FIG. 2b, c illustrate the well-known fact that the difference in the signs of spontaneous deformation of neighboring domains 2 and 3 of the ferroelastic material of sound duct 1 is the cause of a specific macrodeformation of sound duct 1, the shape of which is uniquely determined by the location of PDG 4 separating neighboring domains 2 and 3. It is for this reason the acoustic contact of the transducers 9 and 10 with the sound duct 1 is made using immersion layers 11 and 12, which, on the one hand, ensure that the sound duct 1 accompanied by macro-deformation the natural movement of the PDG 4 along it, and on the other hand, provides the possibility of reliable acoustic contact of the transducers 9, 10 with the sound duct 1 when the shape of macrodeformation changes. In this case, OAV transducers of the longitudinal vibrational mode are used as transducers 9, 10, since it is this OAV mode that can propagate in liquids (immersion layers). As follows from FIG. 2, b, c, the worst conditions for acoustic matching of transducers 9, 10 with sound duct 1 take place when the PDG 4 is placed in the center (coordinate x ₀ ) of its working displacement area (x _to x _n ), which corresponds to the minimum of the dashed curve in FIG. 2 a. It should be noted that due to the implementation of the piezoelectric transducer 9 two-section with acoustically antiphase sections (9 ₁ , 9 ₂ ) and (

) the electrical output signal of the control channel, allocated at terminal 22, is characterized in addition to amplitude modulation as a function of the spatial position of the PDG 4 in the working area of its movement (see Fig. 2, and the dashed curve) also the opposite of phase (phase shift keying) for coordinates the spatial position of the PDG 4 x≤ x ₀ and x ≥ x ₀ , i.e., to the left and to the right of the coordinate x _{0 of the} center of the working area of the movement of the PDG 4 (see Fig. 2, a, b, c). As a result of the detection of such a signal by an amplitude-phase detector (AFD) 21 "at the output of the latter there is a constant electric voltage, the value of A ₂ and the sign of which is uniquely associated with the coordinate x of the spatial position of the PDG 4 in the working area of its movement (see figure 2, and a solid curve.) By choosing the same aperture of the two acoustic antiphase sections (9 ₁ , 9 ₂ ) and (

) of the converter 9, the electric signal at the output 20 of the APD 21 "for the coordinate x x _{0 of the} PDG 4 turns out to be zero and differs in sign for the coordinate areas of the PDG 4 x <x ₀ nx> x _0. As a result, the signal at the output of the AFD 21" is symmetrical in the amplitude and opposite in sign for the coordinates of the PDG 4, equidistant from the coordinate x _{0 of the} center of the working area of its movement, which ensures reproducibility of the adjustment characteristics of the device as a whole. Subsequent comparison of this signal with the setpoint carried out by the comparison element 21 'determines at the output 20 of block 21 the necessary magnitude and sign of the control signal for the regulated source 19, a constant voltage of the corresponding polarity from the output terminals 17, 18 of which is supplied to the control electrodes 15, 16 and provides the required offset PDG 4 to implement a given value of the time delay of the information signal of the device (see Fig. 1, a, b).

 Due to the described embodiment of the spatial position sensor of the PDG 4 in the sound pipe 1 (24, 23, 9, 11, 1, 12, 10, 22), it is possible to measure the location of the PDG 4 in the entire maximum achievable range of its movement, limited only by the size of the sound pipe, and as a result , in the entire maximum achievable range of regulation of the informative parameter of the information signal of the device. The high accuracy of regulation of the value of the informative parameter is guaranteed, as in the prototype device, by using a negative feedback circuit for the location of the PDG 4 in the sound duct 1. Moreover, due to the described embodiment of the control signal generating unit 21, the control characteristics of the device are unambiguous and reproducible throughout the range of regulation of its informative parameter, reaching, as noted above, tens and hundreds of percent.

So, in the inventive adjustable acoustoelectronic device, due to the described implementation of the control and measuring channel, including the PDG spatial position sensor in the sound pipe and the control signal generating device, it is possible to accurately control the time delay of the information signal (due to the use of the negative feedback circuit for the location of the PDG) in a significantly expanded range of regulation, reaching tens and hundreds of percent. In practical laboratory models of the inventive adjustable acoustoelectronic device (in particular, RULZ OAV), constructed according to the schemes of FIG. 1a and 1b, the ranges of tuning the delay time of 200% and 12%, respectively, were achieved with a control accuracy of 0.1%
Sources of information:
1. Alekseev A.N.// Proceedings of the USSR Academy of Sciences. The series is physical. 1989, v. 53, N7, pp. 1424-1433.

 2. Applied Physics Letters; vol. 30, N10, 05.15.77, p.506-508, prototype.

 3. Alekseev A. N. Zlokazov M.V. Osipov I.V. // Proceedings of the USSR Academy of Sciences. The series is physical. 1982, vol. 47, N3, pp. 465-475.

Claims (1)

 An adjustable acoustoelectronic device containing a piezoelectric sound guide made of a polydomain single crystal ferroelastic ferroelectric isomorphic to gadolinium molybdate, in the form of a Z-slice plate containing at least two different-polarity domains separated by a flat domain wall, the main input and output wave volume transducers in acoustic contact with the sound duct and located on its one or two opposite working end faces, perpendicular to Z - to the edges of the sound duct, and forming together with the flat domain wall an acoustic information channel, control electrodes located on two opposite Z-faces of the sound duct in the working area of the flat domain wall displacement and connected to the output of an adjustable source of constant electric voltage, characterized in that additional input and output transducers of volumetric acoustic waves, also in acoustic contact with the sound duct, located in the working area moving the flat domain wall with its complete overlap on the side of two opposite end faces of the sound duct, orthogonal to the Z faces and the working end faces, and forming a control and measuring acoustic channel, a sinusoidal signal generator, the output of which is connected to the input additional transducer of volumetric acoustic waves, and a control signal generating unit connected between an input of an adjustable source of constant electric voltage and an output additional converter the volume of acoustic waves, in this case, piezoelectric transducers of volumetric acoustic waves of the longitudinal vibration mode are used as transducers of volumetric acoustic waves of the control and measuring acoustic channel, the input of them is made two-section with acoustically antiphase sections of the same aperture, and the acoustic contact of these transducers with the sound duct is made using immersion layer, and as the control signal generation unit, amplitudes were used tudno-phase detector with a comparison element with a setting.

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