- Email: [email protected]
Composite lateral electric field excited piezoelectric resonator
Accepted Manuscript Composite Lateral Electric Field Excited Piezoelectric Resonator B.D. Zaitsev, A.M. Shikhabudinov, I.A. Borodina, A.A. Teplykh, I.E. Kuznetsova PII: DOI: Reference:
S0041-624X(16)30155-X http://dx.doi.org/10.1016/j.ultras.2016.08.022 ULTRAS 5362
To appear in:
Ultrasonics
Received Date: Revised Date: Accepted Date:
27 May 2016 26 August 2016 29 August 2016
Please cite this article as: B.D. Zaitsev, A.M. Shikhabudinov, I.A. Borodina, A.A. Teplykh, I.E. Kuznetsova, Composite Lateral Electric Field Excited Piezoelectric Resonator, Ultrasonics (2016), doi: http://dx.doi.org/ 10.1016/j.ultras.2016.08.022
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Composite Lateral Electric Field Excited Piezoelectric Resonator B.D. Zaitsev1, A.M. Shikhabudinov1, I.A. Borodina1, A.A. Teplykh1, I.E. Kuznetsova2 1
Kotel’nikov Institute of Radio Engineering and Electronics of RAS, Saratov Branch, Saratov, 410019, Russia
2
Kotel’nikov Institute of Radio Engineering and Electronics of RAS, Moscow, 125009, Russia e-mail: [email protected]
Abstract. The novel method of suppression of parasitic oscillations in lateral electric field excited piezoelectric resonator is suggested. Traditionally such resonator represents the piezoelectric plate with two electrodes on one side of the plate. The crystallographic orientation of the plate is selected so that the tangential components of electric field excite bulk acoustic wave with given polarization travelling along the normal to the plate sides. However at that the normal components of field excite the parasitic Lamb waves and bulk waves of other polarization which deteriorate the resonant properties of the resonator. In this work we suggest to separate the source of the HF electric field and resounded piezoelectric plate by air gap. In this case the tangential components of the field in piezoelectric plate do not practically weaken but normal components significantly decrease. This method is realized on the composite resonator having the structure “glass plate with rectangular electrodes – air gap – plate of 128 Y X lithium niobate.” It has been shown that there exist the optimal value of the width gap which ensure the good quality of series and parallel resonances in frequency range 3-4 MHz with record values of Q – factor of ~15000 in both cases.
1. Introduction In last years the great attention of researchers is attracted by lateral electric field excited piezoelectric resonators [1-12]. This interest is connected with the fact that acoustic liquid sensors based of aforementioned resonators have some advantages in comparison with 1
resonators with longitudinal electric field. They are the following: (1) at the contact of the resonator with liquids its parameters react on change in mechanical and electrical properties of liquid and (2) there is no the contact of the electrodes with liquid under study. Such properties of these resonators are very useful for development of various biological and liquid sensors for express analysis of liquids of small volumes. But in spite of great amount of papers the problem of suppression of parasitic oscillations and increasing the value of Qfactor of these resonators is as usual urgent. The traditional methods of suppression of such oscillations suppose the proper choice of the shape of the electrodes. Usually electrodes have the shape of half moons [1-9], however, their sizes depend on crystallographic orientation of plate and its shear dimensions. Previously one more method of suppression of unwanted oscillations in lateral electric field excited piezoelectric resonators with electrodes of rectangular form was suggested [10]. In accordance with this method the area around the electrodes and partially electrodes were covered by damping layer. This method has been successfully realized on the plate of lithium niobate of X – cut for which the electric field oriented along Y – axis excites the longitudinal acoustic wave resounding between sides of plate. It has been shown that by changing the width of coating and gap between electrodes one can change Q – factor in wide range for parallel and series resonances [11]. However for some cases especially for development of liquid sensors the shear acoustic wave is more preferable due to the absence of the radiation loss. This paper is devoted to the development of high – quality lateral electric field excited piezoelectric resonator with shear acoustic wave. 2. Resonator with damping layer Theoretical analysis in accordance with formalism of Christoffel-Bechman [13] showed that for the plate of 128 Y- X lithium niobate for orientation of electric field along X – axis the electromechanical coupling coefficient for shear wave with polarization along X – axis
2
and propagating along the normal to the plate is equal 85%. This coefficient for other bulk waves propagating along the same direction is equal zero. In accordance with this analysis the experiment for development of the lateral electric field excited resonator on the plate of 128 Y-X lithium niobate was carried out. Two aluminum electrodes of rectangular shape with dimensions 5×10 mm2 and gap between them of 2 mm were deposited on the surface of lithium niobate plate. The position of electrodes ensures the orientation of electric field along X – axis. Then in accordance with procedure described in [11] the area around electrodes was covered by the damping layer and the real and imaginary parts of the electrical impedance of the resonator were measured. Then electrodes little by little were covered by strips of damping layer with width of ~0.5 mm until all surfaces of electrodes were totally covered (Fig. 1). For each step the measurement were repeated. However at all cases the main resonance was accompanied by parasitic oscillations which did not allow to estimate Q – factor. Fig. 2 shows the best frequency dependencies of real and imaginary parts of electrical impedance for width of electrodes covering of 3 mm. Theoretical estimations have shown that the sources of parasitic oscillations are Lamb waves and bulk shear waves of other polarization which are excited by normal to plate components of electric field under the electrodes. 3. Composite resonator based on dielectric and piezoelectric plates In order to weaken the influence of the pointed normal components of electric field we suggested the structure consisting of two plates [14]. This structure is presented in Fig. 3. The lower plate 1 is the holder of two rectangular electrodes having shear dimensions 5×10 mm2 and gap between them of 2 mm which contact with HF source of voltage and produce exciting electric field. This plate was made of nonpiezoelectric material (glass) with thickness of 0.5 mm. The upper plate 2 made of 128 Y-X lithium niobate without electrodes is placed near the plate 1 with the gap d. The lateral electric field was oriented along the X – axis. It is obviously that the lateral components of electric field in the upper plate have the maximum
3
amplitude due to continuity of the tangential components on the interface of two dielectrics [15]. At that the normal components endure discontinuity and their intensity in upper plate significantly weakens. The frequency dependencies of real and imaginary parts of electrical impedance were measured for the gap between plates changing from 0 to 0.5 mm. Figs. 4 and 5 show the frequency dependencies of the real and imaginary parts of electrical impedance and admittance, respectively, for composite resonator for different values of the width of gap between plates. From Fig. 4 one can see that in all cases with the exception of values of the gap width of 20 and 200 µm there exists clearly expressed parallel resonance without parasitic oscillations. At that the values of Q – factor lie in the range of 14000 – 17000. As for series resonance, Fig. 5 shows that clearly expressed resonance of classic shape exists only for values of gap width of ~20 and 100 µm. In other cases the series resonance is accompanied by nearly situated parasitic modes. Therefore, the pure parallel and series resonances exist only for value of width of the gap of ~100 µm. At that the resonator is characterized by high value of Q – factor of ~15000 in both cases with effective electromechanical coupling coefficient of ~ 2% [14]. It should be noted that the maximum values of Q – factor for parallel and series resonances obtained previously [11] on the longitudinal wave in plate of lithium niobate of X – cut are equal ~1800 and 13000, respectively. So the suggested structure of composite lateral electric field excited piezoelectric resonator allowed to reach the record values of Q – factor of parallel and series resonances. 4. Conclusion The main problem in development of lateral electric field excited piezoelectric resonators is the suppression of parasitic oscillations and increase of the value of Q-factor. The basic sources of parasitic oscillations are normal to plate components of electric field that generate unwanted Lamb and bulk acoustic waves. In this work we suggest to separate the source of the HF electric field and resounded piezoelectric plate by air gap. In this case useful
4
tangential components of the field in piezoelectric plate do not practically weaken but unwanted normal components significantly decrease. This method is realized on the composite resonator having the structure “glass plate with rectangular electrodes – air gap – plate of 128 Y - X lithium niobate.” It has been shown that there exist the optimal value of the width gap which ensure the good quality of series and parallel resonances in frequency range 3-4 MHz with record values of Q – factor of ~15000 in both cases with effective electromechanical coupling coefficient of ~ 2%. The suggested composite lateral electric field excited piezoelectric resonator may be used for development of various liquid and biological sensors operating on shear acoustic wave without radiation attenuation at the contact with liquid. Moreover such resonators may be useful in devices for signal processing which are based on resonant components with high values of Q – factor. Acknowledgments The work is financially supported by the grant of Russian Foundation of Basic Research № 16-07-00821.
5
References [1] J.M. McCann, K. Sgambato, D.F. McCann, and J. Vetelino, Acoustic mode behavior in lateral field excited sensors, in: Proc. IEEE Int. Ultrason. Symp., 2009, pp.645 -648. [2] T.G. Leblois and C.R. Tellier, Design of new lateral field excitation langasite resonant sensors, in: Proc. IEEE Int. Ultrason. Symp., 2009, pp. 2672-2675. [3] J.C.Andle, R.Haskell, M.Chap, and D. Stevens, Improved substrate selection for lateral field TSM sensors, in: Proc. IEEE Int. Ultrason. Symp., 2009, pp. 649-654. [4] D. F. McCann, J.M. McCann, J.M. Parks, D.J. Frankel, M. Rereira da Cunha, and J.F. Vetelino, A lateral-field-excited LiTaO3 high frequency bulk acoustic wave sensor, IEEE Trans. Ultrason. Ferroelectr. Freq. Contr. 56 (2009) 779-787. [5] Z. Zhang, W.Wang, T. Ma, C.Zhang, and G.Feng, Pseudo-LFE sensors with different electrode configurations on X-cut LiNbO3, in: Proc. IEEE Int. Ultrason. Symp., 2009, pp. 655-658. [6] C. Zuo, J. Van der Spiegel, and G. Piazza, 1.05-GHz CMOS oscillator based on lateralfield-excited piezoelectric AlN contour-mode MEMS resonators, IEEE Trans. Ultrason. Ferroelectr. Freq. Contr. 57 (2010) 82-87. [7] U. Hempel, R. Lucklum, P.R. Hauptmann, E.P. EerNisse, D.Puccio and R. Fernandez Diaz, Quarts crystal resonator sensor under lateral field excitation - a theoretical and experimental analysis, Measurement Science and Technology. 19 (2008) 1-11. [8] J.F. Vetelino, A lateral field excited acoustic wave sensor platform in: Proc. IEEE Int. Ultrason. Symp., 2010, pp. 2269 -2272. [9] T. Ma, J. Wang, J.Du, and J. Yang, Resonances and energy trapping in AT-cut quartz resonators operating with fast shear modes driven by lateral electric fields produced by surface electrodes, Ultrasonics. 50 (2015) 14-20.
6
[10] B.D. Zaitsev, I. E. Kuznetsova, A.M. Shikhabudinov, and A.A. Vasil’ev, New method of parasitic mode suppression in lateral-field-excited piezoelectric resonator, Tech. Phys. Lett. 37 (2011) 473-476. [11] B.D. Zaitsev, I.E. Kuznetsova, A.M. Shikhabudinov, A.A. Teplykh, and Borodina I.A., The study of piezoelectric lateral-electric-field-excited resonator, IEEE Trans. Ultrason. Ferroelectr. Freq. Contr. 61 (2014) 166-172. [12] B.D. Zaitsev, A.M. Shikhabudinov, A.A. Teplykh, and I.E. Kuznetsova, Liquid sensor basedon on piezoelectric lateral electric field-excited resonator, Ultrasonics. 63 (2015) 179-183. [13] A. Ballato, Extended Christoffel-Bechmann elastic wave formalism for piezoelectric, dielectric media, in: Proc. IEEE/EIA Int. Freq. Contr. Symp. and Exhibition, 2000, pp. 340-344. [14] B. Zaitsev, A. Shikhabudinov, I. Borodina, A. Teplykh, and I. Kuznetsova, Composite lateral electric field excited piezoelectric resonator, in: Proc. IEEE Int. Ultrason. Symp., 2015, pp.1 - 4, DOI: 10.1109/ULTSYMP.2015.350. [15] I.E. Tamm, Fundamentals of the Theory of Electricity, Moscow, Mir Publisher, 1979.
7
Figure captions Fig. 1. The scheme of the lateral electric field excited resonator with damping layer: 1 – piezoelectric plate, 2 – electrodes, 3 – damping layer. Fig. 2. The best frequency dependencies of real (a) and imaginary (b) parts of the electrical impedance of the lateral electric field excited resonator based on 128 YX lithium niobate plate with thickness of 0.5 mm with two rectangular electrodes with shear dimensions of 5×10 mm2 and width of gap between them of 2 mm. The width of area of electrodes which is covered by damping layer is equal 3 mm. Fig. 3. The scheme of the composite lateral electric field excited resonator: 1 – lower plate, 2 – electrodes, 3 – supports for keeping the given value of width of gap, 4 – upper resounding plate. Fig. 4. The frequency dependencies of real (left column) and imaginary (right column) parts of the electrical impedance of the composite lateral electric field excited resonator based on 128 YX lithium niobate plate. The width of gap between plates is equal 20 µm (a), 100 µm (b), 200 µm (c), 300 µm (d), and 500 µm (e). Fig. 5. The frequency dependencies of real (left column) and imaginary (right column) parts of the electrical admittance of the composite lateral electric field excited resonator based on 128 YX lithium niobate plate. The width of gap between plates is equal 20 µm (a), 100 µm (b), 200 µm (c), 300 µm (d), and 500 µm (e).
8
Figure 1.
1
(a)
2 3 2 3
(b)
9
160 140 120 100 80 60 40 20 0
40 20 0 X , kΩ
R , kΩ
Figure 2.
-20 -40 -60 -80 -100 -120
1
2
3
4 5 f , MHz
6
7
8
1
2
3
4 5 f , MHz
6
7
8
10
Figure 3.
4 3
d
1
2
11
Figure 4
12
Figure 5
13
Highlights 1. 2. 3. 4. 5.
Novel design of lateral electric field excited piezoelectric resonator is offered New method of suppression of parasitic oscillations in such resonators is invented Separation of electrodes holder and piezoelectric plate suppresses parasitic modes For composite resonator Q-factor for series/parallel resonances is equal to 15000 Composite resonator is easy-to-development of liquid sensor without radiation loss
14
S0041-624X(16)30155-X http://dx.doi.org/10.1016/j.ultras.2016.08.022 ULTRAS 5362
To appear in:
Ultrasonics
Received Date: Revised Date: Accepted Date:
27 May 2016 26 August 2016 29 August 2016
Please cite this article as: B.D. Zaitsev, A.M. Shikhabudinov, I.A. Borodina, A.A. Teplykh, I.E. Kuznetsova, Composite Lateral Electric Field Excited Piezoelectric Resonator, Ultrasonics (2016), doi: http://dx.doi.org/ 10.1016/j.ultras.2016.08.022
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Composite Lateral Electric Field Excited Piezoelectric Resonator B.D. Zaitsev1, A.M. Shikhabudinov1, I.A. Borodina1, A.A. Teplykh1, I.E. Kuznetsova2 1
Kotel’nikov Institute of Radio Engineering and Electronics of RAS, Saratov Branch, Saratov, 410019, Russia
2
Kotel’nikov Institute of Radio Engineering and Electronics of RAS, Moscow, 125009, Russia e-mail: [email protected]
Abstract. The novel method of suppression of parasitic oscillations in lateral electric field excited piezoelectric resonator is suggested. Traditionally such resonator represents the piezoelectric plate with two electrodes on one side of the plate. The crystallographic orientation of the plate is selected so that the tangential components of electric field excite bulk acoustic wave with given polarization travelling along the normal to the plate sides. However at that the normal components of field excite the parasitic Lamb waves and bulk waves of other polarization which deteriorate the resonant properties of the resonator. In this work we suggest to separate the source of the HF electric field and resounded piezoelectric plate by air gap. In this case the tangential components of the field in piezoelectric plate do not practically weaken but normal components significantly decrease. This method is realized on the composite resonator having the structure “glass plate with rectangular electrodes – air gap – plate of 128 Y X lithium niobate.” It has been shown that there exist the optimal value of the width gap which ensure the good quality of series and parallel resonances in frequency range 3-4 MHz with record values of Q – factor of ~15000 in both cases.
1. Introduction In last years the great attention of researchers is attracted by lateral electric field excited piezoelectric resonators [1-12]. This interest is connected with the fact that acoustic liquid sensors based of aforementioned resonators have some advantages in comparison with 1
resonators with longitudinal electric field. They are the following: (1) at the contact of the resonator with liquids its parameters react on change in mechanical and electrical properties of liquid and (2) there is no the contact of the electrodes with liquid under study. Such properties of these resonators are very useful for development of various biological and liquid sensors for express analysis of liquids of small volumes. But in spite of great amount of papers the problem of suppression of parasitic oscillations and increasing the value of Qfactor of these resonators is as usual urgent. The traditional methods of suppression of such oscillations suppose the proper choice of the shape of the electrodes. Usually electrodes have the shape of half moons [1-9], however, their sizes depend on crystallographic orientation of plate and its shear dimensions. Previously one more method of suppression of unwanted oscillations in lateral electric field excited piezoelectric resonators with electrodes of rectangular form was suggested [10]. In accordance with this method the area around the electrodes and partially electrodes were covered by damping layer. This method has been successfully realized on the plate of lithium niobate of X – cut for which the electric field oriented along Y – axis excites the longitudinal acoustic wave resounding between sides of plate. It has been shown that by changing the width of coating and gap between electrodes one can change Q – factor in wide range for parallel and series resonances [11]. However for some cases especially for development of liquid sensors the shear acoustic wave is more preferable due to the absence of the radiation loss. This paper is devoted to the development of high – quality lateral electric field excited piezoelectric resonator with shear acoustic wave. 2. Resonator with damping layer Theoretical analysis in accordance with formalism of Christoffel-Bechman [13] showed that for the plate of 128 Y- X lithium niobate for orientation of electric field along X – axis the electromechanical coupling coefficient for shear wave with polarization along X – axis
2
and propagating along the normal to the plate is equal 85%. This coefficient for other bulk waves propagating along the same direction is equal zero. In accordance with this analysis the experiment for development of the lateral electric field excited resonator on the plate of 128 Y-X lithium niobate was carried out. Two aluminum electrodes of rectangular shape with dimensions 5×10 mm2 and gap between them of 2 mm were deposited on the surface of lithium niobate plate. The position of electrodes ensures the orientation of electric field along X – axis. Then in accordance with procedure described in [11] the area around electrodes was covered by the damping layer and the real and imaginary parts of the electrical impedance of the resonator were measured. Then electrodes little by little were covered by strips of damping layer with width of ~0.5 mm until all surfaces of electrodes were totally covered (Fig. 1). For each step the measurement were repeated. However at all cases the main resonance was accompanied by parasitic oscillations which did not allow to estimate Q – factor. Fig. 2 shows the best frequency dependencies of real and imaginary parts of electrical impedance for width of electrodes covering of 3 mm. Theoretical estimations have shown that the sources of parasitic oscillations are Lamb waves and bulk shear waves of other polarization which are excited by normal to plate components of electric field under the electrodes. 3. Composite resonator based on dielectric and piezoelectric plates In order to weaken the influence of the pointed normal components of electric field we suggested the structure consisting of two plates [14]. This structure is presented in Fig. 3. The lower plate 1 is the holder of two rectangular electrodes having shear dimensions 5×10 mm2 and gap between them of 2 mm which contact with HF source of voltage and produce exciting electric field. This plate was made of nonpiezoelectric material (glass) with thickness of 0.5 mm. The upper plate 2 made of 128 Y-X lithium niobate without electrodes is placed near the plate 1 with the gap d. The lateral electric field was oriented along the X – axis. It is obviously that the lateral components of electric field in the upper plate have the maximum
3
amplitude due to continuity of the tangential components on the interface of two dielectrics [15]. At that the normal components endure discontinuity and their intensity in upper plate significantly weakens. The frequency dependencies of real and imaginary parts of electrical impedance were measured for the gap between plates changing from 0 to 0.5 mm. Figs. 4 and 5 show the frequency dependencies of the real and imaginary parts of electrical impedance and admittance, respectively, for composite resonator for different values of the width of gap between plates. From Fig. 4 one can see that in all cases with the exception of values of the gap width of 20 and 200 µm there exists clearly expressed parallel resonance without parasitic oscillations. At that the values of Q – factor lie in the range of 14000 – 17000. As for series resonance, Fig. 5 shows that clearly expressed resonance of classic shape exists only for values of gap width of ~20 and 100 µm. In other cases the series resonance is accompanied by nearly situated parasitic modes. Therefore, the pure parallel and series resonances exist only for value of width of the gap of ~100 µm. At that the resonator is characterized by high value of Q – factor of ~15000 in both cases with effective electromechanical coupling coefficient of ~ 2% [14]. It should be noted that the maximum values of Q – factor for parallel and series resonances obtained previously [11] on the longitudinal wave in plate of lithium niobate of X – cut are equal ~1800 and 13000, respectively. So the suggested structure of composite lateral electric field excited piezoelectric resonator allowed to reach the record values of Q – factor of parallel and series resonances. 4. Conclusion The main problem in development of lateral electric field excited piezoelectric resonators is the suppression of parasitic oscillations and increase of the value of Q-factor. The basic sources of parasitic oscillations are normal to plate components of electric field that generate unwanted Lamb and bulk acoustic waves. In this work we suggest to separate the source of the HF electric field and resounded piezoelectric plate by air gap. In this case useful
4
tangential components of the field in piezoelectric plate do not practically weaken but unwanted normal components significantly decrease. This method is realized on the composite resonator having the structure “glass plate with rectangular electrodes – air gap – plate of 128 Y - X lithium niobate.” It has been shown that there exist the optimal value of the width gap which ensure the good quality of series and parallel resonances in frequency range 3-4 MHz with record values of Q – factor of ~15000 in both cases with effective electromechanical coupling coefficient of ~ 2%. The suggested composite lateral electric field excited piezoelectric resonator may be used for development of various liquid and biological sensors operating on shear acoustic wave without radiation attenuation at the contact with liquid. Moreover such resonators may be useful in devices for signal processing which are based on resonant components with high values of Q – factor. Acknowledgments The work is financially supported by the grant of Russian Foundation of Basic Research № 16-07-00821.
5
References [1] J.M. McCann, K. Sgambato, D.F. McCann, and J. Vetelino, Acoustic mode behavior in lateral field excited sensors, in: Proc. IEEE Int. Ultrason. Symp., 2009, pp.645 -648. [2] T.G. Leblois and C.R. Tellier, Design of new lateral field excitation langasite resonant sensors, in: Proc. IEEE Int. Ultrason. Symp., 2009, pp. 2672-2675. [3] J.C.Andle, R.Haskell, M.Chap, and D. Stevens, Improved substrate selection for lateral field TSM sensors, in: Proc. IEEE Int. Ultrason. Symp., 2009, pp. 649-654. [4] D. F. McCann, J.M. McCann, J.M. Parks, D.J. Frankel, M. Rereira da Cunha, and J.F. Vetelino, A lateral-field-excited LiTaO3 high frequency bulk acoustic wave sensor, IEEE Trans. Ultrason. Ferroelectr. Freq. Contr. 56 (2009) 779-787. [5] Z. Zhang, W.Wang, T. Ma, C.Zhang, and G.Feng, Pseudo-LFE sensors with different electrode configurations on X-cut LiNbO3, in: Proc. IEEE Int. Ultrason. Symp., 2009, pp. 655-658. [6] C. Zuo, J. Van der Spiegel, and G. Piazza, 1.05-GHz CMOS oscillator based on lateralfield-excited piezoelectric AlN contour-mode MEMS resonators, IEEE Trans. Ultrason. Ferroelectr. Freq. Contr. 57 (2010) 82-87. [7] U. Hempel, R. Lucklum, P.R. Hauptmann, E.P. EerNisse, D.Puccio and R. Fernandez Diaz, Quarts crystal resonator sensor under lateral field excitation - a theoretical and experimental analysis, Measurement Science and Technology. 19 (2008) 1-11. [8] J.F. Vetelino, A lateral field excited acoustic wave sensor platform in: Proc. IEEE Int. Ultrason. Symp., 2010, pp. 2269 -2272. [9] T. Ma, J. Wang, J.Du, and J. Yang, Resonances and energy trapping in AT-cut quartz resonators operating with fast shear modes driven by lateral electric fields produced by surface electrodes, Ultrasonics. 50 (2015) 14-20.
6
[10] B.D. Zaitsev, I. E. Kuznetsova, A.M. Shikhabudinov, and A.A. Vasil’ev, New method of parasitic mode suppression in lateral-field-excited piezoelectric resonator, Tech. Phys. Lett. 37 (2011) 473-476. [11] B.D. Zaitsev, I.E. Kuznetsova, A.M. Shikhabudinov, A.A. Teplykh, and Borodina I.A., The study of piezoelectric lateral-electric-field-excited resonator, IEEE Trans. Ultrason. Ferroelectr. Freq. Contr. 61 (2014) 166-172. [12] B.D. Zaitsev, A.M. Shikhabudinov, A.A. Teplykh, and I.E. Kuznetsova, Liquid sensor basedon on piezoelectric lateral electric field-excited resonator, Ultrasonics. 63 (2015) 179-183. [13] A. Ballato, Extended Christoffel-Bechmann elastic wave formalism for piezoelectric, dielectric media, in: Proc. IEEE/EIA Int. Freq. Contr. Symp. and Exhibition, 2000, pp. 340-344. [14] B. Zaitsev, A. Shikhabudinov, I. Borodina, A. Teplykh, and I. Kuznetsova, Composite lateral electric field excited piezoelectric resonator, in: Proc. IEEE Int. Ultrason. Symp., 2015, pp.1 - 4, DOI: 10.1109/ULTSYMP.2015.350. [15] I.E. Tamm, Fundamentals of the Theory of Electricity, Moscow, Mir Publisher, 1979.
7
Figure captions Fig. 1. The scheme of the lateral electric field excited resonator with damping layer: 1 – piezoelectric plate, 2 – electrodes, 3 – damping layer. Fig. 2. The best frequency dependencies of real (a) and imaginary (b) parts of the electrical impedance of the lateral electric field excited resonator based on 128 YX lithium niobate plate with thickness of 0.5 mm with two rectangular electrodes with shear dimensions of 5×10 mm2 and width of gap between them of 2 mm. The width of area of electrodes which is covered by damping layer is equal 3 mm. Fig. 3. The scheme of the composite lateral electric field excited resonator: 1 – lower plate, 2 – electrodes, 3 – supports for keeping the given value of width of gap, 4 – upper resounding plate. Fig. 4. The frequency dependencies of real (left column) and imaginary (right column) parts of the electrical impedance of the composite lateral electric field excited resonator based on 128 YX lithium niobate plate. The width of gap between plates is equal 20 µm (a), 100 µm (b), 200 µm (c), 300 µm (d), and 500 µm (e). Fig. 5. The frequency dependencies of real (left column) and imaginary (right column) parts of the electrical admittance of the composite lateral electric field excited resonator based on 128 YX lithium niobate plate. The width of gap between plates is equal 20 µm (a), 100 µm (b), 200 µm (c), 300 µm (d), and 500 µm (e).
8
Figure 1.
1
(a)
2 3 2 3
(b)
9
160 140 120 100 80 60 40 20 0
40 20 0 X , kΩ
R , kΩ
Figure 2.
-20 -40 -60 -80 -100 -120
1
2
3
4 5 f , MHz
6
7
8
1
2
3
4 5 f , MHz
6
7
8
10
Figure 3.
4 3
d
1
2
11
Figure 4
12
Figure 5
13
Highlights 1. 2. 3. 4. 5.
Novel design of lateral electric field excited piezoelectric resonator is offered New method of suppression of parasitic oscillations in such resonators is invented Separation of electrodes holder and piezoelectric plate suppresses parasitic modes For composite resonator Q-factor for series/parallel resonances is equal to 15000 Composite resonator is easy-to-development of liquid sensor without radiation loss
14