US20150290680A1 - Cost effective broadband transducer assembly and method of use - Google Patents
Cost effective broadband transducer assembly and method of use Download PDFInfo
- Publication number
- US20150290680A1 US20150290680A1 US14/687,659 US201514687659A US2015290680A1 US 20150290680 A1 US20150290680 A1 US 20150290680A1 US 201514687659 A US201514687659 A US 201514687659A US 2015290680 A1 US2015290680 A1 US 2015290680A1
- Authority
- US
- United States
- Prior art keywords
- acoustic structure
- transducer element
- transducer
- sufficiently thin
- transducer assembly
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 27
- 239000000463 material Substances 0.000 claims description 50
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 23
- -1 polyethylene Polymers 0.000 claims description 15
- 239000004676 acrylonitrile butadiene styrene Substances 0.000 claims description 11
- 229920000122 acrylonitrile butadiene styrene Polymers 0.000 claims description 10
- XECAHXYUAAWDEL-UHFFFAOYSA-N acrylonitrile butadiene styrene Chemical compound C=CC=C.C=CC#N.C=CC1=CC=CC=C1 XECAHXYUAAWDEL-UHFFFAOYSA-N 0.000 claims description 9
- 238000002955 isolation Methods 0.000 claims description 8
- 229920004943 Delrin® Polymers 0.000 claims description 7
- 239000004677 Nylon Substances 0.000 claims description 7
- 239000004698 Polyethylene Substances 0.000 claims description 7
- 239000004743 Polypropylene Substances 0.000 claims description 7
- 239000004793 Polystyrene Substances 0.000 claims description 7
- 229920004738 ULTEM® Polymers 0.000 claims description 7
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims description 7
- 229920001778 nylon Polymers 0.000 claims description 7
- 239000004417 polycarbonate Substances 0.000 claims description 7
- 229920000515 polycarbonate Polymers 0.000 claims description 7
- 229920000573 polyethylene Polymers 0.000 claims description 7
- 229920001155 polypropylene Polymers 0.000 claims description 7
- 229920002223 polystyrene Polymers 0.000 claims description 7
- 229920000915 polyvinyl chloride Polymers 0.000 claims description 7
- 239000004800 polyvinyl chloride Substances 0.000 claims description 7
- 229920001567 vinyl ester resin Polymers 0.000 claims description 7
- 239000003822 epoxy resin Substances 0.000 claims description 6
- 238000003384 imaging method Methods 0.000 claims description 6
- 229920003023 plastic Polymers 0.000 claims description 6
- 239000004033 plastic Substances 0.000 claims description 6
- 229920000647 polyepoxide Polymers 0.000 claims description 6
- 229920001225 polyester resin Polymers 0.000 claims description 6
- 239000004645 polyester resin Substances 0.000 claims description 6
- 238000004382 potting Methods 0.000 claims description 6
- 229920005989 resin Polymers 0.000 claims description 6
- 239000011347 resin Substances 0.000 claims description 6
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 claims description 4
- 229910002113 barium titanate Inorganic materials 0.000 claims description 4
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 claims description 4
- 229910001369 Brass Inorganic materials 0.000 claims description 3
- 229910000906 Bronze Inorganic materials 0.000 claims description 3
- 229910000831 Steel Inorganic materials 0.000 claims description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 3
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 claims description 3
- 239000010951 brass Substances 0.000 claims description 3
- 239000010974 bronze Substances 0.000 claims description 3
- KUNSUQLRTQLHQQ-UHFFFAOYSA-N copper tin Chemical compound [Cu].[Sn] KUNSUQLRTQLHQQ-UHFFFAOYSA-N 0.000 claims description 3
- 229920001971 elastomer Polymers 0.000 claims description 3
- 239000005060 rubber Substances 0.000 claims description 3
- 239000010959 steel Substances 0.000 claims description 3
- 230000002708 enhancing effect Effects 0.000 claims 2
- 238000002592 echocardiography Methods 0.000 abstract 1
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 20
- 229910010293 ceramic material Inorganic materials 0.000 description 7
- 239000002131 composite material Substances 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- 230000005684 electric field Effects 0.000 description 7
- 230000008859 change Effects 0.000 description 6
- 239000004593 Epoxy Substances 0.000 description 4
- 239000000853 adhesive Substances 0.000 description 4
- 230000001070 adhesive effect Effects 0.000 description 4
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 3
- 239000000919 ceramic Substances 0.000 description 3
- 239000006260 foam Substances 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 230000010287 polarization Effects 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 241000251468 Actinopterygii Species 0.000 description 2
- 230000000712 assembly Effects 0.000 description 2
- 238000000429 assembly Methods 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 239000013505 freshwater Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 230000035508 accumulation Effects 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000003466 anti-cipated effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000004035 construction material Substances 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 239000007799 cork Substances 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000005281 excited state Effects 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 239000008240 homogeneous mixture Substances 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000000135 prohibitive effect Effects 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000000452 restraining effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
- B06B1/0603—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using a piezoelectric bender, e.g. bimorph
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
- B06B1/0644—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using a single piezoelectric element
- B06B1/0651—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using a single piezoelectric element of circular shape
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/08—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with magnetostriction
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
- G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
- G01S15/88—Sonar systems specially adapted for specific applications
- G01S15/89—Sonar systems specially adapted for specific applications for mapping or imaging
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/52—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S15/00
- G01S7/521—Constructional features
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/004—Mounting transducers, e.g. provided with mechanical moving or orienting device
- G10K11/006—Transducer mounting in underwater equipment, e.g. sonobuoys
Definitions
- FIG. 6 is a cross-sectional view of an exemplary broadband transducer assembly of present invention, taken along line 6 - 6 of FIG. 4 .
- FIG. 13 illustrates an exemplary transducer element of the broadband transducer assembly of the present invention, in operation with voltage applied.
- the broadband transducer assembly of the present invention further comprises an acoustic structure 36 .
- FIG. 6 illustrates therein a cross-section of an embodiment of the broadband transducer assembly 10 taken long line 6 - 6 of FIG. 4 , wherein an exemplary acoustic structure 36 of the present invention readily is seen.
- the acoustic structure 36 comprises a base 38 and a transducer element 40 .
- the base 38 of the acoustic structure 36 may take any form suitable for supporting the transducer element 40 .
- the base 38 of acoustic structure 36 comprises a generally level support for the transducer element 40 .
- the acoustic structure 36 need not comprise an aperture 42 or a cap 44 for the broadband transducer assembly 10 to achieve broadband operation. It will be appreciated, however, that if an aperture 42 and/or a cap 44 are employed as part of or in connection with the acoustic structure 36 , the additional load imparted between the transducer element 40 and the base 38 due to inclusion of either of these components will allow smaller DTT ratios to achieve broadband operation.
- useful DTT ratios range from about 4.5 to about 55, as shown in FIG. 8 .
Abstract
A transducer assembly for transmitting broadband sonar beams and receiving broadband sonar returned echoes with a low-cost transducer element mounted into a low-cost acoustic structure. By using a transducer element which is sufficiently thin, broadband can be achieved at a significant cost savings over existing methods and devices. Since the transducer element is sufficiently thin, a large portion of the signal energy is coupled transversely into the acoustic structure, resulting in a heavy acoustic load on the transducer element which in turn results in broadband operation. Broadband operation may be enhanced by at least partially enclosing the sufficiently thin transducer element within an aperture and/or a cap.
Description
- This application claims priority to U.S. patent application Ser. No. 14/211,049, entitled Cost Effective Broadband Transducer Assembly and Method of Use, filed Mar. 14, 2014, which claims priority to U.S. provisional patent application Ser. No. 61/788,469 which is entitled Cost Effective Broadband Sonar Transducer, filed Mar. 15, 2013, the entirety of which are incorporated herein by reference.
- The present invention relates generally to electroacoustic transducers and more particularly to ultrasonic broadband transducer assemblies used in marine applications. A method of using a broadband transducer assembly in marine environments also is provided.
- The present invention is directed to a broadband acoustic structure operable for the purpose of imaging in marine applications, the acoustic structure having a bandwidth. The acoustic structure comprises a sufficiently thin transducer element for transmitting and receiving acoustic signals, the sufficiently thin transducer element having a transverse resonant frequency, and a base to which the sufficiently thin transducer element is securable. The sufficiently thin transducer element produces transverse vibrations which result in loading of the transducer element and the loading of the transducer element results in broadening of the bandwidth of the acoustic structure, wherein the bandwidth of the acoustic structure includes the transverse resonant frequency of the sufficiently thin transducer element.
- The present invention further is directed to a broadband transducer assembly operable for the purpose of imaging in marine applications. The transducer assembly comprises an acoustic structure having a bandwidth, a base and a sufficiently thin transducer element having a transverse resonant frequency. The sufficiently thin transducer element is securable to the base of the acoustic structure, and the sufficiently thin transducer element produces transverse vibrations which result in loading of the transducer element and wherein the loading of the transducer element results in broadening of the bandwidth of the acoustic structure. The bandwidth of the acoustic structure includes the transverse resonant frequency of the sufficiently thin transducer element.
- Finally, the present invention is directed to a method of imaging marine environments. The method comprises the steps of transmitting an acoustic signal into a sufficiently thin transducer element having a bandwidth and producing transverse vibrations of the sufficiently thin transducer element and thereby loading the sufficiently thin transducer element to result in broadening of the bandwidth of the sufficiently thin transducer element.
- The foregoing and other objects, features, and advantages of the invention will appear more fully hereinafter from a consideration of the detailed description that follows.
-
FIG. 1 illustrates an exploded view of an exemplary configuration by which an embodiment of a transducer assembly of the present invention is mounted to the transom of a watercraft. -
FIG. 2 shows an isometric view of an exemplary broadband transducer assembly of the present invention. -
FIG. 3 is a side elevation view of an exemplary broadband transducer assembly of the present invention. -
FIG. 4 is a rear elevation view of an exemplary broadband transducer assembly of the present invention. -
FIG. 5 is a perspective view of an alternative housing embodiment of the broadband transducer assembly of the present invention, having a window over at least a portion of the acoustic element. -
FIG. 6 is a cross-sectional view of an exemplary broadband transducer assembly of present invention, taken along line 6-6 ofFIG. 4 . -
FIG. 7A illustrates a cross-sectional view of an exemplary acoustic structure of the broadband transducer assembly of the present invention, the acoustic structure comprising a base and a transducer element. -
FIG. 7B illustrates a cross-sectional view of an alternative exemplary acoustic structure wherein an aperture and cap at least partially enclose the transducer element. -
FIG. 7C shows a perspective view of the bottom surface of an exemplary housing of the broadband transducer assembly of the present invention, wherein the base of the acoustic structure forms an aperture for receiving the transducer element. -
FIG. 8 is a graph illustrating favorable ranges of diameter-to-thickness ratios of transducer elements of the broadband transducer assembly of the present invention, both with and without an aperture and/or cap. -
FIG. 9 illustrates a perspective view of an exemplary acoustic structure of the broadband transducer assembly of the present invention, propagating ultrasonic waves longitudinally through water. -
FIG. 10 illustrates a conventional narrowband transducer element, without voltage applied. -
FIG. 11 illustrates a conventional narrowband transducer element in operation with voltage applied. -
FIG. 12 illustrates an exemplary transducer element of the broadband transducer assembly of the present invention, without voltage applied. -
FIG. 13 illustrates an exemplary transducer element of the broadband transducer assembly of the present invention, in operation with voltage applied. -
FIG. 14A is a graph illustrating bandpass characteristics of an exemplary broadband transducer assembly of the present invention. -
FIG. 14B is a graph illustrating bandpass characteristics of an alternative embodiment of an exemplary broadband transducer assembly of the present invention. -
FIG. 15 is a perspective view of an exemplary broadband array transducer assembly of the present invention containing an array of four acoustic structures in the bottom section of a transducer housing. -
FIG. 16 is a side elevation view of the exemplary broadband array transducer assembly ofFIG. 15 . -
FIG. 17 is a rear elevation view of an exemplary broadband array transducer assembly ofFIG. 15 . -
FIG. 18 is cross-sectional view of an exemplary broadband array transducer assembly of the present invention, taken along line 18-18 ofFIG. 17 . - Broadband transducers are electroacoustic devices used to increase sonar resolution and definition of products and have application, for example, in scanning sonar, three-dimensional sonar, echo sounders and sonar-GPS combinations. These devices can determine the depth of the marine floor, locate fish, identify other submerged targets, locate structure, show contours, avoid collisions and produce underwater images and the like.
- Conventional broadband transducers used in military and commercial applications are too expensive to incorporate into most fish finding systems. While broadband transducers offer new capabilities for these devices, a conventional broadband fishfinder must meet the requirements for broadband in each aspect of the device, including the transducer, transmitter, receiver, and signal-processing-software. Most broadband transducers are comprised of porous ceramic elements or composite ceramic elements, which are expensive and contribute to the high cost of broadband devices. These requisite materials and components make broadband fishfinders cost prohibitive for many commercial and recreational marine activities.
- Conventional narrowband fishfinders incorporate transducers that operate within a limited range of active frequencies. Lead zirconate titanate (Pb[ZrxTi1-x]O3 or “PZT”) is a piezoelectric ceramic material widely used in transducers. However, the range of active resonant frequencies of this PZT ceramic material are extremely narrow. Due to the discontinuity between the acoustic impedance of the piezoelectric ceramic material comprising the transducer and the surrounding environment, the bandwidth of conventional narrowband fishfinders typically have a Quality Factor (“Q Factor”) of about 15 and above. These conventional narrowband devices generally are useful in freshwater and some saltwater environments but are limited in capability as compared to broadband devices, which offer many advantages.
- Various tactics have been employed in attempts to create broadband transducers for use in marine applications, including the use of composite or porous piezoelectric ceramic materials. Composite PZT ceramic material (“composite PZT”) comprised of epoxy, plastic and rubber, are placed into a homogeneous mixture with small pieces of PZT ceramic to form a monolithic transducer. The composite PZT transducer will have an acoustic impedance between PZT and epoxy, moving the acoustic impedance closer to that of water and creating a broadband effect. Porous piezoelectric materials (“porous PZT”) are used in commercial and military sonar applications and medical electronics. To create a porous ceramic material, the PZT is mixed with select powders and is heated, leaving microscopic voids in the PZT. The voids reduce specific gravity of the PZT ceramic material, thereby moving the acoustic impedance of the device closer to that of water and achieving broadband results. Both porous PZT and composite PZT are extremely expensive due to material and manufacturing costs. Other methods of achieving broadband include the use of head and tail masses, also impedance matching layers are placed between the piezoelectric element and water.
- The present invention overcomes these problems of expense and complexity. The present invention comprises a cost-effective broadband transducer assembly that not only reduces the cost of existing broadband fishfinder systems but, due to the low cost of the transducer, will allow all fishfinding systems to operate with broadband. The present invention achieves broadband operation by using an internally-housed, low cost transducer element which is sufficiently thin, as described herein, thereby generating a relatively large amount of transverse vibration in the transducer element and increasing the load between the transducer element and an acoustic structure. Broadband operation may be enhanced by at least partially enclosing the transducer element with a cap or within an aperture sized to receive the transducer element, which has the effect of increasing the load between the transducer element and the acoustic structure. As used herein, the term “broadband” and the phrases “broadband operation” or “operates within broadband” and the like are used interchangeably to mean having a Q Factor of about 5 or less.
- Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described herein. All references cited herein, including published or corresponding U.S. or foreign patent applications, issued U.S. or foreign patents, and any other references, are each incorporated by reference in their entireties, including all data, tables, figures, and text presented in the cited references.
- Turning now to the drawings in general and to
FIG. 1 in particular, there is shown therein an embodiment of thebroadband transducer assembly 10 of the present invention mounted to thetransom 12 of a watercraft 14 or other vessel for use in marine applications. As used herein, “marine” and “marine applications” are used interchangeably to refer to activities and/or applications involving or relating to bodies or accumulations water, whether fresh water or salt water, including, without limitation, oceans, seas, lakes, ponds, rivers, streams, springs, creeks, gulfs, sounds, harbors, coves, channels, lagoons and the like. Thetransducer assembly 10 may be affixed to the watercraft 14 via known methods, such as mounting bracket 13, although it will be appreciated that other embodiments and other watercraft mounting methods are possible. For example, thetransducer assembly 10 may be affixed via through-hull-mounting, in-hull-mounting, trolling-motor-mounting, pole-mounting, adhesives and the like. Additionally, thetransducer assembly 10 may be used without affixation to any watercraft or other device and simply may be floated or suspended on or near the surface of thewater 18 where it is to be employed, for example, in marine activities such as ice fishing or from a boathouse and other activities where physical connection with a vessel or watercraft is neither useful nor desirable. - The
broadband transducer assembly 10 optimally is used such thatsonar beam 20 emitted from the transducer assembly is generally perpendicular to thewater surface 18. However, it will be appreciated that the present invention also may be used with thetransducer assembly 10 in any orientation with respect to thewater surface 18 so long as thesonar beam 20 is emitted fromtransducer assembly 10 in a direction that is within the water. For example, thebroadband transducer assembly 10 may be positioned so that thesonar beam 20 is emitted at a 45 degree angle with respect to the surface ofwater 18 or even parallel with respect tosurface 18, so long as the sonar beam is emitted within the water. - Turning now to
FIGS. 2 through 4 , thetransducer assembly 10 comprises ahousing 24. In one embodiment of the invention, thehousing 24 comprises atop surface 26, abottom surface 28 and aconnector 30. There are many types of brackets, clamps, struts, fixtures andother connectors 30 appropriate for use in mounting thetransducer assembly 10 to the watercraft 14 or other vessel or device, depending upon the desired application. As aforementioned, thetransducer assembly 10 need not be connected to another device or vessel to achieve optimal operation, so theconnector 30 is optional. - The
housing 24 may be of any shape that adequately stores the interior components, yet to be described. In one embodiment of the invention, thehousing 24 is comprised of interlocking top andbottom surfaces broadband transducer assembly 10 from water, dust, contaminants and other foreign materials, particles or objects. It will be appreciated that thehousing 24 may be constructed of multiple components or comprise a single, integrally-formed structure having atop surface 26 andbottom surface 28. - The
housing 24 may be comprised of a variety of materials that preferably impart properties of impact resistance, toughness and water-resistance. Some such materials include plastics and metals. Examples of plastic materials suitable for construction of thehousing 24 include polypropylene, delrin, polycarbonate, urethane, polyethylene, polystyrene, nylon, acrylic, polyvinylchloride and ultem. In one embodiment of the invention, thehousing 24 of thebroadband transducer assembly 10 is comprised of acrylonitrile butadiene styrene (“ABS”) plastic. Thehousing 24 also may be constructed of metals, such as bronze, brass, aluminum or steel. Alternatively, thehousing 24 may be constructed from a combination of materials. The material comprising thehousing 24 should be selected so as to yield the most desirable characteristics of acoustic performance, strength, durability and cost-effectiveness for the particular application. - In an alternative embodiment, the
housing 124 is generally tubular, as shown inFIG. 5 , forming atop surface 126 and abottom surface 128, and may be constructed from metal. An acoustic structure 36 (not shown inFIG. 5 ) is acoustically isolated within thehousing 124. Longitudinal waves or thesonar beam 20 from an acoustic structure, yet to be described, are coupled into water through anacoustic window 170, made of urethane or similar material. - Turning now to
FIGS. 6 and 7A through 7C, the broadband transducer assembly of the present invention further comprises anacoustic structure 36.FIG. 6 illustrates therein a cross-section of an embodiment of thebroadband transducer assembly 10 taken long line 6-6 ofFIG. 4 , wherein an exemplaryacoustic structure 36 of the present invention readily is seen. Theacoustic structure 36 comprises abase 38 and atransducer element 40. It will be appreciated that thebase 38 of theacoustic structure 36 may take any form suitable for supporting thetransducer element 40. In one embodiment of the invention, shown inFIG. 7A , thebase 38 ofacoustic structure 36 comprises a generally level support for thetransducer element 40. - Alternatively, the
base 38 of theacoustic structure 36 may form anaperture 42 for receiving thetransducer element 40, as illustrated inFIGS. 6 , 7B and 7C. The depth of theaperture 42 preferably approximates the thickness of thetransducer element 40. Theaperture 42 need not be formed by acontinuous sidewall 46 or sidewalls, depending upon the configuration, and may be formed, for example, with intermittent breaks in the sidewall. Consequently, thesidewall 46 ofaperture 42 either may directly contact thetransducer element 40 or any filler materials therebetween, such as an adhesive or potting compound. Typically, though not necessarily, a gap between thesidewall 46 of theaperture 42 and thetransducer element 40 would be filled with an adhesive that is also used to secure the transducer element to thebase 38. - The
aperture 42 may be formed integrally with or from thebase 38. Theaperture 42 may be formed from the same material as the base 38 or from another material. In one embodiment of the invention, thebase 38 and thesidewall 46 forming theaperture 42 are formed as an integral unit from ABS. It will be appreciated that theaperture 42 may be formed from a separate component that is then connected to thebase 38. - The
base 38 andaperture 42 may comprise the same material or different materials, among which include ABS, nylon, polyethylene, polystyrene, polyvinylchloride, polypropylene, epoxy resin, vinyl ester resin, polyester resin, acrylic, delrin, polycarbonate, ultem and combinations thereof. - The acoustic structure further may comprise a
cap 44, which may be employed in conjunction with theaperture 42 or without the aperture. Theoptional cap 44 serves a variety of purposes, one of which is to provide additional loading of thetransducer element 40. Thecap 44 also reduces side lobes in the beam pattern. It will be appreciated that thebroadband transducer assembly 10 of the present invention achieves broadband without thecap 44. Thecap 44 may be used in conjunction with theaperture 42 to completely enclose thetransducer element 40. Thecap 44 may also be positioned atop oftransducer element 40 without positioning the transducer element within theaperture 42. Thecap 44 may be formed as an integral part of theaperture 42 or as a separate component which is attached to or supported above or on theaperture 42. It is not necessary that thecap 44 completely cover thetransducer element 40 to constrict the transverse vibrations of the transducer element, and to that end the cap may only partially cover or enclose the transducer element. - As shown in
FIG. 6 , thebase 38 of theacoustic structure 36 may be integrally formed withbottom surface 28 ofhousing 24. It will be appreciated, however, that thebase 38 ofacoustic structure 36 may comprise a discrete article separate from thebottom surface 28 ofhousing 24. In one embodiment of the invention, thebase 38 andoptional cap 44 are made from ABS plastic, but other suitable materials such as nylon, polyethylene, polystyrene, polyvinylchloride, polypropylene, epoxy resin, vinyl ester resin, polyester resin, acrylic, delrin, polycarbonate, or ultem may be used to construct the base. In some embodiments, the base 38 oracoustic structure 36 may be constructed from the same material or materials as thehousing 24, ABS for example, or the housing and base may be constructed of different materials. Furthermore, theacoustic structure 36 may be constructed from multiple materials so as to yield the most desirable characteristics of acoustic performance, strength, durability, and cost effectiveness. When thebase 38 andhousing 24 are not integrally formed, the based is secured to thebottom surface 28 of the housing with adhesives or solvents, such as epoxy, vinyl ester, methyl ethyl ketone or acetone, which do not or only minimally acoustically impede vibrations from theacoustic structure 36 into the housing. - While the
acoustic structure 36 often is elliptical, the shape and design of the acoustic structure is not limited to an elliptical profile. Circular, rectangular, polygonal or free-form profiles could be used to tune the desired resonant modes of thetransducer assembly 10. Theacoustic structure 36 could be constructed in any shape and dimension to achieve the desired tuning and minimize the effect of resonant characteristics of the components of thebroadband transducer assembly 10. - With continuing reference to
FIGS. 6 and 7A through 7C, theacoustic structure 36 is at least partially surrounded by anisolation material 48 which serves to minimize radiation of acoustic signals from the acoustic structure into thehousing 24, excepting thebottom surface 28 of the housing. To this end, and with the exception of thebottom surface 28 of thehousing 24, theacoustic structure 36 is isolated from the other components of thetransducer assembly 10 by anisolation material 48. Theisolation material 48 may be any material that creates discontinuity in acoustic impedance so that acoustic energy remains within theacoustic structure 36 or passes into and through thebottom surface 28 ofhousing 24. Some materials suitable for this purpose include foam, cork, vacuum, air and the like. Theisolation material 48 reduces coupling of acoustic signals from theacoustic structure 36 into other parts of thehousing 24 except at thebase 38 of the acoustic structure. - Further, in order to impart rigidity and durability to the both the
transducer assembly 10 and thehousing 24, the housing may be filled with apotting material 50, such as epoxy or rigid foam, which at least partially surrounds theacoustic structure 36. In some embodiments, theisolation material 48 andpotting material 50 may be combined into a single item, such as a rigid cast-in-place foam which would furnish both the isolation and potting functions. - To achieve optimal performance of the
transducer assembly 10, certain components of the transducer assembly must be designed properly for the application. One of these important characteristics includes the tuning of theacoustic structure 36. Theacoustic structure 36 is tuned through appropriate selection of the materials, shape, diameter, thickness and dimensions of the components of the acoustic structure. Nevertheless, while these characteristics are important to performance, they alone will not result in broadband operation. A sufficientlythin transducer element 40 is required to achieve broadband operation. - With continuing reference to
FIGS. 6 and 7A through 7C, thetransducer element 40 of thebroadband transducer assembly 10 of the present invention now will be described. Thetransducer element 40 comprises a piezoelectric material or a magnetostrictive material. In one embodiment of the invention, the transducer element is a piezoelectric material selected from the group consisting of PZT (lead zirconium titanate, (Pb[ZrxTi1-x]O3)) or barium titanate (BaTiO3). In one embodiment of the invention, the piezoelectric material preferably comprises PZT. - The
transducer element 40 is of any shape to be accommodated within theacoustic structure 36 and thehousing 24. Thetransducer assembly 10 of the present invention achieves broadband by employing a sufficientlythin transducer element 40, in operation with thebase 38 ofacoustic structure 36. The extent to which thetransducer element 40 is sufficiently thin can be expressed as the diameter-to-thickness (DTT) ratio of the transducer element. For acircular transducer element 40, the diameter thereof is clearly identifiable. For anon-circular transducer element 40, whether regular or irregular in shape, such as a rectangular, elliptical or polygonal, the characteristic length of the element is substituted for the diameter. As used herein, the term “DTT ratio” will be used to represent all scenarios. - A range of DTT ratios achieve broadband operation in the present invention. For example, a
transducer element 40 which has a DTT ratio of 9 (diameter is 9 times the thickness) or greater will result in broadband operation when included as part of a properacoustic structure 36. As the DTT ratio gets smaller, i.e. as thetransducer element 40 gets thicker and/or smaller in diameter, the amount of transverse vibration in the transducer element decreases, causing less loading between the transducer element and thebase 38 ofacoustic structure 36, thus narrowing the bandwidth. - Typically, a
transducer element 40 having a large DTT ratio of 75 or greater should exhibit broadband operation, although there is a practical upper limit to the DTT ratio for sonar and fishfinder applications. First, as the DTT ratio increases (as the element gets thinner with respect to the diameter) the amount of transmit power which can be input into thetransducer element 40 without damaging it is reduced. If thetransducer element 40 is too thin, it will not be able to handle the required transmit power to produce the desired results in a sonar or fishfinder application. This sets a practical lower limit to the thickness of the element. Second, as the DTT ratio increases, if a reasonable thickness is maintained, the diameter will also increase. Since the present invention operates thetransducer element 40 in the transverse (or radial) mode, larger diameters will result in lower operational frequencies. Center operational frequencies below 20 kHz are not typically useful for sonar and fish-finder applications. This sets a practical upper limit to the diameter of the element. Having a practical lower limit to the element thickness and a practical upper limit to the element diameter (or characteristic length) effectively bounds the practical upper limit of DTT ratios. Preferably, the center frequency of the broadband operation of the broadband assembly of the present invention ranges from about 20 kHz to about 250 kHz. -
FIG. 8 illustrates some preferred DTT ratios of thetransducer element 40 based on operational frequency of thebroadband transducer assembly 10. The graph inFIG. 8 plots the DTT ratio of thetransducer element 40 on the y axis versus the center frequency of broadband operation of thebroadband transducer assembly 10 in operation, on the x axis. The expected useful DTT ratio of thetransducer element 40 of thebroadband transducer assembly 10 ranges from about 9 to about 55. A preferred range of DTT ratios exists based on the most favorable combination oftransducer element 40 operational frequency,transducer element 40 bandwidth, transmit power capability, size and cost. Due to these factors, the most preferable DTT ratio range will be different based on the operational frequency of the transducer element. It will be appreciated that thetransducer element 40 of theacoustic structure 36 is not limited to the DTT ratios shown inFIG. 8 , although it is anticipated that a majority of viable DTT ratios of the transducer element will fall within this range. - The
acoustic structure 36 need not comprise anaperture 42 or acap 44 for thebroadband transducer assembly 10 to achieve broadband operation. It will be appreciated, however, that if anaperture 42 and/or acap 44 are employed as part of or in connection with theacoustic structure 36, the additional load imparted between thetransducer element 40 and thebase 38 due to inclusion of either of these components will allow smaller DTT ratios to achieve broadband operation. When anaperture 42 and/or acap 44 are employed as part of or in connection with theacoustic structure 36, useful DTT ratios range from about 4.5 to about 55, as shown inFIG. 8 . - Turning now to
FIG. 9 , and with continuing reference toFIGS. 6 and 7A through 7C, the operation of thebroadband transducer assembly 10 will be described.FIG. 9 shows thetransducer element 40 positioned within theacoustic structure 36, which is transmitting asonar beam 20 into thewater 18. Thehousing 24 is not shown for purposes of illustration. The transverse restraining forces on thetransducer element 40 increase the load on the transducer element, thus broadening the bandwidth. - The accentuated transverse vibrations from the sufficiently
thin transducer element 40 enable broadband operation of thetransducer assembly 10. Additionally, the constriction of thetransducer element 40 by theaperture 42 andcap 44 will constrict the transverse vibration of the transducer element, which causes loading between the transducer element and the acoustic structure, thus broadening the bandwidth of the acoustic structure. The amount of load created in these circumstances is dependent on a number of factors, includingaperture 42 and cap 44 dimensions, construction materials and configuration. It will be appreciated that while theaperture 42 and/orcap 44 will load thetransducer element 40, the use of a sufficientlythin transducer element 40 in conjunction with both theaperture 42 and/orcap 44 will provide more load than use of only one of the components alone. Thus, in a number of exemplary embodiments of the present invention, both anaperture 42 andcap 44 will be utilized with a sufficientlythin transducer element 40 to achieve enhanced broadband performance. - The
transducer element 40 is connected with a sonar transmitter and a receiver (not shown) via atransducer cable 54. When a sonar pulse is applied to thetransducer cable 54, the pulse, therefore, also is applied to thetransducer element 40. Thetransducer element 40 then vibrates longitudinally or axially, and because it is sufficiently thin, it vibrates aggressively in the transverse or radial direction. These aggressive transverse vibrations are coupled into theacoustic structure 36 and resonate within the structure. Transverse and longitudinal resonances within theacoustic structure 36 then produce longitudinal vibrations that are coupled into the water and longitudinally as the transmittedsonar beam 20 throughwater 18. The longitudinal direction may also be referred to as the axial direction, while the transverse direction may also be referred to herein as the radial direction. - With continuing reference to
FIG. 9 , transverse vibrations from thetransducer element 40 will couple into thebase 38 and cause associated longitudinal vibrations within theacoustic structure 36. Different transverse and longitudinal resonance modes within theacoustic structure 36 are determined by the acoustic structure components, composition, shape, and dimensions. The composite result of these transverse and longitudinal resonances is realized longitudinally at the interface of theacoustic structure 36 with thebottom surface 28 of thehousing 24 and, hence, to thewater 18. The transmitsonar beam 20 is then emitted from theacoustic structure 36 and propagates through water in a longitudinal fashion. - Comparison of the transducer element of a conventional narrowband fishfinder transducer to the
transducer element 40 of an embodiment of thepresent invention 10 demonstrates the following: 1) Longitudinal vibrations are the same in both; 2) transverse vibrations in the sufficientlythin transducer element 40 of the present invention are greatly accentuated over transverse vibrations of conventional narrowband fishfinder transducer elements. -
FIGS. 10 and 11 represent a transducer element of a conventional narrowband fishfinder transducer device.FIGS. 12 and 13 illustrate a sufficientlythin transducer element 40 of an embodiment of the present invention. Both transducer elements are made of the same normal, low-cost, hard PZT. Both elements have the same piezoelectric characteristics and the same initial diameter D0 in the unexcited state, illustrated inFIG. 10 for the conventional transducer element and inFIG. 12 for thetransducer element 40 of thepresent invention 10. However, with the application of an electric field, thetransducer element 40 of the present invention in an excited state has a greater length change in the transverse direction than the conventional transducer element, as illustrated inFIGS. 11 andFIG. 13 . - In general, the change in length of a transducer element due to an applied electric field is shown in EQ 1:
-
ΔL=d ij ×E×L 0 EQ 1: - Where: L0=Initial length (m)
-
- dij=piezoelectric charge constant (pm/V)
- E=applied electric field strength (V/m)
- Since PZT has different piezoelectric charge constants based on orientation to the polarization vector, we arrive at EQ 2 and EQ 3 to find the change in diameter and thickness of a PZT element due to an applied electric field.
-
ΔD=d 31 ×E×d 0 EQ 2: -
ΔT=d 33 ×E×t 0 EQ 3: - Where: T0=Initial diameter (m)
-
- T0=initial thickness (m)
- d31=piezoelectric charge constant orthogonal to the polarization
- vector (pm/V) E=applied electric field strength (V/m)
- d33=piezoelectric charge constant parallel to the polarization vector (pm/V)
- Since the electric field is applied over the initial thickness of the element, E is derived as follows:
-
E=V/T 0 EQ. 4: - Based on established properties for hard PZT, using EQ. 2 and EQ 3. and applying a 600V electric field, the difference in the transverse length for the conventional transducer element and the sufficiently
thin transducer element 40 of the present invention is calculated. -
TABLE 1 Conventional Narrowband Present Invention Transducer Transducer Element Element Figures 10-11 Figures 12-13 Unexcited 25.4 mm 25.4 mm Diameter (D0) Unexcited 11.2 mm 2.0 mm Thickness (T0) d33 5x10−10 m/V d31 −2.3x10−10 m/V Applied 600 V Voltage (V) E V/t0 = 600 V / .0112 m = 53571 V/m V/t0 = 600 V / .002 m = 300000 V/m ΔD ΔT - As shown by the calculations in Table 1, both transducer elements in
FIGS. 11 and 13 have the same longitudinal length change due to an applied voltage, but thetransducer element 40 of the present inventionbroadband transducer assembly 10 has 5.6 times greater length change in the transverse direction than the conventional narrowband transducer element. It will be appreciated that the calculations in Table 1 are a comparison of two specific transducer elements. As the DTT ratio of the sufficientlythin transducer element 40 is changed, so will the difference in transverse length change with respect to a conventional narrowband transducer element with a much smaller DTT ratio. - A typical measurement of transducer performance is Q Factor, which is defined as follows:
-
Q=f c /Δf - Where:
- fc=Center frequency of the bandpass
- Δf=Bandwidth
- In general, transducer assemblies with a lower Q Factor are broader band. Table 2 contains a comparison of the Q Factor for a conventional narrowband transducer, typical low frequency broadband transducer, typical high frequency broadband transducer, with two embodiments of the
broadband transducer assembly 10 of the present invention. While specific embodiments of the present invention will produce different performance, the measured bandpass of two embodiments substantially similar to that shown inFIGS. 2 through 4 andFIGS. 6 through 7C is represented inFIGS. 14A and 14B . Embodiment #1 has a usable bandwidth of 35 kHz with a center frequency of 82.5, while embodiment #2 has a usable bandwidth of 44 kHz with a center frequency of 85 kHz. These embodiments compare favorably with conventional narrowband, conventional high frequency broadband and conventional low frequency broadband transducers, as shown in Table 2. -
TABLE 2 Conventional Conventional Present Present Conventional High Frequency Low Frequency Invention Invention Narrowband Broadband Broadband Broadband Broadband Transducer Transducer Transducer Transducer Transducer Assembly Assembly Assembly Assembly #1 Assembly #2 fc (kHz) 200 200 53.5 82.5 85 Δf (kHz) 12.5 100 23.0 35 44 Q 16.0 2.0 2.3 2.4 1.9
As demonstrated in Table 2 andFIGS. 14A and 14B , the present invention, though being significantly lower cost, is capable of broadband performance that is as good, if not better, than a typical higher cost broadband transducer assembly. - It will be appreciated that the present invention can be embodied in numerous ways. For example, the broadband transducer assembly may include a plurality of
acoustic structures 36 with disk or plate-shapedtransducer elements 40, a singleacoustic structure 36 with aplate transducer element 40 or any other arrangement of one or moreacoustic structures 36 usingtransducer elements 40 which are a disk, plate, rectangular, ellipse, or other profile. - Turning now to
FIGS. 15 through 18 , another embodiment of the present invention is illustrated therein. Abroadband transducer assembly 210 comprises ahousing 224 having atop surface 226 andbottom surface 228 andconnector 230. As shown inFIG. 18 , thebroadband transducer assembly 210 comprises a plurality ofacoustic structures 236A through 236D contained in an array arrangement withinhousing 224. Each of the plurality ofacoustic structures 236A-236D comprises the elements of theacoustic structure 36 heretofore described. Each of the plurality ofacoustic structures 236A through 236D could be operated individually or in a group of two or more to provide multiple transducer cone angles for use in either shallow or deep water. Other embodiments of a broadband array transducer could includeacoustic structures 36 andtransducer elements 40 of various sizes to achieve multiple frequencies and combinations of cone angles within the same transducer housing. - The present invention further comprises a method of using a broadband transducer assembly in a marine environment. The
transducer element 40 is connected with a sonar transmitter and a receiver via atransducer cable 54 as heretofore described. When a sonar pulse is applied to thetransducer cable 54, the pulse is transmitted to thetransducer element 40, which then vibrates longitudinally, or axially. Because thetransducer element 40 is sufficiently thin, it vibrates aggressively in the transverse, or radial, direction. These aggressive transverse vibrations are coupled into theacoustic structure 36 and resonate within the acoustic structure, producing longitudinal vibrations. The vibrations emitted from theacoustic structure 36 propagate longitudinally through thehousing 24 and into thewater 18. - When the
aperture 42 and or cap 44 are incorporated, vibrations from thetransducer element 40 cause loading between the transducer element and the other components of theacoustic structure 36, broadening the band width of thetransducer assembly 10. - The invention of this application has been described above both generically and with regard to specific embodiments. Although the invention has been set forth in what is believed to be preferred embodiments, a wide variety of alternatives known to those of skill in the art can be selected within the generic disclosure. Changes may be made in the combination and arrangement of the various parts, elements, steps and procedures described herein without departing from the spirit and scope of the invention as defined in the following claims.
Claims (63)
1. A broadband acoustic structure operable for the purpose of imaging in marine applications, the acoustic structure having a bandwidth, the acoustic structure comprising:
a sufficiently thin transducer element for transmitting and receiving acoustic signals, the sufficiently thin transducer element having a transverse resonant frequency;
a base to which the sufficiently thin transducer element is securable;
wherein the sufficiently thin transducer element produces transverse vibrations which result in loading of the transducer element and wherein the loading of the transducer element results in broadening of the bandwidth of the acoustic structure; and
wherein the bandwidth of the acoustic structure includes the transverse resonant frequency of the sufficiently thin transducer element.
2. The acoustic structure of claim 1 further comprising a housing, wherein the base of the acoustic structure is integrally formed with the housing.
3. The acoustic structure of claim 1 further comprising a cap.
4. The acoustic structure of claim 1 wherein the base further defines an aperture for receiving the transducer element.
5. The acoustic structure of claim 1 further comprising a component positioned above the base, wherein the component defines an aperture for receiving the transducer element.
6. The acoustic structure of claim 4 further comprising a cap.
7. The acoustic structure of claim 1 further comprising a housing having a bottom surface, wherein the acoustic structure is bonded to the bottom surface of the housing.
8. The acoustic structure of claim 1 wherein the transducer element is piezoelectric.
9. The acoustic structure of claim 8 wherein the transducer element is comprised of a material selected from the group consisting of lead zirconium titanate or barium titanate.
10. The acoustic structure of claim 1 wherein the center frequency of the broadband ranges from about 20 kHz to about 250 kHz.
11. The acoustic structure of claim 1 wherein the transducer element has a diameter to thickness ratio and wherein the diameter to thickness ratio of the transducer element ranges from about 4.5 to about 75.
12. The acoustic structure of claim 1 wherein the shape of the acoustic structure is circular or substantially elliptical.
13. The acoustic structure of claim 1 further having a Q Factor of about 5 or less.
14. The acoustic structure of claim 1 wherein the base of the acoustic structure is comprised of Acrylonitrile Butadiene Styrene (ABS).
15. The acoustic structure of claim 1 wherein the acoustic structure is comprised of a material selected from the group consisting of ABS, nylon, polyethylene, polystyrene, polyvinylchloride, polypropylene, epoxy resin, vinyl ester resin, polyester resin, acrylic, delrin, polycarbonate, ultem and combinations thereof.
16. The acoustic structure of claim 1 wherein the transducer element is a disk having diameter and thickness.
17. The acoustic structure of claim 1 wherein the transducer element is a plate having length, width, and thickness.
18. The acoustic structure of claim 1 further comprising a housing that is constructed of materials selected from the group consisting of urethane, rubber, polyethylene, polystyrene, nylon, acrylic, polyvinylchloride ultem, acrylonitrile butadiene styrene plastic, polypropylene, epoxy resin, vinyl ester resin, polyester resin, delrin, polycarbonate, brass, bronze, steel, aluminum and combinations thereof.
19. The acoustic structure of claim 1 further comprising a housing and an isolation material within the housing to acoustically isolate the acoustic structure.
20. The acoustic structure of claim 1 further comprising a housing material and a potting material.
21. The acoustic structure of claim 1 wherein the transducer element comprises a magnetostrictive material.
22. (canceled)
23. The acoustic structure of claim 1 wherein the vibrations from the transducer element produce a sonar beam and the acoustic structure is positioned so that the sonar beam is emitted generally perpendicular to the surface of water.
24. The acoustic structure of claim 1 wherein the acoustic structure further comprises a sonar transmitter, a sonar receiver and a transducer cable.
25. The acoustic structure of claim 1 further comprising a connector for connecting the acoustic structure to a watercraft.
26. A broadband transducer assembly operable for the purpose of imaging in marine applications, the transducer assembly comprising:
an acoustic structure having a bandwidth;
a base; and
a sufficiently thin transducer element having a transverse resonant frequency;
wherein the sufficiently thin transducer element is securable to the base of the acoustic structure; and
wherein the sufficiently thin transducer element produces transverse vibrations which result in loading of the transducer element and wherein the loading of the transducer element results in broadening of the bandwidth of the acoustic structure; and
wherein the bandwidth of the acoustic structure includes the transverse resonant frequency of the sufficiently thin transducer element.
27. The transducer assembly of claim 26 further comprising a housing, wherein the base of the acoustic structure is integrally formed with the housing.
28. The transducer assembly of claim 26 wherein the acoustic structure further comprises a cap.
29. The transducer assembly of claim 26 wherein the base further defines an aperture for receiving the transducer element.
30. The transducer assembly of claim 26 further comprising a component positioned above the base, wherein the component defines an aperture for receiving the transducer element.
31. The transducer assembly of claim 29 further comprising a cap.
32. The transducer assembly of claim 26 further comprising a housing having a bottom surface, wherein the acoustic structure is bonded to the bottom surface of the housing.
33. The transducer assembly of claim 26 wherein the transducer element is piezoelectric.
34. The transducer assembly of claim 33 wherein the transducer element is comprised of a material selected from the group consisting of lead zirconium titanate or barium titanate.
35. The transducer assembly of claim 26 wherein the center frequency of the broadband ranges from about 20 kHz to about 250 kHz.
36. The transducer assembly of claim 26 wherein the transducer element has a diameter to thickness ratio and wherein the diameter to thickness ratio of the transducer element ranges from about 4.5 to about 75.
37. The transducer assembly of claim 26 wherein the shape of the acoustic structure is circular or substantially elliptical.
38. The transducer assembly of claim 26 further having a Q Factor of about 5 or less.
39. The transducer assembly of claim 26 wherein the base of the acoustic structure is comprised of Acrylonitrile Butadiene Styrene (ABS).
40. The transducer assembly of claim 26 wherein the acoustic structure is comprised of a material selected from the group consisting of ABS, nylon, polyethylene, polystyrene, polyvinylchloride, polypropylene, epoxy resin, vinyl ester resin, polyester resin, acrylic, delrin, polycarbonate, ultem and combinations thereof.
41. The transducer assembly of claim 26 wherein the transducer element is a disk having diameter and thickness.
42. The transducer assembly of claim 26 wherein the transducer element is a plate having length, width, and thickness.
43. The transducer assembly of claim 26 further comprising a housing that is constructed of materials selected from the group consisting of urethane, rubber, polyethylene, polystyrene, nylon, acrylic, polyvinylchloride ultem, acrylonitrile butadiene styrene plastic, polypropylene, epoxy resin, vinyl ester resin, polyester resin, delrin, polycarbonate, brass, bronze, steel, aluminum and combinations thereof.
44. The transducer assembly of claim 26 further comprising a housing and an isolation material within the housing to acoustically isolate the acoustic structure.
45. The transducer assembly of claim 26 further comprising a housing material and a potting material.
46. The transducer assembly of claim 26 wherein the transducer element comprises a magnetostrictive material.
47. (canceled)
48. The transducer assembly of claim 26 wherein the vibrations from the transducer element produce a sonar beam and the transducer assembly is positioned so that the sonar beam is emitted generally perpendicular to the surface of water.
49. The transducer assembly of claim 26 further comprising a sonar transmitter, a receiver for receiving signals from the transmitter and a transducer cable.
50. The transducer assembly of claim 26 further comprising a connector for mounting the transducer assembly to a watercraft.
51. A method of imaging marine environments, the method comprising the steps of:
transmitting an acoustic signal into a sufficiently thin transducer element having a bandwidth;
producing transverse vibrations of the sufficiently thin transducer element and thereby loading the sufficiently thin transducer element to result in broadening of the bandwidth of the sufficiently thin transducer element.
52. The method of claim 51 further comprising the step of producing a sonar beam from the sufficiently thin transducer element and transmitting the sonar beam into the marine environment.
53. The method of claim 52 further comprising the step of emitting the sonar beam into the marine environment at any angle.
54. The method of claim 51 further comprising the step of vibrating the sufficiently thin transducer element within broadband having a Quality Factor of about 5 or less.
55. The method of claim 51 further comprising the step of transmitting a signal into a plurality of sufficiently thin transducer elements and vibrating the plurality of sufficiently thin transducer elements transversely.
56. The method of claim 55 further comprising the step of vibrating the plurality of sufficiently thin transducer elements in one or more groups.
57. The method of claim 55 further comprising the step of vibrating the plurality of sufficiently thin transducer elements individually.
58. The method of claim 51 further comprising the step of transmitting the vibrations from the sufficiently thin transducer element through the base of an acoustic structure through a housing to which the acoustic structure is secured.
59. The method of claim 51 wherein the transducer element has a diameter to thickness ratio and the diameter to thickness ratio ranges from about 4.5 to about 75.
60. The method of claim 51 further comprising the step of receiving acoustic signals from the marine environment.
61. The method of claim 55 wherein the center frequency of the broadband ranges from about 20 kHz to about 250 kHz.
62. The method of claim 54 further comprising the step of enhancing broadband operation by at least partially covering the transducer element with a cap.
63. The method of claim 54 further comprising the step of enhancing broadband operation by at least partially enclosing the transducer element within the sidewalls of an aperture.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/687,659 US20150290680A1 (en) | 2013-03-15 | 2015-04-15 | Cost effective broadband transducer assembly and method of use |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US201361788469P | 2013-03-15 | 2013-03-15 | |
US14/211,940 US9035537B2 (en) | 2013-03-15 | 2014-03-14 | Cost effective broadband transducer assembly and method of use |
US14/687,659 US20150290680A1 (en) | 2013-03-15 | 2015-04-15 | Cost effective broadband transducer assembly and method of use |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/211,940 Continuation US9035537B2 (en) | 2013-03-15 | 2014-03-14 | Cost effective broadband transducer assembly and method of use |
Publications (1)
Publication Number | Publication Date |
---|---|
US20150290680A1 true US20150290680A1 (en) | 2015-10-15 |
Family
ID=51538306
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/211,940 Expired - Fee Related US9035537B2 (en) | 2013-03-15 | 2014-03-14 | Cost effective broadband transducer assembly and method of use |
US14/687,659 Abandoned US20150290680A1 (en) | 2013-03-15 | 2015-04-15 | Cost effective broadband transducer assembly and method of use |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/211,940 Expired - Fee Related US9035537B2 (en) | 2013-03-15 | 2014-03-14 | Cost effective broadband transducer assembly and method of use |
Country Status (2)
Country | Link |
---|---|
US (2) | US9035537B2 (en) |
WO (1) | WO2014144199A2 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP7051625B2 (en) * | 2018-07-12 | 2022-04-11 | 古野電気株式会社 | Underwater detector and underwater detection method |
US10996163B1 (en) * | 2021-01-12 | 2021-05-04 | Endra Life Sciences Inc. | Acoustically isolated thermoacoustic imaging probe and process of manufacture |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5121628A (en) * | 1990-10-09 | 1992-06-16 | Merkl Arthur W | Ultrasonic detection system |
US5176140A (en) * | 1989-08-14 | 1993-01-05 | Olympus Optical Co., Ltd. | Ultrasonic probe |
US7019621B2 (en) * | 2001-01-02 | 2006-03-28 | Stanley E. Woodard | Methods and apparatus to increase sound quality of piezoelectric devices |
US20100103775A1 (en) * | 2004-08-02 | 2010-04-29 | Johnson Outdoors Inc. | Sonar imaging system for mounting to watercraft |
Family Cites Families (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3953828A (en) | 1968-11-08 | 1976-04-27 | The United States Of America As Represented By The Secretary Of The Navy | High power-wide frequency band electroacoustic transducer |
US3753058A (en) | 1970-06-22 | 1973-08-14 | Int Nickel Co | Operation of magnetostrictive apparatus |
US4439847A (en) | 1981-12-21 | 1984-03-27 | The Stoneleigh Trust | High efficiency broadband directional sonar transducer |
US4633119A (en) | 1984-07-02 | 1986-12-30 | Gould Inc. | Broadband multi-resonant longitudinal vibrator transducer |
US4604542A (en) | 1984-07-25 | 1986-08-05 | Gould Inc. | Broadband radial vibrator transducer with multiple resonant frequencies |
US4701658A (en) | 1985-03-11 | 1987-10-20 | United Technologies Corporation | Broadband acoustic point-contact transducer |
DE3620085C2 (en) | 1986-06-14 | 1994-03-10 | Honeywell Elac Nautik Gmbh | Tubular electro-acoustic transducer |
DE3812244C1 (en) | 1988-04-13 | 1989-11-09 | Honeywell-Elac-Nautik Gmbh, 2300 Kiel, De | |
US5343443A (en) | 1990-10-15 | 1994-08-30 | Rowe, Deines Instruments, Inc. | Broadband acoustic transducer |
US5229980A (en) | 1992-05-27 | 1993-07-20 | Sparton Corporation | Broadband electroacoustic transducer |
FR2800229B1 (en) | 1999-10-22 | 2002-04-05 | Thomson Marconi Sonar Sas | BROADBAND SUBMARINE ACOUSTIC TRANSDUCER |
AU2598201A (en) | 1999-12-23 | 2001-07-03 | Therus Corporation | Ultrasound transducers for imaging and therapy |
WO2003012889A1 (en) | 2001-07-30 | 2003-02-13 | Blackstone-Ney Ultrasonics | Highpower ultrasonic transducer with broadband frequency characteristics |
US6822373B1 (en) | 2002-11-25 | 2004-11-23 | The United States Of America As Represented By The Secretary Of The Navy | Broadband triple resonant transducer |
US6984923B1 (en) | 2003-12-24 | 2006-01-10 | The United States Of America As Represented By The Secretary Of The Navy | Broadband and wide field of view composite transducer array |
DE102004004715B4 (en) * | 2004-01-30 | 2006-06-29 | Herold, Horst | Protective device for propelling a watercraft |
US8027224B2 (en) | 2009-11-11 | 2011-09-27 | Brown David A | Broadband underwater acoustic transducer |
DE102010010931A1 (en) * | 2010-03-10 | 2011-09-15 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Piezoresistive converter |
-
2014
- 2014-03-14 WO PCT/US2014/028503 patent/WO2014144199A2/en active Application Filing
- 2014-03-14 US US14/211,940 patent/US9035537B2/en not_active Expired - Fee Related
-
2015
- 2015-04-15 US US14/687,659 patent/US20150290680A1/en not_active Abandoned
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5176140A (en) * | 1989-08-14 | 1993-01-05 | Olympus Optical Co., Ltd. | Ultrasonic probe |
US5121628A (en) * | 1990-10-09 | 1992-06-16 | Merkl Arthur W | Ultrasonic detection system |
US7019621B2 (en) * | 2001-01-02 | 2006-03-28 | Stanley E. Woodard | Methods and apparatus to increase sound quality of piezoelectric devices |
US20100103775A1 (en) * | 2004-08-02 | 2010-04-29 | Johnson Outdoors Inc. | Sonar imaging system for mounting to watercraft |
Also Published As
Publication number | Publication date |
---|---|
WO2014144199A2 (en) | 2014-09-18 |
US9035537B2 (en) | 2015-05-19 |
WO2014144199A3 (en) | 2014-12-04 |
US20140306579A1 (en) | 2014-10-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9308554B2 (en) | Ultrasonic/acoustic transducer | |
US7889601B2 (en) | Lightweight acoustic array | |
US4333028A (en) | Damped acoustic transducers with piezoelectric drivers | |
US4122725A (en) | Length mode piezoelectric ultrasonic transducer for inspection of solid objects | |
US6904798B2 (en) | Multi-functional marine sensing instrument | |
US8085621B2 (en) | Ultrasonic transducer with improved method of beam angle control | |
AU775315B2 (en) | Bow dome sonar | |
US9035537B2 (en) | Cost effective broadband transducer assembly and method of use | |
WO2012070613A1 (en) | Ultrasound probe | |
JPH04230199A (en) | Acoustic transducer | |
US20210270963A1 (en) | Sonar system with acoustic beam reflector | |
US20190257930A1 (en) | Multi frequency piston transducer | |
EP0039986B1 (en) | An acoustic transducer system | |
US7535801B1 (en) | Multiple frequency sonar transducer | |
JP2000509649A (en) | Bending plate acoustic transducer with low resonance frequency | |
US7443081B2 (en) | Multi-frequency transmission/reception apparatus | |
JP2008306315A (en) | Ultrasonic wave echo transceiver | |
JP2000083295A (en) | Composite type vibrator | |
US20190272816A1 (en) | Hybrid transducer apparatus and methods of manufacture and use | |
US9179219B2 (en) | Widebeam acoustic transducer | |
JP5454532B2 (en) | Flexural transducer | |
US11664779B2 (en) | Acoustic impedance matching with bubble resonators | |
JP2007274191A (en) | Ultrasonic vibrator, its manufacturing method, and ultrasonic equipment | |
RU2757358C1 (en) | Broadband hydroacoustic antenna | |
Woollett | Ultrasonic transducers: 2. Underwater sound transducers |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |