Imaging device with piezoelectric transceiver

Abstract

An imaging device having a piezoelectric transceiver. An array (400) of micromachined ultrasonic transducers (MUTs) (402). The array (400) has a first row and a second row, the MUTs (402) in the first row equally spaced in a horizontal direction (403) by a horizontal spacing (430), the MUTs (402) in the second row equally spaced in the horizontal direction by the horizontal spacing (430). The MUTs (702b) in the second row are displaced in the horizontal direction by a first horizontal distance (706) relative to the MUTs (702a) in the first row and displaced in a vertical direction (405) by a first vertical distance (708) relative to the MUTs (702a) in the first row. The first horizontal distance (706) is greater than zero and less than the horizontal spacing (430). The first vertical distance (708) ranges from one-tenth of a horizontal width (712) of the MUTs to one-half of a vertical height (714) of the MUTs.

Description

[0001] This application is a divisional application of Chinese patent application No. 201980039398.0, entitled "Imaging Device with Piezoelectric Transceiver", filed on March 10, 2019 (the corresponding PCT application was filed on March 10, 2019, and has the application number PCT / US2019 / 021515). Technical Field

[0002] This invention relates to imaging devices, and more specifically, to imaging devices having micromechanical ultrasonic transducers (MUTs). Background Technology

[0003] Non-invasive imaging systems used to image and display images of internal organs send signals to the body and receive signals reflected from the organs. The transducers used in these systems are typically called transceivers, and some are based on photoacoustic or ultrasonic effects. Transceivers are commonly used in imaging and other applications such as medical imaging, flow measurement in pipes, loudspeakers, microphones, lithotripsy, heating tissue for treatment, and high-intensity focused ultrasound (HIFU) for surgery.

[0004] Advances in microfabrication technology have allowed sensors and actuators to be efficiently integrated onto a substrate. Specifically, micromechanical ultrasonic transducers (MUTs) using capacitive transducers (cMUTs) or piezoelectric transducers (pMUTs) are particularly advantageous compared to conventional MUTs with large form factors. Figure 1 A two-dimensional linear transceiver array 50 in a conventional system is illustrated. As shown, the transceiver array 50 may include a group of MUTs 52 that generate and transmit pressure waves in transmit mode / process and receive pressure waves in receive mode / process, generating charges in response to the received pressure waves. As shown, the MUTs 52 are uniformly spaced in the x and y directions, i.e., the distance from one MUT to an adjacent MUT along the x (or y) direction is the same throughout the array. The MUTs 52 tend to have a finite number of resonant vibrations, i.e., the MUT array 52 may have a finite bandwidth in the frequency domain. Generally, the wider the bandwidth of the MUTs 52, the more complex the operating modes in which the MUTs 52 can operate, and the better the image that the transceiver array 50 can generate. Therefore, there is a strong need to design MUTs with increased bandwidth to enhance acoustic performance. Summary of the Invention

[0005] In various embodiments, the transducer array includes multiple micromechanical ultrasonic transducers (MUTs) arranged in an asymmetric configuration.

[0006] In various embodiments, the array of micromechanical ultrasonic transducers (MUTs) includes MUTs arranged in a two-dimensional array having a first row and a second row. The MUTs in the first row are equally spaced horizontally in the horizontal direction, and the MUTs in the second row are equally spaced horizontally in the same direction. The MUTs in the second row are shifted horizontally relative to the MUTs in the first row by a first horizontal distance and vertically relative to the MUTs in the first row by a first vertical distance. The first horizontal distance is greater than zero and less than the horizontal spacing. The first vertical distance ranges from one-tenth of the horizontal width of one of the MUTs to half the vertical height of the MUT.

[0007] In various embodiments, the imaging system includes: a transceiver block for generating pressure waves and converting external pressure waves into electrical signals; and a control unit for controlling the transceiver block. The transceiver block includes an array of micromechanical ultrasonic transducers (MUTs), wherein the array comprises a plurality of MUTs arranged in a two-dimensional array having a first row and a second row, the MUTs in the first row being equally spaced horizontally in the horizontal direction, and the MUTs in the second row being equally spaced horizontally in the same horizontal direction. The MUTs in the second row are shifted relative to the MUTs in the first row along the horizontal direction by a first horizontal distance, and are shifted relative to the MUTs in the first row along a first vertical distance in the vertical direction. The first horizontal distance is greater than zero and less than the horizontal spacing. The first vertical distance ranges from one-tenth of the horizontal width of one of the plurality of MUTs to half the vertical height of the MUT. Attached Figure Description

[0008] Reference will be made to embodiments of the invention, examples of which may be illustrated in the accompanying drawings. These figures are illustrative only and not restrictive. Although the invention has been generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these specific embodiments.

[0009] Figure 1 (or “Figure”) illustrates a two-dimensional linear transceiver array in a conventional system.

[0010] Figure 2 An imaging system according to an embodiment of the present disclosure is shown.

[0011] Figure 3 A schematic diagram of an imager according to an embodiment of the present disclosure is shown.

[0012] Figure 4 An asymmetric (or staggered) linear transceiver array according to an embodiment of the present disclosure is shown.

[0013] Figure 5An enlarged view of a MUT array according to an embodiment of the present disclosure is shown.

[0014] Figure 6 An enlarged view of a MUT array according to an embodiment of the present disclosure is shown.

[0015] Figure 7 Two pairs of rectangular MUTs and pads arranged in an alternating configuration according to an embodiment of the present disclosure are shown.

[0016] Figures 8A to 8D The following is illustrated according to an embodiment of the present disclosure. Figure 7 The vibration mode shape of a set of MUTs is taken from the direction 7-7.

[0017] Figure 9 A frequency response graph of an asymmetric array according to an embodiment of the present disclosure is shown.

[0018] Figure 10 A graph showing the beam pattern response of a MUT array according to an embodiment of the present disclosure as a function of elevation angle is shown.

[0019] Figure 11 Two pairs of elliptical MUTs and pads arranged in an alternating configuration according to an embodiment of the present disclosure are shown.

[0020] Figure 12 An asymmetric (or staggered) linear transceiver array according to an embodiment of the present disclosure is shown.

[0021] Figure 13A and Figure 13B A top view and a cross-sectional view of an exemplary MUT according to an embodiment of the present disclosure are shown. Detailed Implementation

[0022] In the following description, specific details are set forth for purposes of explanation in order to provide an understanding of this disclosure. However, those skilled in the art will readily understand that this disclosure may be practiced without these details. Furthermore, those skilled in the art will recognize that embodiments of this disclosure described below can be implemented in various ways, such as processes, apparatuses, systems, or devices.

[0023] The elements / components shown in the figures are illustrative of exemplary embodiments of this disclosure and are intended to avoid obscuring the disclosure. References to “one embodiment,” “preferred embodiment,” “an embodiment,” or “implementation” in the specification refer to a particular feature, structure, characteristic, or function described in connection with that embodiment being included in at least one embodiment of the invention and may be included in more than one embodiment. The phrases “in one embodiment,” “in various embodiments,” or “in various embodiments” appearing in various places in the specification do not necessarily refer to the same embodiment. The terms “comprising,” “including,” “containing,” and “including” should be understood as open terms, and any list below is illustrative and does not imply limitation to the listed items. Any headings used herein are for organizational purposes only and should not be used to limit the scope of the specification or claims. Furthermore, the use of certain terms in various places in the specification is for illustrative purposes and should not be construed as restrictive.

[0024] Figure 2 An imaging system 100 according to an embodiment of the present disclosure is illustrated. As shown, the system 100 may include: an imager 120 that generates and transmits pressure waves 122 to an internal organ 112, such as the heart, in a transmission mode / process; and a device 102 that transmits signals to the imager via a communication channel 130. In various embodiments, the internal organ 112 may reflect a portion of the pressure waves 122 toward the imager 120, and the imager 120 may capture the reflected pressure waves and generate electrical signals in a reception mode / process. The imager 120 may communicate the electrical signals to the device 102, and the device 102 may use the electrical signals to display images of human organs on a display / screen 104.

[0025] Note that imager 120 can also be used to acquire images of the animal's internal organs. It should also be noted that the pressure wave 122 can be a sound wave, ultrasound wave, or photoacoustic wave, which can pass through the human / animal body and be reflected by the internal organs.

[0026] In various embodiments, the imager 120 may be a portable device and communicates with the device 102 wirelessly or via cable through the communication channel 130. In various embodiments, the device 102 may be a mobile device such as a cellular phone, an iPad, or a fixed computing device capable of displaying images to a user.

[0027] Figure 3 A schematic diagram of an imager 120 according to an embodiment of the present disclosure is shown. In various embodiments, the imager 120 may be an ultrasound imager. Figure 2As shown, the imager 120 may include: a transceiver block 210 for transmitting and receiving pressure waves; a coating 212 that serves as a lens to focus the pressure waves and also as an impedance interface between the transceiver block and the human body 110; a control unit 202, such as an ASIC chip, for controlling the transceiver block 210; a microprocessor 214 for controlling the components of the imager 120; a communication unit 208 for communicating data with an external device, such as device 102, via one or more ports 230; a memory 218 for storing data; a battery 206 for providing power to the components of the imager; and optionally, a display 216 for displaying an image of the target organ.

[0028] In various embodiments, device 102 may have a display / screen. In this case, the display may not be included in imager 120. In various embodiments, imager 120 may receive power from device 102 via one of ports 230. In this case, imager 120 may not include battery 206. It should be noted that one or more components of imager 120 may be combined into a single electronic component. Similarly, each component of imager 120 may be implemented in one or more electronic components.

[0029] In various embodiments, the user can apply the gel to the coating 212, thereby improving the impedance matching between the coating 212 and the human body 110, i.e., reducing power loss at the interface.

[0030] Figure 4 An enlarged view of an asymmetric (or staggered) linear transceiver array 400 including MUTs 402 according to an embodiment of the present disclosure is shown. In various embodiments, array 400 may be included in transceiver block 210. MUTs 402 may be arranged in a staggered configuration to provide the benefits of array acoustic performance. Hereinafter, the term staggered (or asymmetric) array refers to an array of MUTs in which MUTs in the first row are shifted relative to MUTs in the second row along the x-direction 403. In various embodiments, MUTs in a row may be equally spaced by a horizontal distance (spacing) P1 430, while MUTs in a column may be equally spaced by a vertical distance (spacing) P2 432.

[0031] In various embodiments, each MUT 402 may be a pMUT and includes a piezoelectric layer formed of at least one of PZT, KNN, PZT-N, PMN-Pt, AlN, Sc-AlN, ZnO, PVDF, and LiNiO3. In alternative embodiments, each MUT 402 may be a cMUT. Figure 4In the figures, each MUT 402 is shown as having a rectangular shape. More specifically, each MUT may include a top electrode having a rectangular projected area. It will be readily understood by those skilled in the art that the top electrode may have other suitable geometries, such as square, circular, elliptical, oval, etc. For illustrative purposes, each MUT is symbolically represented in the figures by the geometry of its top electrode.

[0032] Figure 5 An enlarged view of a MUT array 500 according to an embodiment of the present disclosure is shown. In various embodiments, array 500 may correspond to Figure 4 This refers to a portion of array 404. As shown, array 500 may include MUTs 502 and solder pads 504. In various embodiments, the MUTs 502 and solder pads 504 are arranged in an interleaved configuration. In various embodiments, each solder pad 504 can electrically couple one or more MUTs 502 to a circuit board such as an ASIC or a circuit board. Figure 5 A substrate (not shown) may be included, wherein the substrate may contain electronic devices for transmitting electrical signals to / receiving electrical signals from the MUT 502. In various embodiments, the substrate may be disposed below the MUT array, and each pad 504 may extend in a vertical direction (i.e., in a direction perpendicular to the paper). Note that in Figure 5 Other electrical connections between MUT 502 and pad 504 are not shown, but it will be readily understood by those skilled in the art that suitable electrical connections such as traces and wires can be used to electrically connect MUT 502 to pad 504.

[0033] Figure 6 An enlarged view of a MUT array 600 according to an embodiment of the present disclosure is shown. In various embodiments, array 600 may correspond to Figure 4 The array 404 is a portion thereof. In various embodiments, the MUTs 602 can be arranged in an interleaved or asymmetrical configuration, and a certain amount of randomness can also be introduced into the orientation of each MUT. In various embodiments, randomness can enhance the acoustic signal of the imager by reducing crosstalk between the MUTs 602. In various embodiments, the randomly rotated MUTs 602 can be maintained in the xy plane, and each pad 604 can be arranged in a manner corresponding to the pad positions in the MUT array 500.

[0034] Figure 7 Two pairs of MUTs 702 and pads 704 arranged in an alternating configuration according to an embodiment of the present disclosure are shown. For illustrative purposes, each MUT is represented by a rectangle, which is the projected area of ​​the top electrode of the MUT. In various embodiments, Figure 7The two MUTs 702a and 702b in the array can be two adjacent MUTs in the MUT array 400. As shown, MUTs 702a and 702b can be separated by a horizontal distance HD706 in the x-direction and a vertical distance VD708 in the y-direction. Each MUT 702 can have a rectangular shape with a width W712 and a height H714. In various embodiments, the horizontal distance HD706 can be greater than zero and less than four times the horizontal width 712 of the MUT and less than the spacing in the x-direction.

[0035] Unlike the conventional MUT array 50, in various embodiments, MUTs 702a and 702b can be arranged in an interleaved configuration, that is, a pair of MUTs 702a and pads 704a in the first row can be shifted in the x-direction relative to a pair of MUTs 702b and pads 704b in the second row. As a result of the interleaved configuration, the MUT array 400 can have one or more asymmetric operating modes (or, simply, asymmetric modes), resulting in a wider bandwidth than the conventional MUT array 50. Because the MUT array 400 can have a wider bandwidth, the MUT array can operate in more complex operating modes.

[0036] Typically, the number density of MUTs in a MUT array can affect the resolution of the image produced by the MUT array. In a conventional MUT array 50, the number density of MUTs can be increased by reducing the horizontal distance (or equivalent, horizontal spacing) between MUTs. However, in a conventional MUT array, the mutual impedance between two adjacent MUTs may also increase with a decrease in horizontal spacing, which may offset the benefits gained by increasing digital density. Hereinafter, mutual impedance refers to the acoustic coupling between two MUTs. Conversely, in various embodiments, the diagonal distance P730 can be the effective spacing between MUTs 702a and 702b. Thus, in various embodiments, the mutual impedance can be less than that of a conventional symmetrical MUT array with the same horizontal spacing HD 706. In other words, the staggered configuration can allow for an increase in number density without significantly increasing mutual impedance.

[0037] In various embodiments, the vertical distance 708 can influence the characteristics of asymmetric vibration modes, such as the frequency of the asymmetric mode and the sound pressure level under the vibration mode, as in combination with... Figures 8A to 9 As explained below, the term sound pressure level refers to the level of sound power generated by each MUT. In various embodiments, the vertical distance 708 may preferably be greater than one-tenth of the width 712 and less than half the height 714. In various embodiments, as VD 708 increases to less than half the height 714, the sound pressure amplitude in asymmetric mode may increase.

[0038] Figures 8A to 8DThe following is illustrated according to an embodiment of the present disclosure. Figure 7 The vibration mode shapes of the MUT702b are shown in section 7-7. For illustrative purposes, the MUT 702b is... Figures 8A to 8D The middle part is represented by a single line. However, it will be readily understood by those skilled in the art that a MUT can include a stack of multiple layers. As shown in the figure, Figure 8A and Figure 8B The first vibration mode 801 and the third vibration mode 807 of the MUT 702b at the first resonant frequency and the third resonant frequency, respectively, are presented, with arrow 804 indicating the direction of motion of the MUT 702b. In various embodiments, the first and third vibration modes can be symmetrical, that is, the shape of each mode is symmetrical with respect to the center line 820 of the MUT 702b. In various embodiments, symmetrical modes can be generated even when the MUTs are not interlaced, that is, the symmetrical MUT array 50 can have Figure 8A and Figure 8C Symmetric vibration modes in.

[0039] In each implementation, Figure 8B and Figure 8D The second vibration mode 805 and the fourth vibration mode 809 at the second and fourth resonant frequencies of the MUT 702b are shown, respectively. As shown, the second and fourth vibration modes can be asymmetrical, that is, the MUT is asymmetrical with respect to the center line 820. In various embodiments, the asymmetry of the vibration modes can be obtained by arranging the MUT in an interlaced (asymmetrical) configuration, such as... Figure 4 As shown.

[0040] Typically, sound pressure performance can refer to the energy of the sound pressure wave generated by each MUT at a certain frequency, which increases as the peak amplitude of the MUT at that frequency increases. In various embodiments, when asymmetric modes vibrate at the same order, the asymmetric modes can achieve a wider bandwidth compared to symmetric modes. For example, the third mode 807 and the fourth mode 809 can have the same order, i.e., the same number of nodes, and the peak amplitude 840 of the third mode 807 is smaller than the peak amplitude 842 of the fourth mode 809.

[0041] Figure 9 A frequency response graph 900 of an asymmetric MUT array 400 according to an embodiment of the present disclosure is shown. Figure 9 In the diagram, curve 912 shows the response (y-axis) of array 400 as a function of frequency, where the response refers to the peak amplitude of the pressure wave generated by the array during transmit mode or the peak amplitude of the charge generated during receive mode. Figure 9 In the figure, curve 910 shows the response of the symmetrical array 50 as a function of frequency.

[0042] As shown in the figure, the staggered MUT array 400 can have a resonant vibration mode near a frequency of 914, where the frequency of 914 can also be a resonant vibration mode of the symmetrical MUT array 50. In various embodiments, Figure 7 The interleaved MUT array 400 can have an additional resonant frequency at frequency 916, which is referred to as the asymmetric resonant frequency. In various embodiments, there are symmetric and asymmetric vibration modes, such as... Figure 9 As shown, since the MUT array 400 can operate at both the center-symmetric frequency 914 and the high-asymmetric frequency 916, the gain of the acoustic response can be increased and the bandwidth can be improved.

[0043] Note that frequency response curve 912 can include contributions from all MUTs in array 400. Since each MUT in the staggered MUT array 400 can have the same frequency response characteristics, each MUT has a frequency response curve similar to curve 912, that is, each MUT in the asymmetric array 400 can have a resonant frequency at both the central symmetric frequency 914 and the asymmetric frequency 916.

[0044] In various embodiments, beamforming technology can be used to guide pressure waves emitted by imager 120 to a specific angle. That is, pressure waves from MUT array 400 can be combined such that pressure waves at a specific angle (i.e., the beamforming direction) encounter constructive interference, while at other angles they encounter destructive interference. In various embodiments, control unit 202 can control the phase and / or amplitude of the pressure waves generated by MUT array 400 to manipulate the beamforming direction. Figure 10 A graph showing the beam pattern response of a MUT array according to an embodiment of the present disclosure as a function of elevation angle is shown. Figure 10 In the diagram, each curve shows the acoustic response (y-axis) of the MUT array as a function of the elevation angle, where the acoustic response refers to the peak amplitude of the pressure wave generated by the MUT array during transmit mode (or the charge generated during receive mode), and the elevation angle refers to the angular distance relative to the beamforming direction.

[0045] Typically, directivity (which refers to the blocking of noise outside the direction of interest, 1020°) affects the signal-to-noise ratio in beamforming. (Hereinafter, the term "direction of interest" refers to a preset angular range around the beamforming direction.) Figure 10In the figure, curve 1002 indicates the normalized power directivity of an asymmetric (interlaced) MUT array (e.g., 400) and an asymmetric (non-interlaced) array (e.g., 50) at a frequency of 1.5 MHz. Curves 1006a and 1006b show the directivity of the asymmetric and symmetric arrays at a frequency of 3.0 MHz, respectively. As shown, a symmetric MUT array can have a similar beam pattern to an asymmetric MUT array at frequencies of 1.5 MHz and 3.0 MHz.

[0046] Curves 1004a and 1004b illustrate the beam patterns of the asymmetric and symmetric arrays, respectively, at a frequency of 5.7 MHz. As shown, the asymmetric array exhibits higher (improved) directivity than the symmetric array, resulting in improved signal-to-noise ratio and image quality. For example, curves 1004a and 1004b have regions 1010a and 1010b outside the direction of interest 1020. Since the power level at region 1010b is lower than that at region 1010a, the asymmetric array can have an improved signal-to-noise ratio, thereby improving image quality.

[0047] In various embodiments, the top electrode of the MUT in array 400 can have different geometries, such as circular, elliptical, oval, etc. Figure 11 The diagram illustrates two pairs of elliptical MUTs and circular pads arranged in an alternating configuration according to an embodiment of the present disclosure. As shown, the MUTs 1102 may be separated by a horizontal distance HD1106 in the x-direction and a vertical distance VD1108 in the y-direction. Each MUT 1102 may be elliptical with a width W 1112 and a height H 1114.

[0048] Unlike a conventional MUT array 50, in various embodiments, MUTs 1102a and 1102b can be arranged in an interleaved configuration; that is, a pair of MUTs 1102a and pads 1104a in the first row can be shifted in the x-direction relative to a pair of MUTs 1104b and pads 1104b in the second row. In various embodiments, the vertical distance 1108 can preferably be greater than one-tenth of the horizontal width 1112 and less than half of the vertical height 1114. In various embodiments, as VD 1108 increases to half the vertical height 1114, the sound pressure level amplitude in asymmetric mode may increase.

[0049] As a result of the staggered configuration, Figure 11 A staggered MUT array can have the same configuration as... Figure 7 It has similar advantages to the staggered MUT array, that is, compared with the non-staggered MUT array, Figure 11The staggered MUT array may have improved bandwidth, image resolution, field of view, sound pressure level, and mutual impedance between MUTs. In various embodiments, the MUTs may be separated by a horizontal distance 1106, wherein the horizontal distance 1106 may be greater than zero and less than four times the horizontal width 1112 of the MUTs and less than the spacing in the x-direction.

[0050] Figure 12 An enlarged view of an asymmetric (or staggered) linear transceiver array 1200 including MUT 1202 according to an embodiment of the present disclosure is shown. The MUTs 1202 can be arranged in a staggered configuration to provide benefits for the array's acoustic performance. As shown, the MUTs in each row can be spaced equally horizontally (spacing), while the MUTs in each column can be spaced equally vertically (spacing). In various embodiments, the MUTs in the second row can be shifted a first horizontal distance relative to the MUTs in the first row along the x-direction 1203, and the MUTs in the third row can be shifted a second horizontal distance relative to the MUTs in the first row along the x-direction, wherein the first and second horizontal distances can be greater than zero and less than the horizontal spacing P1.

[0051] Figure 13A A top view of an exemplary MUT 1300 according to an embodiment of the present disclosure is shown. Figure 13B The image shown is a section taken along line 13-13 according to an embodiment of this disclosure. Figure 13A A cross-sectional view of MUT 1300 is shown. As shown, the MUT may include: a film layer 1306 suspended from a substrate 1302; a bottom electrode (O) 1308 disposed on the film layer (or simply film) 1306; a piezoelectric layer 1310 disposed on the bottom electrode (O) 1308; and a top electrode (X) 1312 disposed on the piezoelectric layer 1310. In various embodiments, an electrical pad 1314 may be formed, which may be a through-hole filled with a conductive material, such that the bottom electrode (O) 1308 can be electrically connected to a conductor 1322. In various embodiments, the conductor 1322 may be electrically connected to the top electrode 1312. In various embodiments, the conductors 1320 and 1322 may be wires or traces formed by patterned metal layers. In various embodiments, the pad 1314 and the top electrode 1312 may correspond to pad 704 (or 1104) and MUT 702 (or 1102), respectively.

[0052] In various embodiments, the substrate 1302 and the membrane 1306 may be a single unit, and a cavity 1304 may be formed to define the membrane 1306. In various embodiments, the cavity 1304 may be filled with gas at a predetermined pressure or with an acoustic damping material to control the vibration of the membrane 1306.

[0053] Note that the MUTs in transceiver arrays 400 and 1200 can have the same characteristics as... Figure 13A Other configurations of the MUT 1300 vary. For example, each MUT can have more than one top electrode. This should be readily understood by those skilled in the art. Figures 4 to 7 (or Figures 11 to 12 Each rectangle (or ellipse) in the diagram symbolically represents a MUT, where the MUT may have one or more top electrodes, and the top electrodes may have suitable geometries such as circles, rectangles, ellipses, etc.

[0054] This invention provides, but is not limited to, the following embodiments:

[0055] 1. A transducer array, comprising:

[0056] Multiple micromechanical ultrasonic transducers (MUTs) arranged asymmetrically.

[0057] 2. The transducer array according to embodiment 1, wherein the size of the MUT in one direction is larger than the size of the MUT in another direction.

[0058] 3. The transducer array according to embodiment 1, wherein the center-to-center distance between the plurality of MUTs in one direction is different from the center-to-center distance between the plurality of MUTs in another direction.

[0059] 4. The transducer array according to embodiment 1, wherein the plurality of MUTs have a smaller mutual impedance than the plurality of MUTs arranged symmetrically.

[0060] 5. The transducer array according to embodiment 1, wherein the plurality of MUTs have one or more additional vibration modes compared to a plurality of symmetrically arranged MUTs.

[0061] 6. The transducer array according to embodiment 1, wherein each of the plurality of MUTs has an elongated shape, the elongated shape supporting one or more vibration modes in a flexural operation mode.

[0062] 7. A transducer array according to one of embodiments 1-6, wherein the plurality of MUTs comprises a set of elongated MUTs along an axis, and the set of elongated MUTs is combined with a similar set of PMUTs offset from each other in one direction.

[0063] 8. A transducer array according to any one of embodiments 1-6, wherein the projection area of ​​each of the plurality of MUTs has a rectangular, elliptical or circular shape.

[0064] 9. A transducer array according to any one of embodiments 1-6, wherein the plurality of MUTs have a first effective grating angle without encountering grating lobes, and wherein the plurality of symmetrically arranged MUTs have a second effective grating angle without encountering grating lobes, and wherein the first effective grating angle is greater than the second effective grating angle.

[0065] 10. A transducer array according to any one of embodiments 1-6, wherein the sidelobe amplitude of the beam generated by the plurality of MUTs is lower than that of the beam generated by the plurality of symmetrically arranged MUTs.

[0066] 11. The transducer array according to any one of embodiments 1-6, wherein the bandwidth of the plurality of MUTs is wider than that of a plurality of MUTs arranged symmetrically.

[0067] 12. A transducer array according to any one of embodiments 1-6, wherein each of the plurality of MUTs has a dimension along a first direction, the dimension along the first direction being greater than the dimension along a second direction, and wherein the plurality of MUTs has a wider bandwidth than the other plurality of MUTs, and wherein each of the other plurality of MUTs has the same dimension along the first direction and the second direction.

[0068] 13. A transducer array according to any one of embodiments 1-6, wherein each of the plurality of MUTs is rotated by a random angle relative to the axis.

[0069] 14. The transducer array according to embodiment 1, wherein each of the plurality of MUTs performs at least one of transmitting and receiving ultrasonic waves.

[0070] 15. The transducer array according to embodiment 1, wherein each of the plurality of MUTs operates in at least one mode of symmetric vibration mode and asymmetric vibration mode.

[0071] 16. An array of micromechanical ultrasonic transducers (MUTs), comprising:

[0072] Multiple MUTs are arranged in a two-dimensional array having a first row and a second row, wherein the MUTs in the first row are equally spaced apart in the horizontal direction by a horizontal spacing, and the MUTs in the second row are equally spaced apart in the same horizontal direction.

[0073] The MUT in the second row is shifted by a first horizontal distance relative to the MUT in the first row along the horizontal direction, and by a first vertical distance relative to the MUT in the first row along the vertical direction.

[0074] 17. The array according to embodiment 16, wherein the first horizontal distance is greater than zero and less than the horizontal spacing, and the first vertical distance ranges from one-tenth of the horizontal width of the MUT among the plurality of MUTs to half the vertical height of the MUT.

[0075] 18. The array according to embodiment 16, wherein the two-dimensional array has a third row, and the MUT in the third row is shifted relative to the MUT in the first row along the horizontal direction by a second horizontal distance, wherein the second horizontal distance is greater than zero and less than the first horizontal distance.

[0076] 19. The array according to embodiment 16, wherein each of the plurality of MUTs includes an electrode, and the shape of the projection area of ​​the electrode is one of a rectangle, an ellipse, and a circle.

[0077] 20. The array according to embodiment 16, wherein the vertical height of each of the plurality of MUTs is greater than the horizontal width of the MUT.

[0078] 21. The array according to embodiment 16, wherein each of the plurality of MUTs has one or more asymmetric vibration modes.

[0079] 22. The array according to embodiment 16, wherein each of the plurality of MUTs is rotated by a random angle relative to the vertical direction.

[0080] 23. The array according to embodiment 16, wherein each of the plurality of MUTs is a piezoelectric micromechanical ultrasonic transducer.

[0081] 24. The array according to embodiment 23, wherein each of the plurality of MUTs includes a piezoelectric layer formed of at least one of PZT, KNN, PZT-N, PMN-Pt, AlN, Sc-AlN, ZnO, PVDF and LiNiO3.

[0082] 25. The array according to embodiment 16, wherein the operating bandwidth of the array is wider than the operating bandwidth of the two-dimensional symmetric array of the MUT.

[0083] 26. An imaging system, comprising:

[0084] Transceiver block, used to generate pressure waves and convert external pressure waves into electrical signals; and

[0085] Control unit, used to control the transceiver block;

[0086] The transceiver block includes an array of micromechanical ultrasonic transducers (MUTs), the array comprising:

[0087] Multiple MUTs are arranged in a two-dimensional array having a first row and a second row, wherein the MUTs in the first row are equally spaced apart in the horizontal direction by a horizontal spacing, and the MUTs in the second row are equally spaced apart in the horizontal direction by the same horizontal spacing; and

[0088] The MUT in the second row is shifted by a first horizontal distance relative to the MUT in the first row along the horizontal direction, and by a first vertical distance relative to the MUT in the first row along the vertical direction.

[0089] 27. The imaging system according to embodiment 26, wherein the first horizontal distance is greater than zero and less than the horizontal spacing, and the range of the first vertical distance is from one-tenth of the horizontal width of the MUT among the plurality of MUTs to half the vertical height of the MUT.

[0090] 28. The imaging system according to embodiment 26, wherein the two-dimensional array has a third row, and the MUT in the third row is shifted relative to the MUT in the first row along the horizontal direction by a second horizontal distance, wherein the second horizontal distance is greater than zero and less than the first horizontal distance.

[0091] While the invention is readily adaptable to various modifications and alternatives, specific examples have been shown in the accompanying drawings and described in detail herein. However, it should be understood that the invention is not limited to the specific forms disclosed, but rather covers all modifications, equivalents, and alternatives falling within the scope of the appended claims.

Claims

1. A portable imaging system, comprising: A planar transceiver block is used to generate pressure waves and convert external pressure waves into electrical signals; as well as Control unit, used to control the transceiver block; The transceiver block includes a transducer array, which comprises multiple micromechanical ultrasonic transducers (MUTs) arranged in an alternating pattern. Each of the plurality of MUTs has a dimension along a first direction, which is larger than a dimension along a second direction. In the staggered arrangement, the MUTs in the second row are horizontally shifted relative to the MUTs in the first row, the first and second rows are spaced apart by a first vertical distance, wherein the first vertical distance ranges from one-tenth of the horizontal width of the MUT to half the vertical height of the MUT. Each of the plurality of MUTs has an elongated shape, which supports one or more vibration modes in a flexural operating mode.

2. The portable imaging system of claim 1, wherein the plurality of MUTs of the transducer array are arranged in an asymmetrical configuration.

3. The portable imaging system of claim 2, wherein the center-to-center distance between the plurality of MUTs in one direction is different from the center-to-center distance between the plurality of MUTs in another direction.

4. The portable imaging system of claim 2, wherein the plurality of MUTs has a smaller mutual impedance than a plurality of MUTs arranged symmetrically.

5. The portable imaging system of claim 2, wherein the plurality of MUTs have one or more additional vibration modes compared to a plurality of symmetrically arranged MUTs.

6. The portable imaging system of claim 2, wherein the sidelobe amplitude of the beam generated by the plurality of MUTs is lower than that of the beam generated by the plurality of symmetrically arranged MUTs.

7. The portable imaging system of claim 2, wherein the bandwidth of the plurality of MUTs is wider than that of a plurality of MUTs arranged symmetrically.

8. The portable imaging system of claim 1, wherein the projection area of ​​each of the plurality of MUTs has a rectangular, elliptical, or circular shape.

9. The portable imaging system of claim 1, wherein each of the plurality of MUTs is rotated by a random angle relative to the axis.

10. The portable imaging system of claim 1, wherein each of the plurality of MUTs performs at least one of transmitting and receiving ultrasonic waves.

11. The portable imaging system of claim 1, wherein each of the plurality of MUTs operates in at least one of a symmetrical vibration mode and an asymmetrical vibration mode.

12. The portable imaging system of claim 1, wherein the plurality of MUTs of the transducer array are arranged in a two-dimensional array having a first row and a second row, the MUTs in the first row being equally spaced apart in the horizontal direction by a horizontal spacing, and the MUTs in the second row being equally spaced apart in the horizontal direction by the horizontal spacing; the MUTs in the second row being shifted relative to the MUTs in the first row along the horizontal direction by a first horizontal distance, and shifted relative to the MUTs in the first row along the vertical direction by a first vertical distance.

13. The portable imaging system of claim 12, wherein the two-dimensional array has a third row, and the MUT in the third row is shifted relative to the MUT in the first row along the horizontal direction by a second horizontal distance, wherein the second horizontal distance is greater than zero and less than the first horizontal distance.

14. The portable imaging system of claim 1, wherein the vertical height of each of the plurality of MUTs is greater than the horizontal width of the MUT.

15. The portable imaging system of claim 1, wherein each of the plurality of MUTs has one or more asymmetric vibration modes.

16. The portable imaging system of claim 1, wherein the transducer array has a randomly rotating MUT.

17. The portable imaging system of claim 1, wherein each of the plurality of MUTs is a piezoelectric micromechanical ultrasonic transducer.

18. The portable imaging system of claim 1, wherein each of the plurality of MUTs comprises a piezoelectric layer formed of at least one of PZT, KNN, PZT-N, PMN-Pt, AlN, Sc-AlN, ZnO, PVDF and LiNiO3.

Images