An ultrasonic sensor array addressing and excitation method and circuit

Abstract

The application discloses a kind of ultrasonic sensor array addressing excitation method and circuit, this method is controlled by being controlled to the element in sensor array, then the excitation of the gated element is realized.The addressing excitation method and circuit in the application are mainly used for the ultrasonic sensor array of row-column electrode collinear, each element in sensor array is bidirectional transceiving mode of operation.Element (i,j) is first electrically gated to row and column corresponding to addressing excitation, after element gating, excitation electric pulse is acted on element by circuit loop to generate ultrasonic wave.Addressing excitation circuit mainly includes row, column gating control circuit and excitation electric pulse generation circuit.Element signal connection complexity in sensor array is reduced from traditional N×M to N+M.The application is suitable for row-column addressing ultrasonic sensor array excitation system, and circuit scale is far lower than traditional ultrasonic sensor array excitation circuit, and excitation element gating and excitation are flexible and controllable.

Description

Technical Field

[0001] This invention belongs to the field of ultrasonic testing and relates to an ultrasonic sensor array addressing and excitation method and circuit. Background Technology

[0002] Ultrasonic testing is widely used in material defect detection. Ultrasonic sensor arrays, with their advantages of large scanning range, rich echo information acquisition, and flexible adjustable transmission beam, have been widely applied in ultrasonic phased array testing and ultrasonic full-matrix full-focusing testing. However, the excitation methods of these sensor arrays are relatively simple, and delayed excitation requires high precision and intensity, resulting in high complexity and cost of the sensor array and the detection system composed of transmitting and receiving circuits, which restricts its promotion and application. Furthermore, traditional excitation methods involve each array element being connected to a separate signal line and a reference level line, leading to numerous signal connection lines. When the number of array elements is large, each element requires a separate transmitting and receiving circuit, increasing the number of back-end signal processing modules and complicating the overall system design.

[0003] This invention addresses the current state of ultrasonic sensor array excitation by employing a row-column addressing excitation mode to achieve gating excitation and reception of arbitrary array elements. It also provides a method and implementation circuit system for gating excitation of arbitrary array elements. This invention achieves excitation of arbitrary array elements with fewer element electrode signal leads, significantly reducing the number of channels in the excitation and receiving circuits. This makes the sensor excitation mode more flexible, significantly reduces circuit complexity, and lowers the cost of the detection system, making it particularly suitable for the fabrication of large-scale ultrasonic sensor arrays. Summary of the Invention

[0004] The purpose of this invention is to overcome the limitations of existing ultrasonic sensor arrays by flexibly exciting array elements and receiving reflected ultrasonic signals through the row and column electrodes of an ultrasonic sensor array, thereby reducing circuit complexity and size, improving circuit utilization, and effectively reducing the cost of the detection system. To this end, an addressing and excitation method and circuit for an ultrasonic sensor array are provided.

[0005] To achieve the above objectives, the specific technical solution of the present invention is as follows:

[0006] Step 1: The sensor array is an N×M planar array, with N rows and M columns. Any array element is numbered (i, j), i = 1, 2, ..., N, j = 1, 2, ..., M. Array elements with the same row number are collinearly connected, and array elements with the same column number are collinearly connected.

[0007] Step 2: Use the row collinear electrodes as ground electrodes and the column collinear electrodes as signal electrodes to form N ground electrode leads and M signal leads;

[0008] Step 3: The control circuit generates a square wave signal with an adjustable duty cycle, which is then amplified to obtain G1, G2, ..., Gi, ... GN, which are used for row gating control.

[0009] Step 4: The control circuit generates a square wave signal with an adjustable duty cycle, which is then amplified to obtain T1, T2, ..., Tj, ...TM, which are used for column gating control.

[0010] Step 5: Connect the Gi signal and Tj signal to the input terminals of the row and column gating control circuits, respectively, as gating control signals for electronic switches Q and U;

[0011] Step 6: The circuit generates positive DC high voltage P1 and negative DC high voltage P2, which are then current-limited by resistors and connected to the column selection circuit and row selection circuit respectively.

[0012] Step 7: A low logic level for the row strobe control signal Gi turns on PMOS transistor Q, and a high logic level turns it off. A high logic level for the column strobe control signal Tj turns on NMOS transistor U, and a low logic level turns it off.

[0013] Step 8: When the row control signal Gi and column control signal Tj corresponding to the array element number (i, j) are at logic low level and logic high level respectively, the array element is selected;

[0014] Step 9: Apply a positive DC high voltage P1 to charge capacitor C. When an array element is selected, capacitor C discharges, exciting the array element, which then generates ultrasonic waves.

[0015] Step 10: The array element generates ultrasonic waves, which are reflected by the object being measured. The array element that needs to receive the ultrasonic echo is selected according to the control timing.

[0016] Step 11: After the ultrasonic wave reception is completed, other array elements are selected, excited, and received according to the control timing. This process can be repeated to achieve the selection, excitation, and reception of any array element in the array.

[0017] Step 1 is as follows: The sensor array consists of discrete array elements, all of which are cut and processed from piezoelectric ceramic sheets. The elements are of equal size and have both ultrasonic transmitting and receiving modes. Each element has a unique number (i, j) and a top electrode and a bottom electrode. The top and bottom electrodes of elements in the same row and column are connected collinearly, forming N top row electrodes with the same row number and M bottom column electrodes with the same column number. The gaps between the elements are filled with insulating sound-absorbing material, and there are no other electrical connections between the elements.

[0018] Step 2 specifically involves using the row collinear electrodes as ground electrodes and the column collinear electrodes as signal electrodes, forming N ground electrode leads and M signal leads. The selection of the top and bottom electrodes can be interchanged; this description method is used for ease of description only.

[0019] Step 3 specifically involves: generating a square wave signal with an adjustable duty cycle by the control circuit. This square wave signal is generated by a microcontroller (MCU), and the power amplification is achieved using a charge pump. The signal output from the charge pump is converted from high to low level to obtain G1, G2, ..., Gi, ... GN, which are used for row selection control.

[0020] Step 4 specifically involves: A square wave signal with an adjustable duty cycle is generated by the control circuit. This square wave signal is generated by a microcontroller (MCU), and the power amplification is implemented using a circuit composed of transistors and capacitors. The logic high and low levels differ from the MCU output; the logic high level begins at the falling edge of the MCU output square wave, and the duty cycle decreases. This yields T1, T2, ..., Tj, ... TM, which are used for column gating control.

[0021] Step 5 specifically involves connecting the Gi signal and the Tj signal to the input terminals of the row and column gating control circuits, respectively, with the input terminals being the gates of the MOS transistors.

[0022] Step 6 specifically involves: A positive DC high voltage P1 is generated by the DC high voltage module and used to charge capacitor C, generating an electrical pulse signal to excite the ultrasonic array elements through discharge. A negative DC high voltage P2 is generated by the DC high voltage module and used to block the flow between the excitation electrical pulse and ground. P1 and P2 should satisfy |P1| < |P2|.

[0023] Step 7 is as follows: The column selection control signal Tj is at a logic high level, turning on the NMOS transistor U. After it turns on, the excitation pulse discharges through the capacitor C, exciting the array element to generate ultrasonic waves. After the discharge is complete, U is in the off state. At this time, the circuit charges the capacitor, which is used as the next excitation pulse for the array element to generate ultrasonic waves. After the discharge is complete, transistor Q is in the on state and remains so until the corresponding array element receives the echo signal.

[0024] Step 8 specifically involves: after the array element number (i, j) is selected, the array element excitation pulse discharges to generate ultrasonic waves. This step is the excitation of the array element selection. The receiving array element can only start receiving echo signals after it is turned on according to the control timing sequence, which is determined by the time corresponding to the sound path of the measured object.

[0025] Step 9 specifically involves: when receiving ultrasonic echoes, the receiving array element must always be in the gating state, and the time window must not be less than twice the time it takes for the ultrasonic wave to travel through the object.

[0026] The ultrasonic sensor array addressing excitation circuit of the present invention mainly includes a square wave generation circuit, a power amplification circuit, a gating control circuit, and an excitation electrical pulse generation circuit.

[0027] The square wave generation circuit consists of a microcontroller (MCU), which generates square wave signals through the timer function of the MCU's I / O ports. The frequency of the square wave signal used for row and column gating control is determined by the repetition frequency of the ultrasonic sensor. The MCU first generates the square wave signal corresponding to the column gating control, while the starting point of the row gating square wave signal is determined by the falling edge of the column gating square wave signal. The duration of the gating gate is determined by the actual ultrasonic measurement path.

[0028] The power amplifier circuit described above is mainly used to amplify the power of the square wave generated by the MCU to effectively drive the Q-transistor and U-transistor. The power amplifier circuit for the column control square wave signal consists of transistors and capacitors. The transistors are mainly used for power amplification, while the capacitors are mainly used to capture the rising and falling edges of the square wave signal before power amplification to determine the starting point of the column strobe signal and the duration of the high level of the square wave. The power amplifier circuit for the row control square wave signal is implemented by a charge pump chip and is mainly used for power amplification and high / low level switching of the square wave signal.

[0029] The aforementioned gating control circuit mainly consists of NMOS and PMOS transistors. The NMOS transistor is used to control column gating, and then an excitation pulse is applied to the array element to generate ultrasonic waves. The PMOS transistor is used to control row gating, and then combined with P2 to achieve cutoff and conduction.

[0030] The excitation pulse generation circuit mainly consists of a DC high-voltage module and a capacitor. The DC high-voltage module provides the electrical pulse energy required to excite the array elements, and the capacitor is used for charging and discharging to excite the array elements and generate ultrasonic waves.

[0031] The present invention has the following advantages: The ultrasonic sensor array addressing excitation method is different from the traditional ultrasonic sensor array addressing excitation method. The advantage of the present invention is that it uses three control signals with a certain timing to excite any array element and receive its reflected echo. The hardware circuit structure is simple and easy to implement. A low duty cycle control signal is obtained by using a high duty cycle control signal. While ensuring flexible excitation of array elements, different array elements can be used flexibly to receive echo data. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the ultrasonic sensor array addressing and excitation system of the present invention.

[0033] Figure 2 This is a schematic diagram of an example ultrasonic sensor array structure of the present invention;

[0034] Figure 3This is the default switching configuration of the row and column electrodes when they are not excited, as described in this invention example.

[0035] Figure 3A This is an example of an excitation pulse emission circuit for the present invention;

[0036] Figure 3B This is an example of a ground loop selection circuit for the present invention;

[0037] Figure 4 This invention illustrates the switching configuration of row and column electrodes when any single array element is excited.

[0038] Figure 5 This invention provides an example of the switching configuration of row and column electrodes when any single array element receives data.

[0039] Figure 6 This is a timing diagram illustrating the excitation and receiving switch configuration of any single array element in this invention.

[0040] Figure 7 This is an example of an excitation pulse waveform diagram for the present invention;

[0041] Figure 8 (a) is a waveform diagram of the horizontal electrode bias voltage when the horizontal electrode is configured in a high-resistance state according to an example of the present invention; Figure 8 (b) Waveform diagram of the traveling electrode when configured in the grounding state;

[0042] Figure 9 This is a waveform diagram of the measured ultrasonic echo signal under the single-element excitation mode of the present invention. Detailed Implementation

[0043] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that the present invention can also be applied through other equivalent embodiments. The embodiments and accompanying drawings provided in the following examples are only illustrative of the basic technical concept of the present invention. The model, number, size, material, and other parameters of the relevant components in the embodiments may be changed in the specific implementation environment. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] The 8-row and 8-column array structure used in this invention is mainly because it can perform the aforementioned functions, and can be extended to arrays of different sizes by the addressing excitation method and circuit.

[0045] To facilitate understanding of this addressing excitation method, the addressing method exemplified in this invention will first be described. Figure 1 The diagram illustrates the system composition and principle of the present invention, with a partial view of the sensor array shown below. Figure 1As shown, 101 is the sensor backing layer, 102 is the row electrode, 103 is the sensor element, 104 is the matching layer, and 105 is the column electrode. The sensor array is an N×M planar array, where the number of rows is N and the number of columns is M. Any element is numbered (i, j), i = 1, 2, ..., N, j = 1, 2, ..., M. Elements with the same row number are collinearly connected, and elements with the same column number are collinearly connected. The collinear row electrodes are used as ground electrodes, and the collinear column electrodes are used as signal electrodes, forming N ground electrode leads and M signal leads. A microcontroller (MCU) generates two square wave signals with adjustable duty cycles, which are then amplified to obtain G1 and G2. ..., Gi, ... GN and T1, T2, ..., Tj, ... TM are used for row selection control and column selection control, respectively. The Gi and Tj signals are connected to the input terminals of the row and column selection control circuits, respectively, as selection control signals for electronic switches Q and U. Positive DC high voltage P1 and negative DC high voltage P2 are generated by the high-voltage module, and after current limiting by resistors, they are connected to the column selection circuit and row selection circuit, respectively. A logic low level for the row selection control signal Gi turns on PMOS transistor Q, and a logic high level turns it off. A logic high level for the column selection control signal Tj turns on NMOS transistor U, and a logic low level turns it off. When the row control signal Gi and column control signal Tj corresponding to the array element number (i, j) are at logic low and logic high levels respectively, the array element is selected. The positive DC high voltage P1 charges the capacitor C. When the array element is selected, the capacitor C discharges, exciting the array element, which then generates ultrasonic waves. The ultrasonic waves generated by the array element are reflected by the object under test. According to the control timing, the array element that needs to receive the ultrasonic echo is selected, and the ultrasonic echo is received. After the ultrasonic wave is received, other array elements are selected, excited, and received according to the control timing. This process can be repeated to achieve the selection, excitation, and reception of any array element in the array.

[0046] Figure 2 The target ultrasonic sensor array structure of this invention includes an overall ultrasonic sensor array structure 201, a sensor array backing layer 202, sensor array row electrodes 203, a sensor array 204, sensor array column electrodes 205, and a sensor array matching layer 206. Various coupling techniques can be used to combine these components. For example, conductive silver paste can be applied to the upper and lower surfaces of the array elements, and the row electrodes 203 and column electrodes 205 can be imprinted onto the upper and lower surfaces of the array elements. All array elements are cut from piezoelectric ceramic sheets, are of equal size, and the gaps between the elements are filled with insulating sound-absorbing material. There are no other electrical connections between the array elements. To reduce the attenuation of the ultrasonic signal by the column electrodes, the column electrodes adopt a hollow design. Figure 2 When the sensor array is in a dormant state, the row and column electrodes are in the gating state. When the column electrodes are gating, the receiving state is not selected and the echo signal is not sampled. When the row electrodes are gating, the high impedance state is selected and no excitation or reception of any array element is selected. Figure 3A The column excitation gating circuit includes a power amplifier circuit, a gating control circuit, and an excitation pulse generation circuit. A control signal T is generated via the MCU's I / O port timer function. When the control signal T is a falling edge, it passes through a power amplifier circuit composed of transistors and capacitors to generate a signal Tj. A high-level Tj signal drives the NMOS transistor, causing capacitor C1 to discharge and generate the excitation pulse. When the control signal T is in other states, a low-level Tj signal cuts off the NMOS transistor, and capacitor C1 charges. VCC_PH_Power is connected to the positive high-voltage power supply. Figure 3B The control loop gating circuit, including a power amplifier circuit and a gating control circuit, uses a charge pump chip to amplify the control signal G, which is used to control the PMOS transistor's on / off state. When the control signal G is high, the PMOS transistor is on, and the row electrode is connected to the reference ground, i.e., configured as GND; when the control signal G is low, the PMOS transistor is off, i.e., configured as a high-impedance state. The starting point of the control signal G is determined by the falling edge of the column gating square wave signal, and the duration is determined by the actual ultrasonic measurement path. The frequency of the square wave signal used for row and column gating control is determined by the repetition frequency of the ultrasonic sensor. VCC_NH_Power is connected to a negative high-voltage power supply with an amplitude greater than or equal to the amplitude of VCC_PH_Power. ij The state of array element (i, j) is represented by the following formula.

[0047]

[0048] Among them, L i L represents the state of the i-th row, in the high-impedance state. i =0, L in grounded state i =1; C j Represents the state of column j, where C is the received state. j =0, C in the launch state j =1.

[0049] The following is combined with Figures 4 to 6 Detailed description of the gating timing of the present invention:

[0050] Figure 4 The diagram illustrates the electrode configuration when stimulating (4,4) array elements, with column C4 configured in T4 mode and row L4 configured in GND state. Figure 5 The diagram illustrates the electrode configuration when receiving ultrasonic reflection signals from (4,4) array elements. Column C4 is configured in R4 mode and the signal is sampled, while row L4 is configured in GND state. Figure 6 This is a timing diagram of control signals T, R, and G under the array element excitation and echo signal reception modes. t0 is the start time; at t1, control signal T4 is applied to the pulse transmitting circuit of column C4; at t2, the excitation pulse is generated on the falling edge of control signal T4, and control signal GND is high.44 =1 indicates the excitation state; simultaneously, control signal R4 switches to high level, and sampling of ultrasonic reflection signals in column C4 begins. At time t3, sampling ends, and row L4 is configured as a high-impedance state. The period from t0 to t3 constitutes one excitation cycle. This excitation method can achieve arbitrary single-element excitation and single-element reception of ultrasonic echo data. The time interval from t1 to t3 must not be less than twice the transmission time of the ultrasonic wave within the object.

[0051] Taking the (1,1) array element as an example, when the array element is configured in the emission state, Figure 7 The excitation pulse waveform applied to the column electrodes by the excitation pulse generation circuit has an amplitude of 96V and a pulse width of 1µs. When the row electrode is activated, the row electrode signal is as follows: Figure 8 (a) to Figure 8 As shown in (b), when the bias voltage is reduced from -100V to 0V, the (1,1) array element is selected and excited. The sensor array is placed on a flat end face with a thickness of 3.6cm, and the first bottom echo signal received is tested. Based on the propagation speed of ultrasound in aluminum v = 6300m / s and the thickness of the tested block is 3.6cm, the time when the first bottom echo signal is received can be calculated. like Figure 9 As shown, the first bottom surface echo signal can be observed at the corresponding time.

[0052] The addressing excitation method and circuit described in this invention have the following characteristics:

[0053] S1. This addressing excitation method emits excitation pulses in any column of electrodes, selects a ground loop in any row, and excites only the row and column intersection array elements, which can excite any array element of the sensor array.

[0054] S2. A diode is placed between the excitation pulse and the column electrodes of the ultrasonic sensor array. A bias voltage is applied to the row electrodes, and the unidirectional conductivity of the diode is used to achieve ground selection of the excitation pulse.

[0055] S3. After the designated array element is excited, the column electrode is configured to receive state, and the row electrode continues to be configured to ground state, which can realize the bidirectional transmit and receive mode of the array element.

[0056] The descriptions in the embodiments are merely specific demonstrations of feasible implementations of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent implementations or modifications that do not depart from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for addressing and exciting an ultrasonic sensor array, characterized in that, The main steps include: Step 1, the sensor array is A planar array, wherein the number of array rows is The number of columns is Arbitrary array element numbering is In a sensor array, array elements with the same row number are connected collinearly, and array elements with the same column number are connected collinearly. Step 2: Use the row collinear electrodes as ground electrodes and the column collinear electrodes as signal electrodes to form... ground electrode lead and The signal leads can be interchanged, with the top and bottom electrodes being interchangeable. Step 3: The control circuit generates a square wave signal with an adjustable duty cycle, which is then amplified to obtain... Used for row gating control; The horizontal strobe signal is amplified by power, 1, 2 N represents the row number; Step 4: The control circuit generates a square wave signal with an adjustable duty cycle, which is then amplified to obtain... Used for column gating control; This is the column strobe signal after power amplification; Step 5, Signals and The signals are respectively connected to the input terminals of the row and column gating control circuits, serving as gating control signals for electronic switches Q and U; Step 6: The circuit generates a positive DC high voltage. and negative DC high voltage After being current-limited by resistors, they are connected to the column gating circuit and the row gating circuit respectively; Step 7, Row strobe control signal A logic low level turns on PMOS transistor Q, and a logic high level turns it off; column strobe control signal. A logic high level signal turns on NMOS transistor U, and a logic low level signal turns off NMOS transistor U. Step 8, Array element numbering Corresponding line control signal and train control signals The array element is selected when it is at a logic low level and a logic high level, respectively; Step 9, Positive DC High Voltage The capacitor C is in a charging state. When the array element is selected, the capacitor C discharges, which excites the array element and the array element generates ultrasonic waves. Step 10: The array element generates ultrasonic waves, which are reflected by the object being measured. The array element that needs to receive the ultrasonic echo is selected according to the control timing. Step 11: After the ultrasonic wave reception is completed, other array elements are selected, excited, and received according to the control timing. This process can be repeated to achieve the selection, excitation, and reception of any array element in the array. In step 4, a square wave signal with an adjustable duty cycle is generated by the control circuit. This square wave signal is generated by a microcontroller, and the power amplification is implemented using a circuit composed of transistors and capacitors. The logic high and low levels are different from the MCU output. The logic high level starts at the falling edge of the MCU output square wave, and the duty cycle decreases. Used for column gating control; In step 6, the positive DC high voltage Generated by a DC high-voltage module, used to charge capacitor C, and then discharging to generate an electrical pulse signal to excite the ultrasonic array elements; negative DC high voltage. Generated by a DC high-voltage module, it is used to block the flow between the excitation pulse and ground, and P1 and P2 should satisfy... .

2. The ultrasonic sensor array addressing and excitation method according to claim 1, characterized in that, In step 1, the sensor array is composed of discrete array elements, all of which are made by cutting and processing piezoelectric ceramic sheets. The array elements are of equal size and have both ultrasonic receiving and transmitting modes.

3. The ultrasonic sensor array addressing and excitation method according to claim 1, characterized in that, Each array element in step 1 has a unique number. Each array element has a top electrode and a bottom electrode. The top and bottom electrodes of array elements in the same row and column are connected collinearly to form elements with the same row number. The top row electrode, and the same column number The bottom row of electrodes is filled with insulating sound-absorbing material between the elements, and there are no other electrical connections between the elements.

4. The ultrasonic sensor array addressing and excitation method according to claim 1, characterized in that, In step 3, a square wave signal with an adjustable duty cycle is generated by the control circuit. This square wave signal is generated by a microcontroller (MCU), and the power amplification is achieved using a charge pump. The signal output from the charge pump is then converted from high to low level to obtain... It is used for row gating control.

5. The ultrasonic sensor array addressing and excitation method according to claim 1, characterized in that, In step 7, the column selection control signal A logic high level signal turns on the NMOS transistor U. After it turns on, the excitation pulse discharges through the capacitor C, exciting the array element to generate ultrasonic waves. After the discharge is complete, U is in the off state. At this time, the circuit charges the capacitor, which is used as the next excitation pulse to generate ultrasonic waves for the array element. After the discharge is complete, transistor Q is in the on state and remains so until the corresponding array element receives the echo signal.

6. The ultrasonic sensor array addressing and excitation method according to claim 1, characterized in that, In step 8, the array element numbering After selection, the array element is excited by electrical pulse discharge to generate ultrasonic waves. This step is called excitation of the array element. The receiving array element can only start receiving echo signals after it is turned on according to the control timing. The control timing is determined by the time corresponding to the sound path of the measured object.

7. The ultrasonic sensor array addressing and excitation method according to claim 1, characterized in that, In step 9, when receiving the ultrasonic echo, the receiving array element is always in the gated state, and the time window must not be less than twice the time it takes for the ultrasonic wave to travel through the object.

8. An addressing and excitation circuit for an ultrasonic sensor array, characterized in that, It includes a connected square wave generating circuit, a power amplifier circuit, a gating control circuit, and an excitation pulse generating circuit; The square wave generation circuit consists of a microcontroller (MCU). The square wave signal is generated through the timer function of the MCU's I / O port. The frequency of the square wave signal used for row and column gating control is determined by the repetition frequency of the ultrasonic sensor. The MCU first generates the square wave signal corresponding to the column gating control, while the starting point of the row gating square wave signal is determined by the falling edge of the column gating square wave signal. The duration of the gate is determined by the actual ultrasonic measurement sound path. The power amplifier circuit is mainly used to amplify the power of the square wave generated by the MCU to effectively drive the Q transistor and U transistor. The power amplifier circuit for the column control square wave signal consists of transistors and capacitors. The transistors are mainly used for power amplification, and the capacitors are mainly used to capture the rising and falling edges of the square wave signal before power amplification to determine the starting point of the column strobe signal and the duration of the high level of the square wave. The power amplifier circuit for the row control square wave signal is implemented by a charge pump chip and is mainly used for power amplification and high / low level switching of the square wave signal. The gating control circuit is mainly composed of NMOS and PMOS transistors. The NMOS transistor is used to control column gating, and then the excitation pulse is applied to the array element to generate ultrasonic waves. The PMOS transistor is used to control row gating, and then combined with P2 to realize cutoff and conduction. The excitation pulse generation circuit mainly consists of a DC high-voltage module and a capacitor. The DC high-voltage module provides the electrical pulse energy required for the excitation array elements, and the capacitor is used for charging and discharging to excite the array elements and generate ultrasonic waves.

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