Terahertz MIMO nondestructive testing device

Abstract

The utility model provides a terahertz MIMO (Multiple Input Multiple Output) nondestructive testing device which comprises a servo control system, a one-dimensional MIMO array antenna, a power division network, a frequency conversion channel, a calibration antenna and a signal processor, wherein the servo control system and the one-dimensional MIMO array antenna are connected; the power division network and the frequency conversion channel are electrically connected with the one-dimensional MIMO array antenna in sequence; the calibration antenna is electrically connected with the frequency conversion channel; the power supply module is electrically connected with the servo control system, the one-dimensional MIMO array antenna, the power division network, the frequency conversion channel, the calibration antenna and the signal processor, the conveyor belt is arranged on one side of the servo control system, and the tested target is placed on the conveyor belt and can move forwards along with the conveyor belt. The system is simple in scheme, high in imaging speed and high in cost performance, and meets the requirements of engineering prototypes; and real-time calibration of nondestructive testing of the target object is realized through an external calibration module.

Description

Technical Field

[0001] The utility model relates to the technical field of measurement and testing, and in particular to a terahertz MIMO nondestructive testing device. Background Art

[0002] Nondestructive testing already has a variety of testing methods, including X-ray testing, ultrasonic testing, magnetic particle testing, eddy current testing, infrared thermal imaging testing, laser holographic testing and microwave testing, but each method has its own applicable occasions. In recent years, the terahertz frequency band has received more and more attention due to its unique advantages, and terahertz imaging technology is developing into a new type of nondestructive testing supplement. Its advantages mainly include: low photon energy, especially compared with the X-ray method widely used in industry, it will not cause ionization damage to biological tissues, and it is safe for test materials and operators; strong penetration, terahertz waves are not easily affected by Mie scattering, for most dry dielectrics, such as foam, plastic, wood and ceramics, it has higher transparency than visible light, infrared and ultrasound, and unlike X-rays, it cannot clearly distinguish dielectrics due to excessive penetration; high spatial resolution, short terahertz wavelength, can provide millimeter or submillimeter resolution, meeting the application requirements of most nondestructive testing.

[0003] However, current terahertz nondestructive testing devices generally perform one-dimensional or two-dimensional reciprocating motion, resulting in slow imaging speed, and the existing technology does not have a calibration antenna and cannot perform calibration. Therefore, a terahertz nondestructive testing device that can perform three-dimensional reciprocating motion and has a calibration function is needed. Summary of the invention

[0004] The utility model is to solve the problem of non-destructive testing imaging movement and calibration, and provides a terahertz MIMO non-destructive testing device, including a connected servo control system, a one-dimensional MIMO array antenna, a power division network and a frequency conversion channel electrically connected to the one-dimensional MIMO array antenna in sequence, a calibration antenna electrically connected to the frequency conversion channel, a signal processor electrically connected to the servo control system and the frequency conversion channel, a power module electrically connected to the servo control system, the one-dimensional MIMO array antenna, the power division network, the frequency conversion channel, the calibration antenna, and the signal processor, a conveyor belt arranged on one side of the servo control system, and a target to be measured placed on the conveyor belt and can move forward with the conveyor belt. The utility model has a simple system solution, fast imaging speed, high cost performance, and meets the needs of engineering prototypes; through an external calibration module, real-time calibration of non-destructive testing of target objects is achieved.

[0005] The utility model provides a terahertz MIMO nondestructive testing device, comprising a connected servo control system, a one-dimensional MIMO array antenna, a power division network and a frequency conversion channel electrically connected to the one-dimensional MIMO array antenna in sequence, a calibration antenna electrically connected to the frequency conversion channel, a signal processor electrically connected to the servo control system and the frequency conversion channel, a power module electrically connected to the servo control system, the one-dimensional MIMO array antenna, the power division network, the frequency conversion channel, the calibration antenna, and the signal processor, a conveyor belt arranged on one side of the servo control system, and a target to be measured placed on the conveyor belt and capable of moving forward with the conveyor belt;

[0006] The servo control system drives the one-dimensional MIMO array antenna to move up and down through the servo (mechanical arm) to perform SAR imaging. The one-dimensional MIMO array antenna includes antenna transmitting units and antenna receiving units arranged in a horizontal one-dimensional manner. The number of linear transmitting units and antenna receiving units is at least two. The calibration antenna is used to calibrate the receiving signals of the antenna transmitting units and the antenna receiving units.

[0007] In the terahertz MIMO nondestructive testing device described in the utility model, as a preferred embodiment, the antenna transmitting unit is a coherent transmitter, and the antenna receiving unit is a coherent receiver.

[0008] In the terahertz MIMO nondestructive testing device described in the utility model, as a preferred embodiment, the intervals between the antenna transmitting units are the same, and the intervals between the antenna receiving units are different.

[0009] In the terahertz MIMO nondestructive testing device described in the utility model, as a preferred embodiment, the antenna receiving units are arranged repeatedly and periodically.

[0010] In the terahertz MIMO nondestructive testing device described in the utility model, as a preferred embodiment, the total number of antenna transmitting units and antenna receiving units is 64.

[0011] The terahertz MIMO nondestructive testing device described in the utility model is preferably configured such that the power division network is used to amplify the generated frequency modulated continuous wave signal and distribute it to the antenna transmitting unit;

[0012] The frequency conversion channel is electrically connected to the antenna receiving unit;

[0013] The frequency conversion channel is used to generate a frequency modulated continuous wave signal and frequency-multiply and frequency-convert the frequency modulated continuous wave signal to the terahertz frequency band and output it to the power division network; the frequency conversion channel is used to frequency-convert the mixed signal generated by the antenna receiving unit and output it to the signal processor for signal acquisition.

[0014] In the terahertz MIMO nondestructive testing device described in the utility model, as an optimal mode, the frequency modulated continuous wave signal is 14.5-20.8 GHz, and the frequency conversion channel converts the frequency modulated continuous wave signal by 12 times to 220 GHz.

[0015] The terahertz MIMO nondestructive testing device described in the utility model is preferably a calibration antenna that can receive a terahertz frequency band signal output by an antenna transmitting unit and then output it to an antenna receiving unit, and can also receive a terahertz frequency band signal output by a frequency conversion channel and then output it to the antenna receiving unit.

[0016] The terahertz MIMO nondestructive testing device described in the utility model is preferably a signal processor comprising a synchronous signal controller and an electrically connected signal acquisition board and a signal processing board, the synchronous signal controller is electrically connected to the servo control system and the frequency conversion channel, and the signal acquisition board is electrically connected to the frequency conversion channel.

[0017] The terahertz MIMO nondestructive testing device described in the utility model, as a preferred embodiment, further comprises a host computer electrically connected to the signal processing machine.

[0018] The utility model has the following advantages:

[0019] (1) The utility model places the target to be measured on a conveyor belt, and the system is placed on a mechanical arm above the target to be measured. When the target to be measured passes on the conveyor belt at a certain speed, the system performs real-time three-dimensional imaging of the target to be measured at a certain frame rate.

[0020] (2) The utility model has a simple system solution, fast imaging speed, high cost performance, and meets the requirements of engineering prototypes; through the external calibration module, real-time calibration of non-destructive testing of target objects can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a system block diagram of a terahertz MIMO nondestructive testing device;

[0022] Figure 2 It is a schematic diagram of the structure of a terahertz MIMO nondestructive testing device;

[0023] Figure 3 This is a schematic diagram of the "one-dimensional MIMO + one-dimensional SAR" approach for a terahertz MIMO nondestructive testing device;

[0024] Figure 4 A schematic diagram of a one-dimensional MIMO array antenna of a terahertz MIMO nondestructive testing device;

[0025] Figure 5 A schematic diagram of the calibration of a receiving unit of a terahertz MIMO non-destructive testing device;

[0026] Figure 6 A schematic diagram of the calibration of a transmitting unit of a terahertz MIMO nondestructive testing device.

[0027] Reference numerals:

[0028] 1. Servo control system; 2. One-dimensional MIMO array antenna; 21. Antenna transmitting unit; 22. Antenna receiving unit; 3. Power division network; 4. Frequency conversion channel; 5. Calibration antenna; 6. Signal processor; 61. Synchronous signal controller; 62. Signal acquisition board; 63. Signal processing board; 7. Power module; 8. Conveyor belt; 9. Target to be measured; 10. Host computer. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0030] Example 1

[0031] like Figures 1 to 6 As shown, a terahertz MIMO nondestructive testing device includes a connected servo control system 1, a one-dimensional MIMO array antenna 2, a power division network 3 and a frequency conversion channel 4 electrically connected to the one-dimensional MIMO array antenna 2 in sequence, a calibration antenna 5 electrically connected to the frequency conversion channel 4, a signal processor 6 electrically connected to the servo control system 1 and the frequency conversion channel 4, a power module 7 electrically connected to the servo control system 1, the one-dimensional MIMO array antenna 2, the power division network 3, the frequency conversion channel 4, the calibration antenna 5, and the signal processor 6, a conveyor belt 8 arranged on one side of the servo control system 1, a target 9 placed on the conveyor belt 8 and capable of moving forward with the conveyor belt 8, and a host computer 10 electrically connected to the signal processor 6;

[0032] The servo control system 1 drives the one-dimensional MIMO array antenna 2 to move up and down through the servo to perform SAR imaging. The one-dimensional MIMO array antenna 2 includes an antenna transmitting unit 21 and an antenna receiving unit 22 arranged in a horizontal one-dimensional manner. The number of the linear transmitting unit 21 and the number of the antenna receiving unit 22 are both at least two. The calibration antenna 5 is used to calibrate the receiving signals of the antenna transmitting unit 21 and the antenna receiving unit 22.

[0033] The antenna transmitting unit 21 is a coherent transmitter, and the antenna receiving unit 22 is a coherent receiver;

[0034] The intervals between the antenna transmitting units 21 are the same, and the intervals between the antenna receiving units 22 are different;

[0035] The antenna receiving unit 22 is arranged in a periodic and repeated manner;

[0036] The total number of antenna transmitting units 21 and antenna receiving units 22 is 64;

[0037] The power division network 3 is used to amplify the generated frequency modulated continuous wave signal and distribute it to the antenna transmitting unit 21;

[0038] The frequency conversion channel 4 is electrically connected to the antenna receiving unit 22;

[0039] The frequency conversion channel 4 is used to generate a frequency modulated continuous wave signal and frequency-multiply and frequency-convert the frequency modulated continuous wave signal to the terahertz frequency band and output it to the power division network 3; the frequency conversion channel 4 is used to frequency-convert the mixed signal generated by the antenna receiving unit 22 and output it to the signal processor 6 for signal acquisition;

[0040] The frequency modulated continuous wave signal is 14.5-20.8 GHz, and the frequency conversion channel 4 converts the frequency modulated continuous wave signal by 12 times to 220 GHz;

[0041] The calibration antenna 5 can receive the terahertz frequency band signal output by the antenna transmitting unit 21 and then output it to the antenna receiving unit 22, and can also receive the terahertz frequency band signal output by the frequency conversion channel 4 and then output it to the antenna receiving unit 22;

[0042] The signal processor 6 includes a synchronous signal controller 61 and an electrically connected signal acquisition board 62 and a signal processing board 63 . The synchronous signal controller 61 is electrically connected to the servo control system 1 and the frequency conversion channel 4 , and the signal acquisition board 62 is electrically connected to the frequency conversion channel 4 .

[0043] The method of using this embodiment is as follows: a two-dimensional aperture is formed by scanning with a one-dimensional MIMO linear array 2 and a one-dimensional mechanical motion 1, a coherent transmitter 21 at the position of the two-dimensional aperture actively transmits a broadband 220GHz signal and illuminates a target 9 through a wide beam antenna, the target 9 to be measured reflects the signal back to the two-dimensional aperture, and the coherent receiving array 22 on the aperture receives the signal reflected back by the target, and the signal is digitized by an analog-to-digital converter and then resolved to obtain a three-dimensional image.

[0044] 220G one-dimensional MIMO sparse array antenna 2: includes a radio frequency front end, a transmitting antenna 21, a receiving antenna 22, etc., and is responsible for completing functions such as signal transmission and signal reception. The transmitting antenna 21 radiates to the target 9, and then the receiving antenna 22 receives the scattered signal from the target.

[0045] Calibration antenna 5: used for real-time calibration of the transceiver array 2. The calibration antenna 5 can be used as a transmitter to calibrate the MIMO receiving array 2. The calibration antenna 5 can also be used as a receiver to calibrate the MIMO transmitting array 2.

[0046] Servo control system 1: Control the servo to perform one-dimensional motion to complete SAR imaging.

[0047] The signal processor 6 is responsible for synchronous signal control, echo signal collection, real-time signal processing, system master control and providing external interface functions. The boards are connected through high-speed buses.

[0048] The power module 7 distributes power to various components of the terahertz multi-transmitter and multi-receiver detection system through a power distribution controller.

[0049] In this embodiment, the center frequency is set to 220 GHz, the bandwidth is set to 75 GHz, and the step frequency is set to 200 MHz; the imaging area scene is set to a point target or multiple point targets; the imaging area size is 1m×0.6m, and the imaging area center distance is 1m.

[0050] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A terahertz MIMO nondestructive testing device, characterized in that: The invention comprises a connected servo control system (1), a one-dimensional MIMO array antenna (2), a power division network (3) and a frequency conversion channel (4) electrically connected to the one-dimensional MIMO array antenna (2) in sequence, a calibration antenna (5) electrically connected to the frequency conversion channel (4), a signal processor (6) electrically connected to the servo control system (1) and the frequency conversion channel (4), a power module (7) electrically connected to the servo control system (1), the one-dimensional MIMO array antenna (2), the power division network (3), the frequency conversion channel (4), the calibration antenna (5), and the signal processor (6), a conveyor belt (8) arranged on one side of the servo control system (1), and a measured target (9) placed on the conveyor belt (8) and capable of moving forward with the conveyor belt (8); The servo control system (1) drives the one-dimensional MIMO array antenna (2) to move up and down through servo to perform SAR imaging. The one-dimensional MIMO array antenna (2) comprises antenna transmitting units (21) arranged in a transverse one-dimensional manner and antenna receiving units (22) arranged in a transverse one-dimensional manner. The number of the antenna transmitting units (21) and the number of the antenna receiving units (22) are both at least two. The calibration antenna (5) is used to calibrate the reception signals of the antenna transmitting units (21) and the antenna receiving units (22).

2. A terahertz MIMO nondestructive testing device according to claim 1, characterized in that: The antenna transmitting unit (21) is a coherent transmitter, and the antenna receiving unit (22) is a coherent receiver.

3. A terahertz MIMO nondestructive testing device according to claim 1, characterized in that: The intervals between the antenna transmitting units (21) are the same, and the intervals between the antenna receiving units (22) are different.

4. A terahertz MIMO nondestructive testing device according to claim 3, characterized in that: The antenna receiving units (22) are arranged in a periodic and repeated manner.

5. The terahertz MIMO nondestructive testing device according to claim 1, characterized in that: The total number of the antenna transmitting units (21) and the antenna receiving units (22) is 64.

6. The terahertz MIMO nondestructive testing device according to claim 1, characterized in that: The power division network (3) is used to amplify the generated frequency modulated continuous wave signal and distribute it to the antenna transmitting unit (21); The frequency conversion channel (4) is electrically connected to the antenna receiving unit (22); The frequency conversion channel (4) is used to generate a frequency modulated continuous wave signal and frequency-multiply and frequency-convert the frequency modulated continuous wave signal to a terahertz frequency band and output it to the power division network (3); the frequency conversion channel (4) is used to frequency-convert the mixed signal generated by the antenna receiving unit (22) and output it to the signal processor (6) for signal acquisition.

7. A terahertz MIMO nondestructive testing device according to claim 6, characterized in that: The frequency modulated continuous wave signal is 14.5-20.8 GHz, and the frequency conversion channel (4) converts the frequency modulated continuous wave signal by 12 times to 220 GHz.

8. The terahertz MIMO nondestructive testing device according to claim 1, characterized in that: The calibration antenna (5) can receive the terahertz frequency band signal output by the antenna transmitting unit (21) and then output it to the antenna receiving unit (22), and can also receive the terahertz frequency band signal output by the frequency conversion channel (4) and then output it to the antenna receiving unit (22).

9. The terahertz MIMO nondestructive testing device according to claim 1, characterized in that: The signal processor (6) comprises a synchronous signal controller (61) and an electrically connected signal acquisition board (62) and a signal processing board (63); the synchronous signal controller (61) is electrically connected to the servo control system (1) and the frequency conversion channel (4); and the signal acquisition board (62) is electrically connected to the frequency conversion channel (4).

10. The terahertz MIMO nondestructive testing device according to claim 1, characterized in that: It also includes a host computer (10) electrically connected to the signal processor (6).

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