Liquid crystal holographic phased-array antenna measurement calibration device and test method

Abstract

The invention discloses a liquid crystal holographic phased array antenna measurement calibration device and a test method, and belongs to the technical field of satellite phased array communication antennas. The equipment comprises a rack assembly, a Z-axis jacking assembly, an X-axis moving assembly, a Y-axis moving assembly, an antenna mounting and fixing plate and a polarization rotation measurement centering assembly. The three-axis coordinate mechanism is installed in an inverted mode, so that reflection interference of metal parts on signals in the testing process is effectively reduced. The antenna circular array center can be automatically centered in combination with a polarization rotation measurement assembly, circular interpolation and linear interpolation motion are supported, and the amplitude-phase test requirements of the circular array antenna in the radial direction and the circumferential direction are met; the invention further provides an automatic test and calibration process for the planar radial waveguide and the liquid crystal tunable resonator array, the resonance driving voltage of each liquid crystal resonant cavity under the specific frequency can be efficiently and accurately calibrated, a foundation is laid for generating a high-precision holographic interference pattern, and the test efficiency and the calibration precision are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of satellite phased array communication antenna technology, specifically relating to a liquid crystal holographic phased array antenna measurement and calibration equipment and testing method. Background Technology

[0002] With the rapid development of 5G and future 6G communication technologies, the performance requirements for antennas in wireless communication systems are increasing. Low-Earth orbit satellite internet, as a major deployment method for 6G communication, significantly increases the demand for antenna beam scanning. Traditional mechanically scanned antennas, due to their slow scanning speed and large size, are unable to meet the future demands for high-speed and flexible communication. Phased array antennas, capable of electronic scanning, possess rapid beam switching and flexible beamforming capabilities, making them a crucial component of future wireless communication systems.

[0003] Currently, the most mainstream phased array antenna is the active phased array antenna. However, active phased array antennas are limited in many application scenarios due to their high cost and high power consumption. With the development of low-Earth orbit satellite communication, the market demand for a large number of antennas and low-cost satellite terminals is becoming more urgent.

[0004] As a passive antenna, the liquid crystal phased array antenna has the following advantages: 1. Low cost Its manufacturing process is similar to that of liquid crystal displays (LCDs), utilizing existing mature and efficient display manufacturing technologies to avoid expensive and complex semiconductor processes and assembly. This makes it possible to mass-produce low-cost, large antennas.

[0005] 2. Extremely low energy consumption Its power consumption mainly comes from the control circuit. The power consumption of the liquid crystal unit itself is very small, far lower than that of traditional active phased array antennas that require high-power phase shifters and T / R components.

[0006] 3. Beam reconfigurable By utilizing the principles of holography and loading different holograms (phase distribution maps) onto the antenna, the antenna's pointing beam can be dynamically reconstructed. It's even possible to generate multiple independent beams simultaneously for seamless switching between different satellites.

[0007] Despite the numerous advantages of holographic phased array antennas based on liquid crystal panel technology, as an emerging antenna form, it still faces many challenges in testing and calibrating liquid crystal resonant units. While there are already many mature scanning frames or testing devices on the market for planar active phased array antennas, most employ a three-axis coordinate movement structure. The antenna under test is placed on a platform, and then the three-axis coordinate mechanism is driven to scan a plane several wavelengths away from the antenna under test, measuring the amplitude and phase distribution of the antenna on that plane. However, these scanning frames share a common drawback: with the antenna under test placed below and at least two axes of coordinate movement above it, there are numerous metal objects above the antenna under test. During antenna testing, these objects inevitably reflect the test signal, severely affecting testing accuracy. Furthermore, these scanning frames only support individual movement along the X and Y axes. Since liquid crystal holographic phased array antennas are circular array antennas, it is necessary to test the amplitude and phase distribution in both circumferential and radial directions. Therefore, linear or circular interpolation movement along the X and Y axes is required. Furthermore, liquid crystal holographic phased array antennas require calibration of each liquid crystal resonator, and the efficiency of testing thousands of points using a transmission scanning frame is extremely low. Therefore, to solve the above problems, there is an urgent need to invent a measurement / calibration device for liquid crystal holographic phased array antennas to achieve the testing and calibration objectives during the antenna production process. Summary of the Invention

[0008] The purpose of this invention is to provide a liquid crystal holographic phased array antenna measurement and calibration device and testing method to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a liquid crystal holographic phased array antenna measurement and calibration device, comprising a frame assembly, a Z-axis lifting assembly, an X-axis moving assembly, a Y-axis moving assembly, an antenna mounting plate, and a polarization rotation measurement and centering assembly; the Z-axis lifting assembly, the X-axis moving assembly, and the Y-axis moving assembly are used to drive the antenna mounting plate to perform three-axis movement; the polarization rotation measurement and centering assembly is disposed on the upper side of the frame assembly, and the antenna is disposed on the antenna mounting plate; The polarization rotation measurement centering assembly includes two measurement assembly support columns, which are fixed to the platforms on both sides of the frame assembly. Measurement assembly fixing crossbars are set on the two measurement assembly support columns. A polarization rotation motor fixing plate is set on one of the measurement assembly support columns. A polarization drive motor is set on the polarization rotation motor fixing plate. A driven pulley and an encoder are set in the middle of the measurement assembly fixing crossbar. The output shaft of the encoder is connected to the driven pulley and is used to detect and calibrate the rotation angle of the main shaft when the main shaft rotates. The driven pulley is connected to a rigid coupling, and the rigid coupling is connected to a centering rod or waveguide probe.

[0010] Preferably, the encoder is mounted on an encoder mounting plate, and the encoder mounting plate is connected to the measuring component fixing crossbar via hexagonal studs.

[0011] Preferably, the Z-axis lifting assembly includes a Z-axis lead screw seat fixing plate, which is fixed to the three-axis coordinate assembly mounting platform by four Z-axis assembly fixing columns. The three-axis coordinate assembly mounting platform is mounted on the frame assembly. A Z-axis drive motor is mounted on the Z-axis lead screw seat fixing plate, and the Z-axis drive motor is connected to the Z-axis lead screw. The X-axis moving assembly is connected to the Z-axis lifting plate by lifting guide columns. A Z-axis lead screw nut is mounted on the Z-axis lifting plate. When the Z-axis drive motor rotates, the Z-axis lead screw rotates accordingly, and the Z-axis lifting plate moves up and down under the drive of the Z-axis lead screw nut. The X-axis moving assembly and the Y-axis moving assembly move up and down with the four Z-axis lifting guide columns.

[0012] Preferably, the Z-axis drive motor is fixed to the Z-axis lead screw seat fixing plate via a Z-axis motor fixing seat.

[0013] Preferably, the X-axis moving assembly includes an X-axis drive motor, an X-axis photoelectric limit switch, an X-axis base plate, an X-axis ball screw bearing support, an X-axis ball screw, an X-axis guide rail, an X-axis slider, and an X-axis moving plate. The X-axis base plate is fixed to four Z-axis lifting guide columns via an optical axis fixing flange. Two X-axis guide rails are fixed to the X-axis base plate. The X-axis drive motor and the X-axis ball screw are fixedly supported on the X-axis base plate via the X-axis ball screw bearing support. The X-axis slider is slidably mounted on the X-axis guide rail. The X-axis moving plate is connected to the X-axis slider.

[0014] Preferably, the Y-axis moving assembly includes a Y-axis moving plate, a Y-axis ball screw bearing support, a Y-axis moving plate reinforcing rib, a Y-axis ball screw nut fixing seat, a Y-axis ball screw nut, a Y-axis ball screw, a Y-axis motor fixing seat, a Y-axis drive motor, a Y-axis guide rail, a Y-axis photoelectric limit switch, a Y-axis slider, and the Y-axis slider is fixed on the X-axis moving plate. The Y-axis guide rail is slidably disposed on the Y-axis slider. The Y-axis moving plate is fixed to the Y-axis guide rail. The Y-axis drive motor, Y-axis motor fixing seat, Y-axis ball screw, and Y-axis ball screw nut are also included. A reinforcing rib for the Y-axis moving plate and a Y-axis ball screw bearing support are fixed to the Y-axis moving plate. A Y-axis ball screw nut fixing seat is also provided on the Y-axis moving plate. The Y-axis ball screw passes through the Y-axis ball screw nut. One end of the Y-axis ball screw is connected to the Y-axis drive motor, and the other end is set on the Y-axis ball screw bearing support. The Y-axis ball screw nut fixing seat is connected and fixed to the X-axis moving plate. A Y-axis photoelectric limit switch is provided on the Y-axis moving plate.

[0015] Preferably, the antenna consists of a waveguide-coaxial converter, an excitation probe, a planar radial waveguide, and a liquid crystal tunable resonator array connected in sequence.

[0016] A test method for a liquid crystal holographic phased array antenna measurement and calibration device includes the following steps: 1) Determine the center of the circular antenna array; 2) Planar radial waveguide testing, specifically as follows: The waveguide coaxial converter is connected to port 1 of the vector network analyzer, and the waveguide probe is connected to port 2 of the vector network analyzer. The X-axis and Y-axis motors are controlled to perform circular interpolation motion, with the center of the planar radial waveguide as the center of the circle. The signal amplitude and phase on the concentric circle are measured, and the host computer automatically records the test data. After the test is completed, the control system controls the X-axis and Y-axis motors to perform linear interpolation motion along the circumferential radius, and the host computer automatically records the amplitude and phase data in the radial direction. 3) After the planar radial waveguide test is completed, the liquid crystal tunable resonator array is assembled and positioned above the planar radial waveguide for testing and calibration of the liquid crystal resonator array; details are as follows: 3.1) The control system imports the X, Y, and polarization angle coordinate data of all liquid crystal resonant cavities in advance; 3.2) The test slide moves the antenna under test according to the coordinate data of the resonant cavity, and moves the receiving waveguide probe above the resonant cavity under test. At the same time, the polarization drive motor drives the polarization angle of the receiving waveguide probe to be parallel to the polarization angle of the resonant cavity currently being measured. The vector network analyzer port 1 provides the preset frequency signal to the waveguide coaxial converter, and the vector network analyzer port 2 is connected to the waveguide probe. 3.3) The control system controls the driving board of the liquid crystal tunable resonator array to turn off the electrode driving signals of all resonant cavities and turn on the electrode driving signal of the resonant cavity under test. The electrode driving signal starts from V and increases in steps of .V. After the waveguide probe receives the radiation signal, the voltage is changed to a step value of .V. When the signal gain value received by the vector network analyzer is the maximum, the driving voltage of the current resonant cavity is recorded, and the driving voltage of the resonant cavity at this frequency is calibrated.

[0017] 3.4) The control system drives the X-axis moving component and the Y-axis moving component to the next numbered resonant cavity, repeats the previous test, and records the driving voltage at that frequency.

[0018] Preferably, the specific method for determining the center of the antenna circular array is as follows: The centering rod is clamped and fixed on a rigid coupling. The polarization drive motor is controlled to rotate continuously. Then, the motors of the Z-axis lifting assembly, X-axis moving assembly, and Y-axis moving assembly are manually controlled to rotate. Under the drive of the X, Y, and Z moving assemblies, the centering rod is positioned in the hole in the middle of the antenna mounting plate. The X-axis assembly is manually controlled to move to the right. When the centering rod touches point A on the edge of the hole in the middle of the mounting plate and changes from eccentric rotation to concentric rotation, the X-axis is switched to a small-distance step movement mode. When the centering rod changes from concentric rotation to eccentric rotation again, the X-axis coordinate value X of point A is recorded. AThen, manually control the X-axis assembly to move to the left. When the centering rod touches point B on the edge of the middle hole of the fixed plate and changes from eccentric rotation to concentric rotation, switch the X-axis to small-distance stepping motion mode. When the centering rod changes from concentric rotation to eccentric rotation again, record the X-axis coordinate value of point B. B Calculate the coordinates of the midpoint X0 on the X-axis. A +X B ) / 2, then control the X-axis component to move to the coordinate value X0; Manually control the Y-axis assembly to move forward. When the centering rod touches the edge of the middle hole of the fixed plate at point D, and changes from eccentric rotation to concentric rotation, switch the Y-axis to small-distance stepping motion mode. When the centering rod changes from concentric rotation to eccentric rotation again, record the Y-axis coordinate value of point D. D Then, manually control the Y-axis assembly to move backward. When the centering rod touches point E, the edge of the middle hole of the fixed plate, and changes from eccentric rotation to concentric rotation, switch the Y-axis to small-distance stepping motion mode. When the centering rod changes from concentric rotation to eccentric rotation again, record the Y-axis coordinate value of point E. E Calculate the coordinates of the midpoint Y0 on the Y-axis. D +Y E ) / 2, then control the Y-axis component to move to the coordinate value Y0; After four operations, the center of the hole in the middle of the fixing plate was determined.

[0019] The technical effects and advantages of this invention are as follows: By inverting the X, Y, and Z coordinate mechanism, the antenna under test is positioned above the test probe, which significantly reduces the reflection and obstruction of the antenna signal by the metal structure above the test plane, thereby effectively reducing test errors and improving the accuracy and reliability of measurement data. The equipment control system supports linear and circular interpolation motion along the X and Y axes, which can perfectly adapt to the testing requirements of LCD holographic phased array antennas as circular array antennas, and can efficiently complete the amplitude and phase distribution measurement in the concentric circumference and radial directions. Through an integrated control system, the antenna center can be automatically located, and the test probe can be driven to quickly and accurately position itself to thousands of test points based on the preset resonant cavity coordinate data. Combined with the vector network analyzer and the automatic scanning and recording of the liquid crystal driving voltage, efficient and automated testing and voltage calibration of large-scale liquid crystal resonant cavity arrays are realized, which greatly improves production efficiency and reduces labor costs and operational complexity. By employing precise voltage step scanning, the optimal resonant driving voltage for each resonant cavity at a specific frequency can be accurately located and recorded. This calibration data is crucial for generating accurate holographic interferometry patterns, achieving precise beamforming, and enabling rapid beam switching, thereby comprehensively improving the performance of the liquid crystal phased array antenna. Attached Figure Description

[0020] Figure 1 This is an overall architecture diagram of the device of the present invention; Figure 2 This is a schematic diagram of the X, Y, Z three-axis coordinate mechanism of the present invention; Figure 3 This is a schematic diagram of the center-finding component structure of the polarization rotation measurement component of the present invention; Figure 4 This is a schematic diagram showing the replacement of the centering rod with a test waveguide probe after the centering operation; Figure 5 An exploded view of the main components of a liquid crystal phased array antenna; Figure 6 This is a schematic diagram of a test method for a planar radial waveguide; Figure 7 This is a schematic diagram of the testing and calibration method for a liquid crystal tunable resonator array. Figure 8 for Figure 7 A magnified view of a portion of the image. Detailed Implementation

[0021] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] This invention provides, for example Figures 1-2 The liquid crystal holographic phased array antenna measurement and calibration device shown mainly consists of a frame assembly 1, a Z-axis lifting assembly 2, an X-axis moving assembly 3, a Y-axis moving assembly 4, an antenna mounting and fixing plate 5, a polarization rotation measurement assembly, and a centering assembly 7. The antenna under test 6 is set on the antenna mounting and fixing plate 5.

[0023] The Z-axis lifting assembly 2 has the following structure: the Z-axis lead screw seat fixing plate 2-4 is fixed to the three-axis coordinate assembly mounting platform 1-1 by four Z-axis assembly fixing columns 2-8. The three-axis coordinate assembly mounting platform 1-1 is mounted on the frame assembly 1. The Z-axis drive motor 2-1 is fixed to the Z-axis lead screw seat fixing plate 2-4 by the Z-axis motor fixing seat 2-2. The Z-axis lead screw fixing bearing seat 2-3 is fixed to the Z-axis lead screw seat fixing plate 2-4. The Z-axis lead screw 2-6 is inserted into the bearing hole of the Z-axis lead screw fixing bearing seat 2-3. The Z-axis lead screw 2-6 and the Z-axis drive motor 2-1 are connected by a coupling. The X-axis moving assembly 3 is connected to the Z-axis lifting plate 2-9 via lifting guide posts 2-10. The Z-axis lead screw nut 2-5 is fixed to the Z-axis lifting plate 2-9. The four Z-axis lifting guide posts 2-10 are connected to the Z-axis lifting plate 2-9 via optical axis fixing flanges. When the Z-axis drive motor 2-1 rotates, the Z-axis lead screw 2-6 rotates accordingly. The Z-axis lifting plate 2-9 moves up and down under the drive of the Z-axis lead screw nut 2-5. The X-axis moving assembly 3 and the Y-axis moving assembly 4 move up and down along with the four Z-axis lifting guide posts 2-10 to adjust the distance between the waveguide probe 7-13 and the antenna under test 6. At the same time, the control system limits the Z-axis lifting range via the signal from the Z-axis photoelectric limit switch 2-7.

[0024] The structure of the X-axis moving assembly 3 is as follows: the X-axis base plate 3-3 is fixed to four Z-axis lifting guide columns 2-10 via an optical axis fixing flange; two X-axis guide rails 3-6 are fixed to the X-axis base plate 3-3; the X-axis drive motor 3-1 and the X-axis ball screw 3-5 are fixedly supported on the X-axis base plate 3-3 via an X-axis ball screw bearing support seat 3-4; the X-axis slider 3-7 can slide left and right on the X-axis guide rails 3-6; and the X-axis moving plate 3-8 is connected to the X-axis slider 3-7 and the X-axis ball screw nut (not shown in the figure). When the control system controls the X-axis drive motor 3-1 to rotate, the X-axis ball screw nut drives the X-axis moving plate 3-8 to move left and right. Simultaneously, the control system limits the left and right movement range of the X-axis via a signal from the X-axis photoelectric limit switch 3-2.

[0025] The Y-axis moving assembly 4 includes a Y-axis moving plate 4-1, a Y-axis ball screw bearing support 4-2, a Y-axis moving plate reinforcing rib 4-3, a Y-axis screw nut fixing seat 4-4, a Y-axis screw nut 4-5, a Y-axis ball screw 4-6, a Y-axis motor fixing seat 4-7, a Y-axis drive motor 4-8, a Y-axis guide rail 4-9, a Y-axis photoelectric limit switch 4-10, and a Y-axis slider 4-11. The Y-axis slider 4-11 is fixed on the X-axis moving plate 3-8, the Y-axis guide rail 4-9 is slidably mounted on the Y-axis slider 4-11, the Y-axis moving plate 4-1 is fixed to the Y-axis guide rail 4-9, and the Y-axis drive motor 4-8, Y-axis motor fixing seat 4-7, and Y-axis ball screw 4-6 are also included. The Y-axis lead screw nut 4-5, the Y-axis moving plate reinforcing rib 4-3, and the Y-axis ball screw bearing support 4-2 are fixed on the Y-axis moving plate 4-1. The Y-axis moving plate 4-1 is also provided with a Y-axis lead screw nut fixing seat 4-4. The Y-axis lead screw nut 4-5 is set on the Y-axis lead screw nut fixing seat 4-4. The Y-axis ball screw 4-6 passes through the Y-axis lead screw nut 4-5. One end of the Y-axis ball screw 4-6 is connected to the Y-axis drive motor 4-8, and the other end is set on the Y-axis ball screw bearing support 4-2. The Y-axis lead screw nut fixing seat is connected and fixed to the X-axis moving plate 3-8. The Y-axis photoelectric limit switch 4-10 is set on the Y-axis moving plate 4-1. When the control system controls the Y-axis drive motor 4-8 to rotate, since the Y-axis lead screw nut 4-5 and the X-axis moving plate 3-8 are relatively fixed, the entire Y-axis assembly will move back and forth under the interaction of forces. At the same time, the control system will limit the range of Y-axis movement through the signal of the Y-axis photoelectric limit switch 4-10.

[0026] like Figure 3 , Figure 4 As shown: The antenna mounting plate 5 and the Y-axis moving assembly 4 are fixedly connected.

[0027] Two measuring component support columns 7-1 are fixed to the platforms on both sides of the frame assembly 1. A measuring component fixing crossbar (non-metallic material) 7-2 is fixed to the two measuring component support columns 7-1. A polarized rotary motor fixing plate 7-10 and a polarized drive motor 7-11 are fixed to one side of the support column 7-1. A bearing seat is installed in the middle of the measuring component fixing crossbar 7-2. A driven pulley 7-5 is fixed to the main shaft in the middle of the bearing seat (not shown in the figure). An encoder fixing plate 7-3 and an encoder 7-4 are connected to the measuring component fixing crossbar 7-2 via hexagonal studs. The output shaft of the encoder 7-4 is connected to the driven pulley 7-5, used to detect and calibrate the rotation angle of the main shaft during its rotation. One end of a rigid coupling 7-6 is clamped and fixed to the rotating main shaft (not shown in the figure), and the other end can be replaced with a centering bar 7-7 or a waveguide probe 7-13 as needed.

[0028] This invention also provides a test method for a liquid crystal holographic phased array antenna measurement and calibration device, as detailed below: Since the liquid crystal holographic phased array antenna under test is a circular array antenna, the center of the antenna array must be accurately located to begin testing. When the polarization rotation measurement component's centering component 7 is in centering function, the centering rod 7-7 is clamped and fixed on the rigid coupling 7-6. The polarization drive motor 7-11 is controlled to rotate continuously. Then, the motors of the Z-axis lifting component 2, X-axis moving component 3, and Y-axis moving component 4 are manually controlled to rotate. Under the drive of the X, Y, and Z moving components, the antenna mounting plate 5 is positioned so that the centering rod 7-7 is placed in the hole in the middle of the antenna mounting plate 5. The X-axis component 3 is manually controlled to move to the right. When the centering rod 7-7 touches the edge A of the middle hole of the mounting plate 5 and changes from eccentric rotation to concentric rotation, the X-axis is switched to small-distance step movement mode. When the centering rod changes from concentric rotation to eccentric rotation again, the X-axis coordinate value X of point A is recorded. A Then, manually control the X-axis assembly 3 to move to the left. When the centering rod 7-7 touches the edge of the middle hole of the fixed plate 5 at point B, and changes from eccentric rotation to concentric rotation, switch the X-axis to small-distance stepping motion mode. When the centering rod changes from concentric rotation to eccentric rotation again, record the X-axis coordinate value of point B. B Calculate the coordinates of the midpoint X0 on the X-axis. A +X B ) / 2, then control the X-axis component to move to the coordinate value X0; Manually control the Y-axis assembly 4 to move forward. When the centering rod 7-7 touches the edge D of the middle hole of the fixed plate 5 and changes from eccentric rotation to concentric rotation, switch the Y-axis to small-distance stepping motion mode. When the centering rod changes from concentric rotation to eccentric rotation again, record the Y-axis coordinate value of point D. D Then, manually control the Y-axis assembly 3 to move backward. When the centering rod 7-7 touches the edge E of the middle hole of the fixed plate 5 and changes from eccentric rotation to concentric rotation, switch the Y-axis to small-distance stepping motion mode. When the centering rod changes from concentric rotation to eccentric rotation again, record the Y-axis coordinate value of point E. E Calculate the coordinates of the midpoint Y0 on the Y-axis. D +Y E ) / 2, then control the Y-axis component to move to the coordinate value Y0; After four centering operations, the center of the hole in the fixed plate 5 can be found. At this point, the centering rod 7-7 can be replaced with the waveguide probe 7-13. After the replacement is completed, as follows... Figure 4 As shown, by placing the polarization angle zero-point correction plate 7-12 against the edge of the waveguide probe 7-13, the current polarization angle is reset to 0 degrees in the host computer control system.

[0029] After the above preparations are completed, the testing and calibration process for the liquid crystal phased array antenna can begin.

[0030] like Figure 5 As shown, the radio frequency unit of the liquid crystal phased array antenna mainly consists of a waveguide-coaxial converter 6-1, an excitation probe 6-2, a planar radial waveguide 6-3, and a liquid crystal tunable resonator array 6-4. The waveguide-coaxial converter 6-1 is used to connect to a vector network analyzer for transmitting or receiving signals at a set frequency. The excitation probe 6-2 is used to generate traveling wave signals in the planar radial waveguide 6-3. The liquid crystal tunable resonator array 6-4 adjusts the voltage of the liquid crystal driving electrode of each resonant slot through a control system, thereby adjusting the orientation of the liquid crystal molecules in the slot. The change in the orientation of the liquid crystal molecules causes a change in the capacitance value of the resonant slot, thus changing the resonant frequency of the slot. Therefore, controlling the voltage of the liquid crystal driving electrode of each slot can control the energy radiated outward from each slot. By using multiple resonant slot arrays, a holographic pattern with the desired target beam orientation can be generated.

[0031] like Figure 6 As shown, the performance of the planar radial waveguide 6-3 was tested first. The waveguide-coaxial converter 6-1 was connected to port 1 of the vector network analyzer, and the waveguide probe 7-13 was connected to port 2 of the vector network analyzer. The control system controlled the X-axis and Y-axis motors to perform circular interpolation motion, using the center of the planar radial waveguide 6-3 as the center of the circle. The signal amplitude and phase on the concentric circle were measured at regular intervals (1 / 4 of a distance), and the host computer automatically recorded the test data. After the concentric circle test was completed, the control system controlled the X-axis and Y-axis motors to perform linear interpolation motion along the circumferential radius, and the host computer automatically recorded the amplitude and phase data in the radial direction.

[0032] like Figure 7 and Figure 8 As shown, after the planar radial waveguide 6-3 is tested, the liquid crystal tunable resonator array 6-4 is assembled and positioned above the planar radial waveguide 6-3 to begin testing and calibrating the liquid crystal resonator array.

[0033] The following describes the automatic testing and calibration process for liquid crystal resonant cavities. The control system pre-imports the X, Y, and polarization angle (θ) coordinate data of all liquid crystal resonant cavities; Taking the first liquid crystal resonant cavity as an example, the test slide moves the antenna under test according to the coordinate data of the resonant cavity, and moves the receiving waveguide probe 7-13 above the resonant cavity under test. At the same time, the polarization drive motor 7-11 drives the polarization angle of the receiving waveguide probe 7-13 to be parallel to the θ angle of the resonant cavity currently being measured. The vector network analyzer port 1 provides a preset frequency signal to the waveguide coaxial converter 6-1, and the vector network analyzer port 2 is connected to the waveguide probe 7-13. The control system controls the driving board of the liquid crystal tunable resonator array 6-4 to turn off the electrode driving signals of all resonant cavities and turn on the electrode driving signal of the resonant cavity under test only. The electrode driving signal starts from 0V and increases in steps of 0.5V. After the waveguide probe 7-13 receives the radiated signal, the voltage is changed to a step value of 0.1V. When the signal gain value received by the vector network analyzer is the maximum, the driving voltage of the resonant cavity is recorded. After testing, the driving voltage of the resonant cavity at this frequency can be calibrated. The control system drives the X and Y motors to the next numbered resonant cavity, repeats the previous test, and records the driving voltage at that frequency.

[0034] It should be noted that there are two types of resonant cavities: TX (transmit) and RX (receive). When testing the TX resonant cavity, the vector network analyzer should be switched to S21 mode, and when testing the RX resonant cavity, the vector network analyzer should be switched to S12 mode.

[0035] After testing all the resonant cavities, the voltage reference values ​​for all the resonant cavities at a specific frequency are obtained.

[0036] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A liquid crystal holographic phased array antenna measurement and calibration device, characterized in that: It consists of a frame assembly, a Z-axis lifting assembly, an X-axis moving assembly, a Y-axis moving assembly, an antenna mounting plate, and a polarization rotation measurement centering assembly; the Z-axis lifting assembly, X-axis moving assembly, and Y-axis moving assembly are used to drive the antenna mounting plate to perform three-axis movement; the polarization rotation measurement centering assembly is located on the upper side of the frame assembly, and the antenna is mounted on the antenna mounting plate; The polarization rotation measurement centering assembly includes two measurement assembly support columns, which are fixed to the platforms on both sides of the frame assembly. Measurement assembly fixing crossbars are set on the two measurement assembly support columns. A polarization rotation motor fixing plate is set on one of the measurement assembly support columns. A polarization drive motor is set on the polarization rotation motor fixing plate. A driven pulley and an encoder are set in the middle of the measurement assembly fixing crossbar. The output shaft of the encoder is connected to the driven pulley and is used to detect and calibrate the rotation angle of the main shaft when the main shaft rotates. The driven pulley is connected to a rigid coupling, and the rigid coupling is connected to a centering rod or waveguide probe.

2. The liquid crystal holographic phased array antenna measurement and calibration device according to claim 1, characterized in that: The encoder is mounted on an encoder mounting plate, which is connected to the measuring component fixing crossbar via hexagonal studs.

3. The liquid crystal holographic phased array antenna measurement and calibration device according to claim 1, characterized in that: The Z-axis lifting assembly includes a Z-axis lead screw seat fixing plate, which is fixed to the three-axis coordinate assembly mounting platform by four Z-axis assembly fixing columns. The three-axis coordinate assembly mounting platform is mounted on the frame assembly. A Z-axis drive motor is mounted on the Z-axis lead screw seat fixing plate, and the Z-axis drive motor is connected to the Z-axis lead screw. The X-axis moving assembly is connected to the Z-axis lifting plate through lifting guide columns. A Z-axis lead screw nut is mounted on the Z-axis lifting plate. When the Z-axis drive motor rotates, the Z-axis lead screw rotates accordingly, and the Z-axis lifting plate moves up and down under the drive of the Z-axis lead screw nut. The X-axis moving assembly and the Y-axis moving assembly move up and down with the four Z-axis lifting guide columns.

4. The liquid crystal holographic phased array antenna measurement and calibration device according to claim 3, characterized in that: The Z-axis drive motor is fixed to the Z-axis lead screw seat fixing plate via a Z-axis motor mounting bracket.

5. The liquid crystal holographic phased array antenna measurement and calibration device according to claim 1, characterized in that: The X-axis moving assembly includes an X-axis drive motor, an X-axis photoelectric limit switch, an X-axis base plate, an X-axis ball screw bearing support, an X-axis ball screw, an X-axis guide rail, an X-axis slider, and an X-axis moving plate. The X-axis base plate is fixed to four Z-axis lifting guide columns via an optical axis fixing flange. Two X-axis guide rails are fixed to the X-axis base plate. The X-axis drive motor and the X-axis ball screw are fixedly supported on the X-axis base plate via the X-axis ball screw bearing support. The X-axis slider is slidably mounted on the X-axis guide rail. The X-axis moving plate is connected to the X-axis slider.

6. The liquid crystal holographic phased array antenna measurement and calibration device according to claim 1, characterized in that: The Y-axis moving assembly includes a Y-axis moving plate, a Y-axis ball screw bearing support, a Y-axis moving plate reinforcing rib, a Y-axis ball screw nut fixing seat, a Y-axis ball screw nut, a Y-axis ball screw, a Y-axis motor fixing seat, a Y-axis drive motor, a Y-axis guide rail, a Y-axis photoelectric limit switch, a Y-axis slider, and a Y-axis slider fixed on the X-axis moving plate. The Y-axis guide rail is slidably mounted on the Y-axis slider. The Y-axis moving plate is fixed to the Y-axis guide rail. The Y-axis drive motor, Y-axis motor fixing seat, Y-axis ball screw, Y-axis ball screw nut, and Y-axis... The reinforcing ribs of the moving plate and the Y-axis ball screw bearing support are fixed on the Y-axis moving plate. The Y-axis moving plate is also provided with a Y-axis ball screw nut fixing seat. The Y-axis ball screw passes through the Y-axis ball screw nut. One end of the Y-axis ball screw is connected to the Y-axis drive motor, and the other end is set on the Y-axis ball screw bearing support seat. The Y-axis ball screw nut fixing seat is connected and fixed to the X-axis moving plate. The Y-axis photoelectric limit switch is set on the Y-axis moving plate.

7. The liquid crystal holographic phased array antenna measurement and calibration device according to claim 1, characterized in that: The antenna consists of a waveguide-coaxial converter, an excitation probe, a planar radial waveguide, and a liquid crystal tunable resonator array connected in sequence.

8. A test method for the liquid crystal holographic phased array antenna measurement and calibration device according to claims 1-7, characterized in that, Includes the following steps: 1) Determine the center of the circular antenna array; 2) Planar radial waveguide testing, specifically as follows: The waveguide coaxial converter is connected to port 1 of the vector network analyzer, and the waveguide probe is connected to port 2 of the vector network analyzer. The X-axis and Y-axis motors are controlled to perform circular interpolation motion, with the center of the planar radial waveguide as the center of the circle. The signal amplitude and phase on the concentric circle are measured, and the host computer automatically records the test data. After the test is completed, the control system controls the X-axis and Y-axis motors to perform linear interpolation motion along the circumferential radius, and the host computer automatically records the amplitude and phase data in the radial direction. 3) After the planar radial waveguide test is completed, the liquid crystal tunable resonator array is assembled and positioned above the planar radial waveguide for testing and calibration of the liquid crystal resonator array; details are as follows: 3.1) The control system imports the X, Y, and polarization angle coordinate data of all liquid crystal resonant cavities in advance; 3.2) The test slide moves the antenna under test according to the coordinate data of the resonant cavity, and moves the receiving waveguide probe above the resonant cavity under test. At the same time, the polarization drive motor drives the polarization angle of the receiving waveguide probe to be parallel to the polarization angle of the resonant cavity currently being measured. The vector network analyzer port 1 provides the preset frequency signal to the waveguide coaxial converter, and the vector network analyzer port 2 is connected to the waveguide probe. 3.3) The control system controls the driving board of the liquid crystal tunable resonator array to turn off the electrode driving signals of all resonant cavities and turn on the electrode driving signal of the resonant cavity under test. The electrode driving signal starts from V and increases in steps of .V. After the waveguide probe receives the radiation signal, the voltage is changed to a step value of .V. When the signal gain value received by the vector network analyzer is the maximum, the driving voltage of the current resonant cavity is recorded, and the driving voltage of the resonant cavity at this frequency is calibrated. 3.4) The control system drives the X-axis moving component and the Y-axis moving component to the next numbered resonant cavity, repeats the previous test, and records the driving voltage at that frequency.

9. The test method for a liquid crystal holographic phased array antenna measurement and calibration device according to claim 8, characterized in that: The specific method for determining the center of the antenna circular array is as follows: The centering rod is clamped and fixed onto a rigid coupling. The polarization drive motor is controlled to rotate continuously. Then, the motors of the Z-axis lifting assembly, X-axis moving assembly, and Y-axis moving assembly are manually controlled to rotate. Under the drive of the X, Y, and Z moving assemblies, the centering rod is positioned in the hole in the middle of the antenna mounting plate. The X-axis assembly is manually controlled to move to the right. When the centering rod touches point A on the edge of the hole in the middle of the mounting plate and changes from eccentric rotation to concentric rotation, the X-axis is switched to a small-distance step movement mode. When the centering rod changes from concentric rotation to eccentric rotation again, the X-axis coordinate value X of point A is recorded. A Then, manually control the X-axis assembly to move to the left. When the centering rod touches point B on the edge of the middle hole of the fixed plate and changes from eccentric rotation to concentric rotation, switch the X-axis to small-distance stepping motion mode. When the centering rod changes from concentric rotation to eccentric rotation again, record the X-axis coordinate value of point B. B Calculate the coordinates of the midpoint X0 on the X-axis. A +X B ) / 2, then control the X-axis component to move to the coordinate value X0; Manually control the Y-axis assembly to move forward. When the centering rod touches the edge of the middle hole of the fixed plate at point D, and changes from eccentric rotation to concentric rotation, switch the Y-axis to small-distance stepping motion mode. When the centering rod changes from concentric rotation to eccentric rotation again, record the Y-axis coordinate value of point D. D Then, manually control the Y-axis assembly to move backward. When the centering rod touches point E, the edge of the middle hole of the fixed plate, and changes from eccentric rotation to concentric rotation, switch the Y-axis to small-distance stepping motion mode. When the centering rod changes from concentric rotation to eccentric rotation again, record the Y-axis coordinate value of point E. E Calculate the coordinates of the midpoint Y0 on the Y-axis. D +Y E ) / 2, then control the Y-axis component to move to the coordinate value Y0; After four operations, the center of the hole in the middle of the fixing plate was determined.

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