A phased array antenna in-field calibration device and in-field calibration method

Abstract

The application discloses a kind of phased array antenna field calibration device and field calibration method, it is related to antenna test technical field, and its technical solution main point is: vector network analyzer includes first port and second port, first port is connected with phased array radar antenna, switch network is connected with second port, first horn probe and second horn probe are connected with switch network by radio frequency circuit;Wherein, control machine issues switching instruction to switch network, completes the switching of radio frequency circuit between first horn probe and second horn probe, and issues control instruction to phased array antenna, controls the switch state and phase level of phased array antenna TR channel.The conventional fixed single-horn probe field calibration method is improved to fixed double-horn probe field calibration, so as to improve the amplitude and phase error caused by the wave path difference between each antenna unit of phased array antenna and single horn probe, so that the field calibration accuracy is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of antenna testing, and more particularly to a mid-field calibration device and a mid-field calibration method for a phased array antenna. Background Art

[0002] With the development of phased array radar technology, phased array antennas of different forms, frequencies and apertures are constantly being developed and applied, and various corresponding calibration methods are also constantly being updated and iterated to ensure that the antenna performance meets the design requirements.

[0003] Conventional calibration methods include near-field calibration, far-field calibration, and mid-field calibration. However, near-field and far-field calibration systems are relatively expensive to establish, so mid-field calibration, which offers a simpler calibration system, is generally chosen. However, the individual horn probes used in mid-field calibration are stationary, and there is a certain path difference between each antenna element of a phased array antenna and the individual horn probes. This path difference creates amplitude and phase deviations during calibration, leading to large amplitude and phase errors in the calibration. This results in low mid-field calibration accuracy and degraded phased array antenna performance. Summary of the Invention

[0004] The purpose of the present invention is to provide a mid-field calibration device and method for a phased array antenna, which improves the conventional fixed single-horn probe mid-field calibration method to a fixed dual-horn probe mid-field calibration method, thereby improving the amplitude and phase errors caused by the wave path difference between each antenna unit of the phased array antenna and the single horn probe, thereby improving the mid-field calibration accuracy.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions:

[0006] In a first aspect of the present application, a mid-field calibration device for a phased array antenna is provided, the calibration device comprising a phased array antenna, a first horn probe, a second horn probe, a vector network analyzer, a switch network, and a control machine;

[0007] The vector network analyzer includes a first port and a second port, the first port is connected to the phased array radar antenna, the switch network is connected to the second port, and the first horn probe and the second horn probe are connected to the switch network through a radio frequency circuit;

[0008] Among them, the control machine sends a switching instruction to the switch network to complete the switching of the RF circuit between the first horn probe and the second horn probe, and sends a control instruction to the phased array antenna to control the switching state and phase level of the phased array antenna TR channel.

[0009] In one embodiment, the vertical distance between the phased array antenna and the first horn probe and the second horn probe is a distance requirement for mid-field calibration.

[0010] In an embodiment, the first horn probe and the second horn probe correspond to the reference antenna unit of the phased array antenna vertically, the amplitude and phase obtained by calibrating the reference antenna unit based on the PT calibration are taken as the standard, and the amplitude and phase of the rest of the antenna units are subtracted to eliminate the amplitude and phase difference caused by the fixed wave path difference between each antenna unit of the phased array antenna and the horn probe.

[0011] In an embodiment, the control machine, the vector network analyzer, the phased array antenna, and the switch network are connected through a local area network.

[0012] In an embodiment, the first port of the vector network analyzer is used to collect the amplitude and phase of all phase levels of the phased array antenna TR channel, and the second port of the vector network analyzer is used to transmit a mid-field test continuous wave calibration signal at the same frequency as the phased array antenna.

[0013] In a second aspect of the present application, a mid-field calibration method of a phased array antenna is provided, which is applied to the mid-field calibration device of the phased array antenna as described in any one of the first aspect of the present application, and the method comprises:

[0014] The control machine sends a first switching instruction to the switch network to connect the second port of the vector network analyzer to the first horn probe, and the PT calibration method is used to calibrate the amplitude and phase corresponding to all phase levels of the phased array antenna to obtain the standard amplitude and phase corresponding to all phase levels of the phased array antenna under the first horn probe.

[0015] The control machine sends a second switching instruction to the switch network to connect the second port of the vector network analyzer to the second horn probe, and the PT calibration method is used to calibrate the amplitude and phase corresponding to all phase levels of the phased array antenna to obtain the standard amplitude and phase corresponding to all phase levels of the phased array antenna under the second horn probe.

[0016] The phased array antenna units corresponding to the first horn probe and the second horn probe vertically are taken as the reference antenna unit, the standard amplitude and phase corresponding to all phase levels of the reference antenna unit are taken as the reference, and the standard amplitude and phase of the rest of the phased array antenna units are subtracted to obtain the calibration amplitude and phase of different phase levels corresponding to the first horn probe and the second horn probe.

[0017] The calibration amplitude and phase of different phase levels corresponding to the first horn probe and the second horn probe are summed and averaged to obtain the standard amplitude and phase corresponding to the first horn probe and the amplitude and phase deviation corresponding to the second horn probe.

[0018] The standard amplitude and phase corresponding to the first horn probe and the amplitude and phase deviation corresponding to the second horn probe are summed and averaged to obtain an amplitude and phase calibration error, which calibrates the amplitude and phase difference caused by the fixed wave path difference between each antenna unit of the phased array antenna and the horn probe.

[0019] In an embodiment, the phase level of the phased array antenna is determined according to the number of bits of the digital phase shifter.

[0020] In an embodiment, the phase deviation between each phase level is calculated according to the phase level, and the calculation formula of the phase deviation is 2π / 2 k , k represents the number of bits of the digital phase shifter.

[0021] In an embodiment, the PT calibration method is used to calibrate the amplitudes and phases corresponding to all phase levels of the phased array antenna to obtain the standard amplitudes and phases corresponding to all phase levels of the phased array antenna under the first horn probe, which specifically includes:

[0022] The control machine issues a control instruction to the phased array antenna to control the TR channels of the phased array antenna to be in a switching state, wherein the switching state is that one TR channel is in an open state and the remaining TR channels are in a closed state.

[0023] The control machine controls the phase levels of the phased array antenna in the first state to be the first phase level and the second phase level, wherein the phase difference between the first phase level and the second phase level is 180°.

[0024] Each TR channel of the phased array antenna is controlled to be in the first state, and all phase levels of each TR channel of the phased array antenna are traversed, and the vector network analyzer is used to collect the amplitudes and phases of each TR channel in the first phase level and the second phase level, respectively.

[0025] The amplitudes and phases of each TR channel are summed and averaged according to the PT calibration calculation method to obtain the standard amplitudes and phases corresponding to all phase levels of the phased array antenna under the first horn probe.

[0026] In an embodiment, the PT calibration method is used to calibrate the amplitudes and phases corresponding to all phase levels of the phased array antenna to obtain the standard amplitudes and phases corresponding to all phase levels of the phased array antenna under the second horn probe, which specifically includes:

[0027] The control machine issues a control instruction to the phased array antenna to control the TR channels of the phased array antenna to be in a switching state, wherein the switching state is that one TR channel is in an open state and the remaining TR channels are in a closed state.

[0028] The control machine controls the phase level of the phased array antenna in the first state to be the first phase level and the second phase level, wherein the phase difference between the first phase level and the second phase level is 180°.

[0029] The control machine controls the phase level of the phased array antenna in the first state to be the first phase level and the second phase level, wherein the phase difference between the first phase level and the second phase level is 180°.

[0030] The control machine controls the phase level of the phased array antenna in the first state to be the first phase level and the second phase level, wherein the phase difference between the first phase level and the second phase level is 180°.

[0031] Compared with the prior art, the present application has the following beneficial effects:

[0032] 1、The present application provides a phased array antenna field calibration device, which improves the conventional fixed single horn probe field calibration method to a fixed double horn probe field calibration method, thereby improving the amplitude and phase errors caused by the wave path difference between each antenna unit of the phased array antenna and the single horn probe, and improving the field calibration accuracy.

[0033] 2、The present application provides a phased array antenna field calibration method, which uses the Phase-Toggle calibration method (PT calibration) to improve the amplitude and phase accuracy of the field calibration. DETAILED DESCRIPTION

[0034] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present application and constitute a part of the application, illustrate embodiments of the present application and are used to explain the principle of the present application, but do not limit the present application. In the drawings:

[0035] Figure 1 The structure block diagram of the phased array antenna field calibration device provided by the embodiments of the present application is shown in the figure.

[0036] Figure 2 The flowchart of the phased array antenna field calibration method applied to the phased array antenna field calibration device provided by the embodiments of the present application is shown in the figure. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below with reference to the embodiments and the drawings, and the illustrative embodiments of the present application and the description thereof are used to explain the present application, but do not limit the present application.

[0038] It should be understood that the terms "first", "second", etc. are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or an indicated number of the technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically limited.

[0039] The conventional calibration methods include near-field calibration, far-field calibration and mid-field calibration, but the cost of the near-field and far-field calibration systems is relatively high, so the mid-field calibration with a relatively simple calibration system is generally selected. However, the single horn probe in the mid-field calibration is fixed, and there is a certain wave path difference between each antenna element of the phased array antenna and the single horn probe. The wave path difference causes a deviation of the amplitude and phase during calibration, resulting in a large amplitude and phase error of the calibration, so that the mid-field calibration precision is not high, and the performance of the phased array antenna is deteriorated.

[0040] Therefore, in combination with the actual application scenarios described above, the present application provides a phased array antenna mid-field calibration device, as shown in Figure 1 The calibration device includes a phased array antenna, a first horn probe, a second horn probe, a vector network analyzer, a switch network and a control machine.

[0041] The vector network analyzer includes a first port and a second port, the first port is connected with the phased array radar antenna, the switch network is connected with the second port, and the first horn probe and the second horn probe are connected with the switch network through a radio frequency circuit.

[0042] The control machine sends a switching instruction to the switch network to complete the switching of the radio frequency circuit between the first horn probe and the second horn probe, and sends a control instruction to the phased array antenna to control the switching state and phase level of the TR channel of the phased array antenna.

[0043] Specifically, the phased array antenna is placed in a microwave shielding room, the positions of the first horn probe and the second horn probe and the vertical distance L between the phased array antenna and the horn probes are fixed according to the mid-field calibration device shown in Figure 1 The vertical distance L satisfies the distance requirement of the mid-field calibration. The control machine, the switch network, the vector network analyzer and the phased array antenna communicate with each other through a local area network.

[0044] Phased array antenna: an array composed of multiple radiation elements, through a beam forming network to control the amplitude and phase of the radio frequency signals of each radiation element of the phased array antenna, the accuracy and change of the phase and amplitude of each radiation element directly affect the performance of the synthesized beam.

[0045] The conventional fixed single-horn probe middle field calibration method is improved to a fixed double-horn probe middle field calibration method, so as to improve the amplitude and phase errors caused by the wave path difference between each antenna unit of the phased array antenna and the single-horn probe, and to improve the middle field calibration accuracy.

[0046] In an embodiment, the vertical distance between the phased array antenna and the first horn probe and the second horn probe is the distance requirement of the middle field calibration.

[0047] In an embodiment, the first horn probe and the second horn probe vertically correspond to the phased array antenna units as the reference antenna units, the amplitude and phase obtained by calibrating the reference antenna units based on the PT calibration are taken as the standard, and the amplitude and phase of the remaining antenna units are subtracted to eliminate the amplitude and phase differences caused by the fixed wave path difference between each antenna unit of the phased array antenna and the horn probe.

[0048] As a preferred embodiment, the control machine, the vector network analyzer, the phased array antenna, and the switch network are communicatively connected through a local area network. It can be understood that the control machine, the vector network analyzer, the phased array antenna, and the switch network can also be communicatively connected through a wired connection.

[0049] In an embodiment, the first port of the vector network analyzer is used to collect the amplitudes and phases of all phase levels of the phased array antenna TR channel, and the second port of the vector network analyzer is used to emit a middle field test continuous wave calibration signal at the same frequency as the phased array antenna.

[0050] As common knowledge of those skilled in the art, the first port of the vector network analyzer can be used to collect the amplitudes and phases of all phase levels of the phased array antenna TR channel, and the second port of the vector network analyzer can be controlled by the control machine to emit a middle field test continuous wave calibration signal at the same frequency as the phased array antenna, and therefore, no further description is provided here.

[0051] Please refer to Figure 2 , Figure 2 A phased array antenna middle field calibration method is provided for the phased array antenna middle field calibration device as described in the above embodiment, and the method comprises:

[0052] S210, the control machine issues a first switching instruction to the switch network, so that the second port of the vector network analyzer is connected to the first horn probe, and the PT calibration method is used to calibrate the amplitudes and phases of all phase levels corresponding to the phased array antenna, to obtain the standard amplitudes and phases of all phase levels corresponding to the phased array antenna under the first horn probe;

[0053] S220, the control machine issues a second switching instruction to the switch network, so that the second port of the vector network analyzer is connected with the second horn probe, and the PT calibration method is used to calibrate the amplitudes and phases corresponding to all phase levels of the phased array antenna, so that the standard amplitudes and phases corresponding to all phase levels of the phased array antenna under the second horn probe are obtained.

[0054] S230, the first horn probe and the second horn probe are vertically corresponding to the phased array antenna unit as the reference antenna unit, the standard amplitudes and phases corresponding to all phase levels of the reference antenna unit are taken as the reference, and the standard amplitudes and phases of the remaining phased array antenna units are subtracted to obtain the calibration amplitudes and phases of different phase levels corresponding to the first horn probe and the second horn probe.

[0055] S240, the calibration amplitudes and phases of different phase levels corresponding to the first horn probe and the second horn probe are summed and averaged to obtain the standard amplitude and phase corresponding to the first horn probe and the amplitude and phase deviation corresponding to the second horn probe.

[0056] S250, the standard amplitude and phase corresponding to the first horn probe and the amplitude and phase deviation corresponding to the second horn probe are summed and averaged to obtain the amplitude and phase calibration error, and the amplitude and phase difference caused by the fixed wave path difference between each antenna unit of the phased array antenna and the horn probe is calibrated.

[0057] The working principle of the middle field calibration method provided in the embodiment is as follows:

[0058] 1. The control machine issues a first switching instruction to the switch network through the local area network, so that the radio frequency circuit selects the first horn probe end, and simultaneously controls the second port of the vector network analyzer to transmit a middle field calibration signal, and the first port receives the signal.

[0059] 2. The control machine issues an instruction to the phased array antenna through the local area network, so that the TR1 channel is opened and the remaining channels are closed. The phase level of the TR1 channel of the phased array antenna is controlled to be 0, and the vector network analyzer collects the amplitude and phase of the channel TR1 at this time. Then the phase level of the TR1 channel of the phased array antenna is controlled to be 32 (the phase is flipped by 180°), and the vector network analyzer collects the amplitude and phase of the channel TR1 at this time. Then the calibration amplitude and phase of the TR1 channel are obtained according to the calculation method of the Phase-Toggle calibration (PT calibration). The phase level of the TR1 channel of the phased array antenna is controlled to be 1, and the vector network analyzer collects the amplitude and phase of the channel TR1 at this time. Then the phase level of the TR1 channel of the phased array antenna is controlled to be 33 (the phase is flipped by 180°), and the vector network analyzer collects the amplitude and phase of the channel TR1 at this time. Then the calibration amplitude and phase of the TR1 channel are obtained according to the calculation method of the PT calibration. In this way, all phase levels of the TR1 channel are traversed once.

[0060] 3、Control machine sends instruction to phased array antenna through LAN, so that TR2 channel is opened and the rest of the channels are closed. The phase level of the TR2 channel of the phased array antenna is 0, and the vector network analyzer collects the amplitude and phase of the TR2 channel at this time. Then the phase level of the TR2 channel of the phased array antenna is controlled to be 32 (phase flips 180°), and the vector network analyzer collects the amplitude and phase of the TR2 channel at this time. Then the calibration amplitude and phase of the TR2 channel are obtained according to the PT calibration calculation method. The phase level of the TR2 channel of the phased array antenna is controlled to be 1, and the vector network analyzer collects the amplitude and phase of the TR2 channel at this time. Then the phase level of the TR2 channel of the phased array antenna is controlled to be 33 (phase flips 180°), and the vector network analyzer collects the amplitude and phase of the TR2 channel at this time. Then the calibration amplitude and phase of the TR2 channel are obtained according to the PT calibration calculation method. In this way, the amplitude and phase of each phase level of each unit antenna of the phased array antenna are calibrated by the first horn probe.

[0061] 4、Control machine sends second switching instruction to control the switch network to switch to the first end of the second horn probe, and repeats steps 2 and 3 above to calibrate the amplitude and phase of each phase level of each unit antenna of the phased array antenna using the second horn probe.

[0062] 5、The first horn probe and the second horn probe are vertically corresponding to the reference unit antenna, and the calibrated amplitude and phase are subtracted from the standard to eliminate the amplitude and phase differences caused by the fixed wave path difference between the unit antenna of the phased array antenna and the horn probe, thereby improving the accuracy of the calibrated amplitude and phase.

[0063] In an embodiment, the phase level of the phased array antenna is determined according to the number of bits of the digital phase shifter. The number of bits of the digital phase shifter can be 5 or 6. Taking a digital phase shifter with K = 6 as an example, there are 64 phase levels, and the phase difference between each phase level is 5.625°. The relationship between the phase levels is shown in Table 1:

[0064] Table 1 Relationship table between phase level and phase shift accuracy

[0065] Phase Level 0 1 2 。。。 63 Phase shift accuracy (°) 0 5.625 11.25 。。。 354.375

[0066] As a specific embodiment, the phase deviation between each phase level is calculated according to the phase level, wherein the calculation formula of the phase deviation is 2π / 2 k , and k represents the number of bits of the digital phase shifter.

[0067] In an embodiment, the PT calibration method is used to calibrate the amplitudes and phases corresponding to all phase levels of the phased array antenna, and the standard amplitudes and phases corresponding to all phase levels of the phased array antenna under the first horn probe are obtained, which specifically includes:

[0068] The control machine sends a control instruction to the phased array antenna, and controls the TR channels of the phased array antenna to be in an on-off state, wherein the on-off state is that one TR channel is in an on state and the remaining TR channels are in an off state.

[0069] The control machine controls the phase level of the phased array antenna in the first state to be a first phase level and a second phase level, wherein the phase difference between the first phase level and the second phase level is 180°.

[0070] The control machine controls each TR channel of the phased array antenna to be in a first state, traverses all phase levels of each TR channel of the phased array antenna, and uses a vector network analyzer to collect the amplitude and phase of each TR channel in the first phase level and the second phase level, respectively.

[0071] The amplitudes and phases of each TR channel are summed and averaged according to the calculation method of the PT calibration to obtain the standard amplitudes and phases corresponding to all phase levels of the phased array antenna under the first horn probe.

[0072] In this embodiment, it should be understood that the first phase level is all phase levels that increase from 0 degrees to 180 degrees according to the phase shift accuracy, and the second phase level is a phase level whose phase shift accuracy is 180 degrees different from that of the first phase level. For example, when the phase shift accuracy of the first phase level is 5.625°, the phase shift accuracy of the second phase level is 185.625°. The calibration process of the first horn probe is implemented as follows:

[0073] S211, the control machine sends an instruction to the phased array antenna through a local area network to open the TR1 channel and close the remaining channels. The phase level of the TR1 channel of the phased array antenna is controlled to be 0, the vector network analyzer collects the amplitude and phase of the channel TR1 at this time, then the phase level of the TR1 channel of the phased array antenna is controlled to be 32 (phase flips 180°), the vector network analyzer collects the amplitude and phase of the channel TR1 at this time, then the calibration amplitude and phase of TR1 are obtained according to the calculation method of the PT calibration, and the amplitude and phase obtained by the PT calibration at this time are recorded. The phase level of the TR1 channel of the phased array antenna is controlled to be 1, the vector network analyzer collects the amplitude and phase of the channel TR1 at this time, then the phase level of the TR1 channel of the phased array antenna is controlled to be 33 (phase flips 180°), the vector network analyzer collects the amplitude and phase of the channel TR1 at this time, then the calibration amplitude and phase of TR1 are obtained according to the calculation method of the PT calibration, and the amplitude and phase obtained by the PT calibration at this time are recorded. In this way, all phase levels of the channel TR1 are traversed once.

[0074] S212, the control machine issues an instruction to the phased array antenna through the local area network to open the TR2 channel and close the remaining channels. The phase level of the TR2 channel of the phased array antenna is controlled to be 0, and the amplitude and phase of the channel TR2 at this time are collected by the vector network analyzer. Then the phase level of the TR2 channel of the phased array antenna is controlled to be 32 (phase flip 180°), and the amplitude and phase of the channel TR2 at this time are collected by the vector network analyzer. Then the calibrated amplitude and phase of TR2 are obtained according to the calculation method of PT calibration, and the amplitude and phase obtained by PT calibration at this time are recorded. The phase level of the TR2 channel of the phased array antenna is controlled to be 1, and the amplitude and phase of the channel TR2 at this time are collected by the vector network analyzer. Then the phase level of the TR2 channel of the phased array antenna is controlled to be 33 (phase flip 180°), and the amplitude and phase of the channel TR2 at this time are collected by the vector network analyzer. Then the calibrated amplitude and phase of TR2 are obtained according to the calculation method of PT calibration, and the amplitude and phase obtained by PT calibration at this time are recorded. In this way, the amplitude and phase of each phase level of each element antenna of the phased array antenna are calibrated by the "horn probe a".

[0075] S213, the PT calibration amplitude and phase correlation table corresponding to different phase levels is as shown in Table 2.

[0076] Table 2 PT calibration amplitude and phase correlation table

[0077]

[0078] S214, the first horn probe vertically corresponds to the phased array element antenna as the reference element antenna a, and the calibrated amplitude and phase obtained are the standard.

[0079] S215, according to the above control command, the calibration data obtained by the first horn probe is as shown in Table 3,

[0080] Table 3 First horn probe amplitude and phase calibration data table

[0081]

[0082] In an embodiment, the PT calibration method is used to calibrate the amplitude and phase corresponding to all phase levels of the phased array antenna, and the standard amplitude and phase corresponding to all phase levels of the phased array antenna under the second horn probe are obtained, which specifically includes:

[0083] The control machine issues a control instruction to the phased array antenna, and controls the TR channel of the phased array antenna to be in an on-off state, wherein the on-off state is that one TR channel is in an open state and the remaining TR channels are in a closed state.

[0084] The control machine controls the phase level of the phased array antenna in the first state to be a first phase level and a second phase level, wherein the phase difference between the first phase level and the second phase level is 180°.

[0085] The control of each TR channel of the phased array antenna is in the first state, all phase levels of each TR channel of the phased array antenna are traversed, and the vector network analyzer is used to collect the amplitude and phase of each TR channel in the first phase level and the second phase level respectively;

[0086] The amplitude and phase of each TR channel are summed and averaged according to the calculation method of PT calibration, and the standard amplitude and phase corresponding to all phase levels of the phased array antenna under the second horn probe are obtained.

[0087] In this embodiment, the second switching instruction is issued to the switch network by the control machine, so that the switch network is switched to the first end of the second horn probe b, and the steps S212 and S213 of the above embodiment are repeated to calibrate the amplitude and phase of each phase level of each unit antenna of the phased array antenna with the second horn probe.

[0088] The second horn probe is perpendicular to the corresponding phased array unit antenna as the reference unit antenna b, and the obtained amplitude and phase are calibrated as the standard.

[0089] According to the above control command, the calibration data obtained by the second horn probe is shown in Table 4 as follows:

[0090] Table 4 Amplitude and phase calibration data table of the second horn probe

[0091]

[0092] The reference unit antenna a and the reference unit antenna b are respectively taken as the standard and the difference is obtained with the remaining unit antennas, and the normalized double-horn probe calibration amplitude and phase are obtained, as shown in Tables 5 and 6.

[0093] Table 5

[0094]

[0095] Table 6

[0096]

[0097]

[0098] The amplitudes PT of different phase levels obtained by the first horn probe calibration are added and averaged, so as to reduce the amplitude error caused by the interference signal in the calibration process, so that the amplitude data obtained by the PT calibration is more real, that is, PTa is obtained. Similarly, the phases PT of different phase levels obtained by the second horn probe calibration are added and averaged, so as to reduce the phase error caused by the interference signal in the calibration process, so that the phase data obtained by the PT calibration is more real, that is, PTb is obtained.

[0099] The PTa of the first horn probe and the PTb of the second horn probe are added and averaged to reduce the amplitude and phase errors caused by the fixed wave path difference of the horn probe and the phased array antenna, so that the final obtained calibration amplitude and phase tend to be more real.

[0100] The above detailed description further explains the purposes, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A phased array antenna mid-field calibration method, applied to a phased array antenna mid-field calibration device, the calibration device comprising a phased array antenna, a first horn probe, a second horn probe, a vector network analyzer, a switch network, and a control machine; the vector network analyzer comprising a first port and a second port, the first port being connected to the phased array radar antenna, the switch network being connected to the second port, the first horn probe and the second horn probe being connected to the switch network via a radio frequency circuit; wherein, The controller sends a switching instruction to the switch network to complete the switching of the RF circuit between the first horn probe and the second horn probe, and sends a control instruction to the phased array antenna to control the switching state and phase level of the TR channel of the phased array antenna. The calibration method includes: The control machine sends a first switching instruction to the switch network, connecting the second port of the vector network analyzer to the first horn probe, and calibrating the amplitude and phase corresponding to all phase levels of the phased array antenna using the PT calibration method to obtain the standard amplitude and phase corresponding to all phase levels of the phased array antenna under the first horn probe; The control machine sends a second switching instruction to the switch network, connecting the second port of the vector network analyzer to the second horn probe, and calibrating the amplitude and phase corresponding to all phase levels of the phased array antenna using the PT calibration method to obtain the standard amplitude and phase corresponding to all phase levels of the phased array antenna under the second horn probe; The phased array antenna unit perpendicular to the first horn probe and the second horn probe is used as the reference antenna unit, and the standard amplitude phase corresponding to all phase levels of the reference antenna unit is used as the reference. The difference between the standard amplitude phase and the standard amplitude phase of the remaining phased array antenna units is made to obtain the calibrated amplitude phase at different phase levels corresponding to the first horn probe and the second horn probe; The calibration amplitudes and phases of the first horn probe and the second horn probe at different phase levels are summed and averaged to obtain the standard amplitude and phase corresponding to the first horn probe and the amplitude and phase deviation corresponding to the second horn probe; The standard amplitude and phase corresponding to the first horn probe and the amplitude and phase deviation corresponding to the second horn probe are summed and averaged to obtain the amplitude and phase calibration error, and the amplitude and phase difference caused by the fixed wave path difference between each antenna unit of the phased array antenna and the horn probe is calibrated.

2. The mid-field calibration method for a phased array antenna according to claim 1, characterized in that: The phase level of the phased array antenna is determined by the number of bits of the digital phase shifter.

3. The mid-field calibration method for a phased array antenna according to claim 2, characterized in that: The phase deviation between each phase level is calculated according to the phase level, where the calculation formula of the phase deviation is: , k represents the number of bits of the digital phase shifter.

4. The mid-field calibration method for a phased array antenna according to claim 1, wherein: The PT calibration method is used to calibrate the amplitude and phase corresponding to all phase levels of the phased array antenna, and the standard amplitude and phase corresponding to all phase levels of the phased array antenna under the first horn probe are obtained, specifically including: The control machine sends a control command to the phased array antenna to control the TR channel of the phased array antenna to be in a switching state, wherein the switching state is that one TR channel is in an open state and the remaining TR channels are in a closed state; The control machine controls the phase level of the phased array antenna in the first state to be a first phase level and a second phase level, wherein the phase difference between the first phase level and the second phase level is 180°; Controlling each TR channel of the phased array antenna to be in a first state, traversing all phase levels of each TR channel of the phased array antenna, and using a vector network analyzer to respectively collect the amplitude and phase of each TR channel at all the first phase level and the second phase level; According to the calculation method of PT calibration, the amplitude and phase of each TR channel are summed and averaged to obtain the standard amplitude and phase corresponding to all phase levels of the phased array antenna under the first horn probe.

5. The mid-field calibration method for a phased array antenna according to claim 1, characterized in that: The PT calibration method is used to calibrate the amplitude and phase corresponding to all phase levels of the phased array antenna, and the standard amplitude and phase corresponding to all phase levels of the phased array antenna under the second horn probe are obtained, specifically including: The control machine sends a control command to the phased array antenna to control the TR channel of the phased array antenna to be in a switching state, wherein the switching state is that one TR channel is in an open state and the remaining TR channels are in a closed state; The control machine controls the phase level of the phased array antenna in the first state to be a first phase level and a second phase level, wherein the phase difference between the first phase level and the second phase level is 180°; Controlling each TR channel of the phased array antenna to be in a first state, traversing all phase levels of each TR channel of the phased array antenna, and using a vector network analyzer to respectively collect the amplitude and phase of each TR channel at all the first phase level and the second phase level; According to the calculation method of PT calibration, the amplitude and phase of each TR channel are summed and averaged to obtain the standard amplitude and phase corresponding to all phase levels of the phased array antenna under the second horn probe.

Images