A phase accuracy debugging method

Abstract

The application provides a phase precision debugging method, which comprises the following steps: firstly, processing a debugging board and a positive sample plate for each LTCC combined substrate, obtaining initial phase precision of a beam forming matrix through the debugging board, and then designing a surface phase line of the positive sample plate according to the initial phase precision to realize coarse adjustment of the phase precision; secondly, printing the corrected surface phase line on the surface of the positive sample plate; and finally, cutting the debugging phase line on the surface of the positive sample plate to change the path length of the signal, and then to improve the phase precision and realize fine adjustment of the phase precision. As can be seen, the application can concentrate the phase errors of all components in the system by printing the phase line on the surface of the positive sample plate, and then eliminate or reduce the phase errors by debugging the surface printed phase line, so that the operation is simple and convenient, the reliability of the system is not affected, and other devices and circuits are not needed, which can ensure the overall structure of the system unchanged and solve the phase precision problem through debugging.

Description

Technical Field

[0001] This invention belongs to the fields of communication and radar technology, and in particular relates to a phase accuracy adjustment method. Background Technology

[0002] Beamforming matrices are key components in multi-beam communication, radar, and other systems, and are widely used in satellite communication, radar systems, and other fields. Phase accuracy is one of the key indicators of a beamforming matrix, directly affecting the quality of beamforming. This includes important indicators such as beam pointing, beamwidth, and sidelobe level, ultimately impacting communication quality. When the beamforming matrix is ​​large, it requires complex system design. The system consists of multiple functional circuit modules and connecting cables between modules, all of which affect phase accuracy. Moreover, phase accuracy errors accumulate through errors in each stage of the circuit, eventually failing to meet the system's operational requirements.

[0003] Taking a beamforming matrix with 64 feeds forming 109 beams as an example, the beamforming matrix includes 109 beam input signal power dividers, 109 sets (each set containing several feeds for the corresponding beam) of fixed phase shifters and fixed attenuators, and 64 power combiners outputting to the feeds. The input signal of each beam is first split, with the number of splits equal to the number of feeds forming that beam. Unequal power dividers are used to ensure that the amplitude of each path meets the beam amplitude weighting distribution requirements. Then, the signal passes through fixed phase shifters to ensure that the signal of each path meets the beam phase weighting distribution requirements. Finally, the signals from the feeds shared by all beams are combined by an equal-power, equal-phase combiner and transmitted to the feeds. The number of feeds, feed numbers, and amplitude and phase weights for forming the beams are all predetermined.

[0004] The principle block diagram of the beamforming matrix is ​​as follows: Figure 1 As shown, for convenience, the beamhead is uniformly defined as the power distribution end, and the feedhead is uniformly defined as the power combining end. The connection relationship between the output of the beamhead and the input of the feedhead is given by the amplitude and phase weighting table. From Figure 1 As shown in the block diagram of the beamforming matrix, it comprises three circuit modules: a power distribution circuit at the beam end, a phase-shifting attenuator circuit, and a power combining circuit at the feed end. Signal transmission between these modules is achieved via radio frequency (RF) transmission lines, such as RF cables (including RF connectors), microstrip lines, and striplines.

[0005] Through miniaturization design, it is possible to Figure 1The various circuits in the design utilize LTCC (Low Temperature Cofired Ceramic) three-dimensional stacking technology to transform the planar microwave circuit into a three-dimensional stacked circuit, embedded within multiple layers of LTCC ceramic substrates. This reduces the circuit area and the number of connecting cables. Furthermore, by optimizing the beamforming matrix topology, the number of substrates used is reduced, further miniaturizing the circuit. Figure 2 The diagram shows a miniaturized beamforming matrix LTCC substrate. Signal transmission between different substrates and between the input and input terminals is achieved through radio frequency cables.

[0006] Through miniaturization design, it is possible to Figure 1 The various circuits in the design utilize LTCC (Low Temperature Cofired Ceramic) three-dimensional stacking technology to transform the planar microwave circuit into a three-dimensional stacked circuit, embedded within multiple layers of LTCC ceramic substrates. This reduces the circuit area and the number of connecting cables. Furthermore, by optimizing the beamforming matrix topology, the number of substrates used is reduced, further miniaturizing the circuit. Figure 2 The diagram shows a miniaturized beamforming matrix LTCC substrate. Signal transmission between different substrates and between the input and input terminals is achieved through radio frequency cables.

[0007] The first type of beam power distribution board divides 109 beam signals into two separate signals. This type of board has 109 independent circuits distributed on 14 LTCC substrates with an area of ​​84mm×23mm.

[0008] The second type of beam power distribution and feed power combining assembly board (hereinafter referred to as the assembly board) includes three functions. First, the power distribution at the beam end is performed in rows on the front side of the assembly board. Then, the first equal-power and equal-phase combining at the feed end is performed in columns on the back side of the assembly board. The second power distribution at the beam end and the first equal-power and equal-phase combining at the feed end are connected by a phase shifter and an embedded microwave transmission line. The dimensions of these 11 substrates are 163mm × 163mm. These 11 substrates are the core part of this beamforming matrix and the key component for realizing the miniaturization of the beamforming matrix.

[0009] The function of the third type of feed power combining board is to combine the feeds with the same number on the second type of substrate for a second time. This type of board has 64 independent circuits, distributed on 5 LTCC substrates with an area of ​​100mm×100mm.

[0010] The phase shifter is embedded in the combination board, located between the second power distribution circuit at the beam end and the first power combining circuit at the feed end, with one phase shifter corresponding to each effective channel.

[0011] The phase accuracy of a beam is defined as follows: Assuming a beam involves N feed sources, the difference between the phase test values ​​of these N channels in the beamforming matrix and the target phase weight is denoted as Δφ. i (i = 1, 2, ..., N), take Δφ i The minimum value of (i = 1, 2, ..., N) is denoted as Δφ. min Phase test values ​​and Δφ for all channels min The difference is the phase accuracy of each channel. The required phase accuracy is better than 8°, or predetermined according to the actual use. This invention is described using 8° as an example, but other requirements can also be adjusted using the method of this invention.

[0012] from Figure 2 As can be seen from the system configuration diagram, phase accuracy is related to each stage of the circuit and the connecting cables between these circuits. To meet the phase accuracy requirements, the specifications can be broken down into individual circuit modules and connecting cables, which increases the manufacturing difficulty of each component, or may even make it impossible to achieve.

[0013] One feasible solution to improve phase accuracy is concentrated phase error elimination, which involves setting a phase error adjustment point within the large-scale beamforming matrix to eliminate phase errors caused by all factors. This adjustment point is located within the beamforming matrix... Figure 1 The position of the phase shifter, that is Figure 2 On the assembly board. Since the phase shifter is implemented through transmission lines embedded in the LTCC substrate, a portion of this transmission line needs to be extended to the surface of the substrate through vias for adjustment. The conventional approach is to insert an adjustable phase shifter, such as a digitally controlled phase shifter, at each point where the channel extends to the substrate surface to adjust the phase accuracy. To meet the 8° phase accuracy requirement, the step size of the digitally controlled phase shifter cannot be less than 8°, therefore, the digitally controlled phase shifter needs to be at least 6 bits (step size 360° / 64 = 5.625°).

[0014] The problems with using adjustable phase shifters to adjust phase accuracy are as follows: (1) It increases the complexity of the system. In addition to adding adjustable phase shifters, it is also necessary to add control circuit modules for controlling phase shifters and power supply modules for them. This will greatly increase the size and weight of the system, and also introduce power consumption (originally a passive system with no power consumption); (2) Due to the introduction of adjustable phase shifters, and the fact that phase shifters themselves have losses, and the more bits there are, the greater the losses, this increases the channel losses. In extreme cases, it may be necessary to add amplifiers to compensate for the losses, which will further increase the complexity of the system; (3) The addition of active circuits reduces the reliability of the system, requiring additional thermal design, reliability design, etc., which increases the design cost; (4) Due to the addition of multiple modules, the manufacturing cost also increases significantly. Summary of the Invention

[0015] To address the aforementioned problems, this invention provides a phase accuracy adjustment method that eliminates or reduces phase errors by adjusting the surface-printed phase lines without requiring additional circuitry, thus maintaining the miniaturization of the original system.

[0016] A phase accuracy adjustment method involves simultaneously processing two LTCC composite substrates containing embedded phase shifters, and defining the two as an adjustment board and a positive sample board, respectively.

[0017] After printing phase lines of the same shape and length on the surface of each debugging board, a beamforming matrix is ​​made using each debugging board; wherein, the phase lines are obtained by superimposing debugging phase lines on conventional phase lines, and the debugging phase lines are two or more line segments connected in parallel with the ends of conventional phase lines.

[0018] Test the beamforming matrix to obtain the initial phase accuracy of each beam to its corresponding feed. Using the channel with an initial phase accuracy of 0 in each beam as a reference, calculate the phase degree that other channels need to increase. Then, obtain the surface phase line length corresponding to each channel through the phase degree that needs to be increased.

[0019] The surface phase lines are printed on the corresponding positive template surface. The surface phase lines on the positive template and the phase lines on the debugging board have the same shape, but their lengths are not exactly the same.

[0020] Replace the debugging board in the beamforming matrix with each positive template, retest the beamforming matrix, and obtain the coarse phase adjustment accuracy of each beam to its corresponding feed.

[0021] Using the channel with a coarse phase accuracy of 0 in each beam as a reference, cut off part of the parallel line segment of the adjustment phase line in the channel that does not meet the phase accuracy requirements, so that the phase accuracy of each channel finally meets the requirements.

[0022] Furthermore, the method for calculating the surface phase line length corresponding to each channel of any beam is as follows:

[0023] Assuming the current beam needs to connect N feed sources, corresponding to N channels, the phase difference between the phase test values ​​of each of the N channels and the target phase weight is denoted as... Let the minimum value be denoted as Δφ. min , with Δφ min The channel in question is the reference channel; the phase difference of other channels is reduced by Δφ. min The phase accuracy of the other channels was obtained respectively. Based on Δθ i The size, material properties, and operating frequency of the test board are used to obtain the surface phase line lengths corresponding to each channel of the current beam using electromagnetic field simulation.

[0024] Furthermore, the method for connecting the debugging phase line and the conventional phase line in parallel is as follows:

[0025] Add two or more line segments parallel to the side of the conventional phase line and connect each line segment to the conventional phase line. The more line segments added, the larger the adjustable phase range. At the same time, the spacing between each line segment is the same as the spacing between the first line segment and the conventional phase line, and the larger the spacing, the greater the phase adjustment gradient.

[0026] Furthermore, the phase adjustment gradient is determined according to the phase accuracy requirements.

[0027] Furthermore, the test board and the prototype were prepared using the same batch of materials and the same co-firing process.

[0028] Beneficial effects:

[0029] 1. This invention provides a phase accuracy adjustment method. First, an adjustment board and a prototype board are fabricated for all LTCC composite substrates. Phase lines of the same shape and length are printed on all channels of the adjustment board using the LTCC post-printing and post-burning process. The initial phase accuracy of the beamforming matrix is ​​obtained through the adjustment board. Then, the phase lines of all channels on the prototype board are designed based on the initial phase accuracy. Next, the designed phase lines of all channels are printed on the prototype board using the LTCC post-printing and post-burning process to achieve coarse adjustment of phase accuracy. Finally, the signal path length is changed by cutting the adjustment phase lines on the prototype board, thereby improving phase accuracy and achieving fine adjustment of phase accuracy. As can be seen, this invention concentrates the phase errors of all components in the system by printing phase lines on the adjustment board, and then eliminates or reduces the phase errors by printing corrected phase lines on the prototype board. The operation is simple and convenient, does not affect the reliability of the system, and does not require the introduction of other devices and circuits. This ensures that the overall structure of the system remains unchanged, and the phase accuracy problem can be solved through adjustment.

[0030] 2. This invention provides a phase accuracy adjustment method by adding parallel segments to the end of a conventional phase line. By cutting the parallel segments, the path length of the signal is changed, thereby enabling the adjustment of phase errors at multiple gradients and further improving phase accuracy. At the same time, each gradient can be set according to the specific requirements of phase accuracy. Different gradients can be obtained by adjusting the spacing between the adjustment phase lines. Therefore, this invention can increase the number of parallel segments and the adjustment gradient according to actual system requirements, thereby increasing the range of adjustable phase accuracy.

[0031] 3. This invention provides a phase accuracy debugging method. The debugging board and the positive sample board are prepared using the same batch of materials and the same co-firing process, which can effectively ensure the consistency of the internal circuit performance of the two substrates. Attached Figure Description

[0032] Figure 1 A block diagram illustrating the principle of a beamforming matrix;

[0033] Figure 2 Block diagram of LTCC substrate for beamforming matrix;

[0034] Figure 3(a) shows the phase line diagram on the surface of the debugging substrate;

[0035] Figure 3(b) is a partial enlarged view of the phase line pattern on the surface of the debugging substrate;

[0036] Figure 4(a) shows the phase line diagram on the surface of the positive sample substrate;

[0037] Figure 4(b) is a partial enlarged view of the phase line pattern on the surface of the positive sample substrate;

[0038] Figure 5 A schematic diagram showing the overall phase accuracy of the beamforming matrix for mounting and debugging the board.

[0039] Figure 6 A schematic diagram of the phase accuracy of the beamforming matrix for installing the positive template;

[0040] Figure 7(a) is a schematic diagram of a conventional phase line;

[0041] Figure 7(b) is a schematic diagram of the phase line after adding the parallel line segment phase line;

[0042] Figure 8(a) is a schematic diagram of the original phase line on the positive template;

[0043] Figure 8(b) is a schematic diagram of the phase line after cutting a line segment on the positive template;

[0044] Figure 8(c) is a schematic diagram of the phase line after cutting two line segments on the positive template;

[0045] Figure 9A schematic diagram of the overall phase accuracy of the beamforming matrix after installing the template and thin strips. Detailed Implementation

[0046] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0047] This invention provides a method for adjusting the phase accuracy of a large-scale beamforming matrix. This method does not change the original structure of the system and maintains the miniaturization of the system. Specifically, it includes the following steps:

[0048] Two LTCC composite substrates containing embedded phase shifters were fabricated simultaneously, and the two were defined as the debugging board and the prototype board, respectively.

[0049] After phase lines of the same shape and length are printed on the surface of each debugging board through a post-burn-in process, the debugging boards, beam power distribution boards, and feed power combining boards are assembled into a beamforming matrix. The phase lines are obtained by superimposing debugging phase lines on conventional phase lines, and the debugging phase lines are two or more line segments connected in parallel with the ends of the conventional phase lines. It should be noted that all phase lines on the debugging boards are of the same length, and signal transmission between different substrates is achieved through radio frequency cables according to design requirements.

[0050] Electrical performance tests were performed on the beamforming matrix. Based on the test results, the initial phase accuracy of each beam to its corresponding feed was obtained. Each beam corresponds to multiple feeds, and each feed corresponds to one channel. Each beam has one channel with an initial phase accuracy of 0. Using the channel with an initial phase accuracy of 0 in each beam as a reference, the phase degree that other channels need to be increased was calculated. Then, electromagnetic simulation was performed using the phase degree that needs to be increased to obtain the corrected surface phase line length of each channel. It should be noted that the surface phase line on the positive sample and the phase line on the test board have the same shape. Both are made by superimposing the test phase line on the conventional phase line, that is, by connecting two or more line segments in parallel at the end of the conventional phase line. However, the length of all phase lines on the test board is the same, while the length of the surface phase line of each channel on the positive sample is determined according to the calculation results of the electromagnetic simulation.

[0051] The corrected surface phase lines of all channels are printed onto the corresponding channel positions on the surface of the corresponding positive template using a post-printing and post-burning process. The shape of the surface phase lines is the same as that of the phase lines on the debugging board, which consists of two or more line segments connected in parallel at the end of the conventional phase lines to change the signal path length. This allows for the adjustment of the phase error of the two gradients. The two gradients can be designed according to the phase accuracy requirements. However, the lengths of the phase lines on the debugging board are all equal, while the lengths of the surface phase lines on the positive template are not exactly equal, as they are corrected by electromagnetic simulation calculations.

[0052] Replace the debugging board in the beamforming matrix with each positive template, and then retest the electrical performance of the beamforming matrix to obtain the coarse adjustment phase accuracy of each beam to its corresponding feed. It should be noted that the phase error will be greatly reduced at this time, and the channel qualification rate will also increase significantly. This debugging process is called coarse adjustment.

[0053] Using the channel with a coarse phase accuracy of 0 in each beam as a reference, cut off part of the adjustment phase line in the channel that does not meet the phase accuracy requirements, such as cutting one or two lines to increase the phase length, thereby improving the phase accuracy and making the phase accuracy of each channel finally meet the preset requirements. This adjustment process is called fine adjustment.

[0054] It should be noted that before printing the phase lines, the phase shifters embedded in the LTCC substrate need to be extended to the substrate surface, and then the phase lines are printed on the substrate surface. This allows the phase errors of all components in the system to be concentrated together, and the phase errors can be eliminated or reduced by adjusting the phase lines printed on the surface.

[0055] Therefore, the phase accuracy adjustment of this invention is divided into two processes: coarse adjustment and fine adjustment. The coarse adjustment is performed between the adjustment board and the positive sample board, which can adjust the large phase accuracy to a relatively small range. The fine adjustment is performed on the positive sample board, which can further improve the phase accuracy after the first step of coarse adjustment, so as to finally meet the phase accuracy index requirements. The following is a detailed explanation of the coarse and fine adjustment processes, taking as an example that there are 11 LTCC combination substrates with embedded phase shifters and the phase accuracy requirement is less than 8°.

[0056] (1) Coarse adjustment of phase accuracy is performed using a debugging board and a positive template.

[0057] Phase accuracy tuning is performed on a composite board using LTCC technology. The fabrication process of the LTCC composite board includes two steps: co-firing and post-firing. In the co-firing process, the circuitry (excluding the top and bottom layers) embedded within the substrate is screen-printed onto different LTCC green ceramic tapes. Signal transmission between different layers is achieved through vias. The green ceramic tapes are then laminated together according to the design sequence and finally sintered to form an LTCC circuit board. During co-firing, substrate shrinkage occurs. The degree of shrinkage is related to the substrate material properties, the distribution of metal paste in the circuit, and the sintering temperature. Substrate shrinkage affects circuit performance, including phase, and is difficult to control precisely. Post-firing involves printing the designed circuit patterns onto both sides of the sintered LTCC circuit board before a second sintering process. This process does not involve substrate shrinkage.

[0058] The beamforming matrix comprises 11 different combination boards, with two of each type manufactured simultaneously. To ensure consistency in the internal circuit performance of these two boards, they utilize materials from the same batch, and the entire process is performed synchronously. The two boards after co-firing are defined as the test board and the prototype board, respectively. First, one board is arbitrarily selected as the test board. Through a post-firing process, the designed initial phase lines are printed onto the surface of the board and then fired. After all 11 test boards have been fired, these 11 boards, along with other types of boards and connecting cables, are assembled into the complete unit according to the process flow. Figures 3(a) and 3(b) show the phase line diagram and a partial view of one of the test boards after firing. After assembly, the electrical performance of the beamforming matrix in its entirety is tested. Based on the test results, the phase of each beam to its associated feed source can be obtained, thereby calculating its phase accuracy.

[0059] Under normal circumstances, due to various errors, the worst-case phase accuracy range may be as low as 40°, and this error is random and unpredictable. However, the phase error obtained through testing can be eliminated or reduced by adjusting the length of the phase lines on the surface of the composite board. The method is to recalculate the length of each phase line based on the phase lines on the surface of the test board, and then burn the calculated phase lines onto the positive sample substrate.

[0060] Taking a single beam as an example, this section introduces a method for recalculating the phase line length. Assume the beam has N feed sources, and denote the phase difference between the measured phase values ​​of these N channels and the target phase weight as Δφ. i (i = 1, 2, ..., N), and the minimum value among them is denoted as Δφ. min Using this channel as the reference channel, the phase difference of other channels is reduced by Δφ. min , i.e., Δθ i =Δφ i -Δφ min(i = 1, 2, ..., N), these differences represent the phase accuracy of the channel. The smallest difference is 0, corresponding to the reference channel; all other values ​​are greater than 0, indicating that these channels need to increase the length of the phase line. The increased length value and Δθ i The size, material properties of the substrate used, and operating frequency are all related factors, and can be obtained through electromagnetic field simulation of the actual circuit. Figures 4(a) and 4(b) show the phase line diagram and partial view of the positive template printed on the back of Figures 3(a) and 3(b).

[0061] Theoretically, this debugging method can achieve continuous phase debugging, and if the two substrates are completely identical, zero-error debugging can be achieved. The debug substrate in the beamforming matrix assembly is replaced with the completed prototype substrate (at which point the phase line length on the prototype substrate surface is different from the debugging substrate). Only 11 combined substrates need to be replaced. After completing the individual unit assembly, the entire assembly is tested. At this point, the measured phase accuracy has been greatly improved. Figure 5 The figure shows the phase accuracy distribution of the entire machine after the debugging board is installed. At this time, the worst phase accuracy is 40°, and only 560 channels meet the 8° requirement, accounting for 40%. After coarse adjustment, the positive sample board is replaced in the whole machine. The worst phase accuracy of the whole machine is 15°, and 1297 channels meet the 8° requirement, accounting for 92.6%. This shows that the phase accuracy has been greatly improved by coarse adjustment.

[0062] (2) Fine-tuning of phase accuracy is performed on the positive sample substrate using phase wire cutting.

[0063] Through coarse adjustments using the debugging board and the prototype, the worst-case phase accuracy can be improved from no more than 40° to no more than 16°, and the proportion of qualified channels meeting the 8° requirement can be increased from 40% on the debugging board to 92.6% on the prototype. The remaining errors mostly stem from the consistency of processing between the debugging board and the prototype.

[0064] To further reduce phase accuracy errors caused by inconsistent substrate processing, the surface phase line was designed in the shape shown in Figure 7(b). This is based on the conventional phase line shown in Figure 7(a), with the addition of two line segments parallel to the sides, connecting these two segments to the original phase line. The current transmission path still primarily follows the innermost path, so the phase degree is essentially the same as the conventional design. However, this design establishes the foundation for adjustable phase. The phase lines in Figures 3(a), 3(b), 4(a), and 4(b) all use this shape. However, in Figures 3(a) and 3(b), all phase lines have the same length, while the lengths of the phase lines in Figures 4(a) and 4(b) have been updated based on the test results of the debugging board.

[0065] The fine-tuning process for the phase accuracy of the positive sample substrate is as follows:

[0066] The beamforming matrix was disassembled, and 11 test assembly boards were removed. These 11 prototype assembly boards were then installed back into the main unit, and the overall electrical performance was tested. Taking a single beam as an example, assuming the beam has N feed sources, the phase difference between the phase test values ​​of these N channels and the target phase weight is denoted as Δφ. i (i = 1, 2, ..., N), and the minimum value among them is denoted as Δφ. min Using this channel as the reference channel, the phase difference of other channels is reduced by Δφ. min , i.e., Δθ i =Δφ i -Δφ min (i = 1, 2, ..., N), these differences represent the phase accuracy of the channel. The smallest difference is 0, corresponding to the reference channel; all other values ​​are greater than 0, when Δθ i When the angle (i = 1, 2, ..., N) is less than 8°, the phase accuracy of these channels meets the requirements and no adjustment is needed. When the angle exceeds 8°, it is necessary to lengthen the phase line to ensure that Δθ is within acceptable limits. i Less than 8°. After the initial coarse adjustment, the phase accuracy can reach within 16°. At this point, the phase can be lengthened by cutting one or two lines from left to right in Figure 8(a). As shown in Figure 8(b), after cutting the first line segment, the signal will pass through the second line segment. As shown in Figure 8(c), after cutting the first and second line segments, the signal will pass through the third line segment, thus achieving the purpose of lengthening the phase line. By designing the spacing between the two lines, cutting one line can lengthen it by 5°, thus achieving two gradient adjustments of 5° and 10°. Theoretically, this allows channels with a phase accuracy exceeding 8° to be fine-tuned to within 8°, thereby meeting the 8° phase accuracy requirement with a certain margin. In actual debugging, more than two debugging lines can be added. The number of debugging lines and the debugging gradient can be determined by comprehensively considering the system requirements. Figure 9 The phase accuracy distribution of the beamforming matrix after fine-tuning is given. It can be seen from the figure that all channels can meet the phase accuracy requirements after fine-tuning.

[0067] Therefore, this invention proposes a phase accuracy adjustment method. Although its basic idea is to eliminate errors by focusing on the phase shifter position of the system, it does not require the introduction of other devices and circuits. This ensures that the overall system structure remains unchanged, maintains the miniaturization of the original system, and can solve the phase accuracy problem through adjustment. Specifically, this invention improves phase accuracy by cutting the adjustment phase line to change the signal path length. The operation is simple and convenient and does not affect the reliability of the system. At the same time, the adjustment method proposed in this invention can be customized according to specific system requirements, such as adjustment gradient and adjustment range.

[0068] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A phase accuracy adjustment method, characterized in that, Two LTCC composite substrates containing embedded phase shifters were fabricated simultaneously, and the two were defined as the debugging board and the prototype board, respectively. After printing phase lines of the same shape and length on the surface of each debugging board, a beamforming matrix is ​​made using each debugging board; wherein, the phase lines are obtained by superimposing debugging phase lines on conventional phase lines, and the debugging phase lines are two or more line segments connected in parallel with the ends of conventional phase lines. Test the beamforming matrix to obtain the initial phase accuracy of each beam to its corresponding feed. Using the channel with an initial phase accuracy of 0 in each beam as a reference, calculate the phase degree that other channels need to increase. Then, obtain the surface phase line length corresponding to each channel through the phase degree that needs to be increased. The surface phase lines are printed on the corresponding positive template surface. The surface phase lines on the positive template and the phase lines on the debugging board have the same shape, but their lengths are not exactly the same. Replace the debugging board in the beamforming matrix with each positive template, retest the beamforming matrix, and obtain the coarse phase adjustment accuracy of each beam to its corresponding feed. Using the channel with a coarse phase accuracy of 0 in each beam as a reference, cut off part of the parallel line segment of the adjustment phase line in the channel that does not meet the phase accuracy requirements, so that the phase accuracy of each channel finally meets the requirements.

2. The phase accuracy adjustment method as described in claim 1, characterized in that, The method for calculating the surface phase line length corresponding to each channel of any beam is as follows: Assuming the current beam needs to connect N feed sources, corresponding to N channels, the phase difference between the phase test values ​​of each of the N channels and the target phase weight is denoted as... Let the minimum value be denoted as Δφ. min , with Δφ min The channel in question is the reference channel; the phase difference of other channels is reduced by Δφ. min The phase accuracy of the other channels was obtained respectively. Based on Δθ i The size, material properties, and operating frequency of the test board are used to obtain the surface phase line lengths corresponding to each channel of the current beam using electromagnetic field simulation.

3. The phase accuracy adjustment method as described in claim 1, characterized in that, The method for connecting the debugging phase line and the conventional phase line in parallel is as follows: Add two or more line segments parallel to the side of the conventional phase line and connect each line segment to the conventional phase line. The more line segments added, the larger the adjustable phase range. At the same time, the spacing between each line segment is the same as the spacing between the first line segment and the conventional phase line, and the larger the spacing, the greater the phase adjustment gradient.

4. The phase accuracy adjustment method as described in claim 3, characterized in that, The phase adjustment gradient is determined based on the phase accuracy requirements.

5. A phase accuracy adjustment method as described in any one of claims 1 to 4, characterized in that, The test board and the prototype were prepared using the same batch of materials and the same co-firing process.

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