Test tool system for U6G frequency band multi-stream large-scale antenna array

Abstract

The invention relates to a test tool system for a U6G frequency band multi-stream large-scale antenna array, a BOT layer of a substrate is provided with a plurality of channel array groups which are arranged in an array and are mutually isolated, and each channel array group comprises a plurality of channel units arranged in an array; each channel unit comprises a plurality of one-to-two power dividers which are cascaded in a symmetrical mode, the channel units are connected in series end to end through a first transmission line and a second transmission line, and signal interference is isolated through a grounding shielding wall; the output ends of the one-to-two power dividers are connected through a first phase difference line and a second phase difference line; the first phase difference line is a reference phase, and the second phase difference line is a compensation phase. The one-to-two power dividers are cascaded in a tree-shaped symmetrical mode, phase errors of transmission lines are offset, and then the two differential lines with different phases are connected to compensate phase deviation caused by machining tolerance; and a grounding shielding wall is arranged at the periphery of the channel unit so as to isolate signal interference between the channel units.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of millimeter wave phased array, in particular to a test tool system for multi-stream large-scale antenna array of U6G frequency band. BACKGROUND

[0002] In the prior art, the traditional power divider in the multi-channel signal distribution and phase control tool system for U6G frequency band adopts a cascade mode, and the transmission line length sensitivity of the U6G frequency band easily causes phase mismatch, resulting in phase error. In addition, due to insufficient isolation between multiple channels in the existing tool system, signal crosstalk is easily caused, which directly affects the performance of the large-scale antenna array (MIMO) when the isolation is less than 35 dB.

[0003] However, the prior art cannot simultaneously achieve wideband phase consistency and high isolation and low crosstalk. Therefore, there is an urgent need to provide an efficient test tool system supporting multi-channel and multi-beam, which ensures that the function and performance of the large-scale antenna array meet the standards in complex scenarios, and simultaneously has high quality of phase consistency and high isolation and low crosstalk. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a test tool system for multi-stream large-scale antenna array of U6G frequency band, which can simultaneously achieve phase consistency and high isolation and low crosstalk.

[0005] To solve the above technical problems, the present application provides a test tool system for multi-stream large-scale antenna array of U6G frequency band, comprising a plurality of PCB single boards, each PCB single board comprising a substrate, a plurality of channel array groups arranged in an array and isolated from each other are arranged on the BOT layer of the substrate, and each channel array group comprises a plurality of channel units arranged in an array; the channel unit comprises a plurality of 1-to-2 power dividers cascaded in a symmetrical manner, each channel unit is connected in series through first and second transmission lines at the head and tail, and is isolated from signal interference through a grounded shielding wall; the output ends of the 1-to-2 power dividers are connected through first and second phase difference lines; the first phase difference line is a reference phase, and the second phase difference line is a compensation phase.

[0006] Further, the 1-to-2 power divider realizes multi-stage impedance through the width of the strip line, including an input stage impedance arranged at the input end, an output stage impedance arranged at the output end, and a first stage impedance and a second stage impedance arranged between the input end and the output end; the input stage impedance and the output stage impedance are equal, the first stage impedance is greater than the second stage impedance, and the second stage impedance is greater than the input stage impedance and the output stage impedance.

[0007] Further, the input stage impedance, the output stage impedance, the first stage impedance and the second stage impedance have an impedance value range of 45Ω to 75Ω.

[0008] Further, the output end of the 1:2 power divider is integrated with an LC isolation network, and the LC isolation network comprises a capacitor in series with the output end of the 1:2 power divider and an inductor in parallel with the capacitor.

[0009] Further, the capacitor is 22pF, and the inductor is 3.3nH.

[0010] Further, the first phase difference line and the second phase difference line realize the reference phase and the compensation phase through the line width W of the trace and the curvature radius R of the trace.

[0011] Further, the reference phase is 0°, the first phase difference line is a straight trace, and the curvature radius R is zero; the compensation phase is ±180°, the second phase difference line is a snake-shaped trace, and the curvature radius R is greater than 3×W.

[0012] Further, the first transmission line and the second transmission line comprise a metal wall for shielding signal interference, a transmission strip line arranged on the metal wall, etched lines arranged on both sides of the transmission strip line, and a plurality of metalized holes arranged along the etched lines and forming an electromagnetic bandgap structure.

[0013] Further, the channel unit comprises a first 1:2 power divider connected with the input / output port, and a second 1:2 power divider connected with the first 1:2 power divider and connected with another channel unit; the input end of the first 1:2 power divider is connected with the input / output port, and the output end of the first 1:2 power divider is connected with the output end of the second 1:2 power divider. The input end of the second 1:2 power divider is connected with the input end of the second 1:2 power divider of another channel unit, and the output end of the second 1:2 power divider is connected with the output end of the first 1:2 power divider.

[0014] Further, the input / output port is an SMA connector, and the distance between each two SMA connectors is greater than 20mm, and the two SMA connectors are connected through a radio frequency cable.

[0015] Compared with the prior art, the 1:2 power divider in the present application is cascaded in a tree-shaped symmetrical manner to offset the phase error of the transmission line, and then connected through two different phase difference lines to compensate for the phase deviation caused by the processing tolerance; and a grounding shielding wall is arranged on the outer periphery of the channel unit to isolate the signal interference between the channel units, so that high quality with consistent phase and high isolation and low crosstalk is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a PCB single board structure schematic diagram of a test tool system of a multi-stream large-scale antenna array for a U6G frequency band according to an embodiment of the present application; Figure 2 is a BOT layer structure schematic diagram of a PCB single board of a test tool system of a multi-stream large-scale antenna array for a U6G frequency band according to an embodiment of the present application; Figure 3 is a structure enlarged view of a Wilkinson power divider in the A ring in Figure 2 is a structure enlarged view of a transmission line in the B ring in Figure 4 Figure 2 is a structure enlarged view of a transmission line in the B ring in Figure 5 is an LC isolation network structure schematic diagram of an output end of a 1:2 power divider according to an embodiment of the present application; Figure 6 is a structure diagram of a 64-channel test tool system composed of 24 PCB single boards according to an embodiment of the present application.

[0017] Label explanation: 1. Ground shielding wall; 2. First-stage 1:2 power divider; 3. Base plate; 4. First transmission line; 5. Second transmission line; 6. Second phase difference differential line; 7. First phase difference differential line; 8. Input / output port; 9. Second-stage 1:2 power divider; 10. Input end PCB module; 11. Connection end PCB module; 12. Output end PCB module; 21. Input stage impedance; 22. First-stage impedance; 23. Second-stage impedance; 24. Output stage impedance; 25. Connection hole; 26. Strip line; 41. Metalized hole; 42. Metal wall; 43. Etched line; 44. Transmission strip line; X1-X8. Output end PCB single board; Y1-Y8. Connection end PCB single board; Z1-Z8. Input end PCB single board. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0019] Please refer to Figure 1 ​The test tool system for the multi-stream large-scale antenna array of the U6G frequency band comprises a plurality of PCB single boards, each of which comprises a substrate 3, and the BOT layer of the substrate 3 is provided with a plurality of channel array groups arranged in an array and isolated from each other, and each channel array group comprises a plurality of channel units arranged in an array; the channel unit comprises a plurality of 1:2 power dividers cascaded in a symmetrical manner, and each channel unit is connected in series through a first transmission line 4 and a second transmission line 5 at the head and tail and is isolated from signal interference through a ground shielding wall 1; the output ends of the 1:2 power dividers are connected through a first phase difference line 7 and a second phase difference line 6; the first phase difference line 7 is a reference phase, and the second phase difference line 6 is a compensation phase.

[0020] Figure 1 The PCB single board structure diagram of the 8x8 channel of the embodiment of the application is shown in the figure. The PCB single board comprises two channel array groups, A group and B group, the input / output ports 8 of the A group comprise I1A-I4A and O1A-O4A, and the input / output ports 8 of the B group comprise I1B-I4B and O1B-O4B. Each channel array group comprises four channel units. Each channel unit comprises four 1:2 power dividers, two first-stage 1:2 power dividers 2 connected to the input / output ports 8 and two second-stage 1:2 power dividers 9 connected to the first-stage 1:2 power dividers 2 and connected to another channel unit.

[0021] Specifically, the input end of the first-stage 1:2 power divider 2 is connected to the input / output port 8, and the output end is connected to the output end of the second-stage 1:2 power divider 9. The input end of the second-stage 1:2 power divider 9 is connected to the input end of the second-stage 1:2 power divider 9 of another channel unit, and the output end is connected to the output end of the first-stage 1:2 power divider 2. The two first-stage 1:2 power dividers 2 are arranged in a symmetrical vertical manner, and the two second-stage 1:2 power dividers 9 are arranged at the two ends of the two first-stage 1:2 power dividers 2 in a symmetrical horizontal manner.

[0022] The first phase difference line 7 and the second phase difference line 6 realize the reference phase and the compensation phase through the line width W of the trace and the curvature radius R of the trace. The phase deviation caused by the processing tolerance can be compensated through the compensation phase to meet the consistency requirement of the phase.

[0023] Figure 1The channel unit includes one second phase differential line 6 and three first phase differential lines 7 on the PCB single board shown, the reference phase is 0°, and the compensation phase is ±180°. The first phase differential line 7 is a straight line, and the curvature radius R is zero. The second phase differential line 6 is a serpentine line, and the curvature radius R is greater than 3*W. Specifically, the curvature radius is the curvature radius of the bending position of the serpentine line. The first phase differential line 7 and the second phase differential line 6 of other numerical values and the reference phase and the compensation phase of other numerical values can also be set by the person skilled in the art according to the actual situation, and the implementation of the present application is not affected.

[0024] As shown in Figure 2 , Figure 3 In the embodiment, the 1:2 power divider realizes multi-stage impedance through the width of the strip line 26, including the input stage impedance 21 arranged at the input end, the output stage impedance 24 arranged at the output end, the first stage impedance 22 and the second stage impedance 23 arranged between the input end and the output end; the input stage impedance 21 and the output stage impedance 24 are equal, the first stage impedance 22 is greater than the second stage impedance 23, and the second stage impedance 23 is greater than the input stage impedance 21 and the output stage impedance 24.

[0025] Specifically, the impedance value range of the input stage impedance 21, the output stage impedance 24, the first stage impedance 22 and the second stage impedance 23 can be 45Ω to 75Ω. Figure 3 The 1:2 power divider shown is a Wilkinson power divider, and for the U6G wideband requirement (6425-7125MHz, relative bandwidth 10.8%), the input stage impedance 21 and the output stage impedance 24 of the Wilkinson power divider can be set to 50Ω, the first stage impedance 22 is set to 70.7Ω, and the second stage impedance 23 is set to 58.3Ω, which can realize full-band return loss <-20dB. In addition, the Wilkinson power divider is also provided with a connecting hole 25 for connecting the signal of the power divider in the interlayer to the external device (such as resistance, capacitance, inductance, etc.) for welding.

[0026] Further, as shown in Figure 5 In the embodiment, the output end of the 1:2 power divider is integrated with an LC isolation network to isolate the signal interference between the power dividers. Specifically, the LC isolation network includes a capacitor in series and an inductor in parallel with the output end of the 1:2 power divider. In the embodiment, the capacitor is 22pF, and the inductor is 3.3nH. The person skilled in the art can also set other numerical values according to the actual situation, and the implementation of the present application is not affected.

[0027] Again, as shown in Figure 4As shown in the figure, in the embodiment, the first transmission line 4 and the second transmission line 5 include a metal wall 42 for shielding signal interference, a transmission strip line 44 arranged on the metal wall 42, etching lines 43 arranged on both sides of the transmission strip line 44, and a plurality of metalized holes 41 arranged along the etching lines 43 at intervals and forming an electromagnetic bandgap structure.

[0028] Specifically, in the embodiment, the metal wall 42 is made of copper, the transmission strip line 44 is made of copper, the etching lines 43 are made of copper, and the metalized holes 41 are made of copper. Figure 4 As shown in the figure, the diameter of the metalized holes 41 on the PCB single board is 0.2 mm, and the interval is 0.5 mm. Those skilled in the art can also set other values according to actual conditions, which does not affect the implementation of the present application.

[0029] For example, as shown in the figure, the diameter of the metalized holes 41 on the PCB single board is 0.2 mm, and the interval is 0.5 mm. Those skilled in the art can also set other values according to actual conditions, which does not affect the implementation of the present application. Figure 6 As shown in the figure, it is a structure diagram of a 64-channel test tool system composed of 24 PCB single boards. The 64-channel test tool system includes an input end PCB module 10, a connection end PCB module 11, and an output end PCB module 12. The input end PCB module 10 includes 8 vertically stacked input end PCB single boards Z1-Z8, the connection end PCB module 11 includes 8 horizontally stacked connection end PCB single boards Y1-Y8, and the output end PCB module 12 includes 8 horizontally stacked output end PCB single boards X1-X8.

[0030] The input / output ports 8 on each PCB single board are SMA (subminiature version A, subminiature version A connector) joints, and the interval between each SMA joint is greater than 20 mm, and they are connected by radio frequency cables.

[0031] As described above, the 1 / 2 power dividers of the present application are cascaded in a tree-shaped symmetrical manner to offset the phase error of the transmission line, and then connected by two different phase differential lines to compensate for the phase deviation caused by the processing tolerance; and a grounding shielding wall 1 is arranged on the outer periphery of the channel unit to isolate the signal interference between the channel units, thereby realizing high quality with consistent phase and high isolation and low crosstalk.

[0032] The above embodiments only express the preferred embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the patent of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, such as combining different features in each embodiment, which all belong to the protection scope of the present application.

Claims

1. A test fixture system for multi-stream massive MIMO antenna arrays in the U6G band, characterized in that, The system comprises several PCB boards, each PCB board including a substrate. The BOT layer of the substrate has multiple channel array groups arranged in an array and isolated from each other. Each channel array group includes multiple channel units arranged in an array. Each channel unit includes multiple 1-to-2 power dividers cascaded in a tree-like symmetrical manner. Each channel unit is connected in series through a first transmission line and a second transmission line and is surrounded by a grounded shield wall to isolate signal interference. The output terminals of the 1-to-2 power divider are connected by a first phase differential line and a second phase differential line; the first phase differential line is the reference phase, and the second phase differential line is the compensation phase.

2. The test fixture system for multi-stream massive MIMO antenna arrays in the U6G band as described in claim 1, characterized in that, The 1-to-2 power divider achieves multi-stage impedance through the width of the stripe, including an input stage impedance at the input end, an output stage impedance at the output end, and a first-stage impedance and a second-stage impedance between the input end and the output end; the input stage impedance and the output stage impedance are equal, the first-stage impedance is greater than the second-stage impedance, and the second-stage impedance is greater than both the input stage impedance and the output stage impedance.

3. The test fixture system for multi-stream massive MIMO antenna arrays in the U6G band as described in claim 2, characterized in that, The impedance values ​​of the input stage impedance, the output stage impedance, the first stage impedance, and the second stage impedance range from 45Ω to 75Ω.

4. The test fixture system for multi-stream massive MIMO antenna arrays in the U6G band as described in claim 1 or 2, characterized in that, The output terminal of the 1-to-2 power divider integrates an LC isolation network, which includes a capacitor connected in series with the output terminal of the 1-to-2 power divider and an inductor connected in parallel.

5. The test fixture system for multi-stream massive MIMO antenna arrays in the U6G band as described in claim 4, characterized in that, The capacitor is 22pF and the inductor is 3.3nH.

6. The test fixture system for multi-stream massive MIMO antenna arrays in the U6G band as described in claim 1, characterized in that, The first phase differential line and the second phase differential line realize the reference phase and the compensation phase through the trace width W and the trace curvature radius R.

7. The test fixture system for multi-stream massive MIMO antenna arrays in the U6G band as described in claim 6, characterized in that, The reference phase is 0°, and the first phase difference line is a straight line with a radius of curvature R of zero. The compensation phase is ±180°, and the second phase difference line is a serpentine line with a radius of curvature R > 3 × W.

8. The test fixture system for multi-stream massive MIMO antenna arrays in the U6G band as described in claim 1, characterized in that, The first transmission line and the second transmission line include a metal wall for shielding signal interference, a transmission strip line disposed on the metal wall, etched lines disposed on both sides of the transmission strip line, and a plurality of metallized holes arranged at intervals along the direction of the etched lines to form an electromagnetic bandgap structure.

9. The test fixture system for multi-stream massive MIMO antenna arrays in the U6G band as described in claim 1, characterized in that, The channel unit includes a first-stage 1-to-2 power divider connected to the input / output ports, and a second-stage 1-to-2 power divider connected to the first-stage 1-to-2 power divider and connected to another channel unit; The input terminal of the first-stage 1-to-2 power divider is connected to the input / output port, and the output terminal is connected to the output terminal of the second-stage 1-to-2 power divider. The input terminal of the secondary 1-to-2 power divider is connected to the input terminal of the secondary 1-to-2 power divider of another channel unit, and the output terminal is connected to the output terminal of the primary 1-to-2 power divider.

10. The test fixture system for multi-stream massive MIMO antenna arrays in the U6G band as described in claim 9, characterized in that, The input / output ports are SMA connectors, with a spacing of more than 20mm between each SMA connector, and are connected in pairs via RF cables.

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