Resistance-free structure high-isolation power divider based on electromagnetic radiation principle

Abstract

The invention discloses a high-isolation power divider without a resistor structure based on an electromagnetic radiation principle. An electric signal between output ends of the power divider is radiated through a radiation unit so as to improve the isolation of the power divider; meanwhile, the isolation frequency band performance of the power divider is improved by improving the working frequency band performance of the radiation unit. According to the invention, the power divider, the slot structure and the radiation unit structure are combined to obtain the design of the broadband resistance-free high-isolation power divider, and the bandwidth and performance of the radiation unit are further improved through the design of the horn waveguide structure, the ridge waveguide structure and the like, so that the frequency band performance of the isolation of the power divider is improved. In addition, the size and the height of the radiation unit are reduced through the design of the planar multi-layer PCB stepped horn structure, and the miniaturization and low-profile characteristics of the radiation type power divider are enhanced.

Description

Technical Field

[0001] The invention belongs to the field of microwave technology, and in particular to a high-isolation power divider with a resistance-free structure based on the principle of electromagnetic radiation. Background Art

[0002] As one of the most fundamental and widely used RF components, power dividers (or power splitters) are a crucial component of modern RF communication systems. Years of research and exploration have resulted in continuous optimization of power splitter performance parameters, including loss, isolation, frequency bandwidth, and size. Higher isolation reduces mutual interference and impact between power splitter ports, a crucial consideration in the growing adoption of multi-port power splitter designs and Multiple-Input Multiple-Output (MIMO) communication networks, ensuring signal stability within the network.

[0003] Among the methods for improving power divider isolation, the most widely used method is to introduce resistors based on the traditional Wilkinson power divider. However, while resistive power dividers continue to be optimized for bandwidth performance and size, their resistive structure still limits their application scenarios. In large-scale, multi-layer array networks, the large number of isolation resistors not only increases the difficulty and cost of design and processing, but also consumes a large amount of RF network space, seriously affecting the flexibility and efficiency of the RF network in the multi-layer structure.

[0004] Recently, there have been some studies on optimizing the isolation of power dividers by designing gap or gap coupling structures (1. E. Wang, T. Zhang, L. Chen, A. U. Zaman and J. Yang, A Compact Double-Layer Groove Gap Waveguide Power Divider with High Isolation[C], 2020 14th European Conference on Antennas and Propagation(EuCAP), Copenhagen, Denmark, 2020, pp. 1-3, doi:10.23919 / EuCAP48036.2020.9135741. 2. S. Peng, Y. Pu, Z. Jiang, X. Chen, Z. Wu and Y. Luo, A Simple Way to Enhance the Isolation of Ridge Gap Waveguide T-Junction, for Application to Millimeter-Wave Feeder Networks[J], IEEE Microwave and Wireless Technology Letters, vol. 33, no. 7, pp. 975-978, July 2023, doi: 10.1109 / LMWT.2023.3266894.) Its principle is to achieve complete matching by exporting or radiating part of the radiation energy between the output ports, thereby improving the isolation between the ports. The design of the slot ridge waveguide T-type power divider structure eliminates the need for any isolation resistors, improving the isolation of the T-type power divider and ensuring superior performance and advantages in large-scale arrays. However, the existing technology only radiates part of the radiation through the slot to achieve the effect of improving isolation, and does not use the slot as a radiation unit to further study the improvement of the isolation band performance. As a result, the isolation performance of the existing power divider still has a lot of room for improvement in bandwidth and matching. Summary of the Invention

[0005] The purpose of the present invention is to address the problems existing in the above-mentioned prior art and provide a high-isolation power divider with a resistance-free structure based on the principle of electromagnetic radiation. The present invention starts from establishing a design method for a power divider based on the principle of electromagnetic radiation (referred to as a radiation-type power divider), and improves the isolation performance of the power divider without using a resistor device. By studying the design principles of the power divider and the radiation unit, the research on the isolation performance of the power divider is transformed into the research on the performance of the radiation unit, and further research is carried out using the relevant design methods of the antenna, achieving a significant improvement in the power divider's frequency band performance, isolation performance, size optimization, and simplified design and manufacturing.

[0006] The technical solution for achieving the purpose of the present invention is: a high-isolation power divider with a resistance-free structure based on the principle of electromagnetic radiation, wherein the high-isolation power divider with a resistance-free structure radiates the electrical signal between the output ends of the power divider through a radiation unit to improve the isolation of the power divider; at the same time, the isolation band performance of the power divider is improved by improving the working frequency band performance of the radiation unit.

[0007] Furthermore, the electrical signals between the output ports of the power divider are radiated through the radiation unit, which is specifically realized by combining the rectangular gap structure at the intersection of all ports of the power divider with the planar multilayer waveguide horn radiation unit structure to excite linearly polarized waves and radiate electrical signals between the output ports of the power divider.

[0008] Furthermore, the resistance-free high-isolation power divider is composed of a multi-layer planar PCB structure, including a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer, a third metal layer, a third dielectric layer and a fourth metal layer arranged in sequence from top to bottom, wherein the first metal layer, the first dielectric layer, the second metal layer, the second dielectric layer and the third metal layer constitute a stepped horn waveguide radiation unit structure, and the third metal layer, the third dielectric layer and the fourth metal layer constitute a power divider structure; the rectangular gap structure is arranged on the third metal layer at the connection between the stepped horn waveguide radiation unit structure and the power divider structure.

[0009] Furthermore, the direction in which the stepped horn waveguide radiation unit structure transmits electromagnetic waves is perpendicular to the multi-layer planar PCB structure.

[0010] Furthermore, the rectangular slot structure is arranged at the center of the intersection of all ports of the power divider structure, and its relative position to the stepped horn waveguide radiation unit structure is: located at the center of the stepped horn waveguide radiation unit structure.

[0011] Furthermore, a ridge waveguide structure is introduced into the stepped horn waveguide radiation unit structure.

[0012] Furthermore, along the direction of the long side of the rectangular slot structure, the ridge waveguide structure is located on both sides of the rectangular slot structure.

[0013] Furthermore, the power divider structure is a microstrip power divider, including the fourth metal layer as a metal microstrip structure, the third dielectric layer, and the third metal layer as a metal ground layer.

[0014] Furthermore, the power divider structure is a SIW power divider, including the third metal layer, the third dielectric layer and the fourth metal layer, metal vias connecting the third metal layer and the fourth metal layer, and metal holes for power divider matching.

[0015] Furthermore, the power divider structure is a three-port structure, including one input port and two output ports.

[0016] Compared with the prior art, the present invention has the following significant advantages:

[0017] (1) The present invention combines a power divider, a slot structure and a radiation unit structure to obtain a wide-band, resistance-free, high-isolation power divider design. The rectangular slot structure transmits the electrical signal between the output ends of the power divider to the radiation unit to excite a linearly polarized wave. The electrical signal between the radiated output ends will reduce the influence between the power divider ports, thereby achieving the effect of improving the isolation of the power divider. The structure is simple and easy to implement.

[0018] (2) The working bandwidth and performance of the isolation-enhanced part of the power divider are the working bandwidth and performance of the radiating unit. Therefore, solving the problem of improving the isolation band performance of the power divider can be transformed into the problem of improving the band performance of the radiating unit of the radiating power divider, which is easy to implement and conducive to subsequent improvements.

[0019] (3) The stepped horn waveguide radiating unit structure can further reduce the size and height of the radiating unit, thereby enhancing the miniaturization and low-profile characteristics of the radiating power divider and significantly increasing the bandwidth.

[0020] (4) The bandwidth and performance of the radiating unit can be further improved through the design of speaker waveguide structure, ridge waveguide structure, etc., thereby improving the frequency band performance of the power divider isolation and further reducing the size of the radiating unit.

[0021] The present invention is further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the design principle of a resistance-free high-isolation power divider based on the principle of electromagnetic radiation.

[0023] Figure 2 Schematic diagram of the structure of a slotted rectangular / ridge waveguide microstrip structure radiating power divider in one embodiment, wherein Figure 2 (a) is a top view. Figure 2 (b) in the figure is the main view.

[0024] Figure 3 Schematic diagram of the structure of a slotted rectangular / ridge waveguide SIW structure radiation type power divider in one embodiment, wherein Figure 3 (a) is a top view. Figure 3 (b) in the figure is the main view.

[0025] Figure 4 ] are the S parameters of the rectangular waveguide microstrip structure radiating power divider and the slot ridge waveguide microstrip structure radiating power divider in one embodiment, wherein Figure 4 (a) is the S parameter of the rectangular waveguide microstrip structure radiating power divider. Figure 4 (b) in the figure is the S parameter of the slot ridge waveguide microstrip structure radiating power divider.

[0026] Figure 5 : S parameters of a rectangular waveguide SIW structure radiating power divider and a slot ridge waveguide SIW structure radiating power divider in one embodiment, wherein Figure 5 (a) is the S parameter of the rectangular waveguide SIW structure radiating power divider. Figure 5 (b) in the figure is the S parameter of the slot ridge waveguide SIW structure radiating power divider. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0028] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0029] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features specified as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0030] In one embodiment, a high-isolation power divider with a resistance-free structure based on the principle of electromagnetic radiation is provided. The high-isolation power divider with a resistance-free structure radiates electrical signals between the output ends of the power divider through a radiation unit to improve the isolation of the power divider; at the same time, the isolation band performance of the power divider is improved by improving the operating frequency band performance of the radiation unit.

[0031] Combine Figure 1 The design method of the power divider of the present invention is aimed at the cutting-edge demand of integration and multi-layering of radio frequency circuits in communication systems. It combines the design of power dividers with radiation units, and explores the design method of high-isolation power dividers based on the principle of electromagnetic radiation through principle analysis, simulation modeling, test verification and other design processes. Combining the frequency band performance improvement method of radiation unit design with power divider design, continue to study the wide-band, multi-band and other performance optimization schemes of high-isolation radiation-type power dividers. On this basis, continue to explore the design mechanism of the combination of miniaturized and integrated power dividers and radiation units to cater to the development direction of miniaturization and chipization of modern communication systems, and study the technology of reducing the electromagnetic interference of power divider radiation on surrounding radio frequency devices, so as to ensure the effect of radiation-type power dividers in actual communication system applications.

[0032] Here, the working bandwidth and performance of the isolation-enhanced part of the power splitter are the working bandwidth and performance of the radiating unit. Therefore, solving the problem of improving the isolation band performance of the power splitter can be transformed into the problem of improving the band performance of the radiating unit of the radiating power splitter, which is easy to implement and conducive to subsequent improvements.

[0033] Furthermore, in one of the embodiments, the radiation unit radiates the electrical signal between the output ports of the power divider, which is specifically implemented by combining the rectangular gap structure at the intersection of all ports of the power divider with the planar multilayer waveguide horn radiation unit structure to excite a linearly polarized wave and radiate the electrical signal between the output ports of the power divider.

[0034] The present invention combines a power divider, a slot structure and a radiation unit structure to obtain a wide-band, resistance-free, high-isolation power divider design. The rectangular slot structure transmits the electrical signal between the power divider output ends to the radiation unit to excite a linearly polarized wave. The radiated electrical signal between the output ends will reduce the influence between the power divider ports, thereby achieving the effect of improving the isolation of the power divider. The structure is simple and easy to implement.

[0035] Here, when the power divider is propagating forward to distribute electric power, the current bypasses the narrow side of the rectangular gap and flows to the output port of the power divider, which has little impact on the current, so the impact on the performance of the power divider when distributing power is also small; when the power divider is propagating backward to combine electric power, the current bypasses the wide side of the rectangular gap of about half a wavelength and flows to the output port of the power divider, which has a greater impact on the current, and electromagnetic waves are excited between the wide sides of the rectangular gap to radiate electric signals outward, so the performance of the power divider when combining power is also greatly affected, and part of the signal between the output ports of the power divider can be radiated to achieve the effect of increasing isolation.

[0036] Further, combined with Figure 2 and Figure 3 The resistance-free high-isolation power divider is composed of a multi-layer planar PCB structure, including a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer, a third metal layer, a third dielectric layer and a fourth metal layer arranged in sequence from top to bottom, wherein the first metal layer, the first dielectric layer, the second metal layer, the second dielectric layer and the third metal layer constitute a stepped horn waveguide radiation unit structure, and the third metal layer, the third dielectric layer and the fourth metal layer constitute a power divider structure; the rectangular gap structure is arranged on the third metal layer at the connection between the stepped horn waveguide radiation unit structure and the power divider structure.

[0037] Here, the stepped horn waveguide radiating unit structure can further reduce the size and height of the radiating unit, thereby enhancing the miniaturization and low-profile characteristics of the radiating power divider and significantly increasing the bandwidth.

[0038] Preferably, in some embodiments, the direction in which the stepped horn waveguide radiation unit structure transmits electromagnetic waves is perpendicular to the multi-layer planar PCB structure.

[0039] Preferably, in some embodiments, the rectangular slot structure is arranged at the center of the intersection of all ports of the power divider structure, and its relative position to the stepped horn waveguide radiation unit structure is: located at the center of the stepped horn waveguide radiation unit structure.

[0040] Preferably, in some embodiments, a ridge waveguide structure is introduced into the stepped horn waveguide radiation unit structure to further optimize and reduce the size of the radiation unit while improving the bandwidth and performance of the radiation unit.

[0041] Preferably, in some embodiments, along the direction of the long side of the rectangular slot structure, the ridge waveguide structure is located on both sides of the rectangular slot structure.

[0042] Preferably, in some embodiments, the power divider structure is a microstrip power divider, including the fourth metal layer as a metal microstrip structure, the third dielectric layer, and the third metal layer as a metal ground layer.

[0043] Preferably, in some embodiments, the power divider structure is a SIW power divider, including the third metal layer, the third dielectric layer and the fourth metal layer, metal vias connecting the third metal layer and the fourth metal layer, and metal holes for power divider matching.

[0044] Here, both the microstrip power divider and the SIW power divider are converted into 50Ω transmission lines through a conversion structure, matching the connected 50Ω coaxial transmission line.

[0045] Preferably, in some embodiments, the power divider structure is a three-port structure, including one input port and two output ports.

[0046] Based on the above embodiments, the present invention realizes but is not limited to four designs, namely, a slot rectangular waveguide microstrip structure radiating power divider, a slot ridge waveguide microstrip structure radiating power divider, a slot rectangular waveguide SIW structure radiating power divider and a slot ridge waveguide SIW structure radiating power divider, such as Figure 2 、 Figure 3 shown.

[0047] Preferably, combined Figure 2 In the slot rectangular waveguide microstrip structure radiating power divider structure, the radiation unit length L1 is 10.0mm, the top rectangular waveguide structure width W 1T The bottom rectangular waveguide width is 9.5mm. 1B is 3.5mm, the long side S of the gap structure 1L 4.5mm, short side S 1W The PCB board is made of 4003C material, with a dielectric constant of 3.55 and a loss factor of 0.0027. The thickness of the upper two layers of PCB board T2 is 1.524mm, and the thickness of the lower PCB board T1 is 0.2mm.

[0048] Preferably, combined Figure 2 In the slot ridge waveguide microstrip structure radiation type power divider structure, the radiation unit length L 1R The top ridge waveguide structure is 8.0 mm wide. 1TR The bottom ridge waveguide width is 8.0mm. 1BR is 4.0 mm, and the long side S of the gap structure 1LR 4.5mm, short side S 1WR is 0.35mm, and the waveguide ridge structure length R 1L 1.5mm, width R 1W The PCB board is made of 4003C material with a dielectric constant of 3.55 and a loss factor of 0.0027. The thickness of the upper two layers of PCB board T2 is 1.524mm, and the thickness of the lower PCB board T1 is 0.2mm.

[0049] Preferably, combined Figure 3 In the slot rectangular waveguide SIW structure radiation type power divider structure, the radiation unit length L2 is 10.0mm, the top rectangular waveguide structure width W 2T The bottom rectangular waveguide width is 10.0 mm. 2B is 5mm, the long side S of the gap structure 2L 4.5mm, short side S 2W The PCB board is made of 4003C material, with a dielectric constant of 3.55 and a loss factor of 0.0027. The thickness of the upper two layers of PCB board T2 is 1.524mm, and the thickness of the lower PCB board T3 is 0.4mm.

[0050] Preferably, combined Figure 3 In the slot ridge waveguide SIW structure radiation type power divider structure, the radiation unit length L 2R The top rectangular waveguide structure is 8.0 mm wide. 2TR The bottom rectangular waveguide width is 8.0mm. 2BR is 4 mm, the long side S of the gap structure 2LR 4.5mm, short side S 2WR is 0.5mm, and the waveguide ridge structure length R 2L 2.0mm, width R 2W The PCB board is made of 4003C material with a dielectric constant of 3.55 and a loss factor of 0.0027. The thickness of the upper two layers of PCB board T2 is 1.524mm, and the thickness of the lower PCB board T3 is 0.4mm.

[0051] Combine Figure 4 and Figure 5 For all four designs, both the microstrip and SIW power dividers offer broadband performance below -15dB in the 15GHz to 20GHz frequency range. Influenced by the combined design of the radiating elements, the slot-ridge waveguide-microstrip radiating power divider exhibits isolation below -15dB in the range of approximately 14.4GHz to 17.5GHz; the slot-ridge waveguide-microstrip radiating power divider exhibits isolation below -15dB in the range of approximately 14.5GHz to 17.9GHz; the slot-ridge waveguide-SIW radiating power divider exhibits isolation below -15dB in the range of approximately 15.3GHz to 18.6GHz; and the slot-ridge waveguide-SIW radiating power divider exhibits isolation below -15dB in the range of approximately 15.4GHz to 19.5GHz.

[0052] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only illustrative of the principles of the present invention. Without departing from the spirit and scope of the present invention, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A high-isolation power divider with a resistance-free structure based on the principle of electromagnetic radiation, characterized in that: The resistance-free high-isolation power divider radiates the electrical signal between the output ends of the power divider through the radiation unit to improve the isolation of the power divider; at the same time, the isolation frequency band performance of the power divider is improved by improving the working frequency band performance of the radiation unit.

2. The high-isolation power divider with a resistance-free structure based on the electromagnetic radiation principle according to claim 1, characterized in that: The electrical signals between the output ports of the power divider are radiated through the radiation unit, which is specifically realized by combining the rectangular gap structure at the intersection of all ports of the power divider with the planar multilayer waveguide horn radiation unit structure to excite linearly polarized waves and radiate the electrical signals between the output ports of the power divider.

3. The high-isolation power divider with a resistance-free structure based on the electromagnetic radiation principle according to claim 2, characterized in that: The resistance-free high-isolation power divider is composed of a multi-layer planar PCB structure, including a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer, a third metal layer, a third dielectric layer and a fourth metal layer arranged in sequence from top to bottom, wherein the first metal layer, the first dielectric layer, the second metal layer, the second dielectric layer and the third metal layer constitute a stepped horn waveguide radiation unit structure, and the third metal layer, the third dielectric layer and the fourth metal layer constitute a power divider structure; the rectangular gap structure is provided on the third metal layer at the connection between the stepped horn waveguide radiation unit structure and the power divider structure.

4. The high-isolation power divider with a resistance-free structure based on the electromagnetic radiation principle according to claim 3, characterized in that: The direction in which the stepped horn waveguide radiation unit structure transmits electromagnetic waves is perpendicular to the multi-layer planar PCB structure.

5. The high-isolation power divider with a resistance-free structure based on the electromagnetic radiation principle according to claim 3, characterized in that: The rectangular slot structure is arranged at the center of the intersection of all ports of the power divider structure, and its relative position to the stepped horn waveguide radiation unit structure is: located at the center of the stepped horn waveguide radiation unit structure.

6. The high-isolation power divider with a resistance-free structure based on the electromagnetic radiation principle according to claim 3, characterized in that: A ridge waveguide structure is introduced into the stepped horn waveguide radiation unit structure.

7. The high-isolation power divider with a resistance-free structure based on the electromagnetic radiation principle according to claim 6, characterized in that: Along the direction of the long side of the rectangular slot structure, the ridge waveguide structure is located on both sides of the rectangular slot structure.

8. The high-isolation power divider with a resistance-free structure based on the electromagnetic radiation principle according to claim 3, characterized in that: The power divider structure is a microstrip power divider, including the fourth metal layer as a metal microstrip structure, the third dielectric layer, and the third metal layer as a metal ground layer.

9. The high-isolation power divider with a resistance-free structure based on the electromagnetic radiation principle according to claim 3, characterized in that: The power divider structure is a SIW power divider, including the third metal layer, the third dielectric layer and the fourth metal layer, metal vias connecting the third metal layer and the fourth metal layer, and metal holes for power divider matching.

10. The high-isolation power divider with a resistance-free structure based on the electromagnetic radiation principle according to claim 3, characterized in that: The power divider structure is a three-port structure, including one input port and two output ports.

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