Self-packaging type non-reflection differential filtering power divider with substrate integrated suspended strip line and broadband common-mode absorption characteristic

Abstract

The invention discloses a substrate integrated suspended strip line self-packaging type non-reflection differential filtering power divider with a broadband common-mode absorption characteristic, and relates to the technical field of radio frequency. The power divider comprises a first packaging layer, a first air cavity layer, a circuit layer, a second air cavity layer and a second packaging layer. The first packaging layer comprises a first substrate, and metal layers are arranged on the two end faces, in the first direction, of the first substrate. The second packaging layer comprises a fifth substrate, and metal layers are arranged at the two ends of the fifth substrate in the first direction. The first packaging layer, the first air cavity layer, the circuit layer, the second air cavity layer and the second packaging layer are sequentially stacked in the first direction. By arranging the first packaging layer and the second packaging layer, a self-packaging structure can be formed, external electromagnetic interference and internal signal leakage can be suppressed, a complete and stable grounding layer can be provided, the common-mode rejection ratio can be improved, electromagnetic isolation with other modules can be realized, crosstalk can be reduced, and the anti-interference capability can be remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of radio frequency technology, specifically relating to a self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended striplines and broadband common-mode absorption characteristics. Background Technology

[0002] In microwave radio frequency systems, filters and power dividers are two fundamental and critical microwave devices. With the rapid development of modern wireless communication, radar detection, and other systems towards higher frequencies, higher integration, and higher performance, existing filter power divider designs are mostly based on traditional planar structures such as microstrip lines and striplines. While these designs achieve functional integration to some extent, they still face several key technical challenges. For example, devices designed based on traditional planar structures such as microstrip lines and striplines generally have limited anti-interference capabilities. Summary of the Invention

[0003] To address the aforementioned problems in the prior art, this application provides a self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended striplines and broadband common-mode absorption characteristics. By setting a first encapsulation layer and a second encapsulation layer on both sides of the circuit layer, a self-encapsulated structure can be formed, suppressing external electromagnetic interference and internal signal leakage. It can provide a complete and stable ground plane, effectively releasing common-mode noise, improving the common-mode rejection ratio, and achieving electromagnetic isolation from other modules, reducing crosstalk. Therefore, the self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended striplines and broadband common-mode absorption characteristics provided in this application can significantly improve anti-interference capabilities. The technical problem to be solved by this invention is achieved through the following technical solution: This application provides a self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended strip and broadband common-mode absorption characteristics. The power divider includes a first encapsulation layer, a first air cavity layer, a circuit layer, a second air cavity layer, and a second encapsulation layer. The first encapsulation layer includes a first substrate, with metal layers disposed on both end faces of the first substrate along a first direction; the first air cavity layer includes a second substrate, with metal layers disposed on both end faces of the second substrate along the first direction, and the first air cavity layer forms a through-hole air cavity structure along the first direction; the circuit layer includes a third substrate, with microstrip modules formed by microstrip lines disposed on both end faces of the third substrate along the first direction, the microstrip modules being used for filtering and power distribution of input signals; the second air cavity layer includes a fourth substrate, with metal layers disposed on both ends of the fourth substrate along the first direction, and the second air cavity layer forming a through-hole air cavity structure along the first direction; the second encapsulation layer includes a fifth substrate, with metal layers disposed on both ends of the fifth substrate along the first direction; wherein the first substrate, second substrate, third substrate, fourth substrate, and fifth substrate are all made of insulating material, and the first encapsulation layer, first air cavity layer, circuit layer, second air cavity layer, and second encapsulation layer are stacked sequentially along the first direction.

[0004] In one possible implementation of this application, the third substrate includes a first surface, which is one end face of the third substrate along a first direction; the microstrip module includes a first microstrip unit disposed on the first surface; the first microstrip unit includes a first input component and a first input terminal, a first resonant component, a first power distribution component and a first output terminal, the first input terminal being connected to the input terminal of the first input component, the first output terminal being connected to the output terminal of the first power distribution component, and the first resonant component being connected between the first input component and the first power distribution component.

[0005] In one possible implementation of this application, the first surface has a first center line and a second center line, the first center line extends along a second direction, and the second center line extends along a third direction, the first direction, the second direction and the third direction are perpendicular to each other; the first input component is a U-shaped structure formed by microstrip lines, including a bottom edge and two sides; the bottom edge of the U-shaped structure of the first input component and the sides of the U-shaped structure of the first input component both extend along a straight line and have the same width, and the sides of the U-shaped structure of the first input component have the same height.

[0006] In one possible implementation of this application, the opening of the U-shaped structure of the first input component faces outward from the first surface along a second direction; the first input terminal includes a wide input terminal and a narrow input terminal, both formed by microstrip lines; the wide input terminal is connected to one side of the U-shaped structure of the first input component near the opening of the U-shaped structure; the narrow input terminal is connected to the other side of the U-shaped structure of the first input component near the opening of the U-shaped structure; the center line extending along the second direction of the wide input terminal coincides with the center line of the side of the U-shaped structure of the first input component to which it is connected; the center line extending along the second direction of the narrow input terminal coincides with the center line of the side of the U-shaped structure of the first input component to which it is connected; the dimension of the wide input terminal along a third direction is greater than the width of the side of the U-shaped structure of the first input component, and the dimension of the narrow input terminal along a third direction is less than the width of the side of the U-shaped structure of the first input component.

[0007] In one possible implementation of this application, two common-mode absorption resistors are connected in parallel between the two sides of the U-shaped structure of the first input component.

[0008] In one possible implementation of this application, the first resonant component includes a resonant input line, a resonant body, and a resonant output line; both the resonant input line and the resonant output line are right-angled structures formed by microstrip lines; the resonant body is a hollow H-shaped structure formed by microstrip lines; the H-shaped structure is symmetrical about a second center line, the opening of the H-shaped structure faces an extension direction parallel to the second center line, the H-shaped structure includes a straight side and a concave side, the extension direction of the straight side of the H-shaped structure is parallel to a third direction, and the width of the straight side is smaller than the width of the concave side; the resonant input line includes a first right-angled side and a second right-angled side, and the resonant output line includes a third right-angled side and a fourth right-angled side. The first and third right-angled sides extend along a first direction, and the second and fourth right-angled sides extend along a second direction. The second and fourth right-angled sides are located on the same side of the first center line and have the same length, and the ends of the second and fourth right-angled sides closest to the first center line are both located on the first center line. An H-shaped structure is disposed between the second and fourth right-angled sides, and there is a gap between the second right-angled side and the H-shaped structure, and a gap between the fourth right-angled side and the H-shaped structure. The first right-angled side connects between the first input component and the second right-angled side. The third right-angled side connects between the fourth right-angled side and the first power distribution component.

[0009] In one possible implementation of this application, the center line of the U-shaped structure of the first input component extending along the second direction coincides with the first center line; the first right-angled side coincides with the first center line, and the first right-angled side connects between the bottom side and the second right-angled side of the U-shaped structure of the input component.

[0010] In one possible implementation of this application, the first power distribution component includes a first distribution body, a first distribution line, a second distribution body, and a second distribution line; the first distribution body and the second distribution body are symmetrically arranged about a first center line; the first distribution line and the second distribution line are symmetrically arranged about the first center line; one end of the first distribution line is connected to the first distribution body, one end of the second distribution line is connected to the second distribution body, the other end of the first distribution line is connected to the other end of the second distribution line, and they are both connected to the second right-angled side through a third right-angled side, which coincides with the first center line.

[0011] In one possible implementation of this application, the first distribution line includes a first distribution segment, a second distribution segment, and a third distribution segment; the first and third distribution segments both extend along a third direction, the second distribution segment extends along a second direction, and the second distribution segment is connected between the first and third distribution segments; the end of the first distribution segment away from the second distribution segment is connected to a third straight edge, and the end of the third distribution segment away from the second distribution segment is connected to a first distribution body; the second distribution line includes a fourth, a fifth, and a sixth distribution segment; the fourth and sixth distribution segments both extend along a third direction, the fifth distribution segment extends along a second direction, and the fifth distribution segment is connected between the fourth and sixth distribution segments; the end of the fourth distribution segment away from the fifth distribution segment is connected to a third straight edge, and the end of the sixth distribution segment away from the fifth distribution segment is connected to a second distribution body; both the first and second distribution bodies are U-shaped structures identical to the input component; an isolation resistor is provided between the third and sixth distribution segments.

[0012] In one possible implementation of this application, the third substrate includes a second surface, which is another end face of the third substrate along a third direction; the microstrip module further includes a second microstrip unit, which includes a second input component and a second input terminal, a second resonant component, a second power distribution component, and a second output terminal, wherein the projection of the second input component onto the first surface along the first direction coincides with the first input component, the projection of the second resonant component onto the first surface along the first direction coincides with the first resonant component, and the projection of the second power distribution component onto the first surface along the first direction coincides with the first power distribution component; the projection of the second input terminal onto the first surface along the first direction is mirror-symmetrical to the first input terminal about a first centerline; and the projection of the second output terminal onto the first surface along the first direction is mirror-symmetrical to the first output terminal about the centerline of the U-shaped structure of the first distribution body.

[0013] The self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended lines and broadband common-mode absorption characteristics provided in this application integrates filtering and power distribution functions with the package structure through a self-encapsulated integrated design. This fundamentally eliminates the parasitic effects and interface discontinuities caused by traditional separate assembly, thereby significantly improving electrical performance. Furthermore, the introduction of the self-encapsulation structure enhances structural robustness and environmental adaptability. In addition, this design achieves common-mode reflection-free characteristics, ensuring that input common-mode signal energy inside and outside the passband is not reflected back to the RF front-end, thus avoiding adverse effects on the performance of active devices in the RF front-end. Attached Figure Description

[0014] Figure 1An exploded view of the overall structure of a self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended strip and broadband common-mode absorption characteristics, provided in an embodiment of this application. Figure 2 A cross-sectional schematic diagram of a self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended strip and broadband common-mode absorption characteristics, provided as an embodiment of this application; Figure 3 A schematic diagram of the circuit layer of a self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended strip and broadband common-mode absorption characteristics, provided for an embodiment of this application. Figure 4 A schematic diagram of the first microstrip unit of a self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended strip lines and broadband common-mode absorption characteristics, provided in an embodiment of this application. Figure 5 A schematic diagram showing the dimensions of the first microstrip unit of a self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended striplines and broadband common-mode absorption characteristics, provided in an embodiment of this application. Figure 6 A simulation diagram of the differential mode signal transmission characteristics of a self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended strip and broadband common-mode absorption characteristics, provided in an embodiment of this application; Figure 7 Simulation diagram of amplitude and phase consistency between output ports of a self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended line and broadband common-mode absorption characteristics, provided in an embodiment of this application. Figure 8 Simulation diagram of the output port isolation characteristics of a self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended line and broadband common-mode absorption characteristics, provided in an embodiment of this application; Figure 9 The simulation diagram shows the common-mode energy transfer characteristics of a self-encapsulated, non-reflective differential filter power divider with substrate-integrated suspension lines and broadband common-mode absorption characteristics, provided in an embodiment of this application.

[0015] Figure label: 1-First encapsulation layer; 11-First substrate; 2-First air cavity layer; 21-Second substrate; 3-Circuit layer; 3a-Third substrate; 3b-First surface; 3c-Second surface; 31-Microstrip module; 311-First microstrip unit; 3111-First input component; 31111-U-shaped structure; 311111-Bottom edge; 311112-Side edge; 3112-First input terminal; 31121-Wide input terminal; 31122 - Narrow input terminal; 3113 - First resonant component; 31131 - Resonant input line; 311311 - First right-angled side; 311312 - Second right-angled side; 31132 - Resonator; 311321 - Straight side; 311322 - Concave side; 31133 - Resonant output line; 311331 - Third right-angled side; 311332 - Fourth right-angled side; 3114 - First power distribution component; 31141 - First distribution body; 31142 - First distribution line; 311421 - First distribution sub-segment; 311422 - Second distribution sub-segment; 311423 - Third distribution sub-segment; 31143 - Second distribution body; 31144 - Second distribution line; 311441 - Fourth distribution sub-segment; 311442 - Fifth distribution sub-segment; 311443 - Sixth distribution sub-segment; 3115 - First output terminal; 312 - Second microstrip unit; 3121 - Second input component; 3122 - Second input terminal; 3123 - Second resonant component; 3124 - Second power distribution component; 3125 - Second output terminal; 4 - Second air cavity layer; 41 - Fourth substrate; 5 - Second encapsulation layer; 51 - Fifth substrate; 6 - Common mode absorption resistor; 7 - Isolation resistor; AA - First center line; BB - Second center line; a - First direction; b - Second direction; c - Third direction. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0017] Currently, filters and power dividers are two fundamental and critical microwave devices in microwave RF systems. With the rapid development of modern wireless communication, radar detection, and other systems towards higher frequencies, higher integration, and higher performance, traditional designs typically employ a cascaded combination of a filter and a power divider to achieve signal frequency selection and power distribution. However, this discrete architecture has significant limitations: firstly, cascading multiple independent devices leads to a large system size and increased insertion loss, making it difficult to meet the urgent demands for miniaturization and lightweighting; secondly, the cascaded structure introduces additional impedance matching problems and parasitic effects, affecting overall performance optimization. In recent years, filter-power dividers have emerged, aiming to integrate filtering and power distribution functions into a single structure, thereby achieving structural simplification, reduced loss, and improved performance. However, existing filter-power divider designs are mostly based on traditional planar structures such as microstrip lines and striplines. While achieving functional integration to some extent, they still face several key technical challenges: for example, devices designed based on traditional planar structures such as microstrip lines and striplines generally have limited anti-interference capabilities.

[0018] In view of this, embodiments of this application provide a self-packaged, reflection-free differential filter power divider with substrate-integrated suspended striplines and broadband common-mode absorption characteristics. Through this self-packaged integrated design, filtering and power distribution functions are integrated with the packaging structure, fundamentally eliminating the parasitic effects and interface discontinuities caused by traditional separate assembly, thereby significantly improving electrical performance. Furthermore, the introduction of the self-packaged structure enhances structural robustness and environmental adaptability. In addition, this design achieves common-mode reflection-free characteristics, ensuring that input common-mode signal energy inside and outside the passband is not reflected to the RF front-end, thus avoiding adverse effects on the performance of active devices in the RF front-end.

[0019] Specifically, refer to Figures 1 to 6The self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended striplines and broadband common-mode absorption characteristics provided in this application embodiment includes a first encapsulation layer 1, a first air cavity layer 2, a circuit layer 3, a second air cavity layer 4, and a second encapsulation layer 5. The first encapsulation layer 1 includes a first substrate 11, with metal layers disposed on both end faces of the first substrate 11 along the first direction a; the first air cavity layer 2 includes a second substrate 21, with metal layers disposed on both end faces of the second substrate 21 along the first direction a, forming a through-hole air cavity structure along the first direction a; the circuit layer 3 includes a third substrate 3a, with microstrip modules 31 formed by microstrip lines disposed on both end faces of the third substrate 3a along the first direction a, the microstrip modules 31 being used for filtering and power distribution of the input signal; the second air cavity layer... 4 includes a fourth substrate 41, with metal layers disposed at both ends of the fourth substrate 41 along the first direction a, and a second air cavity layer 4 forming a through air cavity structure along the first direction a; the second encapsulation layer 5 includes a fifth substrate 51, with metal layers disposed at both ends of the fifth substrate 51 along the first direction a; wherein, the first substrate 11, the second substrate 21, the third substrate 3a, the fourth substrate 41 and the fifth substrate 51 are all made of insulating material, and the first encapsulation layer 1, the first air cavity layer 2, the circuit layer 3, the second air cavity layer 4 and the second encapsulation layer 5 are stacked sequentially along the first direction a.

[0020] It is understood that in the embodiments of this application, the first substrate 11, the second substrate 21, the third substrate 3a, the fourth substrate 41, and the fifth substrate 51 are all insulating materials. In the embodiments of this application, the type of insulating material is not limited. For example, the third substrate 3a can be made of F4BM material with excellent high-frequency performance; the other substrates can be made of FR4 material, which has lower cost and more mature processing technology.

[0021] Furthermore, in this embodiment, the first direction 'a' can be considered as the stacking direction of the first encapsulation layer 1, the first air cavity layer 2, the circuit layer 3, the second air cavity layer 4, and the second encapsulation layer 5, as shown in the reference. Figure 1 and Figure 2 ,by Figure 1 and Figure 2 Taking the relative position in the diagram as an example, the first direction 'a' can refer to the vertical direction.

[0022] Specifically, refer to Figure 1 In this embodiment, the first air cavity layer 2 and the second air cavity layer 4 can retain only their edge structures, forming a hollow space in the middle. Furthermore, notches can be provided according to the input and output terminals of the power divider to facilitate the installation of the input and output terminals.

[0023] For example, the first air cavity layer 2 and the second air cavity layer 4 can be etched to form an air cavity structure, which can effectively confine the electromagnetic field energy to the cavity region to reduce losses.

[0024] It is understood that, in the embodiments of this application, by setting a microstrip line structure on the surface of the third substrate 3a, a filter circuit and a power divider circuit can be formed, thereby enabling the signal to be filtered and the power to be distributed.

[0025] Thus, the self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended lines and broadband common-mode absorption characteristics provided in this application integrates filtering and power distribution functions with the package structure through a self-encapsulated integrated design. This fundamentally eliminates the parasitic effects and interface discontinuities caused by traditional separate assembly, thereby significantly improving electrical performance. Furthermore, the introduction of the self-encapsulation structure enhances structural robustness and environmental adaptability. In addition, this design achieves common-mode reflection-free characteristics, ensuring that input common-mode signal energy inside and outside the passband is not reflected to the RF front-end, thus avoiding adverse effects on the performance of active devices in the RF front-end.

[0026] Based on this, refer to Figures 1 to 3 In the power divider provided in this application embodiment, the third substrate 3a includes a first surface 3b, which is one end face of the third substrate 3a along the first direction a; the microstrip module 31 includes a first microstrip unit 311, which is disposed on the first surface 3b; the first microstrip unit 311 includes a first input component 3111, a first input terminal 3112, a first resonant component 3113, a first power distribution component 3114, and a first output terminal 3115. The first input terminal 3112 is connected to the input terminal of the first input component 3111, the first output terminal 3115 is connected to the output terminal of the first power distribution component 3114, and the first resonant component 3113 is connected between the first input component 3111 and the first power distribution component 3114.

[0027] It is understood that in the embodiments of this application, the third substrate 3a is a thin plate structure with two large surfaces. For example, refer to... Figure 3 ,by Figure 3 Taking the relative positions in the diagram as an example, one of the upper and lower surfaces of the first substrate 11 can be referred to as the first surface 3b, and the other as the second surface 3c. Based on this, by setting different types of microstrip lines on the first surface 3b, different circuit structures can be formed, including components with resonant functions and components with power distribution. For example, in the embodiments of this application, the first resonant component 3113 can be configured as a ring resonator, and the first power distribution component 3114 can be configured as a Wilkinson power divider.

[0028] It should be noted that the SMA terminal can be used to input signals to the first input terminal 3112. Based on this, the first input terminal 3112 can be configured according to the SMA terminal to facilitate connection with the SMA terminal. Based on this, the second input terminal 3122 can be configured with reference to the first input terminal 3112.

[0029] Based on this, in the embodiments of this application, refer to Figure 3 and Figure 4 The first surface 3b has a first center line AA and a second center line BB. The first center line AA extends along a second direction b, and the second center line BB extends along a third direction c. The first direction a, the second direction b, and the third direction c are perpendicular to each other. The first input component 3111 is a U-shaped structure 31111 formed by microstrip lines, including a bottom edge 311111 and two sides 311112. The bottom edge 311111 and the sides 311112 of the U-shaped structure 31111 of the first input component 3111 both extend along a straight line and have the same width. The sides 311112 of the U-shaped structure 31111 of the first input component 3111 both have the same height.

[0030] For example, refer to Figure 3 and Figure 4 The first surface 3b can be shaped as a rectangle, thus naturally possessing a first centerline AA and a second centerline BB. The direction of the first centerline AA can be considered the second direction b, and the direction of the second centerline BB can be considered the third direction c. It is understood that the first direction a, the second direction b, and the third direction c are mutually perpendicular, forming a spatial rectangular coordinate system.

[0031] Based on this, refer to Figure 3 and Figure 4 By arranging the microstrip lines, the first input component 3111 can be U-shaped, and both the bottom edge 311111 and the side edge 311112 of the U-shaped structure 31111 can extend along a straight line and have the same width. The heights of the two side edges 311112 of the U-shaped structure 31111 can also be made the same. Thus, the side edges 311112 of the U-shaped structure 31111 form parallel stripline transmission lines.

[0032] Furthermore, in some embodiments of this application, the opening of the U-shaped structure 31111 of the first input component 3111 faces outward along the second direction b toward the first surface 3b; the first input terminal 3112 includes a wide input terminal 31121 and a narrow input terminal 31122, both of which are formed by microstrip lines; the wide input terminal 31121 is connected to one side 311112 of the U-shaped structure 31111 of the first input component 3111 near the opening of the U-shaped structure 31111; the narrow input terminal 31122 is connected to the other side 311112 of the U-shaped structure 31111 of the first input component 3111 near the opening of the first input component 3111. The opening end of the U-shaped structure 31111 of the first input component 3111; the center line of the wide input terminal 31121 extending along the second direction b coincides with the center line of the side 311112 of the U-shaped structure 31111 of the first input component 3111 connected to it; the center line of the narrow input terminal 31122 extending along the second direction b coincides with the center line of the side 311112 of the U-shaped structure 31111 of the first input component 3111 connected to it; the dimension of the wide input terminal 31121 along the third direction c is greater than the width of the side 311112 of the U-shaped structure 31111 of the first input component 3111, and the dimension of the narrow input terminal 31122 along the third direction c is less than the width of the side 311112 of the U-shaped structure 31111 of the first input component 3111.

[0033] It is understandable that the U-shaped structure 31111 has an opening, as shown in the reference. Figure 3 ,by Figure 3 Taking the relative position in the middle as an example, Figure 3 The opening of the U-shaped structure 31111 of the first input component 3111 faces the lower right.

[0034] In this embodiment of the application, by setting the width of the microstrip line forming the wide input terminal 31121, the width of the wide input terminal 31121 can be greater than the width of the side 311112 of the U-shaped structure 31111, and the width of the narrow input terminal 31122 can be less than the width of the side 311112 of the U-shaped structure 31111.

[0035] In this embodiment, two common-mode absorption resistors 6 are connected in parallel between the two sides 311112 of the U-shaped structure 31111 of the first input component 3111. By setting the common-mode absorption resistors 6, common-mode absorption within a certain range can be achieved, thereby realizing the non-reflective characteristic.

[0036] Based on this, in some embodiments of this application, the first resonant component 3113 includes a resonant input line 31131, a resonator 31132, and a resonant output line 31133; both the resonant input line 31131 and the resonant output line 31133 are right-angled structures formed by microstrip lines; the resonator 31132 is a hollow H-shaped structure formed by microstrip lines; the H-shaped structure is symmetrical about the second center line BB, the opening of the H-shaped structure faces the extension direction parallel to the second center line BB, the H-shaped structure includes a straight side 311321 and a concave side 311322, the extension direction of the straight side 311321 is parallel to the third direction c, and the width of the straight side 311321 is smaller than the width of the concave side 311322; the resonant input line 31131 includes a first right-angled side 311311 and a second right-angled side 311312, and the resonant output line 31133 includes a third right-angled side 311331 and a fourth right-angled side 311332. The first right-angled side 311311 and the third right-angled side 311331 extend along the first direction a, and the second right-angled side 311312 and the fourth right-angled side 311332 extend along the second direction b; the second right-angled side 311312 and the fourth right-angled side 311332 are located on the same side of the first center line AA and have the same length, and the ends of the second right-angled side 311312 and the fourth right-angled side 311332 closest to the first center line AA are both located on the first center line AA; H-shaped The structure is positioned between the second right-angled side 311312 and the fourth right-angled side 311332, with a gap between the second right-angled side 311312 and the H-shaped structure, and a gap between the fourth right-angled side 311332 and the H-shaped structure; the first right-angled side 311311 is connected between the first input component 3111 and the second right-angled side 311312; the third right-angled side 311331 is connected between the fourth right-angled side 311332 and the first power distribution component 3114.

[0037] Understandably, the first resonant component 3113 is a ring resonator used for differential mode signal passband selection and to generate two transmission zeros.

[0038] Furthermore, in some embodiments of this application, the center line of the U-shaped structure 31111 of the first input component 3111 extending along the second direction b coincides with the first center line AA; the first right-angled side 311311 coincides with the first center line AA, and the first right-angled side 311311 connects between the bottom side 311111 and the second right-angled side 311312 of the U-shaped structure 31111 of the input component.

[0039] It is understood that, in this embodiment of the application, by setting the position of the U-shaped structure 31111 of the first input component 3111, the center line of the U-shaped structure 31111 along the second direction b can be made to coincide with the first center line AA. Furthermore, by setting the position of the first right-angled side 311311, the first right-angled side 311311 can be made to coincide with the first center line AA.

[0040] Furthermore, refer to Figure 4 In some embodiments of this application, the first power distribution component 3114 includes a first distribution body 31141, a first distribution line 31142, a second distribution body 31143, and a second distribution line 31144; the first distribution body 31141 and the second distribution body 31143 are symmetrically arranged about the first center line AA; the first distribution line 31142 and the second distribution line 31144 are symmetrically arranged about the first center line AA; one end of the first distribution line 31142 is connected to the first distribution body 31141, one end of the second distribution line 31144 is connected to the second distribution body 31143, the other end of the first distribution line 31142 is connected to the other end of the second distribution line 31144, and they are connected to the second right-angled side 311312 through the third right-angled side 311331, which coincides with the first center line AA.

[0041] It is understandable that by adapting the relative positions of the first distribution body 31141, the first distribution line 31142, the second distribution body 31143, and the second distribution line 31144, the first distribution body 31141 and the second distribution body 31143 can be symmetrically arranged about the first center line AA, and the first distribution line 31142 and the second distribution line 31144 can be symmetrically arranged about the first center line AA.

[0042] Based on this, refer to Figure 4Specifically, the first distribution line 31142 includes a first distribution sub-segment 311421, a second distribution sub-segment 311422, and a third distribution sub-segment 311423. The first and third distribution sub-segments 311421 and 311423 both extend along a third direction c, while the second distribution sub-segment 311422 extends along a second direction b, connecting the first and third distribution sub-segments 311421 and 311423. The end of the first distribution sub-segment 311421 furthest from the second distribution sub-segment 311422 is connected to the third straight edge 311321, and the end of the third distribution sub-segment 311423 furthest from the second distribution sub-segment 311422 is connected to the first distribution body 31141. The second distribution line 31144 includes a fourth distribution sub-segment 311441 and a fifth distribution sub-segment. 311442 and the sixth sub-segment 311443; the fourth sub-segment 311441 and the sixth sub-segment 311443 both extend along the third direction c, the fifth sub-segment 311442 extends along the second direction b, and the fifth sub-segment 311442 is connected between the fourth sub-segment 311441 and the sixth sub-segment 311443; the end of the fourth sub-segment 311441 away from the fifth sub-segment 311442 is connected to the third straight edge 311321, and the end of the sixth sub-segment 311443 away from the fifth sub-segment 311442 is connected to the second sub-body 31143; the first sub-body 31141 and the second sub-body 31143 are both U-shaped structures with the same as the input component; an isolation resistor 7 is provided between the third sub-segment 311423 and the sixth sub-segment 311443.

[0043] Furthermore, refer to Figure 3 In some embodiments of this application, the third substrate 3a includes a second surface 3c, which is another end face of the third substrate 3a along a third direction c; the microstrip module 31 also includes a second microstrip unit 312, which includes a second input component 3121 and a second input terminal 3122, a second resonant component 3123, a second power distribution component 3124, and a second output terminal 3125, wherein the projection of the second input component 3121 along the first direction a onto the first surface 3b coincides with the first input component 3111, and the projection of the second resonant component 3123 along the first direction a onto the first surface 3b coincides with the projection of the second input component 3121 along the first direction a onto the first surface 3b. The projection of the first direction a onto the first surface 3b coincides with the first resonant component 3113; the projection of the second power distribution component 3124 onto the first surface 3b along the first direction a coincides with the first power distribution component 3114; the projection of the second input terminal 3122 onto the first surface 3b along the first direction a is mirror-symmetrical with the first input terminal 3112 about the first center line AA; the projection of the second output terminal 3125 onto the first surface 3b along the first direction a is mirror-symmetrical with the first output terminal 3115 about the center line of the U-shaped structure 31111 of the first distribution body 31141.

[0044] Specifically, refer to Figure 3 This application provides a self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended striplines and broadband common-mode absorption characteristics. The third substrate 3a of this power divider has microstrip modules 31 formed by microstrip lines on both end faces along the first direction a. For example, see [reference needed]. Figure 3 ,by Figure 3 Taking the relative positions in the middle as an example, the first surface 3b can be considered as the upper surface of the third substrate 3a, the second surface 3c as the lower surface of the third substrate 3a, the first microstrip unit 311 is disposed on the upper surface of the third substrate 3a, and the second microstrip unit 312 is disposed on the lower surface of the third substrate 3a.

[0045] And, as Figure 3 As shown, the projection of the second input component 3121 onto the first surface 3b in the vertical direction coincides with the first input component 3111, the projection of the second resonant component 3123 onto the first surface 3b in the vertical direction coincides with the first resonant component 3113, and the projection of the second power distribution component 3124 onto the first surface 3b in the vertical direction coincides with the first power distribution component 3114.

[0046] The projection of the second input terminal 3122 onto the first surface 3b along the first direction a is mirror-symmetrical to the input terminal about the first center line AA. It should be noted that, referring to... Figure 3 ,by Figure 3 Taking the relative positions in the diagram as an example, the wide input terminal 31121 of the second input terminal 3122 is located on the left, and the narrow input terminal 31122 of the second input terminal 3122 is located on the right. The wide input terminal 31121 of the first input terminal 3112 is located on the right, and the narrow input terminal 31122 of the first input terminal 3112 is located on the left.

[0047] Similarly, refer to Figure 3 and Figure 4 It can be understood that the projection of the second output terminal 3125 along the first direction a onto the first surface 3b is mirror-symmetrical with respect to the center line of the U-shaped structure 31111 of the first distribution body 31141.

[0048] For specific details, please refer to Figure 5 The power divider in this embodiment is manufactured using the dimensions specified in the application, and its specific parameters are as follows: The third substrate 3a is made of F4BM material with a dielectric constant of 2.2, dimensions of 166.6 mm × 153.3 mm, and a thickness of 0.8 mm. The dimensions (mm) represented by each letter are as follows: W 0a =8、W 0b=2.6, L0=5, L1=11, L2=25.9, L3=27, W1=3.1, W2=2, W3=0.2, L4=10, L5=2.6, L6=29. 3. S1=0.2, L7=29.5, L8=17.4, W4=0.78, W5=0.6, W6=0.6, W7=0.4, L9=2.6, W8=4.1, L 10 =15.6, W9=3.8, L 11 =25.5, W 10 =5、L 12 =4.

[0049] The resistor values ​​are: R1=110 ohms, R2=39 ohms, R3=30 ohms.

[0050] Thus, the first input component 3111 and the second input component 3121 form a pair of double-sided parallel stripline transmission lines. Their excitation method involves inverting the feed on top of the differential signal. The bottom edge 311111 and the side edge 311112 of the U-shaped structure 31111 of the first input component 3111 have the same width. A common-mode absorption resistor 6 can be connected in parallel every quarter wavelength along the transmission line formed by the bottom edge 311111 and the side edge 311112 of the U-shaped structure 31111. The resistance of the common-mode absorption resistor 6 closest to the opening of the U-shaped structure 31111 can be set to 110 ohms, and the resistance of the other common-mode absorption resistor 6 furthest from the opening of the U-shaped structure 31111 can be set to 39 ohms.

[0051] The first resonant component 3113 and the second resonant component 3123 consist of a pair of quarter-wavelength parallel coupled resonators and a pair of quarter-wavelength transmission lines. The two quarter-wavelength parallel resonators are symmetrical about the second center line BB and are connected by two quarter-wavelength transmission lines. The two quarter-wavelength transmission lines are bent (the concave side 311322 of the H-shaped structure). The midpoint of the two quarter-wavelength transmission lines coincides with the second center line BB. The coupling distance S1 = 0.2 mm (the gap between the second right-angled side 311312 and the H-shaped structure, and the gap between the fourth right-angled side 311332 and the H-shaped structure).

[0052] The first power distribution component 3114 and the second power distribution component 3124 mainly include a Wilkinson power divider structure, which consists of an impedance transformation transmission line (first distribution line 31142), an output port transmission line, and an isolation resistor 7. The resistance of the isolation resistor 7 is 30 ohms (isolation resistor 7 between the third distribution segment 311423 and the sixth distribution).

[0053] Both the first input terminal 3112 and the first output terminal 3115 can be equipped with 50-ohm microstrip lines connected to SMA connectors, with a dimension of L0 = 5mm (the dimension of the wide input terminal 31121 and the narrow input terminal 31122 along the second direction b), W 0a =8mm (dimension of wide input terminal 31121 along the third direction c), W 0b =2.6mm (dimension of narrow input terminal 31122 along the third direction c). Other dimensions are detailed in the attached drawings.

[0054] Thus, when the end containing the first input component 3111 is used as the differential input terminal and the end containing the first power distribution component 3114 is used as the differential output terminal, the signal input method adopts a form of further applying inverse feeding on the basis of differential signal. Under common-mode excitation, the vertical plane in the middle of the U-shaped structure 31111 of the first input component 3111 is equivalent to an electric wall, thereby significantly suppressing common-mode energy over a wide frequency band and effectively improving the common-mode rejection level. Conversely, under differential-mode signal excitation, this plane is equivalent to a magnetic wall, which can effectively excite the first resonant component 3113 and the second resonant component 3123 located in the center of the structure. Therefore, under differential-mode signal excitation, the signal in the passband can smoothly pass through the first resonant component 3113 and the second resonant component 3123, and then enter the first power distribution component 3114 and the second power distribution component 3124 for power distribution, and finally be transmitted to the first output terminal 3115. For common-mode signals within a certain bandwidth, since they cannot be reflected by the first resonant component 3113 and the second resonant component 3123, this reflected energy can be absorbed and dissipated by the common-mode absorption resistor 6 connected in parallel between the transmission lines, thereby achieving the non-reflection characteristic of common-mode signals over a wide bandwidth. Furthermore, when the first resonant component 3113 and the second resonant component 3123 are excited by a differential-mode signal, two transmission zeros will be generated on both sides of the passband. This significantly improves the frequency selectivity of the differential-mode passband. Finally, the integration of a self-encapsulating shell on the outside of the entire structure effectively enhances the anti-interference performance and structural stability of the filter power divider.

[0055] The following section will describe, in conjunction with simulation experiments, a self-encapsulated, non-reflective differential filter power divider with substrate-integrated suspended strip and broadband common-mode absorption characteristics provided in the embodiments of this application.

[0056] For example, the performance indicators of this power divider can be simulated using the three-dimensional structural electromagnetic field simulation software ANSYS Electronics Desktop 2024.R2, and compared with a common-mode absorption power divider proposed in the paper "Compact Balanced-to-Balanced Filtering Power Divider With Wide Range and High Level of Reflectionless, Isolation, Common-Mode Rejection, and Enhanced Frequency Selectivity" published by Gangxiong Wu et al. in IEEE Transactions on Circuits and Systems I: Regular Papers (Volume. 72, No. 7, pp. 3620-3630, July. 2025).

[0057] Experiment 1 simulates the differential-mode signal transmission characteristics of the power divider provided in this application embodiment, including the differential-mode signal return loss and the insertion loss, amplitude, and phase consistency of the differential-mode signal from the first input terminal 3112 (second input terminal 3122) to the first output terminal 3115 (second output terminal 3125). The results are shown in […]. Figure 6 and Figure 7 ; Experiment 2 simulates the differential signal transmission characteristics provided in the embodiments of this application, including simulation diagrams of the isolation characteristics between the two first output terminals 3115 (second output terminal 3125). The results are shown in [the diagram]. Figure 8 ; Experiment 3 simulates the common-mode energy transfer characteristics provided in the embodiments of this application, including the common-mode energy return loss and the common-mode energy insertion loss from the first input terminal 3112 (second input terminal 3122) to the first output terminal 3115 (second output terminal 3125). The results are shown in [the table below]. Figure 9 .

[0058] Figure 6The minimum differential-mode insertion loss (including 3dB inherent power distribution loss) for the differential-mode signal from the first input terminal 3112 (second input terminal 3122) to the first output terminal 3115 (second output terminal 3125) is 3.92dB, with a rectangularity factor K=1.25 (K= BW20dB / BW10dB). Compared to the work in the aforementioned articles, the differential-mode signal selectivity of this design is improved by 4.3%. Furthermore, the out-of-band rejection reaches 27.1dB at 4.91GHz (with a relative bandwidth of 288.83%), and compared to the work in the aforementioned articles, the stopband rejection range of the differential-mode signal is extended by 25.67%.

[0059] Figure 7 This is a difference diagram showing the amplitude and phase consistency of the differential signal between the first output terminal 3115 (the second output terminal 3125), which can maintain good phase and amplitude consistency between the output ports throughout the passband.

[0060] Figure 8 The isolation characteristics between the first output terminal 3115 (the second output terminal 3125) show that the isolation between the two output ports is good.

[0061] like Figure 9 As shown, regardless of whether it is in or out of the passband, the transmission of the common-mode signal is suppressed to below -36.1 dB. The common-mode return loss of the first input terminal 3112 (second input terminal 3122) is greater than 10 dB in the range of 0.64 GHz to 3.00 GHz (with a relative bandwidth of 138.82%). Compared with the work in the previous article, this structure improves the common-mode rejection level by 15.1 dB and expands the relative bandwidth of common-mode absorption by 81.42%.

[0062] It should be noted that, in the description of this invention, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0063] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0064] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0065] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0066] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A self-encapsulated, reflection-free differential filter power divider with substrate-integrated suspended strip and broadband common-mode absorption characteristics, characterized in that, include: The first encapsulation layer includes a first substrate, and a metal layer is disposed on both end faces of the first substrate along a first direction. The first air cavity layer includes a second substrate, and a metal layer is disposed on both end faces of the second substrate along the first direction. The first air cavity layer forms a through air cavity structure along the first direction. The circuit layer includes a third substrate, and microstrip modules formed by microstrip lines are disposed on both end faces of the third substrate along the first direction. The microstrip modules are used to filter and distribute the input signal. The second air cavity layer includes a fourth substrate, and metal layers are provided at both ends of the fourth substrate along the first direction. The second air cavity layer forms a through air cavity structure along the first direction. The second encapsulation layer includes a fifth substrate, and a metal layer is provided at both ends of the fifth substrate along the first direction. The first substrate, the second substrate, the third substrate, the fourth substrate, and the fifth substrate are all made of insulating material, and the first encapsulation layer, the first air cavity layer, the circuit layer, the second air cavity layer, and the second encapsulation layer are stacked sequentially along the first direction.

2. The power divider according to claim 1, characterized in that, The third substrate includes a first surface, which is one end face of the third substrate along a first direction; The microstrip module includes a first microstrip unit disposed on a first surface; The first microstrip unit includes a first input component and a first input terminal, a first resonant component, a first power distribution component, and a first output terminal. The first input terminal is connected to the input terminal of the first input component, the first output terminal is connected to the output terminal of the first power distribution component, and the first resonant component is connected between the first input component and the first power distribution component.

3. The power divider according to claim 2, characterized in that, The first surface has a first centerline and a second centerline, the first centerline extending along a second direction and the second centerline extending along a third direction, the first direction, the second direction and the third direction being perpendicular to each other; The first input component is a U-shaped structure formed by microstrip lines, including a bottom edge and two sides; The bottom edge and the side edge of the U-shaped structure of the first input component both extend along a straight line and have the same width, and the side edge of the U-shaped structure of the first input component has the same height.

4. The power divider according to claim 3, characterized in that, The opening of the U-shaped structure of the first input component faces outward from the first surface along the second direction; The first input terminal includes a wide input terminal and a narrow input terminal, both of which are formed by microstrip lines; The wide input terminal is connected to one side of the U-shaped structure of the first input component, near the end of the opening of the U-shaped structure of the first input component; The narrow input terminal is connected to the other side of the U-shaped structure of the first input component, near the end of the opening of the U-shaped structure of the first input component; The center line of the wide input terminal extending in the second direction coincides with the center line of the side of the U-shaped structure of the first input component to which it is connected; the center line of the narrow input terminal extending in the second direction coincides with the center line of the side of the U-shaped structure of the first input component to which it is connected. The dimension of the wide input terminal along the third direction is greater than the width of the side of the U-shaped structure of the first input component, and the dimension of the narrow input terminal along the third direction is less than the width of the side of the U-shaped structure of the first input component.

5. The power divider according to claim 4, characterized in that, Two common-mode absorption resistors are connected in parallel between the two sides of the U-shaped structure of the first input component.

6. The power divider according to claim 5, characterized in that, The first resonant component includes a resonant input line, a resonant body, and a resonant output line; Both the resonant input line and the resonant output line are right-angled structures formed by microstrip lines; The resonator is a hollow H-shaped structure formed by microstrip lines; The H-shaped structure is symmetrical about the second center line. The opening of the H-shaped structure faces the extension direction parallel to the second center line. The H-shaped structure includes a straight edge and a concave edge. The extension direction of the straight edge of the H-shaped structure is parallel to the third direction, and the width of the straight edge is smaller than the width of the concave edge. The resonant input line includes a first right-angled side and a second right-angled side, and the resonant output line includes a third right-angled side and a fourth right-angled side. The first right-angled side and the third right-angled side extend along a first direction, and the second right-angled side and the fourth right-angled side extend along a second direction. The second right-angled side and the fourth right-angled side are located on the same side of the first center line and have the same length, and the ends of the second right-angled side and the fourth right-angled side closest to the first center line are both located on the first center line; The H-shaped structure is positioned between the second right-angled side and the fourth right-angled side, with a gap between the second right-angled side and the H-shaped structure, and a gap between the fourth right-angled side and the H-shaped structure. The first right-angled side connects between the first input component and the second right-angled side; the third right-angled side connects between the fourth right-angled side and the first power distribution component.

7. The power divider according to claim 6, characterized in that, The centerline of the U-shaped structure of the first input component extending along the second direction coincides with the first centerline; The first right-angled side coincides with the first center line, and the first right-angled side connects between the bottom side and the second right-angled side of the U-shaped structure of the input component.

8. The power divider according to claim 7, characterized in that, The first power distribution component includes a first distribution body, a first distribution line, a second distribution body, and a second distribution line; The first distribution body and the second distribution body are symmetrically arranged about the first center line; the first distribution line and the second distribution line are symmetrically arranged about the first center line; One end of the first distribution line is connected to the first distribution body, one end of the second distribution line is connected to the second distribution body, the other end of the first distribution line is connected to the other end of the second distribution line, and they are connected to the second right-angled side through the third right-angled side, which coincides with the first center line.

9. The power divider according to claim 8, characterized in that, The first distribution line includes a first distribution sub-segment, a second distribution sub-segment, and a third distribution sub-segment; the first distribution sub-segment and the third distribution sub-segment both extend along a third direction, the second distribution sub-segment extends along a second direction, and the second distribution sub-segment connects the first distribution sub-segment and the third distribution sub-segment; the end of the first distribution sub-segment away from the second distribution sub-segment is connected to the third straight edge, and the end of the third distribution sub-segment away from the second distribution sub-segment is connected to the first distribution body; The second distribution line includes a fourth distribution sub-segment, a fifth distribution sub-segment, and a sixth distribution sub-segment; the fourth and sixth distribution sub-segments both extend along a third direction, the fifth distribution sub-segment extends along a second direction, and the fifth distribution sub-segment connects the fourth and sixth distribution sub-segments; the end of the fourth distribution sub-segment furthest from the fifth distribution sub-segment is connected to the third straight edge, and the end of the sixth distribution sub-segment furthest from the fifth distribution sub-segment is connected to the second distribution body; Both the first and second distribution bodies are U-shaped structures identical to the input components; An isolation resistor is provided between the third and sixth distribution sub-segments.

10. The power divider according to claim 9, characterized in that, The third substrate includes a second surface, which is another end face of the third substrate along a third direction; The microstrip module also includes a second microstrip unit, which includes a second input component and a second input terminal, a second resonant component, a second power distribution component, and a second output terminal. Among them, the projection of the second input component onto the first surface along the first direction coincides with the first input component, the projection of the second resonant component onto the first surface along the first direction coincides with the first resonant component, and the projection of the second power distribution component onto the first surface along the first direction coincides with the first power distribution component. The projection of the second input terminal onto the first surface along the first direction is mirror-symmetrical to the first input terminal about the first center line; The projection of the second output terminal onto the first surface along the first direction is mirror-symmetrical to the center line of the first output terminal about the center line of the U-shaped structure of the first distribution body.

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