A surface-mountable micro-coaxial ultra-wideband Lange coupler

Abstract

The present invention belongs to the field of wireless communication technology and relates to a surface-mountable micro-coaxial ultra-wideband Lange coupler, comprising a metal shell, a first metal inner core located inside the metal shell, the first metal inner core having a first connection terminal, a second connection terminal, a third connection terminal, and a fourth connection terminal; a transmission medium filled between the metal shell and the first metal inner core; a rectangular micro-coaxial line board-level integrated transition structure comprising an input port, a through port, a coupling port, and an isolation port provided on a first side surface of the metal shell and connected one-to-one with the first connection terminal, the second connection terminal, the third connection terminal, and the fourth connection terminal; and a defective ground structure provided on a second side surface of the metal shell, the second side surface being arranged opposite to the first side surface. The present invention operates in the millimeter wave frequency band, has a spatial three-dimensional structure, and has high coupling, low loss, high reliability, a short design cycle, low economic cost, and can achieve board-level integration, thus broadening the scope of application.

Description

Technical Field

[0001] The invention belongs to the technical field of wireless communications, and in particular relates to a surface-mountable micro-coaxial ultra-wideband Lange coupler. Background Art

[0002] With the advancement of microwave communication technology and the scarcity of spectrum resources, communication systems are gradually moving towards higher frequency bands, and microwave integrated circuits play a crucial role in this. As a relatively independent type of circuit, the Lange coupler, due to its small size and wide bandwidth, can be used to form important circuits such as power combiners, power dividers, mixers, and modulators, making it a highly valued member of the microwave integrated circuit family.

[0003] A Lange coupler, a microstrip circuit in the form of a planar circuit, consists of multiple closely spaced, parallel coupled lines. This structure utilizes stray fields from the two edges of the lines to improve coupling and achieve tight coupling. Furthermore, the coupled lines provide 3dB coupling within an octave or even wider bandwidth, effectively matching odd and even mode impedances, compensating for unequal phase velocities and improving the coupler's bandwidth.

[0004] In traditional manufacturing processes, Lange couplers are completed using a printed circuit-based approach. Depending on the process layout, these processes can be categorized into two typical approaches: photolithography followed by electroplating, and electroplating followed by photolithography. Under these two processes, the quality of the Lange coupler is closely related to the substrate's dielectric constant, substrate thickness, the width of the conductors that make up the circuit pattern, the width of the conductor gap, the thickness and uniformity of the conductors, and the surface finish of the film layer. For a Lange coupler with a certain index N, the coupling characteristics are very sensitive to the spacing between the interdigital lines and the thickness of the metal conduction strip.

[0005] However, in actual production, planar Lange couplers fabricated using these two typical manufacturing processes have been found to suffer from poor coupling, insufficient isolation, phase shift deviation, and poor reliability. To compensate for these performance deficiencies, many designers must add extensive compensation circuitry and extensive debugging to achieve the desired performance. This significantly increases design cycles and overall production costs. Summary of the Invention

[0006] In view of this, the present invention provides a surface-mountable micro-coaxial ultra-wideband Lange coupler with a spatial three-dimensional structure and capable of operating in the millimeter wave frequency band. It has the advantages of high coupling, high isolation, low loss, low amplitude imbalance, low phase imbalance, wide bandwidth and self-packaging. In addition, the present invention can achieve board-level interconnection integration, high reliability, short design cycle and low overall economic cost of production.

[0007] The technical solution of the present invention is:

[0008] A surface-mountable micro-coaxial ultra-wideband Lange coupler, comprising:

[0009] Metal housing;

[0010] a first metal inner core located inside the metal shell, the first metal inner core having a first connecting terminal, a second connecting terminal, a third connecting terminal and a fourth connecting terminal;

[0011] A transmission medium is filled between the metal shell and the first metal inner core;

[0012] A rectangular micro-coaxial line board-level integrated transition structure is used to apply signal excitation while connecting to an external device. The rectangular micro-coaxial line board-level integrated transition structure includes an input port, a coupling port, a through port, and an isolation port provided on the first side surface of the metal shell. The input port, through port, coupling port, and isolation port are respectively connected to the first connection terminal, the second connection terminal, the third connection terminal, and the fourth connection terminal in a one-to-one correspondence;

[0013] The defective structure is used to increase the coupling degree of the coupler and is arranged on the second side surface of the metal shell, and the second side surface is arranged opposite to the first side surface.

[0014] Preferably, the transmission medium is air.

[0015] Preferably, the first metal inner core includes a first connecting terminal, a second connecting terminal, a third connecting terminal, a fourth connecting terminal, a first short finger wire, a second long finger wire, a third long finger wire, a fourth long finger wire, a fifth short finger wire, a first jumper wire, a second jumper wire and a third jumper wire, wherein one end of the first short finger wire is connected to the third connecting terminal, one end of the second long finger wire is connected to the second connecting terminal, both ends of the third long finger wire are connected to the third connecting terminal and the fourth connecting terminal respectively, the fourth long finger wire is connected to the first connecting terminal, one end of the fifth short finger wire is connected to the fourth connecting terminal, the first jumper wire and the third jumper wire are parallel and spaced apart, and are both connected to the second long finger wire and the fourth long finger wire, and the second jumper wire connects the first short finger wire and the fifth short finger wire.

[0016] Preferably, the first connecting terminal, the second connecting terminal, the third connecting terminal and the fourth connecting terminal are 50-ohm transmission lines, and a side adjacent to the first connecting terminal and the third connecting terminal and a side adjacent to the second connecting terminal and the fourth connecting terminal are both provided with chamfers.

[0017] Preferably, the input port, coupling port, through port and isolation port have the same structure.

[0018] Preferably, the input port includes a second metal core with a stepped transition structure, the length direction of the second metal core is perpendicular to the length direction of the first metal core, one end of the second metal core is connected to the first connecting terminal, and is used to convert the horizontal transmission signal on the first connecting terminal to a vertical direction, and a through opening is opened on the metal shell, the position of the through opening corresponds to the position of the second metal core, the second metal core is inserted into the through opening and the end face of the other end of the second metal core is flush with the upper surface of the metal shell, and the other end of the second metal core is used to connect to a test probe or a dielectric substrate to realize the transmission of the signal from the first metal core through the second metal core.

[0019] Preferably, the second metal inner core includes a first connector and a second connector stacked up and down, the first connector and the second connector are both rectangular, and the cross-sectional area of ​​the first connector is larger than the cross-sectional area of ​​the second connector, the first connector is connected to the first connecting terminal, the second connector is passed through the through opening, and the upper end surface of the second connector is flush with the upper surface of the metal shell.

[0020] Preferably, the defective ground structure includes a plurality of periodic window structures, the cross-section of the window structure is rectangular, and the plurality of window structures are centrally symmetrically distributed with the geometric center of the bottom surface of the metal shell as the center point.

[0021] Preferably, a plurality of supporting dielectric strips are provided between the metal shell and the first metal inner core to support the first metal inner core for positioning. The plurality of supporting dielectric strips are periodically arranged at predetermined intervals. The supporting dielectric strips are passed through the first metal inner core, and both ends are embedded in the metal shell. One pair of side surfaces of the supporting dielectric strips are respectively fixed to a pair of inner walls of the metal shell to improve the stability of the supporting dielectric strips.

[0022] Compared with the prior art, the present invention provides a surface-mountable micro-coaxial ultra-wideband Lange coupler, which includes a first metal inner core located in a metal shell, a transmission medium filled between the first metal inner core and the metal shell to form a rectangular micro-coaxial line, the first metal inner core having a first connection terminal, a second connection terminal, a third connection terminal and a fourth connection terminal, the first connection terminal, the second connection terminal, the third connection terminal and the fourth connection terminal are respectively connected one-to-one with the input port, the straight-through port, the coupling port and the isolation port located on the first side of the metal shell, the input port, the straight-through port, the coupling port and the isolation port constitute a rectangular micro-coaxial line board-level integrated transition structure, which is used to apply signal excitation to the coupler while connecting to an external device, and a defect ground structure for increasing the coupling degree of the coupler is provided on the second side of the metal shell, the defect ground structure is used to release photoresist and cooperate with the first metal inner core to adjust the coupling degree of the coupler. The present invention forms a 3D rectangular micro-coaxial transmission structure through a first metal inner core and a metal shell, and uses the first metal inner core to achieve a directional coupling function in a coupled line coupling manner. The structure has a three-dimensional spatial structure and can operate in the millimeter wave frequency band. The volume of the device is truly much smaller than that of the device based on the traditional waveguide structure. At the same time, the performance is better than that of the chip-level coupler. It has the advantages of high coupling, high isolation, low loss, low amplitude imbalance, low phase imbalance, wide bandwidth and self-packaging. In addition, the board-level integrated transition structure using multiple rectangular micro-coaxial lines is conducive to board-level integration of Lange couplers with other devices, broadening the application range of Lange couplers. The coupler of the present invention has a short design cycle, low overall economic cost of production, high reliability and large bandwidth, can achieve high integration and high performance of microwave millimeter wave systems, and has good application prospects in the field of microwave technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0024] Figure 2 It is a bottom view of the structure of the present invention.

[0025] Figure 3 It is a schematic diagram of the local structure of the present invention Figure 1 .

[0026] Figure 4 It is a schematic diagram of the local structure of the present invention Figure 2 .

[0027] Figure 5 It is the phase imbalance of the surface-mountable micro-coaxial ultra-wideband Lange coupler of the present invention.

[0028] Figure 6 The return loss of the surface-mountable micro-coaxial ultra-wideband Lange coupler of the present invention is shown in FIG.

[0029] Figure 7 It is the amplitude imbalance of the surface-mountable micro-coaxial ultra-wideband Lange coupler of the present invention.

[0030] Figure 8 It is the isolation degree of the surface-mountable micro-coaxial ultra-wideband Lange coupler of the present invention. DETAILED DESCRIPTION

[0031] Current Lange couplers suffer from poor coupling, insufficient isolation, phase shift deviation, and poor reliability. To compensate for these performance deficiencies, designers often need to add numerous compensation circuits and conduct extensive debugging to achieve the desired performance. This significantly increases design cycles and overall production costs.

[0032] In order to solve the above-mentioned technical problems, the technical solution of this application is specially designed.

[0033] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below with reference to specific embodiments and drawings.

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention. The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features specified as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0035] The present invention provides a surface mountable micro-coaxial ultra-wideband Lange coupler. Figures 1 to 8 The present invention is described with reference to a structural schematic diagram of FIG.

[0036] Example 1

[0037] Please refer to Figures 1 to 4The present invention provides a surface-mountable micro-coaxial ultra-wideband Lange coupler, which includes a metal shell 105 and a first metal inner core. The first metal inner core is located inside the metal shell 105 and together with the metal shell 105 constitutes a micro-coaxial structure. A cavity structure is formed between the metal shell 105 and the first metal inner core, and a transmission medium is filled between the two. The first metal inner core is provided with a first connecting terminal, a second connecting terminal, a third connecting terminal, and a fourth connecting terminal. Correspondingly, a rectangular micro-coaxial line board-level integrated transition structure is provided on the first side surface of the metal shell 105. The rectangular micro-coaxial line board-level integrated transition structure includes an input port 101, a through port 102, a coupling port 103 and an isolation port 104 with the same structure. The input port 101, the through port 102, the coupling port 103 and the isolation port 104 are respectively connected to the first connection terminal, the second connection terminal, the third connection terminal and the fourth connection terminal in a one-to-one correspondence, forming an interface end for connecting to an external device. The interface end is used to apply signal excitation while connecting to the external device. A defective ground structure for increasing the coupling degree of the coupler is provided on the second side surface of the metal shell 105. The second side surface is arranged opposite to the first side surface.

[0038] Specifically, the transmission medium is air, which has low capacitive loss and a nearly ideal low-loss characteristic.

[0039] Specifically, such as Figure 3 As shown, the structure of the first metal inner core includes a first connecting terminal, a second connecting terminal, a third connecting terminal, a fourth connecting terminal, a first short finger line 205, a second long finger line 206, a third long finger line 207, a fourth long finger line 208, a fifth short finger line 209, a first jumper line 211, a second jumper line 210 and a third jumper line 212, wherein one end of the first short finger line 205 is connected to the third connecting terminal, one end of the second long finger line 206 is connected to the second connecting terminal, two ends of the third long finger line 207 are respectively connected to the third connecting terminal and the fourth connecting terminal, the fourth long finger line 208 is connected to the first connecting terminal, one end of the fifth short finger line 209 is connected to the fourth connecting terminal, the first jumper line 211 and the third jumper line 212 are arranged in parallel and at intervals, and are both connected to the second long finger line 206 and the fourth long finger line 208, and the second jumper line 210 connects the first short finger line 205 and the fifth short finger line 209.

[0040] Specifically, the three long interdigital lines connected to each other in the first metal core include the second long interdigital line 206, the third long interdigital line 207 and the fourth long interdigital line 208, the two short interdigital lines include the first short interdigital line 205 and the fifth short interdigital line 209, and the three jumper lines include the first jumper line 211, the second jumper line 210 and the third jumper line 212. The lengths of the three long interdigital lines are similar, and the lengths of the two short interdigital lines are approximately half of the long interdigital lines. The three long interdigital lines are connected by three jumper lines, arranged side by side, with equal spacing and equal width, which helps to compensate for the unequal phase velocities of odd and even modes, improve the bandwidth, and have ultra-wideband characteristics.

[0041] Specifically, the first connection terminal, the second connection terminal, the third connection terminal and the fourth connection terminal are 50-ohm transmission lines for achieving impedance matching.

[0042] Specifically, the length between the isolation port 104 and the input port 101 is 4.2 mm, the width between the input port 101 and the coupling port 103 is 1.96 mm, the height of the metal shell 105 is 0.9 mm, the widths of the first short finger line 205, the second long finger line 206, the third long finger line 207, the fourth long finger line 208 and the fifth short finger line 209 are all 0.06 mm, and the first short finger line 205, the second long finger line 206, the second long finger line 206 The spacing between the third long finger line 207, the third long finger line 207 and the fourth long finger line 208, and the fourth long finger line 208 and the fifth short finger line 209 is 0.05 mm. The first short finger line 205, the second long finger line 206, the third long finger line 207, the fourth long finger line 208 and the fifth short finger line 209 are connected by the first jumper line 211, the second jumper line 210 and the third jumper line 212, utilizing the edge stray fields on both sides of the line to achieve 3dB tight coupling.

[0043] Furthermore, the lengths of the first short finger line 205 and the fifth short finger line 209 are both 1.125 mm, the length of the third long finger line 207 is 2.15 mm, the end of the second long finger line 206 is 0.18 mm away from the first connecting terminal, the end of the fourth long finger line 208 is 0.18 mm away from the inner side of the second connecting terminal, the first connecting terminal and the second connecting terminal are equal in length, and the third connecting terminal and the fourth connecting terminal are equal in length.

[0044] Furthermore, the adjacent sides of the first connecting terminal and the third connecting terminal are both beveled, and the adjacent sides of the second connecting terminal and the fourth connecting terminal are both beveled. The width of the corresponding right-angled sides is 0.17 mm, and the angle between the beveled sides and the outer sides is 135°. This chamfering treatment can improve the discontinuity of impedance and reduce parasitic effects.

[0045] Furthermore, the width of the first jumper line 211 , the second jumper line 210 , and the third jumper line 212 are all 0.1 mm.

[0046] Furthermore, if Figure 1 and Figure 4 As shown, the rectangular micro-coaxial line board-level integrated transition structure includes an input port 101, a through port 102, a coupling port 103 and an isolation port 104, which are respectively used to connect to external devices and apply signal excitation. The rectangular micro-coaxial line board-level integrated transition structure is applied to the coupler input and output and the isolation port. The micro-coaxial line gradient structure is used to achieve a good transition between the two structures, making the device surface mountable.

[0047] Specifically, since the structures of the input port 101 , the through port 102 , the coupled port 103 and the isolated port 104 are the same, only the input port 101 is used as an example to illustrate its structure.

[0048] like Figure 1 、 Figure 3 and Figure 4 As shown, the input port 101 includes a second metal core with a stepped transition structure, with its length perpendicular to that of the first metal core. Specifically, the second metal core includes a first connector and a second connector stacked one above the other. Both the first connector and the second connector are rectangular parallelepipeds, with the first connector having a larger cross-sectional area than the second connector. The first connector is connected to the first connection terminal and is used to convert the horizontal transmission signal on the first connection terminal to a vertical direction. A through-hole is defined in the metal housing 105 corresponding to the position of the second connector. The second connector is disposed within the through-hole, with its upper end surface flush with the surface of the metal housing 105. The second connector and the through-hole form a coplanar waveguide interconnected with external components. The through-hole exposes the end of the second connector, facilitating connection to a test probe or dielectric substrate. An air gap is formed between the periphery of the second connector and the inner wall of the through-hole, allowing the signal to pass from the first metal core through the first connector and finally be output from the second connector.

[0049] Specifically, the second connector is a rectangular parallelepiped with dimensions of 200 μm×200 μm×100 μm, and the first connector is a rectangular parallelepiped with dimensions of 340 μm×200 μm×300 μm.

[0050] Furthermore, if Figure 2 As shown, the defective structure includes a plurality of periodic window structures 106 , and the cross section of the window structure 106 is rectangular.

[0051] Specifically, there are five window structures 106 in the embodiment of the present invention. The window structures 106 are rectangular gaps opened on one side surface of the metal shell 105. The five rectangular gaps are symmetrically distributed with the geometric center of the bottom surface of the metal shell 105 as the center point. The five rectangular gaps are used to cooperate with the first metal core to increase the coupling degree of the coupler, reduce the amplitude imbalance, and release the photoresist during the processing.

[0052] Furthermore, the metal shell 105 , the first metal inner core, and the four rectangular micro-coaxial line board-level integrated transition structures with the same structure are centrally symmetrical structures, so as to improve the machinability.

[0053] The surface-mountable micro-coaxial ultra-wideband Lange coupler provided by the present invention is prepared using a copper-based rectangular micro-coaxial process, which requires multiple layers to be stacked to form a 3D coaxial structure. The general process flow can be divided into the following steps:

[0054] A sacrificial layer is formed on the substrate using photoresist, and the desired structure is made on the sacrificial layer using photolithography. Copper is deposited on the surface using electrochemical methods and flattened. The above steps are repeated until the desired 3D structure is completely formed. The sacrificial layer is removed using a stripping solution to form a 3D micro-coaxial structure.

[0055] In particular, in order for the stripping liquid to better remove the sacrificial layer, it is necessary to design periodic release holes on the metal shell 105. The number of release holes should be designed according to the size of the device. Too many release holes will increase radiation loss, and too few release holes will make the sacrificial layer not removed cleanly. In this embodiment, the role of the release holes is achieved by introducing a defective structure.

[0056] Furthermore, to ensure the relative positions of the various structures within the first metal core during processing, multiple periodically arranged support dielectric strips 301 are added to the first metal core to facilitate positioning and support of the first, second, third, and fourth connection terminals, the first short finger 205, the second long finger 206, the third long finger 207, the fourth long finger 208, the fifth short finger 209, the first jumper 211, the second jumper 210, and the third jumper 212. The multiple support dielectric strips 301 are periodically arranged at predetermined intervals and penetrate the first metal core, with both ends embedded within the metal shell 105. A pair of side surfaces of the support dielectric strips 301 are fixed to a pair of inner walls of the metal shell 105, respectively, to enhance the stability of the support dielectric strips 301.

[0057] Please refer to Figures 5 to 8The surface-mountable micro-coaxial ultra-wideband Lange coupler provided by the present invention has an echo S11 of greater than 19dB at the input port 101 and an isolation S41 of greater than 18dB at the isolation port 104 within the frequency range of 18GHz to 40GHz. The transmission coefficient S21 from the input port 101 to the through port 102 fluctuates within the range of 2.85dB to 3.71dB; and the transmission coefficient S31 from the through port 102 to the isolation port 104 fluctuates within the range of 2.62dB to 3.54dB. The fluctuation range of these two transmission coefficients is very small, and both meet the design indicators of a 3dB coupler.

[0058] The structure and dimensions of the coupler provided by the present invention are obtained by optimizing the topology of the Lange coupler circuit through three-dimensional software. Through repeated verification and correction through multiple simulations and experiments, the appropriate width and spacing of the interdigital lines are obtained, and the circuit interconnection between the interdigital lines is achieved through the cross-connection of internal conductors.

[0059] The surface-mountable micro-coaxial ultra-wideband Lange coupler provided by the present invention has a length × width × height of 4.2 mm × 1.96 mm × 0.9 mm, an insertion loss of ±0.45 dB, and a frequency band of 75.9%. The technical indicators that can be achieved are:

[0060] Operating frequency: 18-40GHz,

[0061] Insertion loss: ≤0.7dB,

[0062] Input and output standing wave: ≤1.3,

[0063] Amplitude imbalance: ≤1dB,

[0064] Phase imbalance: ≤0.5°.

[0065] Compared with the prior art, the present invention forms a 3D rectangular micro-coaxial transmission structure through a first metal core and a metal shell, and implements directional coupling by coupling line coupling. The device is manufactured using advanced copper-based MEMS technology, ultimately achieving a small device size, low insertion loss, and wide bandwidth. This truly achieves a device volume far smaller than that of devices based on traditional waveguide structures, while also outperforming chip-level couplers. The present invention has a three-dimensional structure and can operate in the millimeter-wave frequency band, offering the advantages of high coupling, high isolation, low loss, low amplitude imbalance, low phase imbalance, wide bandwidth, and self-packaging. Furthermore, the use of multiple rectangular micro-coaxial line board-level integrated transition structures facilitates board-level integration of Lange couplers with other devices, broadening the application range of Lange couplers. The present invention offers high reliability, a short design cycle, low overall economic costs for production, and strong practicality, making it worthy of promotion.

[0066] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0067] The above disclosure is only a preferred specific embodiment of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the scope of protection of the present invention.

Claims

1. A surface-mountable micro-coaxial ultra-wideband Lange coupler, characterized in that: include: Metal housing (105); A first metal inner core is located inside the metal shell (105), and the first metal inner core has a first connecting terminal, a second connecting terminal, a third connecting terminal, and a fourth connecting terminal; A transmission medium is filled between the metal shell (105) and the first metal inner core; A rectangular micro-coaxial line board-level integrated transition structure is used for applying signal excitation while being connected to an external device. The rectangular micro-coaxial line board-level integrated transition structure comprises an input port (101), a through port (102), a coupling port (103), and an isolation port (104) arranged on a first side surface of the metal shell (105). The input port (101), the through port (102), the coupling port (103), and the isolation port (104) are respectively connected to the first connection terminal, the second connection terminal, the third connection terminal, and the fourth connection terminal in a one-to-one correspondence. A defective structure for increasing the coupling degree of the coupler is provided on the second side of the metal housing (105), the second side being arranged opposite to the first side; The first metal inner core comprises a first connecting terminal, a second connecting terminal, a third connecting terminal, a fourth connecting terminal, a first short finger line (205), a second long finger line (206), a third long finger line (207), a fourth long finger line (208), a fifth short finger line (209), a first jumper line (211), a second jumper line (210) and a third jumper line (212), wherein one end of the first short finger line (205) is connected to the third connecting terminal, one end of the second long finger line (206) is connected to the second connecting terminal, and one end of the second short finger line (205) is connected to the third connecting terminal. The terminals are connected, the two ends of the third long finger line (207) are connected to the third connection terminal and the fourth connection terminal respectively, the fourth long finger line (208) is connected to the first connection terminal, one end of the fifth short finger line (209) is connected to the fourth connection terminal, the first jumper line (211) and the third jumper line (212) are parallel and spaced apart, and are both connected to the second long finger line (206) and the fourth long finger line (208), and the second jumper line (210) is connected to the first short finger line (205) and the fifth short finger line (209).

2. The surface-mountable micro-coaxial ultra-wideband Lange coupler according to claim 1, wherein: The transmission medium is air.

3. The surface-mountable micro-coaxial ultra-wideband Lange coupler according to claim 1, wherein: The first connection terminal, the second connection terminal, the third connection terminal and the fourth connection terminal are 50-ohm transmission lines, and a side adjacent to the first connection terminal and the third connection terminal and a side adjacent to the second connection terminal and the fourth connection terminal are both provided with chamfers.

4. The surface-mountable micro-coaxial ultra-wideband Lange coupler according to claim 1, wherein: The input port (101), the through port (102), the coupling port (103) and the isolation port (104) have the same structure.

5. The surface-mountable micro-coaxial ultra-wideband Lange coupler according to claim 4, wherein: The input port (101) includes a second metal core with a stepped transition structure, the length direction of the second metal core is perpendicular to the length direction of the first metal core, one end of the second metal core is connected to the first connecting terminal, and is used to convert the horizontal transmission signal on the first connecting terminal to the vertical direction, the metal shell (105) is provided with a through opening, the position of the through opening corresponds to the position of the second metal core, the second metal core is inserted into the through opening, and the end face of the other end of the second metal core is flush with the upper surface of the metal shell (105), and the other end of the second metal core is used to connect to a test probe or a dielectric substrate to realize the transmission of the signal from the first metal core to the second metal core.

6. The surface-mountable micro-coaxial ultra-wideband Lange coupler according to claim 5, wherein: The second metal inner core comprises a first connector and a second connector stacked up and down, the first connector and the second connector are both rectangular parallelepipeds, and the cross-sectional area of ​​the first connector is larger than that of the second connector, the first connector is connected to the first connecting terminal, the second connector is passed through the through opening, and the upper end surface of the second connector is flush with the upper surface of the metal shell (105).

7. The surface-mountable micro-coaxial ultra-wideband Lange coupler according to claim 1, wherein: The defective ground structure includes a plurality of periodic window structures (106), the cross section of the window structure (106) is rectangular, and the plurality of window structures (106) are centrally symmetrically distributed with the geometric center of the bottom surface of the metal shell (105) as the center point.

8. The surface-mountable micro-coaxial ultra-wideband Lange coupler according to claim 1, wherein: A plurality of supporting dielectric strips (301) are provided between the metal shell (105) and the first metal inner core to support the first metal inner core for positioning. The plurality of supporting dielectric strips (301) are periodically arranged at predetermined intervals. The supporting dielectric strips (301) are passed through the first metal inner core, and both ends are embedded in the metal shell (105). A pair of side surfaces of the supporting dielectric strips (301) are respectively fixed to a pair of inner walls of the metal shell (105) to improve the stability of the supporting dielectric strips (301).

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