Planar coaxial transmission line

Abstract

The planar coaxial transmission line comprises a signal line, an upper layer metal ground, a lower layer metal ground, a plated-through hole, a dielectric substrate and a shielding cover, the upper layer metal ground and the lower layer metal ground are arranged on the upper surface and the lower surface of the dielectric substrate respectively, and the plated-through hole is connected with the upper layer metal ground and the lower layer metal ground. The signal line and the upper-layer metal ground are located on the same plane, a medium groove is arranged between the upper-layer metal ground and the signal line, and a shielding cover is arranged above the signal line and is connected with the upper-layer metal ground. The planar coaxial transmission line can be applied to implementation of a radio frequency microwave circuit module and system with low loss and high shielding performance, and can be directly interconnected and integrated with an existing planar transmission line circuit, an existing coaxial line circuit, an existing electronic component and an existing chip device, electromagnetic shielding isolation is improved, electromagnetic signal transmission is enhanced, and the transmission efficiency is improved. And the size and weight of the circuit module and the system are simplified, the reliability is higher, the design is simpler, and the cost is lower.

Description

Technical Field

[0001] The invention relates to a planar coaxial transmission line, belonging to the technical field of radio frequency microwaves. Background Art

[0002] Planar transmission lines such as microstrip, coplanar waveguide (CPW), and grounded coplanar waveguide (GCPW) are widely used in RF microwave circuits and systems due to their good processability. Combined with planar printed circuit (PCB) technology, they can realize planar integration of microwave and analog and digital signal circuits in double-layer and multi-layer PCB circuits. However, since microstrip, CPW, and GCPW are semi-open transmission lines, such as Figure 1 , electromagnetic signals will leak radiation when transmitted in them, increasing the transmission loss of signals; in addition, these semi-open transmission lines are susceptible to external electromagnetic interference, and are also very likely to cause crosstalk with analog and digital signals inside the circuit system. Therefore, existing RF microwave circuits and systems are usually encapsulated in metal cavities and connected to each other using through-wall coaxial connectors and coaxial lines. These metal cavities, coaxial connectors and coaxial lines greatly increase the volume, weight and cost of RF microwave circuit modules and systems, and will introduce self-excitation at the cavity self-resonance frequency, destroying the working state of the entire circuit module and system.

[0003] On the other hand, coaxial transmission line is a fully enclosed two-conductor transmission line. Figure 2 , with very good electromagnetic shielding and transmission characteristics, is widely used in RF microwave coaxial cables to achieve the interconnection of different RF microwave circuit modules and systems. However, the existing coaxial transmission lines are all three-dimensional structures, which cannot be directly integrated with PCB planar circuits. Therefore, precise electromagnetic design is required to ensure the interconnection and transmission characteristics of electromagnetic signals between planar circuits and coaxial circuits.

[0004] In a paper published in 2006, a folded ground transmission line (such as Figure 3 ), forming an inverted microstrip transmission line, which presents a semi-closed structure as a whole. Therefore, when electromagnetic signals are transmitted in it, there will be downward radiation causing energy loss, and it will interfere with the circuit below or be interfered with by the circuit below. Due to the inverted structure, when this transmission line structure is interconnected with the existing planar circuit transmission line (such as microstrip, CPW, GCPW), their ground planes are not in the same plane, so it is necessary to design a switching circuit to achieve interconnection, which increases the complexity of the design and reduces the reliability of signal transmission.

[0005] In the granted patents, see Figure 4, by adding metal covers on the top and bottom of the multilayer CPW transmission line, a low-loss and high-shielding transmission line is achieved; however, there are the following defects:

[0006] 1) Actual chip devices require good grounding characteristics when used in PCB circuits, especially the back of the chip needs to be completely grounded. However, this transmission line technology is a multi-layer CPW, and the signal line is located in the middle of each layer. When interconnected with the chip, there is no RF microwave ground that can be directly connected directly under the chip, and the good grounding of the chip cannot be guaranteed. Therefore, it is not suitable for the integrated design and development of electronic components and chips in actual applications;

[0007] 2) Electronic components or chip devices are generally located on the surface of the circuit board, that is, the top layer or bottom layer. However, when the transmission line technology is used, only the signal lines on the top layer or bottom layer are connected to the electronic components and chip devices, and the signal lines on other layers that are not connected are suspended, which will introduce discontinuity and deteriorate the interconnection matching of RF microwave signals, reducing the transmission quality;

[0008] 3) In this patent, each metal layer is divided into signal lines and metal ground. Without a complete metal ground, the electromagnetic shielding effect is limited. This will introduce inter-layer crosstalk when mixed with other analog and digital signal circuits in the system;

[0009] 4) The signal line is located in the middle of each layer of the circuit, and metalized vias are required to connect the multi-layer signal lines, which greatly increases the processing complexity of the transmission line circuit and the transmission reliability of the electromagnetic signal. At the same time, it will introduce parasitic parameters to the transmission line, limit the working bandwidth of the transmission line, and deteriorate the transmission of the electromagnetic signal;

[0010] 5) When the transmission line is interconnected with the existing PCB planar transmission line and coaxial connection line, its signal layer is divided into each layer, but only the signal line of the top layer or the bottom layer can be connected with the conductor of the PCB planar transmission line and the inner conductor of the coaxial line. The unconnected signal lines in other layers will introduce discontinuity due to the asymmetry of the connection, which increases the complexity of the design and introduces high-order mode effects to deteriorate the interconnection transmission characteristics of the electromagnetic signal. Summary of the invention

[0011] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention proposes a planar coaxial transmission line that uses only two layers of metal circuits, one of which is a complete metal ground plane, to achieve a fully enclosed planar coaxial transmission line. It can be directly interconnected and integrated with existing transmission line circuits, electronic components and chip devices, which not only improves electromagnetic shielding isolation, but also simplifies the circuit structure, has higher reliability and simpler design.

[0012] Technical solution: To solve the above technical problems, a planar coaxial transmission line of the present invention comprises a signal line, an upper metal ground, a lower metal ground, a metallized hole, a dielectric substrate, and a shielding cover. The upper surface and the lower surface of the dielectric substrate are respectively provided with an upper metal ground and a lower metal ground. The upper metal ground is connected to the lower metal ground through the metallized hole, and the shielding cover is connected to the upper metal ground. A through groove is provided on the upper metal ground, and a signal line is provided in the through groove. A shielding cover is provided above the signal line. The shielding cover, the upper metal ground, the metallized hole, and the lower metal ground constitute the outer conductor of the coaxial line. The signal line is the inner conductor of the coaxial line. The outer conductor and the inner conductor together constitute a fully enclosed planar coaxial transmission line.

[0013] Preferably, the signal line and the upper metal ground are located in the same plane, the shielding cover is located above the signal line and connected to the upper metal ground, and the lower metal ground is a complete metal ground plane.

[0014] Preferably, the planar coaxial transmission line is a double-layer circuit, and other dielectric layers and metal layer circuits may be provided below the lower metal ground to form a multi-layer planar circuit.

[0015] Preferably, the metallized hole is a blind hole or a through hole. If the metallized hole is a through hole, it passes through the ground of all metal layers, the upper metal ground and the lower metal ground; if the metallized hole is a blind hole, it only connects the upper metal ground and the lower metal ground.

[0016] Preferably, the dielectric substrates on both sides of the signal line are provided with slots, that is, the dielectric directly below the air gap between the signal line and the upper metal ground is removed to reduce the loss of electromagnetic signal propagation. Preferably, the shielding cover is a shielding cover made of a material with good conductive properties, and the material of the shielding cover is gold, silver, copper, aluminum or other metals with conductive properties.

[0017] Preferably, the shielding cover and the upper surface metal ground may be fully closed and connected, or a plurality of openings may be provided at the connection of the shielding cover, and circuit wiring on the circuit board may pass through the openings.

[0018] Preferably, when there are no electronic components or chip devices on the signal line routing, the shielding cover is an integrally formed shielding cover; if there are electronic components or chip devices on the signal line routing, the shielding cover is split into a shielding wall directly connected to the upper metal ground and the shielding wall is located on both sides of the signal line, and a cover connected to the shielding wall and can be removed, so as to facilitate the maintenance and replacement of the electronic components and chip devices in the shielding cover.

[0019] Preferably, the shielding cover can be a surface mounted component directly connected to the upper metal layer, or a mechanical structure connected to the upper metal layer through screws;

[0020] Preferably, the signal line is a single-line transmission line or a double-line differential transmission line consisting of a first signal line and a second signal line in parallel, and a circuit consisting of a single-line transmission line or a double-line differential transmission line.

[0021] Preferably, the planar coaxial transmission line is in a straight line, a bent shape or a multi-branched shape, and the shape of the shielding cover matches the shape of the signal line.

[0022] Preferably, the signal line in the planar coaxial transmission line is a radio frequency microwave circuit, and the shape of the shielding cover is adapted to the shape of the signal line.

[0023] Preferably, electronic components and chip devices are placed on the signal line, and the electronic components and chip devices are located inside the shielding cover, and a gap is provided between the upper surface of the electronic components and chip devices and the shielding cover; for the electronic components and chip devices that generate heat, the gap can be filled with thermally conductive material so that the heat is transferred from the electronic components and chip devices to the shielding cover for heat dissipation.

[0024] In the present invention, the planar transmission line can be used in part of the RF microwave circuit, that is, partial circuit shielding and isolation, and can also be used in the entire RF microwave circuit including electronic components and chip devices, that is, full circuit shielding and isolation.

[0025] The present invention aims to solve the problems of integrability, low loss and high isolation in the prior art. Specifically, the existing microstrip, cpw and GCPW are all semi-open transmission lines, which have energy leakage, i.e. transmission loss and isolation interference problems; in the existing invention patent technology, the signal line is located in the middle of each layer, and there is no RF microwave ground that can be directly connected directly under the chip when interconnected with the chip, and the good grounding of the chip cannot be guaranteed, so it is not suitable for the integration of electronic components and chips in actual circuits and systems. In addition, the signal line of the transmission line involved in the existing invention patent is generally located on the top layer, and the electronic components and chip devices are also located on the surface of the circuit board. Therefore, when the transmission line is used, only the signal line of the top layer or the bottom layer is connected to the existing transmission line circuit and electronic components and chip devices, and the signal lines of other layers that are not connected are suspended, which will introduce discontinuity and deteriorate the interconnection matching of RF microwave signals, reducing the transmission quality; finally, in the patent technology, each layer of metal is divided into signal lines and metal grounds, without a complete whole-surface metal ground, and the electromagnetic shielding effect is limited. When this is mixed with other analog and digital signal circuits in the system, it will introduce inter-layer strings, and metallized holes are required to connect multiple layers of signal lines, which greatly increases the complexity and reliability of signal transmission lines, introduces parasitic parameters to the transmission lines, limits the bandwidth of the transmission lines, and deteriorates the transmission of electromagnetic signals.

[0026] Beneficial effects: The planar coaxial transmission line of the present invention realizes a fully enclosed planar coaxial transmission line by introducing a metal shielding cover on the traditional GCPW transmission line. The proposed planar coaxial transmission line uses a complete ground plane to completely isolate the other circuits of the system, solving the crosstalk problem between the circuit and the system; due to the fully enclosed structure, the outward radiation of electromagnetic signals and the internal interference of external electromagnetic signals are eliminated, and the transmission quality of radio frequency microwave signals is increased; the planar coaxial transmission line only uses two layers of metal circuits, and one layer is a complete metal ground plane, which can ensure the continuity of radio frequency microwave grounding between electronic components and chip devices when connected; because the shielding cover is placed along the signal line, it is small in size, which solves the self-resonance problem in the traditional metal cavity shielding, and greatly reduces the volume, weight and cost; the planar coaxial transmission line can be fully integrated with the double-layer and multi-layer PCB circuit board process; the planar coaxial transmission line and the existing coaxial connector and coaxial cable can be directly interconnected. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the existing semi-open microstrip transmission line and GCPW transmission line structure.

[0028] Figure 2 Schematic diagram of the structure of a coaxial transmission line.

[0029] Figure 3 Schematic diagram of the structure of a semi-closed semi-coaxial transmission line.

[0030] Figure 4 Schematic diagram of the structure of a double-sided shielded multi-layer CPW transmission line.

[0031] Figure 5 It is a structural schematic diagram of the present invention.

[0032] Figure 6 Schematic diagram of the planar coaxial transmission line structure in a multi-layer PCB circuit.

[0033] Figure 7 Schematic diagram of the planar coaxial transmission line structure with dielectric slots.

[0034] Figure 8 Schematic diagram of the planar coaxial transmission line structure with a circular shielding metal cover.

[0035] Fig. 9 Schematic diagram of the structure of a planar coaxial transmission line with periodic slots.

[0036] Fig.10 Schematic diagram of the planar coaxial differential transmission line structure.

[0037] Fig.11 Schematic diagram of the structure of a multi-branch curved planar coaxial transmission line.

[0038] Fig.12 This is a schematic diagram of the structure of planar coaxial transmission lines used in microwave circuit design.

[0039] Fig.13 Schematic diagram of the planar coaxial transmission line structure used for electronic components and chip devices.

[0040] Fig.14 Schematic diagram of a planar coaxial transmission line structure with a detachable and repairable shielding cover for electronic components and chip devices

[0041] Fig.15 Schematic diagram of the interconnection structure between planar transmission line and coaxial line.

[0042] Fig.16 This is a comparison diagram of the reflection coefficient technology effects of the embodiment of the present invention and the traditional GCPW transmission line.

[0043] Fig.17 This is a comparison diagram of the transmission coefficient technology effects of the embodiment of the present invention and the traditional GCPW transmission line.

[0044] In the figure: signal line 1; upper metal ground 2; lower metal ground 3; metallized hole 4; dielectric substrate 5; shielding cover 6; second dielectric substrate 7; first metal layer circuit 8; third dielectric substrate 9; second metal layer circuit 10; first dielectric slot 11; second dielectric slot 12; first signal line 13; second signal line 14; metal outer conductor 15; insulating medium 16; metal inner conductor 17; electronic components 18. DETAILED DESCRIPTION

[0045] The present invention will be further described below in conjunction with the accompanying drawings.

[0046] like Figure 5 As shown, a planar coaxial transmission line of the present invention comprises a signal line, an upper metal ground, a lower metal ground, a metallized hole, and a dielectric substrate. The upper surface and the lower surface of the dielectric substrate are provided with an upper metal ground and a lower metal ground respectively, and the upper metal ground is provided with a metallized hole. The signal line 1, the upper metal ground 2, the lower metal ground 3, the metallized hole 4 and the dielectric substrate 5 constitute a semi-open semi-coaxial transmission line, that is, a traditional grounded coplanar waveguide transmission line (GCPW). The upper metal ground is provided with a through groove, the signal line is provided in the through groove, a shielding cover is provided above the through groove, and the shielding cover is installed on the upper metal ground.

[0047] In the present invention, the shielding cover 6 and the GCPW form a fully enclosed coaxial transmission line, which can be directly interconnected with existing coaxial cables and coaxial connectors; the coaxial transmission line uses only two layers of metal, wherein the lower metal ground 3 is a complete metal ground plane, thereby ensuring the integrity of the ground of the transmission line, and can be directly interconnected with existing planar transmission lines, such as microstrip lines, CPW, and GCPW.

[0048] In the present invention, the upper metal ground 2, the lower metal ground 3, the metallized hole 4 and the shielding cover 6 form a fully enclosed metal outer conductor, which has three functions: eliminating the outward radiation of the radio frequency microwave signal on the signal line 1 to enhance signal transmission; eliminating the radiation interference of the radio frequency microwave signal on the signal line 1 to other circuits on the dielectric substrate to purify the electromagnetic environment of the system; eliminating the interference of the external space signal on the internal signal line 1; the shielding characteristics of the metal outer conductor avoid the use of the traditional metal cavity, greatly reducing the volume, weight and cost of the radio frequency microwave module and the system;

[0049] In the present invention, there is a complete metal ground directly below the signal line 1. When interconnected with actual electronic components and chip devices, it can be directly connected to the ground of the planar coaxial transmission line through the metallized through-holes directly below the chip, thereby ensuring the continuity of the RF microwave ground and increasing the interconnection transmission characteristics of the RF microwave signal; the shielding cover 6 can be directly welded on top of the upper metal ground 2 as a surface-mount component, or it can be connected to the metal ground 2 through metal screws.

[0050] In the present invention, the proposed planar coaxial transmission line belongs to a planar transmission line, which can be integrated with existing planar RF microwave circuits and coaxial lines, and can also be applied to advanced hybrid integrated circuits to achieve low-loss and high-shielding interconnection within and between chips.

[0051] like Figure 6 As shown, the present invention is applied to a multi-layer circuit, wherein several layers of dielectric substrates are arranged below the lower metal ground, adjacent dielectric substrate layers are arranged with metal layer circuits, and a metal layer circuit is also arranged below the lowest dielectric substrate. The metallized hole 4 may be a through hole that penetrates the ground of all metal layers and connects the ground of the planar coaxial transmission line and the ground of the metal layer circuit 8 and the ground of the metal layer circuit 10 together.

[0052] In the present invention, the metallized hole 4 can also be a blind hole, which only connects the upper metal ground 2 and the lower metal ground 3; the complete lower metal ground 3 isolates the planar coaxial transmission line from the first metal layer circuit 8 and the second metal layer circuit 10 below, so other signal circuits can be freely designed to pass under the planar coaxial transmission line.

[0053] like Figure 7 As shown, the dielectric below the gap between the signal 1 and the top metal ground 2 can be dug out to form a first dielectric slot 11 and a second dielectric slot 12, which can reduce signal transmission loss.

[0054] like Figure 8 As shown, there is no specific requirement for the shape of the shielding cover, and a U-shape or an arc shape is preferred.

[0055] like Fig. 9As shown, the shielding cover and the upper surface metal ground can be fully closed and connected, or a plurality of openings can be provided at the connection of the shielding cover, and the circuit wiring on the circuit board can be passed through the openings.

[0056] like Fig.10 As shown, a planar coaxial differential transmission line consisting of two lines is designed in the through slot, and the first signal line 13 and the second signal line 14 constitute a differential transmission line of the planar coaxial transmission line involved in the present invention.

[0057] In the present invention, the signal line is in a straight line, a bent shape or a multi-branched shape, and the shape of the shielding cover is adapted to the shape of the signal line. Figure 1 As shown in the figure, the signal line is a straight line and the shielding cover is a straight line. Fig.11 As shown, the signal line is in a multi-branch shape, and the signal line has one branch. The signal line can also be provided with multiple branches, and the shielding cover is adapted to the shape of the through slot according to the actual situation. Fig.12 As shown, the signal line of the planar coaxial line can be designed as a radio frequency microwave circuit with certain functions, not limited to a specific microwave circuit, as long as it is a microwave transmission line circuit, the coaxial transmission line can be used, the shape of the shielding cover 6 is adapted to the shape of the radio frequency microwave circuit, and the shielding cover 6 is connected to the metal ground 2. The realized radio frequency microwave circuit has a self-shielding feature, which can not only transmit electromagnetic signals, but also has a shielding effect, and does not require an additional metal cavity like a traditional radio frequency microwave circuit.

[0058] When the planar coaxial transmission line of the present invention is interconnected with electronic components and chip devices, such as Fig.13 As shown, the shielding cover 6 is an integrally formed shielding cover and is connected to the upper metal ground 2. The shielding cover 6 can be changed according to the appearance and output pins of the electronic components and chip devices, not only to achieve the shielding of the signal line, but also to achieve the shielding isolation of the electronic components and chip devices, thereby achieving full shielding isolation of the circuit and the system; the shielding cover 6 is not in contact with the upper surface of the electronic components and chip devices; the gap between the shielding cover 6 and the upper surface of the electronic components and chip devices can use conductive glue or conductive sheets to conduct the heat of the electronic components and chip devices during operation to the shielding cover 6 and the upper metal ground 2, and the shielding cover 6 plays a role in conduction and heat dissipation. Fig.14 As shown, the shielding cover 6 can also be split into a shielding wall directly connected to the upper metal ground 2 and the shielding wall is located on both sides of the signal line, and a cover connected to the shielding wall and can be removed, so as to facilitate the maintenance and replacement of electronic components and chip devices in the shielding cover.

[0059] The planar coaxial transmission line and the coaxial line (such as a coaxial connector and a coaxial cable) involved in the present invention can be directly interconnected, such as Fig.15The metal outer conductor 15, the metal inner conductor 16 and the insulating medium 17 form a coaxial line, the metal inner conductor 16 is directly connected to the signal line 1, and the metal outer conductor 15 is directly connected to the shielding cover 6 of the planar coaxial transmission line and the upper metal ground 2 and the lower metal ground 3. The connection method can be but not limited to soldering, electroplating and screw mechanical fastening connection.

[0060] like Fig.16 and Fig.17 The embodiment of the present invention includes a comparison of technical effects of a planar coaxial transmission line, a planar coaxial transmission line with dielectric slots and a traditional GCPW transmission line under the same material and the same length.

[0061] in Fig.16 It is a comparison of the effects of the reflection coefficient technology. It can be seen that the technology involved in the present invention, such as opening a dielectric slot and adding a metal cover, does not affect the impedance characteristics of the transmission line;

[0062] in Fig.17 It is a comparison of the transmission coefficient technical effects. It can be seen that the planar coaxial transmission line and the planar coaxial transmission line with dielectric slots involved in the present invention both have lower transmission loss than the traditional GCPW transmission line, and the planar coaxial transmission line with dielectric slots has the lowest transmission loss.

[0063] The present invention is not limited to the listed implementation schemes, the present invention is not limited to planar coaxial transmission lines and their differential forms, but also includes the use of these planar coaxial transmission lines in the design and implementation of RF microwave functional circuits; any partial or complete use of the technical means involved in the present invention and its deformation forms, including the shape, size, and installation method of each component of the planar coaxial transmission line, are within the scope of the patent protection authority of the present invention; in addition, the planar coaxial transmission line technology involved in the present invention can not only be used for the transmission of RF microwave electromagnetic signals in the RF microwave field, but also can be used in high-speed, high-sensitivity digital analog hybrid circuits and optical-microwave hybrid circuits.

[0064] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A planar coaxial transmission line, comprising a signal line, an upper metal ground, a lower metal ground, a metallized hole, a dielectric substrate, and a shielding cover, wherein the upper metal ground and the lower metal ground are respectively provided on the upper surface and the lower surface of the dielectric substrate, the upper metal ground is connected to the lower metal ground through the metallized hole, and the shielding cover is connected to the upper metal ground, characterized in that: The upper metal ground is provided with a through groove, a signal line is provided in the through groove, a shielding cover is provided above the signal line, the shielding cover, the upper metal ground, the metallized hole, and the lower metal ground constitute the outer conductor of the coaxial line, the signal line is the inner conductor of the coaxial line, and the outer conductor and the inner conductor together constitute a fully enclosed planar coaxial transmission line.

2. The planar coaxial transmission line according to claim 1, characterized in that: The signal line and the upper metal ground are located in the same plane, the shielding cover is located above the signal line and connected to the upper metal ground, and the lower metal ground is a complete metal ground plane.

3. The planar coaxial transmission line according to claim 1 or 2, characterized in that: The planar coaxial transmission line is a double-layer circuit, and other dielectric layers and metal layer circuits are arranged below the lower metal ground to form a multi-layer planar circuit.

4. The planar coaxial transmission line according to claim 1 or 2, characterized in that: The metallized hole is a blind hole or a through hole. If the metallized hole is a through hole, it passes through the ground of all metal layers, the upper metal ground and the lower metal ground; if the metallized hole is a blind hole, it only connects the upper metal ground and the lower metal ground.

5. The planar coaxial transmission line according to claim 1, characterized in that: The signal line is a single-line transmission line or a double-line differential transmission line formed by a first signal line and a second signal line in parallel, and a circuit formed by the single-line transmission line or the double-line differential transmission line.

6. The planar coaxial transmission line according to claim 1 or 5, characterized in that: The signal line is in a straight line shape, a bent shape, or a multi-branch shape, and the shape of the shielding cover is adapted to the shape of the signal line.

7. The planar coaxial transmission line according to claim 1 or 5, characterized in that: The dielectric substrates on both sides of the signal line are provided with slots.

8. The planar coaxial transmission line according to claim 6, characterized in that: When there are no electronic components or chip devices on the signal line routing, the shielding cover is an integrally formed shielding cover; if there are electronic components or chip devices on the signal line routing, the shielding cover can be split into a shielding wall directly connected to the upper metal ground and a cover connected to the shielding wall and can be removed.

9. The planar coaxial transmission line according to claim 1 or 8, characterized in that: Electronic components and chip devices are placed on the signal line, and the signal line, electronic components and chip devices are all located in the shielding cover to form a fully enclosed planar coaxial line circuit.

10. The planar coaxial transmission line according to claim 1 or 8, characterized in that: The shielding cover is a surface mount component and is installed through a surface mount circuit process.

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