Transmission structure for transmitting millimeter wave and terahertz signals in vertical direction

Abstract

The invention belongs to the technical field of wireless communication systems, and particularly discloses a transmission structure for transmitting millimeter wave and terahertz signals in the vertical direction, which comprises a grounding coplanar waveguide, an electromagnetic coupling structure and a vertical substrate integrated waveguide, the grounding coplanar waveguides are located at the top layer and the bottom layer of the transmission structure and serve as an input port and an output port respectively, and electromagnetic coupling structures are arranged on the grounding coplanar waveguides; the electromagnetic coupling structure is used for impedance matching and electromagnetic signal mode conversion; the vertical substrate integrated waveguide performs single-mode transmission of electromagnetic signals in the vertical direction through multi-layer stacking of the grounding through holes. According to the scheme, the technical problem that high integration level and miniaturization of the T / R assembly and the wireless communication system cannot be realized is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communication systems, and in particular relates to a transmission structure for transmitting millimeter waves and terahertz signals in a vertical direction. Background Art

[0002] With the rapid development of wireless communication technology and semiconductor process technology, millimeter wave and terahertz T / R components are developing towards miniaturization, low cost and high integration, and are widely used in millimeter wave and terahertz wireless communication systems. The quality of their performance directly affects the communication quality of the entire wireless communication system. Therefore, high-integration, high-precision, small-size millimeter wave and terahertz passive transmission structures play a vital role in improving the integration of millimeter wave and terahertz communication systems.

[0003] In the design process of T / R components in the millimeter wave and terahertz frequency bands, it is necessary to design a suitable passive structure to realize the interconnection of active and passive devices in the system, so as to realize the transformation of the transmission mode of electromagnetic signals in the wireless communication system, and complete the high integration and miniaturization design of the overall system. HTCC high temperature co-fired ceramic multilayer wiring technology has the advantages of high integration, high airtightness and small volume, which is consistent with the characteristics of high frequency and short wavelength of millimeter wave and terahertz signals, so it is widely used in the design of miniaturization of millimeter wave and terahertz T / R components. For the interconnection of active and passive devices or structures in the same plane, traditional microstrip lines, strip lines, coplanar waveguides and other structures can be used to realize the transformation of electromagnetic signal modes; for the interconnection of active and passive devices in different planes and vertical directions, connectors such as wool buttons or vertical transmission structures such as coaxial and rectangular metal waveguides can be used to realize the interconnection of structures and complete the transmission of millimeter wave and terahertz signals in the vertical direction.

[0004] There are several common ways to transmit millimeter-wave and terahertz signals between different planes: The first method is to use a microstrip line to a quasi-coaxial structure to complete the transformation of the electromagnetic signal from a quasi-TEM wave to a standard TEM wave mode. Since the electromagnetic signal frequency is high and the wavelength is short in the millimeter-wave and terahertz frequency bands, the spacing between the central transmission via and the surrounding isolation vias is extremely small, thereby ensuring the single-mode transmission of the electromagnetic signal in the quasi-coaxial, which greatly increases the difficulty of design and process. The second method uses a microstrip line to a rectangular waveguide probe structure. However, this structure uses two different materials, a microstrip substrate and a metal cavity, and because the structure requires a waveguide short-circuit surface structure, the overall integration is low and the size is large. Summary of the invention

[0005] The purpose of the present invention is to provide a transmission structure for transmitting millimeter waves and terahertz signals in a vertical direction, so as to solve the technical problem of being unable to achieve high integration and miniaturization of T / R components and wireless communication systems.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] A transmission structure for transmitting millimeter waves and terahertz signals in a vertical direction, comprising: a grounded coplanar waveguide, an electromagnetic coupling structure and a vertical substrate integrated waveguide; the grounded coplanar waveguide is located at the top and bottom layers of the transmission structure, serving as an input port and an output port respectively, and an electromagnetic coupling structure is provided on the grounded coplanar waveguide; the electromagnetic coupling structure is used for impedance matching and electromagnetic signal mode conversion; the vertical substrate integrated waveguide performs single-mode transmission of electromagnetic signals in a vertical direction through multi-layer stacking of grounded through holes.

[0008] Preferably, the electromagnetic coupling structure comprises a matching pad and an anti-pad, and the matching pad and the anti-pad convert the quasi-TEM mode into a TE mode through coupling. 10 mold.

[0009] Preferably, the matching pad is located above the center of the vertical substrate integrated waveguide.

[0010] Preferably, the matching pad is located at a half of the narrow side of the vertical substrate integrated waveguide.

[0011] Preferably, a metal coupling wall structure is provided below the matching pad.

[0012] Preferably, the electromagnetic coupling structure further comprises a grounding hole, and the grounding hole is connected to the anti-pad and the lower ground plane structure.

[0013] Preferably, the diameter of the grounding holes is 0.06 mm, and the spacing between the grounding holes is 0.15 mm.

[0014] Preferably, each substrate layer of the vertical substrate integrated waveguide comprises a single-layer ceramic substrate and a single-layer metal, wherein the thickness of the single-layer ceramic substrate is greater than that of the single-layer metal.

[0015] Preferably, the thickness of the single-layer ceramic substrate is 0.1 mm, and the thickness of the single-layer metal is 0.01 mm.

[0016] Preferably, the above-mentioned single-layer ceramic substrate adopts a KCH90 ceramic substrate medium with a dielectric constant of 8.7.

[0017] In the present invention, a grounded coplanar waveguide is located at the top and bottom layers of a transmission structure, serving as an input port and an output port respectively, and an electromagnetic coupling structure is arranged on the grounded coplanar waveguide; the electromagnetic coupling structure is used for impedance matching and electromagnetic signal mode conversion; the vertical substrate integrated waveguide performs single-mode transmission of electromagnetic signals in a vertical direction through multi-layer stacking of grounded through holes, and a horizontal coupling structure is used to realize mode conversion from the grounded coplanar waveguide to the vertical substrate integrated waveguide, and the vertical transmission of millimeter-wave and terahertz signals is realized through the vertical substrate integrated waveguide. Compared with the traditional metal cavity transmission structure, it has a higher degree of integration, and at the same time greatly reduces the difficulty of processing and assembly, greatly reduces the size and volume of the vertical transmission structure of millimeter-wave and terahertz signals, and the overall structure has a higher degree of integration and flexibility, which solves the technical problem that high integration and miniaturization of T / R components and wireless communication systems cannot be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a transmission structure for transmitting millimeter waves and terahertz signals in a vertical direction in an embodiment of the present invention;

[0019] Figure 2 is a cross-sectional schematic diagram of a transmission structure for vertically transmitting millimeter wave and terahertz signals in an embodiment of the present invention;

[0020] Figure 3 is a top view schematic diagram of a transmission structure for vertically transmitting millimeter wave and terahertz signals in an embodiment of the present invention;

[0021] Figure 4 It is a simulation schematic diagram of a transmission structure for transmitting millimeter waves and terahertz signals in a vertical direction in an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are all in very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0023] It should be noted that, in order to clearly explain the content of the present invention, the present invention specifically cites multiple embodiments to further illustrate different implementations of the present invention, wherein the multiple embodiments are enumerated rather than exhaustive. In addition, for the sake of brevity of explanation, the contents mentioned in the previous embodiments are often omitted in the subsequent embodiments. Therefore, the contents not mentioned in the subsequent embodiments can refer to the previous embodiments accordingly.

[0024] Example 1

[0025] A transmission structure for transmitting millimeter waves and terahertz signals in a vertical direction, the transmission structure comprising: a grounded coplanar waveguide, an electromagnetic coupling structure and a vertical substrate integrated waveguide; the grounded coplanar waveguide is located at the top and bottom layers of the transmission structure, serving as an input port and an output port respectively, and an electromagnetic coupling structure is arranged on the grounded coplanar waveguide; the electromagnetic coupling structure is used for impedance matching and electromagnetic signal mode conversion; the vertical substrate integrated waveguide performs single-mode transmission of electromagnetic signals in a vertical direction through multi-layer stacking of grounded through holes.

[0026] Not limited to Figure 1 As shown, the transmission structure is a grounded coplanar waveguide-vertical substrate integrated waveguide-grounded coplanar waveguide (GCPW-VSIW-GCPW) structure, including a grounded coplanar waveguide (GCPW), an electromagnetic coupling structure and a vertical substrate integrated waveguide (VSIW), and the vertical substrate integrated waveguide (VSIW) includes a HTCC multilayer ceramic substrate.

[0027] By using the GCPW structure as the input and output port, effective electromagnetic shielding and confinement of millimeter-wave terahertz signals can be achieved.

[0028] As an optional implementation, each substrate layer of the vertical substrate integrated waveguide includes a single-layer ceramic substrate and a single-layer metal, wherein the thickness of the single-layer ceramic substrate is greater than that of the single-layer metal.

[0029] The multi-layer substrate is not limited to the integrated design, but can realize electromagnetic signal mode conversion and impedance matching, greatly improving the integration and design flexibility of millimeter wave and terahertz circuits.

[0030] As an optional implementation, the thickness of the single-layer ceramic substrate is 0.1 mm, and the thickness of the single-layer metal is 0.01 mm.

[0031] As an optional implementation, the single-layer ceramic substrate uses a KCH90 ceramic substrate medium with a dielectric constant of 8.7.

[0032] As an optional implementation, the electromagnetic coupling structure includes a matching pad and an anti-pad, and the matching pad and the anti-pad convert the quasi-TEM mode into a TE mode through coupling. 10 mold.

[0033] As an optional embodiment, the matching pad is located above the center of the vertical substrate integrated waveguide.

[0034] As an optional implementation, the matching pad is located at a half of the narrow side of the vertical substrate integrated waveguide.

[0035] As an optional implementation, a metal coupling wall structure is disposed under the matching pad.

[0036] As an optional implementation, the electromagnetic coupling structure further includes a grounding hole, wherein the grounding hole is connected to the anti-pad and the lower ground plane structure.

[0037] As an optional implementation, the diameter of the grounding hole is 0.06 mm, and the spacing between the grounding holes is 0.15 mm.

[0038] Not limited to Figure 2 , Figure 3 As shown in the figure, through the coupling structure composed of matching pads, anti-pads and the ground plane under the GCPW, impedance matching and electromagnetic signal conversion from quasi-TEM mode in GCPW to TE mode in VSIW can be completed without the need for a "short circuit" structure. 10 mold.

[0039] In the GCPW structure, the single-layer metal wide side and narrow side constitute the "defective ground" structure, and the multi-layer "defective ground" structure and the grounding vias surrounding it constitute the VSIW structure. The matching pad is located above the center of the VSIW, and its position is half of the narrow side of the VSIW. A metal coupling wall structure is set under the matching pad.

[0040] Specifically, the transmission structure for vertical transmission of millimeter wave and terahertz signals is based on the grounded coplanar waveguide-vertical substrate integrated waveguide-grounded coplanar waveguide (GCPW-VSIW-GCPW) structure, including a grounded coplanar waveguide (GCPW), an electromagnetic coupling structure and a vertical substrate integrated waveguide (VSIW). The vertical substrate integrated waveguide (VSIW) uses a KCH90 ceramic substrate medium with a dielectric constant of 8.7, a single-layer ceramic substrate thickness of 0.1 mm, a single-layer metal thickness of 0.01 mm, a grounding hole diameter of 0.06 mm, and a grounding hole spacing of 0.15 mm, to achieve effective isolation and electromagnetic shielding of millimeter wave and terahertz signals. The grounded coplanar waveguide (GCPW) structure is used as the input and output port. The electromagnetic signal is transmitted in the quasi-TEM mode in the GCPW structure. The terminal open circuit and the lower coupling surface structure couple the electromagnetic signal to the lower VSIW structure, thereby achieving impedance matching of the two different structures and completing the conversion of the quasi-TEM mode in the GCPW into the TE in the VSIW without a "short circuit" structure. 10 Transmit the main mode, while reducing the impedance discontinuity and transmission loss caused by different transmission structures, and reducing the difficulty of design and processing. Among them, the VSIW structure is stacked by multiple layers of "defective ground" and its surrounding grounding via structures. The wide and narrow side dimensions of the single-layer "defective ground" structure are calculated to ensure single-mode transmission in the VSIW structure.

[0041] The embodiment of the present application adopts a GCPW-VSIW-GCPW integrated structural design so that electromagnetic signals are transmitted in the same material, replacing the traditional microstrip substrate-metal waveguide probe transmission structure, thereby improving system integration and ensuring the airtight design requirements during the use of the T / R component; at the same time, a planar coupling structure is designed to replace the waveguide probe short-circuit surface structure, reducing the overall size of the system and realizing the miniaturized design of the T / R component. At the same time, the design difficulty and processing and assembly precision requirements of traditional millimeter wave and terahertz T / R components are greatly reduced, and it has great engineering application value in millimeter wave and terahertz circuit design.

[0042] In the field simulation software HFSS, the following Figure 1 The GCPW-VSIW-GCPW transmission structure shown in the figure. GCPW is used as the input and output port of the electromagnetic signal, and the terminal is an open-circuit branch. The electromagnetic coupling structure composed of the matching pad, the anti-pad and the lower ground plane completes the impedance matching of GCPW and VSIW and transmits the electromagnetic signal in GCPW to the VSIW structure. A back-to-back design is adopted, and the electromagnetic coupling structure is also used at the bottom of VSIW to complete the vertical transmission of the electromagnetic signal from VSIW to the GCPW output port, thereby realizing the transmission of electromagnetic signals in different planes. Not limited to Figure 4 The electromagnetic simulation results given show that the overall reflection coefficient S11 of the vertical transmission structure at the port is less than -20dB at 90-110GHz, which indicates that the structure has good RF transmission performance.

[0043] In the embodiment of the present application, vertical transmission between layers of millimeter wave and terahertz signals is realized through a grounded coplanar waveguide-substrate integrated waveguide-grounded coplanar waveguide structure. Based on the traditional design concept of substrate integrated waveguide in the horizontal direction, it is extended in the vertical direction to realize the transmission of millimeter wave and terahertz signals in the vertical direction. The use of a new horizontal coupling structure realizes the mode transition of the field from grounded coplanar waveguide (GCPW) to vertical substrate integrated waveguide (VSIW), and the transmission of millimeter wave and terahertz signals in the vertical direction is realized in the form of substrate integrated waveguide. Compared with the traditional metal cavity transmission structure, it has a higher degree of integration, the difficulty of processing and assembly is greatly reduced, the design process is simpler, and the size and volume of the vertical transmission structure of millimeter wave and terahertz signals are greatly reduced. In addition, the design of the overall system has a higher degree of integration and flexibility.

Claims

1. A transmission structure for transmitting millimeter wave and terahertz signals in a vertical direction, characterized in that: include: Grounded coplanar waveguides, electromagnetically coupled structures, and vertical substrate integrated waveguides; The grounded coplanar waveguide is located at the top layer and the bottom layer of the transmission structure, serving as an input port and an output port respectively, and an electromagnetic coupling structure is provided on the grounded coplanar waveguide; The electromagnetic coupling structure is used for impedance matching and electromagnetic signal mode conversion; The vertical substrate integrated waveguide performs single-mode transmission of electromagnetic signals in a vertical direction through multi-layer stacking of ground vias.

2. The transmission structure for vertically transmitting millimeter waves and terahertz signals according to claim 1, characterized in that: The electromagnetic coupling structure includes a matching pad and an anti-pad, wherein the matching pad and the anti-pad convert the quasi-TEM mode into a TE mode through coupling. 10 mold.

3. The transmission structure for vertically transmitting millimeter waves and terahertz signals according to claim 2, characterized in that: The matching pad is located over the center of the vertical substrate integrated waveguide.

4. The transmission structure for vertically transmitting millimeter waves and terahertz signals according to claim 3, characterized in that: The matching pad is located at a half of the narrow side of the vertical substrate integrated waveguide.

5. The transmission structure for vertically transmitting millimeter waves and terahertz signals according to claim 1, characterized in that: A metal coupling wall structure is arranged below the matching pad.

6. The transmission structure for vertically transmitting millimeter waves and terahertz signals according to claim 2, characterized in that: The electromagnetic coupling structure further includes a grounding hole, wherein the grounding hole is connected to the anti-pad and a lower ground plane structure.

7. The transmission structure for vertically transmitting millimeter waves and terahertz signals according to claim 6, characterized in that: The diameter of the grounding hole is 0.06 mm, and the spacing between the grounding holes is 0.15 mm.

8. The transmission structure for vertically transmitting millimeter waves and terahertz signals according to claim 1, characterized in that: Each substrate layer of the vertical substrate integrated waveguide includes a single-layer ceramic substrate and a single-layer metal, wherein the thickness of the single-layer ceramic substrate is greater than that of the single-layer metal.

9. The transmission structure for vertically transmitting millimeter waves and terahertz signals according to claim 8, characterized in that: The thickness of the single-layer ceramic substrate is 0.1 mm, and the thickness of the single-layer metal is 0.01 mm.

10. The transmission structure for vertically transmitting millimeter waves and terahertz signals according to claim 8, characterized in that: The single-layer ceramic substrate adopts a KCH90 ceramic substrate medium with a dielectric constant of 8.7.

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