Ridge-added substrate integrated waveguide transmission structure for W wave band

Abstract

The invention relates to a ridged substrate integrated waveguide transmission structure for a W wave band, which belongs to the technical field of electronics, and is characterized in that a printed board stack is formed by a single or a plurality of substrates, the top layer and the bottom layer of each substrate are made of metal, and the substrates are provided with rectangular waveguide cavities which are the same in size and correspond to the rectangular waveguide cavities in position, the bottom layer of the lowermost substrate of the lowermost printed board is a grounded all-metal layer, and the top layer of the uppermost substrate of the lowermost printed board is provided with a lower feed port connected with the lower microstrip line; the uppermost printed board is of a double-ridge structure, the double ridges are oppositely arranged on the two long sides of the rectangular waveguide cavity, and one ridge on the top layer of the uppermost substrate of the uppermost printed board is provided with a feed port connected with the upper microstrip line; metal through holes are uniformly formed in the edge of the rectangular waveguide cavity of each layer of printed board, and the printed boards are welded into a whole through metal layers around the waveguide cavities, so that the problem that an existing waveguide structure for transmitting W-band signals in the prior art cannot give consideration to high integration level, low transmission loss and electromagnetic leakage prevention is solved.

Description

Technical Field

[0001] This invention relates to the field of electronic technology, and more particularly to a ridged substrate integrated waveguide transmission structure for W-band. Background Technology

[0002] The W-band, with its relatively large bandwidth, short wavelength, strong anti-interference capability, and high frequency, has broad application prospects in high-speed communication and other fields, and has always been a research hotspot in the industry. Ridged substrate integrated waveguide (RSIW) structures have the characteristics of low loss, high power handling capability, and good electromagnetic shielding performance, and are often used in communication systems and equipment in the microwave and millimeter-wave bands.

[0003] In the existing technology, although metal waveguide components have good transmission performance in the W-band, their closed structure leads to reduced integration and large space occupation. While microstrip circuits have advantages such as easy processing and high integration, they are basically semi-open structures, which can easily lead to electromagnetic leakage and high transmission loss.

[0004] Therefore, how to balance high integration, low transmission loss, and electromagnetic leakage in waveguide structures used to transmit W-band electromagnetic signals has always been a difficult problem for the industry. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a ridged substrate integrated waveguide transmission structure for W-band, in order to solve the problems that existing waveguide structures for transmitting W-band signals cannot simultaneously achieve high integration, low transmission loss, and avoid electromagnetic leakage.

[0006] On one hand, embodiments of the present invention provide a ridged substrate integrated waveguide transmission structure for the W-band. The structure includes multiple stacked printed circuit boards (PCBs), each PCB being constructed from multiple substrate layers. The top and bottom layers of each substrate are metal, and the middle layers are non-metallic.

[0007] The bottommost printed circuit board has a rectangular waveguide cavity on the top layer of the bottommost substrate and the top and bottom metal layers of the other substrates. The upper edge of the rectangular waveguide cavity has a rectangular ridge. The lower long edge of the waveguide cavity on the top layer of the top substrate of the bottommost printed circuit board has a bottom feed port.

[0008] The top and bottom layers of each substrate of the remaining printed circuit boards are provided with rectangular waveguide cavities with the same length and width as the waveguide cavity of the bottommost printed circuit board and corresponding to the position. The uppermost printed circuit board has rectangular ridges of the same size and facing each other on the upper and lower long sides of the waveguide cavity of each substrate. The uppermost printed circuit board has an upper feed port on one of the rectangular ridges on the uppermost substrate.

[0009] The printed circuit boards are sequentially metal-welded together through metal layers near the edge of the waveguide cavity.

[0010] Each layer of printed circuit board waveguide cavity is also provided with uniformly arranged metal through holes around its perimeter.

[0011] The beneficial effects of the above technical solution are as follows: In the waveguide transmission structure composed of multiple stacked printed circuit boards, each printed circuit board is composed of multiple substrates laminated together. The top and bottom layers of the substrates are metal layers. The bottom metal layer of the bottommost substrate of the bottommost printed circuit board is used for grounding. The top layer of the bottommost substrate and the metal layers of the remaining substrates are provided with rectangular waveguide cavities, bottom feed ports, and single-ridge structures, which can effectively realize signal feeding through microstrip lines. The top and bottom layers of the remaining substrates are provided with waveguide cavities with the same length and width as the waveguide cavity of the bottommost printed circuit board and corresponding in position. The printed circuit boards are formed into an integral structure by welding the metal layers at the edges of the waveguide cavities. The waveguide features uniformly arranged metal vias and rectangular double-ridge structures with identical dimensions and facing positions on the upper and lower long sides of the waveguide cavities of each layer of the uppermost printed circuit board. This provides a suitable electromagnetic field environment for signal transmission. The metal vias around the waveguide cavities form a good shielding structure, enabling W-band electromagnetic waves to be transmitted within the waveguide transmission structure without leakage. Furthermore, the waveguide transmission structure is tightly integrated with the printed circuit board, exhibiting high integration and occupying minimal space. Additionally, a feed port on a rectangular ridge at the top of the uppermost substrate can feed out electromagnetic signals by connecting microstrip lines, solving the problem that existing waveguide structures for transmitting W-band signals cannot simultaneously achieve high integration, low transmission loss, and avoid electromagnetic leakage.

[0012] Based on the further improvement of the above structure, the upper and lower long sides of the waveguide cavity of each substrate of each printed circuit board other than the bottommost and topmost printed circuit boards are also provided with rectangular ridges of the same size and position as the rectangular ridges of each substrate of the topmost printed circuit board.

[0013] The beneficial effect of the above-mentioned further improvement scheme is that the waveguide cavity of each substrate of each printed circuit board other than the bottommost and topmost printed circuit boards is ridged, which makes it easier to adapt to different processing and application requirements during implementation.

[0014] Based on the further improvement of the above structure, by removing the metal at the corresponding position of the corresponding metal layer of each printed circuit board substrate, each rectangular waveguide cavity, each rectangular ridge, upper feed port, and lower feed port are obtained respectively.

[0015] The beneficial effects of the above-mentioned further improvement scheme are: by removing the metal at the corresponding position of the corresponding metal layer of each substrate of each printed circuit board, the rectangular waveguide cavity, the rectangular ridge, the upper feed port, and the lower feed port are obtained. This not only preserves the non-metallic layer of each substrate of each printed circuit board, making the overall waveguide transmission structure more stable after forming, but also reduces the processing difficulty.

[0016] Based on the further improvement of the above structure, the dimensions of each rectangular waveguide cavity and the rectangular ridge dimension in the structure are calculated through the following process, which specifically includes:

[0017] S31: Set the initial values ​​of the long side and wide side of the rectangular waveguide cavity, and the initial values ​​of the long side and wide side of the rectangular ridged cavity;

[0018] S32: The resonant frequency is calculated based on the initial values ​​of the long side and the wide side of the rectangular waveguide cavity, and the initial values ​​of the long side and the wide side of the rectangular ridge.

[0019] S33: The corresponding cutoff wavelength is then calculated based on the resonant frequency;

[0020] S34: Determine whether the cutoff wavelength meets the required W-band wavelength. If so, use the initial values ​​of the long side and the wide side of the rectangular waveguide cavity as the length of the long side and the width of the rectangular waveguide cavity, respectively, and use the initial values ​​of the long side and the wide side of the rectangular ridge as the length of the long side and the width of the rectangular ridge, respectively.

[0021] S35: Otherwise, adjust the length of the long side and the length of the wide side of the rectangular waveguide cavity, and the length of the long side and the length of the wide side of the rectangular ridge, and return to execute S32-S34 until the cutoff wavelength meets the requirements.

[0022] The beneficial effects of the above-mentioned further improvement scheme are: the long side length and wide side length of the rectangular waveguide cavity of the top and bottom printed circuit boards obtained by the above-mentioned further improvement scheme, as well as the long side length and wide side length of the corresponding rectangular ridge, can be used to obtain the corresponding rectangular waveguide cavity and rectangular ridge dimensions, and thus the waveguide structure obtained has the advantage of high integration.

[0023] Based on further improvements to the above structure, the resonant frequency is calculated using the following formula, based on the initial values ​​of the long and wide sides of the rectangular waveguide cavity, and the initial values ​​of the long and wide sides of the rectangular ridge:

[0024] In the formula,

[0025] f c ε is the resonant frequency, μ is the dielectric constant of the nonmetallic layer, and c is the magnetic permeability of the nonmetallic layer. fLet a1 be the length of the long side of the rectangular waveguide cavity, b1 be the length of the wide side of the rectangular waveguide cavity, a2 be the length of the long side of the rectangular waveguide cavity with ridge, and b2 be the length of the wide side of the rectangular waveguide cavity with ridge.

[0026] The beneficial effects of the above-mentioned further improvement scheme are: the resonant frequency of each waveguide cavity is obtained by calculation, which helps to obtain the waveguide cavity size and ridge size, and the corresponding waveguide has the advantage of high integration.

[0027] Based on further improvements to the above structure, the corresponding cutoff wavelength is calculated from the resonant frequency using the following formula, which is as follows:

[0028] In the formula, λ c This is the cutoff wavelength.

[0029] The beneficial effects of the above-mentioned further improvement scheme are: calculating the cutoff wavelength of each waveguide cavity helps to obtain the waveguide cavity size and ridge size, and the corresponding waveguide has the advantage of high integration.

[0030] Based on a further improvement to the above structure, the edge capacitance at the corner of the rectangle with its ridge is calculated using the following formula:

[0031] In the formula,

[0032] The beneficial effects of the above-mentioned further improvement scheme are: by obtaining the edge capacitance at the corner of the rectangular ridge of the uppermost substrate and the lowermost substrate respectively, it is helpful to obtain the waveguide cavity size and ridge size, and the corresponding waveguide obtained has the advantage of high integration.

[0033] Based on the further improvement of the above structure, the top power supply port provided on a rectangular ridge on the top layer of the uppermost printed circuit board specifically includes a pad and a microstrip line, wherein the pad and the microstrip line are integrally formed; wherein, one of the metal through holes of the uppermost printed circuit board is located at the center of the pad.

[0034] The beneficial effects of the above-mentioned further improvement scheme are: the feed port set on the top layer of the top substrate of the top printed circuit board can be connected to the microstrip line to bring out electromagnetic signals, and by setting a metal through hole in the center of the pad, the conversion of different forms of electric field can be realized, so as to achieve good matching of signal from waveguide cavity to microstrip line structure.

[0035] Based on the further improvement of the above structure, the spacing of the metal vias is adjusted through the following steps, the specific steps of which include:

[0036] Electromagnetic simulation of the waveguide transmission structure is performed based on preset aperture, preset spacing, long and wide side lengths of rectangular waveguide cavity, and long and wide side lengths of rectangular ridged cavity, and magnetic field distribution map is output.

[0037] If the magnetic field distribution map shows magnetic field leakage, adjust the hole spacing until the magnetic field distribution map output by simulation shows no magnetic field leakage. Then, based on the preset hole diameter and the adjusted hole spacing, set metal through holes around the edge of the substrate waveguide cavity.

[0038] The beneficial effect of the above-mentioned further improvement scheme is that it enables the rectangular waveguide cavities of each substrate to obtain a metal through-hole distribution structure with good shielding effect.

[0039] On the other hand, embodiments of the present invention also provide a waveguide, the waveguide including a ridged substrate integrated waveguide transmission structure for W-band disclosed in embodiments of the present invention.

[0040] The beneficial effects of the above technical solution are as follows: The waveguide provided by the embodiments of the present invention not only has the characteristics of high integration, but also can transmit W-band signals with low transmission loss and no electromagnetic leakage.

[0041] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0042] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0043] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention;

[0044] Figure 2 This is a schematic diagram of the bottom printed circuit board structure in an embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram of the uppermost printed circuit board structure in an embodiment of the present invention;

[0046] Figure 4 This is a schematic diagram showing the dimensions of the bottommost substrate of the bottommost printed circuit board, as a specific example of an embodiment of the present invention.

[0047] Figure 5 This is a schematic diagram showing the dimensions of the topmost substrate of the topmost printed circuit board, which is a specific example of an embodiment of the present invention. Detailed Implementation

[0048] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0049] Example 1:

[0050] A specific embodiment of the present invention discloses a ridged substrate integrated waveguide transmission structure for the W-band, such as... Figure 1 As shown.

[0051] The structure includes multiple stacked printed circuit boards, each composed of multiple laminated substrates. The top and bottom layers of each substrate are metal, while the middle layers are non-metallic.

[0052] The bottommost printed circuit board has a rectangular waveguide cavity on the top layer of the bottommost substrate and the top and bottom metal layers of the other substrates. The upper edge of the rectangular waveguide cavity has a rectangular ridge. The lower long edge of the waveguide cavity on the top layer of the top substrate of the bottommost printed circuit board has a bottom feed port.

[0053] The top and bottom layers of each substrate of the remaining printed circuit boards are provided with rectangular waveguide cavities with the same length and width as the waveguide cavity of the bottommost printed circuit board and corresponding to the position. The uppermost printed circuit board has rectangular ridges of the same size and facing each other on the upper and lower long sides of the waveguide cavity of each substrate. The uppermost printed circuit board has an upper feed port on one of the rectangular ridges on the uppermost substrate.

[0054] Each layer of printed circuit board is connected by sequentially welding the metal layers around the edges of each waveguide cavity.

[0055] Each layer of printed circuit board waveguide cavity is also provided with uniformly arranged metal through holes around its perimeter.

[0056] In this embodiment, a waveguide transmission structure capable of transmitting W-band signals is provided by combining a ridged substrate integrated waveguide transmission structure with a microstrip line structure. The ridged substrate integrated waveguide transmission structure in this embodiment is composed of multiple layers of printed circuit boards (PCBs), wherein each PCB is composed of multiple substrate layers, with the top and bottom layers being metal layers and the middle layers being non-metallic layers. In this embodiment, there are no special limitations on the number of substrate layers, the shape of the PCBs, or whether the shapes of the PCBs constituting the ridged substrate integrated waveguide transmission structure are the same.

[0057] like Figure 2As shown, in this embodiment, the bottom metal layer of the bottommost substrate of the bottommost printed circuit board remains unchanged and is used for grounding and bottom electromagnetic shielding; the top and bottom waveguide cavities of the top layer of the bottommost substrate of the bottommost printed circuit board and the top and bottom layers of the other substrates are all single-ridge structures, specifically including: the top layer of the bottommost substrate of the bottommost printed circuit board and the top and bottom metal layers of the other substrates are all provided with rectangular waveguide cavities, and the upper edge of the rectangular waveguide cavity is provided with a rectangular ridge, wherein the lower long side of the top waveguide cavity of the top layer of the top substrate of the bottommost printed circuit board is provided with a bottom feed port.

[0058] like Figure 3 As shown, each layer of the uppermost printed circuit board is configured with a double-ridge structure. Specifically, it includes rectangular waveguide cavities with the same length and width as the waveguide cavity of the lowermost printed circuit board, and corresponding to the top and bottom layers of each layer of the uppermost printed circuit board. Each layer of the uppermost printed circuit board has rectangular ridges of the same size and facing each other on the upper and lower long sides of the waveguide cavity. One of the rectangular ridges on the upper surface of the uppermost printed circuit board has an upper feed port. This provides a simpler structure for field coupling between the waveguide structure and the microstrip line, making it easier to connect the feed port to the waveguide and simplifying the structure and electromagnetic matching of the waveguide.

[0059] Furthermore, the top feed port on a rectangular ridge on the top layer of the uppermost printed circuit board specifically includes a pad and a microstrip line, which are integrally formed.

[0060] Furthermore, by removing the metal at the corresponding positions of the corresponding metal layers of each printed circuit board substrate, each rectangular waveguide cavity, each rectangular ridge, upper feed port, and lower feed port are obtained respectively.

[0061] The top and bottom layers of each substrate of the remaining printed circuit boards (excluding the top and bottom layers) are respectively provided with rectangular waveguide cavities of the same length and width as the waveguide cavity of the bottom layer printed circuit board, and in corresponding positions. By stacking the printed circuit boards according to the corresponding positions of their rectangular waveguide cavities, a closed waveguide cavity structure is formed by the corresponding rectangular waveguide cavities of the printed circuit boards from bottom to top, which has the advantage of high integration compared to existing technologies.

[0062] The dimensions of each rectangular waveguide cavity and the rectangular ridge dimension in the structure are calculated through the following process, which specifically includes:

[0063] S31: Set the initial values ​​of the long side and wide side of the rectangular waveguide cavity, and the initial values ​​of the long side and wide side of the rectangular ridged cavity;

[0064] S32: The resonant frequency is calculated based on the initial values ​​of the long side and the wide side of the rectangular waveguide cavity, and the initial values ​​of the long side and the wide side of the rectangular ridge.

[0065] S33: The corresponding cutoff wavelength is then calculated based on the resonant frequency;

[0066] S34: Determine whether the cutoff wavelength meets the required W-band wavelength. If so, use the initial values ​​of the long side and the wide side of the rectangular waveguide cavity as the length of the long side and the width of the rectangular waveguide cavity, respectively, and use the initial values ​​of the long side and the wide side of the rectangular ridge as the length of the long side and the width of the rectangular ridge, respectively.

[0067] S35: Otherwise, adjust the length of the long side and the length of the wide side of the rectangular waveguide cavity, and the length of the long side and the length of the wide side of the rectangular ridge, and return to execute S32-S34 until the cutoff wavelength meets the requirements.

[0068] In principle, in this embodiment, the rectangular ridges of both the uppermost and lowermost printed circuit boards are positive ridge waveguide structures. The electric field structure of the transmitted electromagnetic wave is more concentrated on the protruding parts of the rectangular ridges, with non-uniform electric fields at the corners of the ridges. The magnetic field is more concentrated on both sides of the ridges. When the operating wavelength of the transmitted electromagnetic wave signal equals the cutoff wavelength, there is no axial energy transmission of the electromagnetic wave; it only reflects back and forth between the two side walls of the waveguide cavity, forming a transverse resonance. The corresponding frequency at this time is the resonant frequency, which is also the cutoff frequency. Therefore, there is a corresponding relationship between the dimensions of the rectangular waveguide cavity, the dimensions of the rectangular ridges, and the cutoff wavelength and resonant frequency of the transmitted electromagnetic wave.

[0069] In this embodiment, since the cutoff wavelength of the W-band signal is a known quantity, the length and width of the rectangular waveguide cavity of each substrate constituting the ridged substrate integrated waveguide transmission structure, as well as the length and width of the rectangular ridge, can be obtained by reverse derivation combined with simulation verification.

[0070] First, based on experience, set the initial values ​​of the long side and the wide side of the rectangular waveguide cavity on the current substrate, and the initial values ​​of the long side and the wide side of the rectangular ridge.

[0071] Furthermore, based on the initial values ​​of the long side and the wide side of the rectangular waveguide cavity, the initial values ​​of the long side and the wide side of the rectangular ridge are calculated using the following formula, which is as follows:

[0072] In the formula,

[0073] f c ε is the resonant frequency, μ is the dielectric constant of the nonmetallic layer, and c is the magnetic permeability of the nonmetallic layer. f Let a1 be the length of the long side of the rectangular waveguide cavity, b1 be the length of the wide side of the rectangular waveguide cavity, a2 be the length of the long side of the rectangular waveguide cavity with ridge, and b2 be the length of the wide side of the rectangular waveguide cavity with ridge.

[0074] The dielectric constant ε and permeability μ of the non-metallic layer are known quantities. The lengths a1 (long side) and b1 (wide side) of the rectangular waveguide cavity, a2 (long side) and b2 (wide side) of the rectangular waveguide cavity with ridge have all been given initial values ​​and are also known quantities. Substituting these values ​​into the formula for calculating the resonant frequency yields the resonant frequency f. c The edge capacitance c at the corners of the rectangle and the ridge f The relational expression.

[0075] Furthermore, the edge capacitance at the corner of the rectangle plus the ridge is calculated using the following formula:

[0076] In the formula,

[0077] Furthermore, the corresponding cutoff wavelength is calculated based on the resonant frequency using the following formula, which is as follows:

[0078] In the formula, λ c This is the cutoff wavelength.

[0079] Substituting the formulas for calculating the edge capacitance at the corners of the rectangle with added ridges and the formula for calculating the corresponding cutoff wavelength into the formula for calculating the resonant frequency, the cutoff wavelength λ is obtained. c Given the relationships between the lengths of the long side (a1), the wide side (b1), the long side (a2), and the wide side (b2) of the rectangular waveguide cavity with ridge, and based on the initial values ​​of a1, b1, a2, and b2, the cutoff wavelength λ can be obtained. c .

[0080] Next, the cutoff wavelength λ is determined. c If the wavelength is the same as the W-band signal wavelength, then the initial values ​​of the long side length, wide side length, long side length of the rectangular waveguide cavity, and wide side length of the rectangular ridge are used as the length and width of the rectangular waveguide cavity and the length and width of the rectangular ridge on the current printed circuit board; otherwise, based on the cutoff wavelength λ... c The relationships between the long side length a1, the wide side length b1, the long side length a2, and the wide side length b2 of the rectangular waveguide cavity with ridge are used to adjust these lengths until the calculated cutoff wavelength λ is obtained. c If the wavelength is the same as that of the W-band signal, then the length and width of the long side of the corresponding rectangular waveguide cavity, and the length and width of the long side of the rectangular ridge are used as the length and width of the rectangular waveguide cavity and the length and width of the rectangular ridge of the current printed circuit board.

[0081] In this embodiment, the length and width of the rectangular waveguide cavities of each substrate layer of each printed circuit board are the same. The difference is that the bottommost printed circuit board is a single-ridge rectangular cavity with a ridge, and the topmost printed circuit board is a double-ridge rectangular cavity with a ridge. Therefore, the length and width of the rectangular waveguide cavities, as well as the length and width of the rectangular ridges of the corresponding substrate layers in the corresponding printed circuit board, can be obtained first from the bottommost or topmost printed circuit board. Then, based on the obtained length and width of the rectangular waveguide cavities, the length and width of the rectangular ridges of the substrate layers of the remaining printed circuit boards can be obtained based on the same principle.

[0082] In a preferred embodiment of this example, the waveguide cavities of each substrate of each printed circuit board other than the bottommost and topmost printed circuit boards are further provided with rectangular ridges of the same size and position as the rectangular ridges of each substrate of the topmost printed circuit board.

[0083] Specifically, the specific implementation methods of this embodiment can be flexibly combined as needed. Based on the correspondence between the cutoff wavelength and the length and width of the rectangular waveguide cavity, and the length and width of the rectangular ridge, the theoretical derived values ​​of the length and width of the rectangular waveguide cavity and the rectangular ridge can be obtained by calculating and deriving the dielectric constant and magnetic permeability of the non-metallic materials used in each printed circuit board and each substrate.

[0084] Next, metal welding is required around the metal layers at the edges of the rectangular waveguide cavities between each printed circuit board layer.

[0085] The purpose of metal welding around the edges of the rectangular waveguide cavities on each printed circuit board is to connect the waveguide cavities of each printed circuit board into a whole, ensuring structural stability.

[0086] Optionally, metal welding can be performed by evenly arranging solder balls with gaps around the rectangular waveguide cavity, or by using a fully enclosed welding method. If the solder balls are arranged, the spacing between the solder balls can be set according to the minimum requirements of the substrate design and processing technology. Then, simulation debugging can be used to detect whether there is magnetic field leakage in the arranged solder balls. If there is magnetic field leakage, it can be gradually adjusted by reducing the gap until the magnetic field leakage is eliminated.

[0087] Furthermore, uniformly arranged metal through holes are provided around the edges of the waveguide cavities of each layer of printed circuit boards. Metal is electroplated in the metal through holes, and the waveguide cavities of each layer are connected through the metal.

[0088] Specifically, in the substrate integrated waveguide transmission structure, by uniformly arranging metal vias around the waveguide cavity, on the one hand, the metal vias connect the upper and lower metal layers of each printed circuit board, and on the other hand, the uniformly arranged metal vias form electromagnetic shielding in the non-metallic layers between the metal layers of the substrate, effectively preventing electromagnetic leakage.

[0089] Furthermore, the spacing between metal vias is adjusted through the following steps, specifically including:

[0090] Electromagnetic simulation of the waveguide transmission structure is performed based on preset aperture, preset spacing, long and wide side lengths of rectangular waveguide cavity, and long and wide side lengths of rectangular ridged cavity, and magnetic field distribution map is output.

[0091] If the magnetic field distribution map shows magnetic field leakage, adjust the hole spacing until the magnetic field distribution map output by simulation shows no magnetic field leakage. Then, based on the preset hole diameter and the adjusted hole spacing, set metal through holes around the edge of the substrate waveguide cavity.

[0092] The preset aperture and preset spacing depend on the minimum processing requirements of the substrate.

[0093] One of the metal vias on the topmost printed circuit board is located at the center of the pad. The purpose is to convert the electromagnetic field within the waveguide into a magnetic field mode that can be transmitted through the microstrip line.

[0094] This embodiment discloses a ridged substrate integrated waveguide transmission structure composed of multiple stacked substrates. Each layer of the bottom printed circuit board (PCB) except the bottom layer of the bottom substrate has a rectangular waveguide cavity. A single-ridge rectangular ridge is positioned on the top layer of the top substrate of the bottom PCB and the upper long sides of the rectangular waveguide cavities on the top and bottom layers of the remaining substrates. A bottom feed port is provided on the lower long side of the top layer of the bottom substrate of the bottom PCB, connecting to a microstrip line. The W-band signal fed in is then transmitted through rectangular waveguide cavities of the intermediate PCBs, with the same dimensions and corresponding positions as the rectangular waveguide cavity of the bottom PCB, to the top PCB. The top PCB has rectangular waveguide cavities of the same dimensions and corresponding positions as the rectangular waveguide cavity of the bottom PCB. The corresponding rectangular waveguide cavity has double-ridged rectangular ridges on the upper and lower long sides of the rectangular waveguide cavity of each substrate of the uppermost printed circuit board. The feed port on the top rectangular ridge of the uppermost substrate of the uppermost printed circuit board receives the transmitted W-band signal and then outputs it through the connected microstrip line. The metal welding structure with metal layers around the edges of the rectangular waveguide cavities between each printed circuit board, and the metal through holes around the rectangular waveguide cavities of each printed circuit board, form a good shielding structure, which enables the W-band signal to be transmitted without leakage in the waveguide transmission structure provided in this embodiment. This solves the problem that the waveguide structure for transmitting W-band signals in the prior art cannot simultaneously achieve high integration, low transmission loss, and avoid electromagnetic leakage.

[0095] like Figure 4 , Figure 5As shown in the actual example of this embodiment, a ridged substrate integrated waveguide is composed of two printed circuit boards stacked together. The waveguide dimensions are 3mm*3mm*1.184mm, the solder ball diameter between the two printed circuit boards is 0.5mm, the waveguide cavity dimensions are 1.9mm*1.1mm*1.184mm, the center-to-center distance of the metal vias is approximately 0.3mm, the distance from the center of the metal via to the outer frame of the waveguide is 0.15mm, and the diameter of the metal via is 0.1mm.

[0096] Figure 4 The dimensions and structure of the bottom printed circuit board in the actual example are shown. Specifically, the bottom feed port pattern consists of two connected rectangles. The rectangle located in the middle of the waveguide cavity has dimensions of 0.6mm*0.35mm. The other rectangle, which connects to the rectangle located in the middle of the waveguide cavity, has dimensions of 1.1mm*0.16mm and is used to connect the microstrip line. The distance between the rectangle located in the middle of the waveguide cavity and the ridge is 0.15mm. The ridge has dimensions of 0.15*0.6mm.

[0097] Figure 5 The dimensions and structure of the top printed circuit board in the actual example are shown. Specifically, the pad radius in the top power supply port is 0.2mm, and the microstrip line connecting the pad is 0.2mm*1mm in size. In the double-ridge structure, the rectangular ridge is 0.3mm*0.7mm in size, and the metal via at the center of the pad has a radius of 0.25mm.

[0098] Example 2:

[0099] A second specific embodiment of the present invention discloses a waveguide for transmitting W-band signals. The waveguide includes the ridged substrate integrated waveguide transmission structure for W-band described in Embodiment 1. Embodiment 2 includes all the technical features of Embodiment 1.

[0100] The waveguide provided in this embodiment, compared with the prior art, not only has the characteristics of high integration, but also can transmit W-band signals with low loss and no electromagnetic leakage.

[0101] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0102] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A ridged substrate integrated waveguide transmission structure for the W-band, characterized in that, The structure includes multiple stacked printed circuit boards, each composed of multiple laminated substrates. The top and bottom layers of each substrate are metal, while the middle layers are non-metallic. The bottommost printed circuit board has a rectangular waveguide cavity on the top layer of the bottommost substrate and the top and bottom metal layers of the other substrates. The upper edge of the rectangular waveguide cavity has a rectangular ridge. The lower long edge of the waveguide cavity on the top layer of the top substrate of the bottommost printed circuit board has a bottom feed port. The top and bottom layers of each substrate of the remaining printed circuit boards are provided with rectangular waveguide cavities with the same length and width as the waveguide cavity of the bottommost printed circuit board and corresponding to the position. The uppermost printed circuit board has rectangular ridges of the same size and facing each other on the upper and lower long sides of the waveguide cavity of each substrate. The uppermost printed circuit board has an upper feed port on one of the rectangular ridges on the uppermost substrate. The printed circuit boards are sequentially metal-welded together through metal layers near the edge of the waveguide cavity. Each layer of printed circuit board waveguide cavity is also provided with uniformly arranged metal through holes around its perimeter.

2. The ridged substrate integrated waveguide transmission structure for W-band according to claim 1, characterized in that, The waveguide cavities of each substrate of each printed circuit board other than the bottommost and topmost printed circuit boards are provided with rectangular ridges of the same size and position as the rectangular ridges of each substrate of the topmost printed circuit board.

3. The ridged substrate integrated waveguide transmission structure for W-band according to claim 2, characterized in that, By removing the metal at the corresponding positions of the corresponding metal layers of each printed circuit board substrate, the rectangular waveguide cavities, the rectangular ridges, the upper feed port, and the lower feed port are obtained respectively.

4. The ridged substrate integrated waveguide transmission structure for W-band according to claim 3, characterized in that, The dimensions of each rectangular waveguide cavity and the rectangular ridge dimension in the structure are calculated through the following process, which specifically includes: S31: Set the initial values ​​of the long side and wide side of the rectangular waveguide cavity, and the initial values ​​of the long side and wide side of the rectangular ridged cavity; S32: The resonant frequency is calculated based on the initial values ​​of the long side and the wide side of the rectangular waveguide cavity, and the initial values ​​of the long side and the wide side of the rectangular ridge. S33: The corresponding cutoff wavelength is then calculated based on the resonant frequency; S34: Determine whether the cutoff wavelength meets the required W-band wavelength. If so, use the initial values ​​of the long side and the wide side of the rectangular waveguide cavity as the length of the long side and the width of the rectangular waveguide cavity, respectively, and use the initial values ​​of the long side and the wide side of the rectangular ridge as the length of the long side and the width of the rectangular ridge, respectively. S35: Otherwise, adjust the length of the long side and the length of the wide side of the rectangular waveguide cavity, and the length of the long side and the length of the wide side of the rectangular ridge, and return to execute S32-S34 until the cutoff wavelength meets the requirements.

5. A ridged substrate integrated waveguide transmission structure for W-band according to claim 4, characterized in that, Based on the initial values ​​of the long side and the wide side of the rectangular waveguide cavity, the initial values ​​of the long side and the wide side of the ridged rectangle are calculated using the following formula, which is as follows: f c ε is the resonant frequency, μ is the dielectric constant of the nonmetallic layer, and c is the magnetic permeability of the nonmetallic layer. f Let a1 be the length of the long side of the rectangular waveguide cavity, b1 be the length of the wide side of the rectangular waveguide cavity, a2 be the length of the long side of the rectangular waveguide cavity with ridge, and b2 be the length of the wide side of the rectangular waveguide cavity with ridge.

6. A ridged substrate integrated waveguide transmission structure for W-band according to claim 5, characterized in that, The corresponding cutoff wavelength is calculated based on the resonant frequency using the following formula, which is as follows: In the formula, λ c This is the cutoff wavelength.

7. A ridged substrate integrated waveguide transmission structure for W-band according to claim 6, characterized in that, The edge capacitance at the corner of the rectangle with its ridge is calculated using the following formula: In the formula, 8. A ridged substrate integrated waveguide transmission structure for W-band according to claim 7, characterized in that, The uppermost printed circuit board has an upper power supply port on a rectangular ridge on the top layer of the uppermost substrate, which specifically includes a pad and a microstrip line. The pad and the microstrip line are integrally formed. One of the metal through holes of the uppermost printed circuit board is located at the center of the pad.

9. A ridged substrate integrated waveguide transmission structure for W-band according to claim 8, characterized in that, The spacing between metal vias is adjusted by the following steps, which specifically include: Electromagnetic simulation of the waveguide transmission structure is performed based on preset aperture, preset spacing, long and wide side lengths of rectangular waveguide cavity, and long and wide side lengths of rectangular ridged cavity, and magnetic field distribution map is output. If the magnetic field distribution map shows magnetic field leakage, adjust the hole spacing until the magnetic field distribution map output by simulation shows no magnetic field leakage. Then, based on the preset hole diameter and the adjusted hole spacing, set metal through holes around the edge of the substrate waveguide cavity.

10. A waveguide for W-band signal transmission, characterized in that, The waveguide includes a ridged substrate integrated waveguide transmission structure for W-band as described in any one of claims 1-9.

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