Millimeter wave waveguide anti-leakage interface device

Abstract

The invention discloses a millimeter wave waveguide anti-leakage interface device. The device comprises a first rectangular waveguide and a PCB substrate. A first waveguide penetrating through the PCB substrate is arranged on the first side of the PCB substrate, and the center of a waveguide port of the first rectangular waveguide is aligned with the center of a waveguide port, located on the first side of the PCB substrate, of the first waveguide; a periodic structure is arranged around a waveguide port on a layer where a first side of a PCB substrate is located, and when electromagnetic waves are transmitted from a first rectangular waveguide to a first waveguide arranged on the PCB substrate through the waveguide port, the periodic structure forms an ideal magnetic wall PMC on a corresponding surface and surrounds the waveguide port, so that the electromagnetic waves are transmitted to the first waveguide through the waveguide port. The waveguide ports are used for preventing electromagnetic waves from leaking out from gaps between the waveguide ports, it is ensured that the electromagnetic waves are stably transmitted between the first rectangular waveguide and the first waveguide, the periodic structure is designed through the PCB technology, the structure is simple, the technology is mature, integration is convenient, the complexity and production difficulty of a waveguide antenna part mold are effectively reduced, and the production cost is reduced. Therefore, the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of millimeter wave radars, and in particular to a millimeter wave waveguide leakage prevention interface device. Background Art

[0002] With the rapid development of ADAS technology, while its functions and performance are becoming more and more powerful, the performance requirements of the sensors used are also getting higher and higher. As a very important sensor in the ADAS system, millimeter-wave radar inevitably puts forward new and higher requirements for its performance. Microstrip lines are widely used in millimeter-wave radars due to their low cost, simple processing, and easy integration. However, microstrip lines have large losses and narrow bandwidths, which seriously affect the detection performance of millimeter-wave radars. Therefore, replacing the original microstrip antenna with a waveguide antenna with low loss and large bandwidth naturally becomes an important direction for the performance breakthrough of 77GHz millimeter-wave radars. At present, more and more radar RF chips use LIP packaging technology, and the conventional RF transceiver BGA pins on the RF chip that were originally used to be attached to the PCB are changed to waveguide ports. After the RF chip is attached to the PCB, only the corresponding waveguide port is left on the other side of the PCB for connection with the waveguide antenna. However, because the waveguide antenna and PCB are two completely different production processes, when the waveguide ports of the two production processes are connected, there is usually a gap in the waveguide interface between the waveguide antenna and the PCB due to the production process, which leads to signal leakage, seriously affecting the transmission quality of the millimeter-wave signal.

[0003] Therefore, how to ensure the stable transmission of millimeter waves in the presence of gaps becomes an important issue that needs to be urgently solved in the application of waveguide antennas in millimeter-wave radars. Summary of the invention

[0004] The present invention proposes a millimeter wave waveguide leakage prevention interface device. When an electromagnetic wave propagates from a first rectangular waveguide through a waveguide port to a first waveguide arranged on a PCB substrate, a periodic structure forms an ideal magnetic wall PMC on a corresponding surface, surrounding the waveguide port, so as to prevent the electromagnetic wave from leaking out from a gap between the waveguide ports, thereby ensuring stable transmission of the electromagnetic wave between the first rectangular waveguide and the first waveguide. In addition, a PCB process is used to design the periodic structure, so the structure is simple, the process is mature, and it is easy to integrate. The complexity and production difficulty of a mold of a waveguide antenna part are also effectively reduced, thereby reducing the production cost.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0006] A millimeter wave waveguide leakage prevention interface device, the device comprising a first rectangular waveguide 1 and a PCB substrate 2;

[0007] The first rectangular waveguide 1 is disposed on the first side of the PCB substrate 2. The first side of the PCB substrate 2 is provided with a first waveguide 21 penetrating the PCB substrate 2. The center of the waveguide opening 11 of the first rectangular waveguide 1 is aligned with the center of the waveguide opening 211 of the first waveguide 21 located on the first side of the PCB substrate 2.

[0008] A periodic structure 22 is arranged around the waveguide opening 211 in the layer where the first side of the PCB substrate 2 is located. When the electromagnetic wave propagates from the first rectangular waveguide 1 through the waveguide opening 11 and the waveguide opening 211 to the first waveguide 21 arranged on the PCB substrate, the periodic structure 22 forms an ideal magnetic wall PMC on the corresponding surface, surrounding the waveguide opening 11 and the waveguide opening 211, so as to prevent the electromagnetic wave from leaking out from the gap between the waveguide opening 11 and the waveguide opening 211, thereby ensuring the stable transmission of the electromagnetic wave between the first rectangular waveguide 1 and the first waveguide 21 located on the PCB substrate 2.

[0009] Furthermore, the cross section of the first rectangular waveguide 1 is rectangular, and the width and height of the cross section are determined based on the requirements of the electromagnetic wave signal of the frequency band to be transmitted;

[0010] The first rectangular waveguide 1 is placed perpendicular to the PCB substrate 2 , and its midline along the propagation direction is perpendicular to the PCB substrate 2 . The annular side wall 111 of the waveguide opening 11 of the first rectangular waveguide 1 is in the same plane and remains parallel to the PCB substrate 2 .

[0011] Furthermore, the first rectangular waveguide 1 is manufactured based on metal CNC processing or based on injection-molded plastic metallization.

[0012] Furthermore, the PCB substrate 2 is a high-frequency PCB board material, and a first waveguide 21 that runs through the PCB substrate 2 is arranged at a position on the PCB substrate 2 corresponding to the first rectangular waveguide 1. The first waveguide 21 must meet the size requirements for transmitting electromagnetic waves in the required frequency band, and also meet the matching requirements with the waveguide interface of the RF chip to ensure stable transmission of electromagnetic waves between the first waveguide 21 and the RF chip.

[0013] Furthermore, the first waveguide 21 includes a waveguide hole 212 arranged on the PCB substrate 2 and a waveguide wall 213 attached to the waveguide hole 212. The waveguide hole 212 is processed on the PCB substrate 2 according to specific size requirements by a milling cutter or a rotary head. The waveguide wall 213 is a layer of copper plated by electroplating attached to the waveguide hole 212, and an aperture ring 214 is formed on the layer where the first side of the PCB substrate 2 is located, and an aperture ring 215 is formed on the layer where the second side of the PCB substrate 2 is located.

[0014] Further, a periodic structure 22 is arranged around the waveguide opening 211 of the first waveguide 21 on the layer where the first side of the PCB substrate 2 is located. The periodic structure 22 is a plurality of regular polygonal patches with equal side lengths. The distances between the patches are the same. A metallized via 221 is arranged at the center of the patch. The metallized via 221 connects the patch and a metal floor 23 arranged on the layer where the second side of the PCB substrate is located. The patch close to the hole ring 214 on the layer where the first side is located is connected to the hole ring 214 or not connected to the hole ring 214. The periodic structure 22 and the annular side wall 111 of the waveguide opening 11 of the first rectangular waveguide 1 form an electromagnetic wave leakage prevention structure, wherein the periodic structure 22 is manufactured together with the PCB waveguide cavity when the PCB substrate 2 is produced;

[0015] The periodic structure patch located at the first side of the waveguide port 211 is connected to the hole ring 214 of the waveguide port 211 without leaving a gap, and the periodic structure patch located at the second side of the waveguide port 211 is connected to the hole ring 214 or maintains a maximum spacing of no more than 30% of the size of the periodic structure 22, wherein the first side is longer than the second side, and the periodic structure patch is a patch corresponding to the periodic structure (22);

[0016] The innermost periodic structure 22 surrounding the hole ring 214 of the waveguide opening 211 is arranged according to the actual size of the hole ring 214, allowing the innermost periodic structure 22 surrounding the hole ring 214 to have a gap, and the gap is blocked by using a periodic patch in the outer layer, or the periodic structure patch is made to surround the hole ring 214 by increasing the gap between the patches;

[0017] The spacing between the periodic structure patches is set to be equal spacing or unequal spacing, or a mixture of partial equal spacing and partial unequal spacing according to the size of the actual hole ring 214 to be surrounded.

[0018] Further, the side length of the patch and the spacing between the patches are determined based on the required operating frequency and the dielectric constant and thickness of the PCB substrate 2;

[0019] The side length of the patch and the spacing between the patches are determined based on the required operating frequency and the dielectric constant and thickness of the PCB substrate 2, including:

[0020] Determining a free space wavelength of the PCB substrate 2 based on a desired operating frequency;

[0021] Determining an effective dielectric constant based on the dielectric constant and thickness of the PCB substrate 2;

[0022] Determine the effective wavelength of the PCB substrate 2 based on the free space wavelength and the effective dielectric constant;

[0023] The side length of the patch and the spacing between the patches are determined based on the effective wavelength of the PCB substrate 2 .

[0024] Furthermore, the PCB substrate 2 adopts a dielectric plate with a dielectric constant of 3.32, a loss tangent of 0.004, and a thickness of 0.088 mm;

[0025] The periodic structure 22 uses square patches, the side length of the square patches is 0.91 mm, the patch spacing is 0.12 mm-0.16 mm, and a metal via with a diameter of 0.3 mm is used in the middle of the square patch.

[0026] Furthermore, when there is a gap between the waveguide port 11 of the first rectangular waveguide 1 and the waveguide port 211 of the first waveguide 21 located on the PCB substrate 2, an ideal magnetic wall will be formed on the surface of the first waveguide 21 surrounding the waveguide port 211, so as to add an invisible waveguide cavity surrounded by an ideal magnetic wall between the waveguide port 11 of the first rectangular waveguide 1 and the waveguide port 211 of the first waveguide 21 located on the PCB substrate 2, so as to prevent electromagnetic waves from leaking from the gap between the waveguide port 11 of the first rectangular waveguide 1 and the waveguide port 211 of the first waveguide 21 located on the PCB substrate 2, thereby realizing stable transmission of electromagnetic waves between the first rectangular waveguide 1 and the first waveguide 21 located on the PCB substrate 2.

[0027] Furthermore, when there is a 0.2 mm gap between the waveguide port 11 of the first rectangular waveguide 1 and the waveguide port 211 of the first waveguide 21 located on the PCB substrate 2, the transmission loss from the first rectangular waveguide 1 to the first waveguide 21 on the PCB substrate 2 in the frequency band of 74 GHz-83 GHz is less than 0.2 dB.

[0028] Furthermore, when the PCB substrate 2 is adapted to 8 waveguide ports, when there is a 0.2 mm gap between the waveguide ports, the insertion losses of the 8 channel interfaces are all lower than 0.25 dB within the frequency band of 75 GHz-82 GHz.

[0029] The beneficial effects of a millimeter wave waveguide anti-leakage interface device provided by the present invention are as follows:

[0030] When the electromagnetic wave propagates from the first rectangular waveguide through the waveguide opening to the first waveguide arranged on the PCB substrate, the periodic structure forms an ideal magnetic wall PMC on the corresponding surface, surrounding the waveguide opening to prevent the electromagnetic wave from leaking out from the gap between the waveguide openings, thereby ensuring the stable transmission of the electromagnetic wave between the first rectangular waveguide and the first waveguide. In addition, the periodic structure is designed using PCB technology, which has a simple structure, mature technology, and is easy to integrate. It also effectively reduces the complexity and production difficulty of the waveguide antenna part mold, thereby reducing the production cost.

[0031] Moreover, the millimeter-wave waveguide anti-leakage interface device designed by the present invention has a wide bandwidth and low loss; the device has a good tolerance to gaps, which is convenient for the production and assembly of waveguide antennas; in addition, the PCB process is used to design the periodic structure, which has a simple structure, mature process, and is easy to integrate, which can effectively reduce the complexity and production difficulty of some molds of the waveguide antenna, thereby reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the following briefly introduces the drawings required for use in the embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 A schematic structural diagram of a millimeter wave guide anti-leakage interface device provided in an embodiment of the present invention;

[0034] Figure 2 A structural perspective view of a millimeter wave guide anti-leakage interface device provided by an embodiment of the present invention;

[0035] Figure 3 A top view of a PCB substrate of a millimeter wave guide anti-leakage interface device provided by an embodiment of the present invention;

[0036] Figure 4 A bottom view of a first rectangular waveguide of a millimeter wave guide anti-leakage interface device provided by an embodiment of the present invention;

[0037] Figure 5 A structural perspective view of a millimeter wave waveguide anti-leakage interface device adapted to a 4-transmit 4-receive radio frequency chip provided in an embodiment of the present invention;

[0038] Figure 6 A schematic diagram of the structure of a PCB substrate portion of a millimeter wave waveguide anti-leakage interface device adapted to a 4-transmit 4-receive radio frequency chip provided in an embodiment of the present invention;

[0039] Figure 7 A bottom view of the rectangular waveguide structure of a millimeter wave waveguide anti-leakage interface device adapted to a 4-transmit 4-receive radio frequency chip provided in an embodiment of the present invention;

[0040] Figure 8 A millimeter wave guide anti-leakage interface device S parameter simulation curve diagram provided by an embodiment of the present invention;

[0041] Fig. 9 An S-parameter simulation curve diagram of a millimeter-wave waveguide anti-leakage interface device adapted to a 4-transmit 4-receive RF chip provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and Examples. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention.

[0043] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0044] The technical solution provided by the embodiments of the present invention is described below in conjunction with the accompanying drawings.

[0045] like Figure 1 As shown, the present invention is a schematic structural diagram of a millimeter wave guide anti-leakage interface device, the device comprising a first rectangular waveguide 1 and a PCB substrate 2;

[0046] The first rectangular waveguide 1 is disposed on the first side of the PCB substrate 2. The first side of the PCB substrate 2 is provided with a first waveguide 21 penetrating the PCB substrate 2. The center of the waveguide opening 11 of the first rectangular waveguide 1 is aligned with the center of the waveguide opening 211 of the first waveguide 21 located on the first side of the PCB substrate 2. The first side of the PCB substrate 2 can be understood as Figure 1 The upper side of the PCB substrate 2, the second side of the PCB substrate 2 can be understood as Figure 1 The lower side of the PCB substrate 2;

[0047] A periodic structure 22 is arranged around the waveguide opening 211 in the layer where the first side of the PCB substrate 2 is located. When the electromagnetic wave propagates from the first rectangular waveguide 1 through the waveguide opening 11 and the waveguide opening 211 to the first waveguide 21 arranged on the PCB substrate, the periodic structure 22 forms an ideal magnetic wall PMC on the corresponding surface, surrounding the waveguide opening 11 and the waveguide opening 211, so as to prevent the electromagnetic wave from leaking out from the gap between the waveguide opening 11 and the waveguide opening 211, thereby ensuring that the electromagnetic wave is stably transmitted between the first rectangular waveguide 1 and the first waveguide 21 located on the PCB substrate 2, wherein the perfect magnetic wall (Perfectly Magnetic Conductor, PMC) is a boundary condition commonly used in electromagnetic theory and simulation experiments, which refers to a hypothetical surface that completely reflects the magnetic field without energy loss. Specifically, the characteristic of the ideal magnetic wall is that the magnetic field component in the normal direction of the surface is zero, and the electric field component in the tangential direction is zero.

[0048] Combined with Figures 2 to 9 ,right Figure 1 The description continues with the structural schematic diagram of the millimeter-wave waveguide anti-leakage interface device.

[0049] In some embodiments, the cross section of the first rectangular waveguide 1 is rectangular, and the width and height of the cross section are determined based on the requirements of the electromagnetic wave signal in the frequency band to be transmitted;

[0050] The first rectangular waveguide 1 is placed perpendicular to the PCB substrate 2 , and its midline along the propagation direction is perpendicular to the PCB substrate 2 . The annular side wall 111 of the waveguide opening 11 of the first rectangular waveguide 1 is in the same plane and remains parallel to the PCB substrate 2 .

[0051] In some embodiments, the first rectangular waveguide 1 is manufactured based on metal CNC machining or based on injection-molded plastic metallization.

[0052] In some embodiments, the PCB substrate 2 is a high-frequency PCB board, and a first waveguide 21 that runs through the PCB substrate 2 is provided at a position on the PCB substrate corresponding to the first rectangular waveguide 1. The first waveguide 21 must meet the size requirements for transmitting electromagnetic waves in the required frequency band, and also meet the matching requirements with the waveguide interface of the RF chip to ensure stable transmission of electromagnetic waves between the first waveguide 21 and the RF chip.

[0053] In some embodiments, the first waveguide 21 includes a waveguide hole 212 provided on the PCB substrate and a waveguide wall 213 attached to the waveguide hole 212. The waveguide hole 212 is processed on the PCB substrate 2 according to specific size requirements by a milling cutter or a rotary head. The waveguide wall 213 is a layer of copper plated formed by electroplating and attached to the waveguide hole 212. An aperture ring 214 is formed on the layer where the first side of the PCB substrate 2 is located, and an aperture ring 215 is formed on the layer where the second side of the PCB substrate 2 is located.

[0054] In some embodiments, a periodic structure 22 is provided around the waveguide opening 211 of the first waveguide 21 on the layer where the first side of the PCB substrate 2 is located. The periodic structure 22 is a plurality of regular polygonal patches with equal side lengths. The distances between the patches are the same. A metallized via 221 is provided at the center of the patch. The metallized via 221 connects the patch and a metal floor 23 provided on the layer where the second side of the PCB substrate is located. The patch close to the hole ring 214 on the layer where the first side is located is connected to the hole ring 214 or not connected. The periodic structure 22 and the annular side wall 111 of the waveguide opening 11 of the first rectangular waveguide 1 form an electromagnetic wave leakage prevention structure, wherein the periodic structure 22 is manufactured together with the PCB waveguide cavity when the PCB substrate 2 is produced;

[0055] The periodic structure patch located at the first side of the waveguide port 211 is connected to the hole ring 214 of the waveguide port 211 without leaving a gap, and the periodic structure patch located at the second side of the waveguide port 211 is connected to the hole ring 214 or maintains a maximum spacing of no more than 30% of the size of the periodic structure 22, wherein the first side is longer than the second side, and the periodic structure patch is a patch corresponding to the periodic structure (22);

[0056] The innermost periodic structure 22 surrounding the hole ring 214 of the waveguide opening 211 is arranged according to the actual size of the hole ring 214, allowing the innermost periodic structure 22 surrounding the hole ring 214 to have a gap, and the gap is blocked by using a periodic patch in the outer layer, or the periodic structure patch is made to surround the hole ring 214 by increasing the gap between the patches;

[0057] The spacing between the periodic structure patches is set to be equal spacing or unequal spacing, or a mixture of partial equal spacing and partial unequal spacing according to the size of the actual hole ring 214 to be surrounded.

[0058] That is to say, the periodic structure patch located on the long side of the waveguide port 211 is connected to the hole ring 214 of the waveguide port 211 without leaving a gap, and the periodic structure patch located on the short side of the waveguide port 211 can be connected to the hole ring 214 or maintain an appropriate distance, and the maximum distance does not exceed 30% of the periodic structure size.

[0059] Moreover, the innermost periodic structure of the hole ring 214 surrounding the waveguide opening 211 is reasonably arranged according to the actual size of the hole ring 214. Due to space limitations, a larger spacing can be allowed for the innermost periodic structure surrounding the hole ring 214, but the larger spacing must be blocked by periodic patches on the outer layer. The periodic structure patches can also be reasonably placed around the hole ring 214 by appropriately increasing the spacing between the patches.

[0060] The spacing between the periodic structure patches can be set to be equal spacing or unequal spacing according to the size of the actual hole ring 214 to be surrounded, or a mixture of partial equal spacing and partial unequal spacing, but the size of the periodic structure patches is the same.

[0061] In some embodiments, the side length of the patch and the spacing between the patches are determined based on the required operating frequency and the dielectric constant and thickness of the PCB substrate 2;

[0062] The side length of the patch and the spacing between the patches are determined based on the required operating frequency and the dielectric constant and thickness of the PCB substrate 2, including:

[0063] Determining a free space wavelength of the PCB substrate 2 based on a desired operating frequency;

[0064] Determining an effective dielectric constant based on the dielectric constant and thickness of the PCB substrate 2;

[0065] Determine the effective wavelength of the PCB substrate 2 based on the free space wavelength and the effective dielectric constant;

[0066] The side length of the patch and the spacing between the patches are determined based on the effective wavelength of the PCB substrate 2 .

[0067] In some embodiments, the PCB substrate 2 uses a dielectric plate with a dielectric constant of 3.32, a loss tangent of 0.004, and a thickness of 0.088 mm;

[0068] The periodic structure 22 uses square patches, the side length of the square patches is 0.91 mm, the patch spacing is 0.12 mm-0.16 mm, and a metal via with a diameter of 0.3 mm is used in the middle of the square patch.

[0069] In some embodiments, when there is a gap between the waveguide port 11 of the first rectangular waveguide 1 and the waveguide port 211 of the first waveguide 21 located on the PCB substrate, an ideal magnetic wall will be formed on the surface of the first waveguide 21 surrounding the waveguide port 211, so as to add an invisible waveguide cavity surrounded by an ideal magnetic wall between the waveguide port 11 of the first rectangular waveguide 1 and the waveguide port 211 of the first waveguide 21 located on the PCB substrate, so as to prevent electromagnetic waves from leaking from the gap between the waveguide port 11 of the first rectangular waveguide 1 and the waveguide port 211 of the first waveguide 21 located on the PCB substrate, thereby realizing stable transmission of electromagnetic waves between the first rectangular waveguide 1 and the first waveguide 21 located on the PCB substrate 2.

[0070] Combination Figure 8 As shown in the S parameter curve of the anti-leakage device based on the square patch periodic structure designed according to the present embodiment, it can be seen from the curve that when there is a 0.2 mm gap between the waveguide port 11 of the first rectangular waveguide 1 and the waveguide port 211 of the first waveguide 21 located on the PCB substrate 2, the transmission loss from the first rectangular waveguide 1 to the first waveguide 21 on the PCB substrate in the frequency band range of 74 GHz - 83 GHz is less than 0.2 dB.

[0071] That is to say, in some embodiments, when there is a 0.2 mm gap between the waveguide port 11 of the first rectangular waveguide 1 and the waveguide port 211 of the first waveguide 21 located on the PCB substrate 2, the transmission loss from the first rectangular waveguide 1 to the first waveguide 21 on the PCB substrate in the frequency band range of 74 GHz-83 GHz is less than 0.2 dB.

[0072] In addition, the millimeter wave waveguide anti-leakage interface device designed by the present invention can also adapt to the situation where multiple waveguide ports are simultaneously connected to the PCB substrate. Figure 6 A perspective view of the structure of the anti-leakage interface device when eight waveguide ports of four transmitting and four receiving radio frequency chips are connected according to an embodiment of the present invention is shown. Figure 7 A schematic diagram of the PCB substrate structure of the anti-leakage interface device when 8 waveguide ports of 4-transmitting and 4-receiving radio frequency chips are connected according to an embodiment of the present invention is shown. Fig. 9 It is an S parameter simulation curve of the anti-leakage interface device of 8 waveguide ports of 4-transmit and 4-receive RF chips designed according to an embodiment of the present invention. It can be seen from the curve that when there is a 0.2mm gap, the insertion loss of the 8 channel interfaces does not exceed 0.25dB in the frequency band range of 75GHz-82GHz.

[0073] The millimeter wave waveguide leakage prevention interface device of the present invention comprises a first rectangular waveguide and a PCB substrate, wherein the first rectangular waveguide is arranged above the PCB substrate, the first rectangular waveguide is perpendicular to the PCB substrate along the electromagnetic wave transmission direction, and is butted with the first waveguide arranged on the PCB substrate, and a plurality of periodic structures are arranged around the waveguide opening of the first waveguide located on the upper layer side of the PCB substrate, and these periodic structures arranged on the PCB substrate with mature technology and simple structure cooperate with the annular side wall of the waveguide opening of the first rectangular waveguide butted with the first waveguide on the PCB substrate to form an ideal magnetic wall around the first rectangular waveguide and the waveguide opening butted with the first waveguide, so as to prevent electromagnetic waves from leaking from the gap between them, thereby ensuring the stable transmission of electromagnetic waves between the first rectangular waveguide and the first waveguide on the PCB substrate.

[0074] The millimeter wave waveguide anti-leakage interface device of the present invention has the following advantages:

[0075] First, the millimeter wave waveguide anti-leakage interface device designed by the present invention has a wide bandwidth and low loss;

[0076] Second, the millimeter wave waveguide anti-leakage interface device designed by the present invention has a good tolerance to gaps, which is convenient for the production and assembly of waveguide antennas;

[0077] Third, the millimeter-wave waveguide anti-leakage interface device designed in the present invention adopts PCB technology to design a periodic structure, which has a simple structure, mature technology, and is easy to integrate. It can effectively reduce the complexity and production difficulty of the waveguide antenna part mold, thereby reducing the production cost.

[0078] It should be clear that the present invention is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present invention.

[0079] The functional blocks shown in the structural block diagram described above can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), appropriate firmware, plug-in, function card, etc. When implemented in software, the elements of the present invention are programs or code segments used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or communication link by a data signal carried in a carrier. "Machine-readable medium" may include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, read-only memory (Read-Only Memory, ROM), flash memory, erasable read-only memory (ErasableRead Only Memory, EROM), floppy disks, compact disc read-only memory (Compact Disc Read-Only Memory, CD-ROM), optical discs, hard disks, optical fiber media, radio frequency (Radio Frequency, RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0080] It should also be noted that the exemplary embodiments mentioned in the present invention describe some methods or systems based on a series of steps or devices. However, the present invention is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiments, or in a different order from the embodiments, or several steps can be performed simultaneously.

[0081] Aspects of the present disclosure are described above with reference to the flowchart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0082] The above is only a specific implementation of the present invention. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the system, module and unit described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be covered within the protection scope of the present invention.

Claims

1. A millimeter wave waveguide anti-leakage interface device, characterized in that: The device comprises a first rectangular waveguide (1) and a PCB substrate (2); The first rectangular waveguide (1) is arranged on a first side of a PCB substrate (2); a first waveguide (21) penetrating the PCB substrate (2) is arranged on the first side of the PCB substrate (2); the center of the waveguide opening (11) of the first rectangular waveguide (1) is aligned with the center of the waveguide opening (211) of the first waveguide (21) located on the first side of the PCB substrate (2); A periodic structure (22) is arranged around a waveguide opening (211) in a layer on a first side of a PCB substrate (2); when an electromagnetic wave propagates from a first rectangular waveguide (1) through a waveguide opening (11) and a waveguide opening (211) to a first waveguide (21) arranged on the PCB substrate, the periodic structure (22) forms an ideal magnetic wall PMC on a corresponding surface, surrounding the waveguide opening (11) and the waveguide opening (211), so as to prevent the electromagnetic wave from leaking out from a gap between the waveguide opening (11) and the waveguide opening (211), thereby ensuring stable transmission of the electromagnetic wave between the first rectangular waveguide (1) and the first waveguide (21) located on the PCB substrate (2).

2. The device according to claim 1, characterized in that The cross section of the first rectangular waveguide (1) is rectangular, and the width and height of the cross section are determined based on the requirements of the electromagnetic wave signal in the frequency band to be transmitted; The first rectangular waveguide (1) is placed perpendicular to the PCB substrate (2), and its midline along the propagation direction is perpendicular to the PCB substrate (2); the annular side wall (111) of the waveguide opening (11) of the first rectangular waveguide (1) is in the same plane and remains parallel to the PCB substrate (2); The first rectangular waveguide (1) is manufactured based on metal CNC processing or based on injection-molded plastic metallization.

3. The device according to claim 1, characterized in that The PCB substrate (2) is a high-frequency PCB plate material. A first waveguide (21) that runs through the PCB substrate (2) is arranged at a position on the PCB substrate (2) corresponding to the first rectangular waveguide (1). The first waveguide (21) must meet the size requirements for transmitting electromagnetic waves in a required frequency band and also meet the matching requirements with the waveguide interface of the radio frequency chip, so as to ensure stable transmission of electromagnetic waves between the first waveguide (21) and the radio frequency chip.

4. The device according to claim 3, characterized in that The first waveguide (21) comprises a waveguide hole (212) arranged on a PCB substrate (2) and a waveguide wall (213) attached to the waveguide hole (212); the waveguide hole (212) is machined on the PCB substrate (2) according to specific size requirements by a milling cutter or a rotary head; the waveguide wall (213) is a layer of copper plating attached to the waveguide hole (212) formed by electroplating, and an annular ring (214) is formed on a layer where a first side of the PCB substrate (2) is located, and an annular ring (215) is formed on a layer where a second side of the PCB substrate (2) is located.

5. The device according to claim 1, characterized in that A periodic structure (22) is arranged around the waveguide opening (211) of the first waveguide (21) on the layer where the first side of the PCB substrate (2) is located. The periodic structure (22) is a plurality of regular polygonal patches with equal side lengths. The distances between the patches are the same. A metallized via (221) is arranged at the center of the patch. The metallized via (221) connects the patch and a metal floor (23) arranged on the layer where the second side of the PCB substrate is located. The patch close to the hole ring (214) on the layer where the first side is located is connected to the hole ring (214) or not connected to the hole ring (214). The periodic structure (22) and the annular side wall (111) of the waveguide opening (11) of the first rectangular waveguide (1) form an electromagnetic wave leakage prevention structure. The periodic structure (22) is manufactured together with the PCB waveguide cavity when the PCB substrate (2) is produced. The periodic structure patch located at the first side of the waveguide opening (211) is connected to the hole ring (214) of the waveguide opening (211) without leaving a gap, and the periodic structure patch located at the second side of the waveguide opening (211) is connected to the hole ring (214) or maintains a maximum spacing of no more than 30% of the size of the periodic structure (22), wherein the first side is longer than the second side, and the periodic structure patch is a patch corresponding to the periodic structure (22); The innermost periodic structure (22) surrounding the hole ring (214) of the waveguide opening (211) is arranged according to the actual size of the hole ring (214), allowing the innermost periodic structure (22) surrounding the hole ring (214) to have a spacing, and the spacing is blocked by using a periodic patch on the outer layer, or the periodic structure patch is made to surround the hole ring (214) by increasing the spacing between the patches; The spacing between the periodic structure patches is set to be equal spacing or unequal spacing according to the size of the actual hole ring (214) to be surrounded, or a mixture of partial equal spacing and partial unequal spacing.

6. The device according to claim 5, characterized in that The side length of the patch and the spacing between the patches are determined based on the required operating frequency and the dielectric constant and thickness of the PCB substrate (2); The side length of the patch and the spacing between the patches are determined based on the required operating frequency and the dielectric constant and thickness of the PCB substrate (2), including: Determining a free space wavelength of the PCB substrate (2) based on a desired operating frequency; Determining an effective dielectric constant based on the dielectric constant and thickness of the PCB substrate (2); Determining the effective wavelength of the PCB substrate (2) based on the free space wavelength and the effective dielectric constant; The side length of the patch and the spacing between the patches are determined based on the effective wavelength of the PCB substrate (2).

7. The device according to claim 6, characterized in that The PCB substrate (2) is a dielectric plate with a dielectric constant of 3.32, a loss tangent of 0.004, and a thickness of 0.088 mm; The periodic structure (22) uses square patches, the side length of the square patches is 0.91 mm, the patch spacing is 0.12 mm-0.16 mm, and a metal via with a diameter of 0.3 mm is used in the middle of the square patch.

8. The device according to claim 6, characterized in that When a gap exists between the waveguide opening (11) of the first rectangular waveguide (1) and the waveguide opening (211) of the first waveguide (21) located on the PCB substrate (2), an ideal magnetic wall is formed on the surface of the first waveguide (21) and surrounds the waveguide opening (211), so as to add an invisible waveguide cavity surrounded by an ideal magnetic wall between the waveguide opening (11) of the first rectangular waveguide (1) and the waveguide opening (211) of the first waveguide (21) located on the PCB substrate (2), thereby preventing electromagnetic waves from leaking from the gap between the waveguide opening (11) of the first rectangular waveguide (1) and the waveguide opening (211) of the first waveguide (21) located on the PCB substrate (2), thereby achieving stable transmission of electromagnetic waves between the first rectangular waveguide (1) and the first waveguide (21) located on the PCB substrate (2).

9. The device according to claim 1, characterized in that When there is a 0.2 mm gap between the waveguide opening (11) of the first rectangular waveguide (1) and the waveguide opening (211) of the first waveguide (21) located on the PCB substrate (2), the transmission loss from the first rectangular waveguide (1) to the first waveguide (21) on the PCB substrate (2) in the frequency range of 74 GHz to 83 GHz is less than 0.2 dB.

10. The device according to claim 9, characterized in that When the PCB substrate (2) is adapted to eight waveguide ports and there is a 0.2 mm gap between the waveguide ports, the insertion losses of the eight channel interfaces are all lower than 0.25 dB within the frequency range of 75 GHz to 82 GHz.

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