Board-to-board waveguide feeding structure

Abstract

The present invention discloses a board-to-board waveguide feeding structure, comprising a waveguide, a first PCB board and a second PCB board. The first end of the waveguide and the second end of the waveguide are closed, a chamber is arranged inside the waveguide, the chamber comprises a first working chamber, a second working chamber and a third working chamber which are connected in sequence, the first end of the first PCB board is arranged between the first working chamber and the second working chamber, the first end of the first PCB board is arranged with a first through hole matching the chamber, the first PCB board is arranged with a first transmission line and a first waveguide-microstrip conversion probe which are electrically connected to each other; the first end of the second PCB board is arranged between the second working chamber and the third working chamber, the first end of the second PCB board is arranged with a second through hole matching the chamber, the second PCB board is arranged with a second transmission line and a second waveguide-microstrip conversion probe which are electrically connected to each other. The board-to-board waveguide feeding structure of the present invention can be applied to the feeding of high-frequency signals, and the structure is more compact.

Description

Technical Field

[0001] The invention relates to the field of microwave technology, and in particular to a board-to-board waveguide feeding structure. Background Art

[0002] With the development of science and technology, communication equipment or radar equipment is becoming more and more powerful and has better performance. To achieve powerful functions and good performance, it is bound to put forward higher requirements on the difficulty of circuit design, the complexity of circuits, the performance of circuits, etc., and the frequency points used will also become higher and higher. There will be more and more combined assemblies such as heat dissipation housings, shielded metal housings, multiple PCBs and multiple functional modules. In order to avoid the occurrence of undesirable problems such as signal crosstalk, leakage, excessive signal strength loss or signal purity degradation, higher requirements will eventually be put forward on the feed interconnection between PCBs and the feed interconnection between modules.

[0003] At present, conventional feeding methods include through-the-wall coaxial cable feeding, external coaxial feeding, and board-to-board connector feeding. Through-the-wall coaxial cable feeding is difficult to assemble and weld, has high labor costs, and is prone to problems at higher frequencies. External coaxial feeding requires the addition of microstrip to coaxial connectors and corresponding upper and lower connecting coaxial cables, which requires more assembly steps and welding work. For board-to-board connector feeding, at higher frequencies, there are few connectors that can meet the requirements, and there are also problems such as large losses and poor signal shielding protection performance. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a board-to-board waveguide feeding structure, which can be suitable for feeding high-frequency signals and has a more compact structure.

[0005] According to an embodiment of the present invention, a board-to-board waveguide feeding structure includes: a waveguide, wherein a first end of the waveguide and a second end of the waveguide are closed, a chamber is arranged inside the waveguide, and the chamber includes a first working chamber, a second working chamber, and a third working chamber that are connected in sequence; a first PCB board, wherein a first end of the first PCB board is arranged between the first working chamber and the second working chamber, a first through hole matching the chamber is arranged at the first end of the PCB board, a first transmission line and a first waveguide-microstrip conversion probe are arranged on the first PCB board, the first transmission line is electrically connected to the first end of the first waveguide-microstrip conversion probe, and the second end of the first waveguide-microstrip conversion probe is located in the first through hole; and a second PCB board, wherein a first end of the second PCB board is arranged between the second working chamber and the third working chamber, a second through hole matching the chamber is arranged at the first end of the second PCB board, a second transmission line and a second waveguide-microstrip conversion probe are arranged on the second PCB board, the second transmission line is electrically connected to the first end of the second waveguide-microstrip conversion probe, and the second end of the second waveguide-microstrip conversion probe is located in the second through hole.

[0006] The board-to-board waveguide feeding structure according to the embodiment of the present invention has at least the following beneficial effects: the high-frequency signal enters the first waveguide-microstrip conversion probe through the first transmission line, and enters the cavity of the waveguide through the second end of the first waveguide-microstrip conversion probe. Since the first end and the second end of the waveguide are closed, the first working cavity is connected to the second working cavity through the first through hole, and the second working cavity is connected to the third working cavity through the second through hole. The high-frequency signal is restricted to propagate in the cavity. When the high-frequency signal propagates to the second waveguide-microstrip conversion probe, it enters the second transmission line through the second waveguide-microstrip conversion probe to complete the board-to-board feeding. That is, the board-to-board waveguide feeding structure can be suitable for feeding high-frequency signals, and uses fewer devices and structures, making the board-to-board waveguide feeding structure more compact.

[0007] According to some embodiments of the present invention, the waveguide is provided with a first channel and a second channel, the second end of the first waveguide-microstrip conversion probe is passed through the first channel and is arranged in the chamber, and the second end of the second waveguide-microstrip conversion probe is passed through the second channel and is arranged in the chamber, so that the first waveguide-microstrip conversion probe and the second waveguide-microstrip conversion probe are fed through the waveguide.

[0008] According to some embodiments of the present invention, a first via hole is provided at the first end of the first PCB board, and the middle portion of the waveguide and the upper portion of the waveguide are fixedly connected through the first via hole, so as to fix the first PCB board between the middle portion of the waveguide and the upper portion of the waveguide.

[0009] According to some embodiments of the present invention, a second via hole is provided at the first end of the second PCB board, and the middle portion of the waveguide and the lower portion of the waveguide are fixedly connected through the second via hole, so as to fix the second PCB board between the middle portion of the waveguide and the lower portion of the waveguide.

[0010] According to some embodiments of the present invention, the waveguide is a rectangular waveguide, and the length and width of the chamber satisfy the formula: λ c is the cutoff wavelength of the rectangular waveguide, m and n together represent the mode of the electromagnetic wave, a is the length of the cavity, b is the width of the cavity, and a is greater than or equal to b, so as to better realize the feeding of high-frequency signals between boards.

[0011] According to some embodiments of the present invention, the length of the second end of the first waveguide-microstrip conversion probe and / or the second end of the second waveguide-microstrip conversion probe is in the range of 0.2 to 0.25 times the length of the chamber, so as to better realize the feeding of high-frequency signals between boards.

[0012] According to some embodiments of the present invention, the height of the first working chamber is a first height, the height of the second working chamber is a second height, and the height of the third working chamber is a third height. The sum of the first height, the second height and the third height is an integer multiple of the wavelength of the electromagnetic wave, and is at least one times, so as to better realize the feeding of high-frequency signals between boards.

[0013] According to some embodiments of the present invention, the first height is equal to the third height, so as to better implement the feeding of high-frequency signals between boards.

[0014] According to some embodiments of the present invention, the first transmission line and / or the second transmission line is a microstrip line or a stripline to facilitate transmission of high-frequency signals.

[0015] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0017] Figure 1 It is a structural schematic diagram of a board-to-board waveguide feeding structure according to an embodiment of the present invention;

[0018] Figure 2 for Figure 1 A cross-sectional view of a waveguide of a board-to-board waveguide feeding structure is shown;

[0019] Figure 3 for Figure 1 A top view of a second PCB board of the board-to-board waveguide feeding structure shown;

[0020] Figure 4 for Figure 1 The schematic diagram of the structure of the first PCB board provided with a microstrip line is shown;

[0021] Figure 5 for Figure 1 The schematic diagram of the structure of the second PCB board provided with strip lines is shown.

[0022] The reference numerals are as follows:

[0023] Waveguide 100, chamber 110, first working chamber 111, second working chamber 112, third working chamber 113, first channel 120, second channel 130, rectangular waveguide 140;

[0024] A first PCB board 200, a first through hole 210, a first transmission line 220, a microstrip line 221, a first waveguide-microstrip conversion probe 230, a first via hole 240, a first dielectric substrate 250, and a first ground layer 260;

[0025] The second PCB board 300 , the second through hole 310 , the second transmission line 320 , the strip line 321 , the second waveguide-microstrip conversion probe 330 , the second via hole 340 , the second dielectric substrate 350 , and the second ground layer 360 . DETAILED DESCRIPTION

[0026] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0027] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0028] In the description of the present invention, "several" means one or more, "more" means two or more, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of the first, second, and third, it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0029] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0030] Reference Figure 1 The board-to-board waveguide feeding structure includes: a waveguide 100, a first PCB board 200 and a second PCB board 300. The first end of the waveguide 100 and the second end of the waveguide 100 are closed, and a chamber 110 is arranged inside the waveguide 100. The chamber 110 includes a first working chamber 111, a second working chamber 112 and a third working chamber 113 that are connected in sequence. The height of the first working chamber 111 is a first height, the height of the second working chamber 112 is a second height, and the height of the third working chamber 113 is a third height; the first end of the first PCB board 200 is arranged between the first working chamber 111 and the second working chamber 112, the first end of the first PCB board 200 is provided with a first through hole 210 that matches the chamber 110, and the first PCB board 200 is provided with a first transmission line 220 and a first waveguide-microstrip conversion The probe 230, the first transmission line 220 is electrically connected to the first end of the first waveguide-microstrip conversion probe 230, and the second end of the first waveguide-microstrip conversion probe 230 is located in the first through hole 210; the first end of the second PCB board 300 is arranged between the second working cavity 112 and the third working cavity 113, and the first end of the second PCB board 300 is provided with a second through hole 310 matching the cavity 110, and the second PCB board 300 is provided with a second transmission line 320 and a second waveguide-microstrip conversion probe 330, the second transmission line 320 is electrically connected to the first end of the second waveguide-microstrip conversion probe 330, and the second end of the second waveguide-microstrip conversion probe 330 is located in the second through hole 310.

[0031] Specifically, the high-frequency signal is transmitted to the first waveguide-microstrip conversion probe 230 through the first transmission line 220, and then transmitted to the cavity 110 of the waveguide 100. Since the first end and the second end of the waveguide 100 are closed, the high-frequency signal propagates in the cavity 110 of the waveguide 100. When the high-frequency signal propagates to the second waveguide-microstrip conversion probe 330, it is transmitted to the second transmission line 320 through the second waveguide-microstrip conversion probe 330, thereby completing the feeding of the high-frequency signal between the boards.

[0032] It should be noted that, refer to Figure 1 , the first end of the waveguide 100 refers to the upper end of the waveguide 100 , and the second end of the waveguide 100 refers to the lower end of the waveguide 100 .

[0033] It should be noted that the chamber 110 of the waveguide 100 can be divided into a first working chamber 111, a second working chamber 112 and a third working chamber 113, and the first height of the first working chamber 111 and the third height of the third working chamber 113 are both 0.25+n wavelengths λ, the second height of the second working chamber 112 is 0.5+m wavelengths λ, and the total height of the chamber 110 is the sum of the first height, the second height and the third height. Then, the total height of the chamber 110 is 1+m+n wavelengths λ, wherein m and n are both integers greater than or equal to 0, and are used to represent the mode of the electromagnetic wave, that is, the total height of the chamber 110 is at least one wavelength λ, and the wavelength λ refers to the wavelength of the electromagnetic wave.

[0034] The high frequency signal propagates in the cavity 110 of the waveguide 100 in the form of electromagnetic waves, with TE mn Taking the electromagnetic wave of the mode as an example, when m is 1 and n is 0, the mode of the electromagnetic wave is TE 10 , so that the first height and the third height are both 0.25 wavelengths λ, the second height is 1.5 wavelengths λ, and the total height of the chamber 110 is 2 wavelengths λ. In addition, according to actual needs, there may be a certain error among the first height, the second height, and the third height, that is, the first height and the third height are slightly greater than or slightly less than 0.25+n wavelengths λ, and the second height is slightly greater than or slightly less than 0.5+m wavelengths λ.

[0035] It should be noted that the board-to-board waveguide feeding structure uses fewer devices and structures, and the total height of the cavity 110 of the waveguide 100 is smaller, so the total height of the waveguide 100 is also smaller, making the board-to-board waveguide feeding structure more compact in structure.

[0036] It should be noted that the first working chamber 111 is connected to the second working chamber 112 through the first through hole 210 of the first PCB board 200, and the second working chamber 112 is connected to the third working chamber 113 through the second through hole 310 of the second PCB board 300, so that the first working chamber 111, the second working chamber 112 and the third working chamber 113 are connected in sequence, so that the high-frequency signal can propagate in the chamber 110 in the form of electromagnetic waves. In addition, the first through hole 210 matches the chamber 110, which means that the shape and size of the first through hole 210 are close to the shape and size of the cross section of the chamber 110, so as to avoid affecting the propagation characteristics of the waveguide 100. That is, the shape and size of the first through hole 210 need to be adjusted according to actual conditions, so that the shape and size of the first through hole 210 are equal to the shape and size of the cross section of the chamber 110; or the shape of the first through hole 210 is equal to the shape of the cross section of the chamber 110, and the size of the first through hole 210 is slightly larger or slightly smaller than the size of the cross section of the chamber 110.

[0037] The second through hole 310 matches the chamber 110, which means that the shape and size of the second through hole 310 are close to the shape and size of the cross section of the chamber 110, so as to avoid affecting the propagation characteristics of the waveguide 100. That is, the shape and size of the second through hole 310 need to be adjusted according to actual conditions, so that the shape and size of the second through hole 310 are equal to the shape and size of the cross section of the chamber 110; or the shape of the second through hole 310 is equal to the shape of the cross section of the chamber 110, while the size of the second through hole 310 is slightly larger or smaller than the size of the cross section of the chamber 110.

[0038] Reference Figure 1 and Figure 2 The waveguide 100 is provided with a first channel 120 and a second channel 130. The second end of the first waveguide-microstrip conversion probe 230 is disposed in the chamber 110 through the first channel 120, and the second end of the second waveguide-microstrip conversion probe 330 is disposed in the chamber 110 through the second channel 130. Specifically, the first channel 120 is used to accommodate the second end of the first waveguide-microstrip conversion probe 230, so that the second end of the first waveguide-microstrip conversion probe 230 can be disposed in the chamber 110, so that the high-frequency signal is transmitted to the chamber 110 through the first waveguide-microstrip conversion probe 230; the second channel 130 is used to accommodate the second end of the second waveguide-microstrip conversion probe 330, so that the second end of the second waveguide-microstrip conversion probe 330 can be disposed in the chamber 110, so that the high-frequency signal is transmitted to the second transmission line 320 through the second waveguide-microstrip conversion probe 330.

[0039] Reference Figure 1, a first via hole 240 is provided at a first end of the first PCB board 200, and the middle portion of the waveguide 100 and the upper portion of the waveguide 100 are fixedly connected through the first via hole 240. Specifically, the upper portion of the waveguide 100 is fixedly connected to the middle portion of the waveguide 100 through the first via hole 240, and at the same time, the first PCB board 200 is fixed between the upper portion of the waveguide 100 and the middle portion of the waveguide 100, so that the high-frequency signal can be stably transmitted to the cavity 110 of the waveguide 100.

[0040] Reference Figure 1 and Figure 3 , a second via hole 340 is provided at the first end of the second PCB board 300, and the middle part of the waveguide 100 and the lower part of the waveguide 100 are fixedly connected through the second via hole 340. Specifically, the middle part of the waveguide 100 is fixedly connected to the lower part of the waveguide 100 through the second via hole 340, and at the same time, the second PCB board 300 is fixed between the middle part of the waveguide 100 and the lower part of the waveguide 100, so that the high-frequency signal can be stably transmitted to the second transmission line 320.

[0041] It should be noted that the first via hole 240 and the second via hole 340 are both metallized via holes, so as to facilitate the connection between the upper part of the waveguide 100 , the middle part of the waveguide 100 , and the lower part of the waveguide 100 .

[0042] Reference Figure 1 and Figure 2 , the waveguide 100 is a rectangular waveguide 140, and the length and width of the chamber 110 satisfy the formula:

[0043] λ c is the cutoff wavelength of the rectangular waveguide 140, m and n together represent the mode of the electromagnetic wave, a is the length of the chamber 110, b is the width of the chamber 110, and a is greater than or equal to b. Specifically, different transmission modes of the rectangular waveguide 140 can be achieved by adjusting the values ​​of a and b, that is, adjusting the cutoff wavelength and cutoff frequency of the rectangular waveguide 140. For example, if a is greater than b, the main mode transmission is achieved, which is generally TE 10 mold.

[0044] It should be noted that the relationship between the wavelength of the electromagnetic wave and the operating frequency satisfies the formula: in, c is the speed of light, f is the operating frequency of the electromagnetic wave, f c is the cutoff frequency of the rectangular waveguide 140. In the rectangular waveguide 140, the wavelength of the electromagnetic wave needs to be smaller than the cutoff wavelength of the rectangular waveguide 140. Then, the wavelength of the electromagnetic wave can be calculated, and then the length and width of the chamber 110 are adjusted to make the cutoff wavelength of the rectangular waveguide 140 larger than the wavelength of the electromagnetic wave, so as to realize the feeding of high-frequency signals between boards.

[0045] It should be noted that the length of the second end of the first waveguide-microstrip conversion probe 230 and / or the second end of the second waveguide-microstrip conversion probe 330 is in the range of 0.2 to 0.25 times the length of the chamber 110. The length of the second end of the first waveguide-microstrip conversion probe 230 and / or the length of the second end of the second waveguide-microstrip conversion probe 330 needs to be adjusted according to the working mode and working frequency of the electromagnetic wave to TE 10 Taking the electromagnetic wave as an example, the length of the second end of the first waveguide-microstrip conversion probe 230 and the second end of the second waveguide-microstrip conversion probe 330 is in the range of 0.2 times to 0.25 times the length of the chamber 110 .

[0046] For example, the length of the second end of the first waveguide-microstrip conversion probe 230 is 0.2 times the length of the chamber 110, and the length of the second end of the second waveguide-microstrip conversion probe 330 is 0.25 times the length of the chamber 110, so that the first waveguide-microstrip conversion probe 230 can transmit high-frequency signals and the second waveguide-microstrip conversion probe 330 can receive high-frequency signals to realize the feeding of high-frequency signals between boards.

[0047] Alternatively, the length of the second end of the first waveguide-microstrip conversion probe 230 is 0.25 times the length of the chamber 110, and the length of the second end of the second waveguide-microstrip conversion probe 330 is 0.2 times the length of the chamber 110, so that the first waveguide-microstrip conversion probe 230 can transmit high-frequency signals and the second waveguide-microstrip conversion probe 330 can receive high-frequency signals to realize the feeding of high-frequency signals between boards.

[0048] It should be noted that the shape of the first waveguide-microstrip conversion probe 230 and the shape of the second waveguide-microstrip conversion probe 330 also need to be adjusted according to actual conditions. Figure 3 The second end of the second waveguide-microstrip conversion probe 330 is thicker than the first end, so that the high-frequency signal can be transmitted to the chamber 110 at the second end of the second waveguide-microstrip conversion probe 330 .

[0049] Reference Figure 4 and Figure 5 , the first transmission line 220 and / or the second transmission line 320 is a microstrip line 221 or a strip line 321. Specifically, the first transmission line 220 may be a microstrip line 221 or a strip line 321, and the second transmission line 320 may be a microstrip line 221 or a strip line 321. Figure 4 The first transmission line 220 is a microstrip line 221, and the corresponding first PCB board 200 includes a first dielectric substrate 250 and a first grounding layer 260. The microstrip line 221 and the first grounding layer 260 are respectively arranged on opposite sides of the first dielectric substrate 250 to realize the microstrip line 221 to transmit high-frequency signals. Figure 5The second transmission line 320 is a strip line 321, and the corresponding second PCB board 300 includes two second dielectric substrates 350 and two second ground layers 360. The second dielectric substrates 350 are respectively arranged on the opposite sides of the strip line 321, and the second ground layer 360 is arranged on the side of the second dielectric substrate 350 opposite to the strip line 321, so as to realize the strip line 321 to transmit high-frequency signals.

[0050] It should be noted that the microstrip line 221 is conducive to transmitting signals with high transmission speed requirements and has strong anti-interference ability; the impedance of the strip line 321 is easy to control and has good shielding performance, but the transmission speed is slow.

[0051] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. Board-to-board waveguide feeding structure, It is characterized in that include: A waveguide, wherein the first end of the waveguide and the second end of the waveguide are closed, a chamber is arranged inside the waveguide, and the chamber includes a first working chamber, a second working chamber and a third working chamber which are connected in sequence; the waveguide is a rectangular waveguide, and the length and width of the chamber satisfy the formula: λ c is the cut-off wavelength of the rectangular waveguide, m and n together represent the mode of the electromagnetic wave, a is the length of the chamber, b is the width of the chamber, and a is greater than or equal to b; by adjusting the values ​​of a and b, the cut-off wavelength and cut-off frequency of the rectangular waveguide are adjusted; A first PCB board, wherein a first end of the first PCB board is disposed between the first working cavity and the second working cavity, a first through hole matching the cavity is disposed at the first end of the first PCB board, a first transmission line and a first waveguide-microstrip conversion probe are disposed on the first PCB board, the first transmission line is electrically connected to a first end of the first waveguide-microstrip conversion probe, and a second end of the first waveguide-microstrip conversion probe is located in the first through hole; A second PCB board, wherein the first end of the second PCB board is arranged between the second working cavity and the third working cavity, the first end of the second PCB board is provided with a second through hole matching the cavity, the second PCB board is provided with a second transmission line and a second waveguide-microstrip conversion probe, the second transmission line is electrically connected to the first end of the second waveguide-microstrip conversion probe, the second end of the second waveguide-microstrip conversion probe is located in the second through hole, the length range of the second end of the first waveguide-microstrip conversion probe and / or the second end of the second waveguide-microstrip conversion probe is 0.2 times to 0.25 times the length of the cavity, the height of the first working cavity is the first height, the height of the second working cavity is the second height, the height of the third working cavity is the third height, the sum of the first height, the second height and the third height is an integral multiple of the wavelength of the electromagnetic wave, and is at least one times, the first height of the first working cavity and the third height of the third working cavity are both 0.25+n wavelengths λ, and the second height of the second working cavity is 0.5+m wavelengths λ; the first height is equal to the third height.

2. The board-to-board waveguide feeding structure according to claim 1, It is characterized in that The waveguide is provided with a first channel and a second channel, the second end of the first waveguide-microstrip conversion probe is passed through the first channel and is arranged in the chamber, and the second end of the second waveguide-microstrip conversion probe is passed through the second channel and is arranged in the chamber.

3. The board-to-board waveguide feeding structure according to claim 1, It is characterized in that A first via hole is provided at the first end of the first PCB board, and the middle portion of the waveguide and the upper portion of the waveguide are fixedly connected through the first via hole.

4. The board-to-board waveguide feeding structure according to claim 1 or 3, It is characterized in that A second via hole is disposed at the first end of the second PCB board, and the middle portion of the waveguide and the lower portion of the waveguide are fixedly connected via the second via hole.

5. The board-to-board waveguide feeding structure according to claim 1, It is characterized in that The first transmission line and / or the second transmission line is a microstrip line or a stripline.

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