Circuit board

Abstract

The utility model provides a circuit board, and relates to the technical field of couplers. The device comprises a first signal layer; the second signal layer is electrically connected with the first signal layer; the first microstrip line is arranged on the first signal layer and comprises a first coupling section extending in the first direction; and the second microstrip line is arranged on the second signal layer, the second microstrip line is provided with a second coupling section which is the same as the first coupling section in extension direction and is overlapped with the first coupling section, and the second coupling section is used for coupling the radio frequency signal in the first microstrip line.

Description

Technical Field

[0001] This application relates to the technical field of couplers, and particularly to a circuit board. Background Art

[0002] In the field of microwave technology, couplers are indispensable core components. Couplers play a crucial role in microwave systems, acting as the mainstay for signal transmission and regulation, ensuring the efficient execution of the role of the bridge for information circulation within the system.

[0003] Currently, in the design of radio frequency circuits, operators usually directly connect the coupler devices purchased from manufacturers to the circuit. The finished coupler devices usually come with their own packages, including shells, pins, or connectors, etc. These additional structures not only increase the physical size but also occupy additional PCB space; connecting the finished coupler to the PCB requires methods such as soldering or sockets. These additional connection points not only increase the assembly complexity, but each additional connection means one more transition on the signal path, and each transition may introduce signal attenuation and reflection, thus increasing the insertion loss.

[0004] Therefore, how to provide a circuit board that occupies less space and has a coupling function is an urgent problem to be solved currently. Summary of the Utility Model

[0005] To solve the above technical problems, the embodiments of this application provide the following technical solutions:

[0006] This application provides a circuit board, including: a first signal layer; a second signal layer electrically connected to the first signal layer; a first microstrip line disposed on the first signal layer, and the first microstrip line includes a first coupling section extending along a first direction; and a second microstrip line disposed on the second signal layer, the second microstrip line having a second coupling section that extends in the same direction as and overlaps with the first coupling section, for coupling the radio frequency signal in the first microstrip line.

[0007] In some alternative embodiments of the first aspect of this application, it further includes: a signal transmitter for transmitting a radio frequency signal, the input end of the first microstrip line is connected to the signal transmitter so that the radio frequency signal passes through the first coupling section; a test socket, the output end of the first microstrip line is connected to the test socket; a transceiver chip, the input end of the second microstrip line is grounded, and the output end is connected to the transceiver chip. The second coupling section overlapping with the first coupling section couples a part of the radio frequency signal in the first microstrip line into the second microstrip line and transmits it to the transceiver chip.

[0008] In some embodiments, a first clearance area is provided in the first signal layer, and the first clearance area corresponds to and is adapted to the first coupling section; a second clearance area is provided in the second signal layer, and the second clearance area corresponds to the second coupling section and the first clearance area and is adapted to the second coupling section; wherein, the first signal layer and the second signal layer are adjacent to each other.

[0009] In some embodiments, a coupling gap is provided between the first coupling section and the second coupling section.

[0010] In some embodiments, the center line of the first coupling section along the first direction coincides with the center line of the second coupling section along the first direction.

[0011] In some embodiments, the first coupling section starts from the midpoint of the first microstrip line and extends towards the other end of the first microstrip line.

[0012] In some embodiments, the line width of the first coupling section along the second direction is greater than the line width of the second coupling section along the second direction; the second direction is perpendicular to the first direction.

[0013] In some embodiments, extension sections extending along the first direction are respectively provided at both ends of the second coupling section, and the two extension sections are staggered from the first microstrip line respectively.

[0014] In some embodiments, the line width of the first coupling section along the second direction is greater than the width of the rest of the first microstrip line in the same direction; the line width of the second coupling section along the second direction is greater than the width of the rest of the second microstrip line in the same direction; the second direction is perpendicular to the first direction.

[0015] In some embodiments, a third clearance area corresponding to and adapted to the first clearance area is provided in the third signal layer on the side of the first signal layer and the second signal layer that are opposite to and adjacent to each other, and / or a fourth clearance area corresponding to and adapted to the second clearance area is provided in the fourth signal layer on the side of the second signal layer and the first signal layer that are opposite to and adjacent to each other. Description of the Drawings

[0016] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features and advantages of the exemplary embodiments of the present application will become readily understood. In the drawings, several embodiments of the present application are shown in an exemplary rather than restrictive manner, and the same or corresponding reference numerals indicate the same or corresponding parts, wherein:

[0017] Figure 1 Schematically shows a schematic structural diagram of a circuit board provided by the present application;

[0018] Figure 2 Schematically shows a circuit insertion loss curve diagram of a circuit board provided by the present application;

[0019] Figure 3Schematically shows a circuit coupling degree curve diagram of a circuit board provided by the present application;

[0020] Figure 4 Schematically shows a schematic diagram of the positional relationship between a first microstrip line and a second microstrip line of another circuit board provided by the present application;

[0021] Figure 5 Schematically shows a schematic diagram of the positional relationship between a first microstrip line and a second microstrip line of yet another circuit board provided by the present application.

[0022] Explanation of reference numerals in the drawings:

[0023] 1. First microstrip line; 11. First coupling section; 2. Second microstrip line; 21. Second coupling section; 3. First clearance area; 4. Second clearance area; 5. Extension section; A. First direction; B. Second direction. Detailed implementation manners

[0024] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be completely conveyed to those skilled in the art.

[0025] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the present application should have the ordinary meanings understood by those skilled in the art to which the present application belongs.

[0026] The inventor found that connecting a coupler directly purchased from the manufacturer to the circuit not only increases the cost but also increases the volume of the circuit board. Connecting the coupler to the circuit requires continuous debugging, which takes a long time and has a large insertion loss. The inventor wants to directly change the structure of the circuit board and directly process a PCB board with a coupling function to replace the external coupler to solve the above problems.

[0027] Embodiment 1

[0028] Refer to the appendix Figure 1 , the present application proposes a circuit board, including: a first signal layer; a second signal layer, which is electrically connected to the first signal layer; a first microstrip line 1, disposed on the first signal layer and the first microstrip line 1 includes a first coupling section 11 extending along the first direction A; and a second microstrip line 2, disposed on the second signal layer, the second microstrip line 2 has a second coupling section 21 that extends in the same direction as and overlaps with the first coupling section 11, and is used for coupling the radio frequency signal in the first microstrip line 1.

[0029] Specifically, as Figure 1As shown, the first signal layer and the second signal layer of the circuit board are electrically connected. The first signal layer and the second signal layer can be adjacent, that is, directly above or below each other; or other signal layers can be provided between them, which means that the first signal layer and the second signal layer are not directly adjacent, but are separated by other signal layers. The first signal layer is provided with a first microstrip line 1, and the second signal layer is provided with a second microstrip line 2. The lengths and widths of the first microstrip line 1 and the second microstrip line 2 can be set according to actual needs. The first microstrip line 1 includes a first coupling section 11. The number of the first coupling sections 11 can be multiple, that is, multiple first coupling sections 11 can be arranged at intervals on one microstrip line. The interval distance between the multiple first coupling sections 11 can be set according to actual needs. For example, the interval distances between the multiple first coupling sections 11 are the same or different. At the same time, multiple second coupling sections 21 can be provided on the second microstrip line 2. The interval distance between the multiple second coupling sections 21 can be set according to actual needs. For example, the interval distances between the multiple second coupling sections 21 are the same or different. The first coupling section 11 overlaps with the second coupling section 21, that is, the projection parts of the first coupling section 11 and the second coupling section 21 in the thickness direction of the circuit board overlap partially or completely.

[0030] For the circuit board provided in this application, by respectively arranging microstrip lines on different signal layers, the space of the circuit board can be fully utilized, making the circuit board more compact. The coupling is achieved through the first coupling section 11 of the first microstrip line 1 and the second coupling section 21 of the second microstrip line 2. By using the built-in coupling sections instead of external couplers, the number of solder joints is reduced. In addition, reducing the number of solder joints helps to reduce the insertion loss caused by the solder joints and improve the signal transmission efficiency. Therefore, this circuit board can fully utilize the space of the circuit board, use its own microstrip lines to achieve the coupling function, make the circuit board occupy less space, reduce the number of solder joints, and reduce the insertion loss caused by the solder joints.

[0031] In some modified implementation manners of the first aspect of this application, it further includes: a signal transmitter for transmitting a radio frequency signal. The input end of the first microstrip line 1 is connected to the signal transmitter so that the radio frequency signal passes through the first coupling section 11; a test socket, the output end of the first microstrip line 1 is connected to the test socket; a transceiver chip, the input end of the second microstrip line 2 is grounded, and the output end is connected to the transceiver chip. The second coupling section 21 overlapping with the first coupling section 11 couples a part of the radio frequency signal of the first microstrip line 1 into the second microstrip line 2 and transmits it to the transceiver chip.

[0032] Specifically, the signal transmitter is used to generate and transmit radio frequency signals. The input end of the first microstrip line 1 is signal-connected to the signal transmitter and is used to receive radio frequency signals. The output end of the first microstrip line 1 is connected to the test socket, and the test socket can be used to test the signal quality. The transceiver chip has the functions of a receiver and a transmitter and can send and receive signals simultaneously. The input end of the second microstrip line 2 is grounded. The input end passes through a via to another signal layer adjacent to or spaced from the second signal layer, and then continues to pass through a via to the surface layer, which is usually the top layer or the bottom layer of the circuit board and is used to place components, connectors, etc. The input end of the second microstrip line 2 is led to the surface layer through a via, which is convenient for connecting to external components or devices. The input end of the second microstrip line 2 is directly connected to the ground layer, which can ensure the stability of the signal reference ground and reduce signal interference. The radio frequency signal is transmitted on the first microstrip line 1 to generate an electromagnetic field. The second coupling section 21 of the second microstrip line 2 overlaps with the first coupling section 11 of the first microstrip line 1. The second microstrip line 2 can sense the electromagnetic field generated by the first microstrip line 1, so as to couple a part of the signal into the second microstrip. The output end of the second microstrip line 2 transmits the radio frequency signal coupled from the first microstrip line 1 to the transceiver chip. The transceiver chip can demodulate, amplify, etc. the received signal, or modulate, amplify, etc. the signal to be transmitted. In addition, a matching network can also be added between the output end of the second microstrip line 2 and the transceiver chip to ensure impedance matching and reduce signal reflection.

[0033] In some embodiments, the first signal layer is provided with a first clearance area 3, and the first clearance area 3 corresponds to and is adapted to the first coupling section 11; the second signal layer is provided with a second clearance area 4, and the second clearance area 4 corresponds to the second coupling section 21 and the first clearance area 3 and is adapted to the second coupling section 21; wherein, the first signal layer is adjacent to the second signal layer.

[0034] Specifically, such as Figure 1As shown, in order to reduce the conductors and other signal lines near the first coupling section 11 and the second coupling section 21, thereby reducing crosstalk between signals, a first clearance area 3 is provided at the position of the first coupling section 11 on the first signal layer, and a second clearance area 4 is provided at the position of the second coupling section 21 on the second signal layer. The first clearance area 3 and the second clearance area 4 are respectively holes dug on the first signal layer and the second signal layer. The area size of the first clearance area 3 matches that of the first coupling section 11, enabling the first coupling section 11 to be exposed from the side of the first signal layer facing away from the first microstrip line 1. The area size of the second clearance area 4 matches that of the second coupling section 21, enabling the second coupling section 21 to be exposed from the side of the second signal layer facing away from the second microstrip line 2. The areas of the first clearance area 3 and the second clearance area 4 can be the same or different, and the projection parts of the first clearance area 3 and the second clearance area 4 in the thickness direction of the circuit board overlap partially or completely. In order to strengthen the coupled signals, the first signal layer and the second signal layer are two adjacent signal layers. By providing the first clearance area 3 and the second clearance area 4, the performance of the circuit board can be effectively improved, and the signal quality and reliability can be enhanced.

[0035] In some embodiments, a third clearance area corresponding to and adapted to the first clearance area 3 is provided on a third signal layer on the side of the first signal layer adjacent to and opposite the second signal layer, and / or a fourth clearance area corresponding to and adapted to the second clearance area 4 is provided on a fourth signal layer on the side of the second signal layer adjacent to and opposite the first signal layer.

[0036] Specifically, in order to reduce signal interference from other signal layers to the first coupling section 11 and the second coupling section 21, a third clearance area corresponding to and adapted to the first clearance area 3 (not shown in the figure) is provided on a third signal layer on the side of the first signal layer adjacent to and opposite the second signal layer. The area and position of the third clearance area correspond to and are adapted to those of the first clearance area 3, and / or a fourth clearance area corresponding to and adapted to the second clearance area 4 (not shown in the figure) is provided on a fourth signal layer on the side of the second signal layer adjacent to and opposite the first signal layer. The area and position of the fourth clearance area correspond to and are adapted to those of the second clearance area 4.

[0037] In some embodiments, a coupling gap is provided between the first coupling section 11 and the second coupling section 21.

[0038] Specifically, in order to reduce the signal crosstalk between the first microstrip line 1 and the second microstrip line 2 and improve the signal integrity, a coupling gap (not shown in the figure) is provided between the first coupling section 11 and the second coupling section 21. The coupling gap is the distance between the first coupling section 11 and the second coupling section 21 in the thickness direction of the circuit board. By adjusting the size of the coupling gap, the effective dielectric constant of the two microstrip lines can be precisely controlled, and then the characteristic impedance of the two microstrip lines can be adjusted to ensure good impedance matching. The larger the coupling coefficient, the smaller the distance between the first coupling section 11 and the second coupling section 21.

[0039] In some embodiments, the center line of the first coupling section 11 along the first direction A coincides with the center line of the second coupling section 21 along the first direction A.

[0040] Specifically, as Figure 1 shown, the center line of the first coupling section 11 along the first direction A coincides with the center line of the second coupling section 21 along the first direction A, which can ensure the maximum electromagnetic field coupling, reduce the attenuation of the signal during the coupling process, maintain the signal integrity, help reduce the loss of the signal during the transmission process, and improve the signal quality.

[0041] In some embodiments, the first coupling section 11 starts from the midpoint of the first microstrip line 1 and extends towards the other end of the first microstrip line 1.

[0042] Specifically, as Figure 1 shown, when the first microstrip line 1 transmits radio frequency signals, an electromagnetic field will be generated, and this electromagnetic field is distributed around the first microstrip line 1. The first coupling section 11 starts from the midpoint of the first microstrip line 1, that is, the coupling position starts from the middle position of the first microstrip line 1. Then the coupling position is at the position where the electromagnetic field generated by the first microstrip line 1 is the strongest, and the second coupling section 21 can interact with the electromagnetic field of the first microstrip line 1 to the maximum extent, so as to achieve the maximum coupling efficiency.

[0043] This circuit board can be applied to different frequency ranges. Figure 2 is the circuit insertion loss curve graph of this circuit board. Figure 3 is the circuit coupling degree curve graph of this circuit board. It can be seen from the figure that the low-frequency coupling degree is 27 dB and the insertion loss is 0.07 dB; the intermediate-frequency coupling degree is 20 dB and the insertion loss is 0.17 dB.

[0044] Embodiment 2

[0045] In some embodiments, the line width of the first coupling section 11 along the second direction B is greater than the line width of the second coupling section 21 along the second direction B; the second direction B is perpendicular to the first direction A and the longitudinal direction.

[0046] Specifically, as Figure 4As shown, the width of the first coupling section 11 along the second direction B is greater than the line width of the second coupling section 21 along the second direction B. The wider first coupling section 11 can provide a larger electromagnetic field interaction area, thereby improving the coupling efficiency with the second coupling section 21. The larger coupling area helps to ensure that more signal energy can be effectively captured by the second coupling section 21.

[0047] In some embodiments, extension sections 5 extending along the first direction A are respectively provided at both ends of the second coupling section 21, and the two extension sections 5 are staggered from the first microstrip line 1 respectively.

[0048] Specifically, as Figure 5 shown, the lengths of the two extension sections 5 can be the same or different. The two extension sections 5 can be located on the same side of the first microstrip line 1, or can be respectively located on both sides of the first microstrip line 1. The extension section 5 can reduce the attenuation of the signal during the coupling process and maintain the stability of the signal.

[0049] Embodiment Three

[0050] In some embodiments, the line width of the first coupling section 11 along the second direction B is greater than the width of the remaining part of the first microstrip line 1 in the same direction; the line width of the second coupling section 21 along the second direction B is greater than the width of the remaining part of the second microstrip line 2 in the same direction; the second direction B is perpendicular to the first direction A and the longitudinal direction.

[0051] Specifically, as shown in the figure, a wider microstrip line has a lower characteristic impedance, while a narrower microstrip line has a higher characteristic impedance. The line width of the first coupling section 11 along the second direction B is greater than the width of the remaining part of the first microstrip line 1 in the same direction, and the line width of the second coupling section 21 along the second direction B is greater than the width of the remaining part of the second microstrip line 2 in the same direction, which can reduce its impedance. By adjusting the width of the first coupling section 11, it is possible to ensure that the characteristic impedance of this section matches the impedance of the other parts of the entire microstrip line and the second coupling section 21 coupled thereto, which helps to reduce the reflection of the signal during the coupling process and improve the signal transmission efficiency.

[0052] It should be noted that in the description of this specification, the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present application; terms such as "connection", "installation", and "fixation" should all be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0053] In the description of this specification, the descriptions of the terms "one embodiment", "some embodiments", "specific embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0054] As described above, the above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, and all should be covered by the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims described.

Claims

1. A circuit board, characterized in that, Comprising: A first signal layer; A second signal layer, electrically connected to the first signal layer; A first microstrip line, disposed on the first signal layer and the first microstrip line includes a first coupling section extending in a first direction; And A second microstrip line, disposed on the second signal layer, the second microstrip line having a second coupling section extending in the same direction and overlapping with the first coupling section for coupling a radio frequency signal in the first microstrip line.

2. The circuit board according to claim 1, wherein Further comprising: A signal transmitter for transmitting the radio frequency signal, an input end of the first microstrip line is connected to the signal transmitter so that the radio frequency signal passes through the first coupling section; A test socket, an output end of the first microstrip line is connected to the test socket; A transceiver chip, an input end of the second microstrip line is grounded, an output end is connected to the transceiver chip, and the second coupling section overlapping with the first coupling section couples a part of the radio frequency signal in the first microstrip line into the second microstrip line and transmits it to the transceiver chip.

3. The circuit board according to claim 1, wherein The first signal layer is provided with a first clearance area and the first clearance area corresponds to and adapts to the first coupling section; The second signal layer is provided with a second clearance area and the second clearance area corresponds to and adapts to the second coupling section and the first clearance area; Wherein, the first signal layer and the second signal layer are adjacent.

4. The circuit board according to claim 3, wherein A coupling gap is provided between the first coupling section and the second coupling section.

5. The circuit board according to claim 1, wherein A center line of the first coupling section along the first direction coincides with a center line of the second coupling section along the first direction.

6. The circuit board according to claim 1, wherein The first coupling section starts from the midpoint of the first microstrip line and extends towards the other end of the first microstrip line.

7. The circuit board according to claim 1, wherein A line width of the first coupling section along a second direction is greater than a line width of the second coupling section along the second direction; The second direction is perpendicular to the first direction.

8. The circuit board according to claim 1, wherein Extension sections extending in the first direction are respectively provided at two ends of the second coupling section and the two extension sections are respectively staggered from the first microstrip line.

9. The circuit board according to claim 1, wherein A line width of the first coupling section along a second direction is greater than a width of the rest of the first microstrip line in the same direction; A line width of the second coupling section along the second direction is greater than a width of the rest of the second microstrip line in the same direction; The second direction is perpendicular to the first direction.

10. The circuit board according to claim 3, wherein A third clearance area corresponding to and adapting to the first clearance area is provided on a third signal layer on a side of the first signal layer and the second signal layer that are opposite and adjacent, and / or a fourth clearance area corresponding to and adapting to the second clearance area is provided on a fourth signal layer on a side of the second signal layer and the first signal layer that are opposite and adjacent.

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