Directional coupler and radio frequency front-end module

Abstract

The invention relates to the field of radio frequency communication, and discloses a directional coupler. The directional coupler comprises a straight-through main line, a first coupling branch line and a second coupling branch line. The straight-through main line, the first coupling branch line and the second coupling branch line are arranged on the substrate. Wherein the first coupling branch line and the second coupling branch line are arranged on the two sides of the straight-through main line respectively. The first coupling branch line and the second coupling branch line are connected through a plurality of bonding lines.

Description

Technical Field

[0001] This application relates to the field of radio frequency communication, and particularly to a directional coupler and a radio frequency front-end module. Background Art

[0002] The radio frequency front-end module is a core component of radio frequency communication devices, and its main function is to be responsible for the reception and transmission of wireless signals. Power detection needs to be performed in the radio frequency front-end module. Among them, the design of the coupler is directly related to the accuracy and stability of power detection.

[0003] As the frequency coverage range of radio frequency mobile terminals becomes wider and wider, broadband directional couplers need to be adopted. Since the signal wavelength corresponding to the low-frequency band is longer, compared with the directional coupler that only covers the high-frequency band, the broadband directional coupler covering the low-frequency band requires a longer through main line and coupling branch line. In this way, it will occupy a larger substrate area, and at the same time, the insertion loss in the high-frequency band is relatively large. Summary of the Invention

[0004] In view of this, the embodiments of this application provide a directional coupler and a radio frequency front-end module, which can reduce the occupation of the substrate and reduce the insertion loss.

[0005] The technical solution of the embodiments of this application is implemented as follows:

[0006] The embodiments of this application provide a directional coupler, which is applied to a radio frequency front-end module. The directional coupler includes: a through main line, a first coupling branch line, and a second coupling branch line; the through main line, the first coupling branch line, and the second coupling branch line are all arranged on a substrate; wherein, the first coupling branch line and the second coupling branch line are respectively arranged on both sides of the through main line; between the first coupling branch line and the second coupling branch line, they are connected by a plurality of bonding wires.

[0007] In some embodiments of this application, the plurality of bonding wires are arranged in sequence along the extending direction of the through main line; each bonding wire straddles the through main line; both ends of each bonding wire are respectively bonded to the first coupling branch line and the second coupling branch line.

[0008] In some embodiments of this application, the plurality of bonding wires are divided into at least one coupling region; in each coupling region, the shape and position of the bonding wire are determined based on a corresponding frequency band.

[0009] In some embodiments of the present application, the directional coupler further includes: a flatness adjustment module, an isolation adjustment module, and an impedance adjustment module; the flatness adjustment module is connected to the first end of the first coupling branch, or is connected to the first end of the second coupling branch; the isolation adjustment module is connected to the second end of the first coupling branch, or is connected to the second end of the second coupling branch; the impedance adjustment module is connected to the first end of the first coupling branch, or is connected to the first end of the second coupling branch; wherein, the first end of the first coupling branch and the first end of the second coupling branch are close to the input end of the through main line; the second end of the first coupling branch and the second end of the second coupling branch are close to the output end of the through main line.

[0010] In some embodiments of the present application, the devices in the flatness adjustment module, the isolation adjustment module, and the impedance adjustment module are surface mount devices.

[0011] In some embodiments of the present application, the flatness adjustment module includes: a first capacitor; the first end of the first capacitor is connected to the first end of the first coupling branch, or is connected to the first end of the second coupling branch; the second end of the first capacitor is grounded; the isolation adjustment module includes: a first resistor; the first end of the first resistor is connected to the second end of the first coupling branch, or is connected to the second end of the second coupling branch; the second end of the first resistor is grounded; the impedance adjustment module includes: a second resistor and a first inductor; the second resistor and the first inductor are in parallel; and, one end of the parallel connection is connected to the first end of the first coupling branch, or is connected to the first end of the second coupling branch.

[0012] In some embodiments of the present application, the isolation adjustment module further includes: a second capacitor; the first end of the second capacitor is connected to the second end of the first coupling branch, or is connected to the second end of the second coupling branch; the second end of the second capacitor is grounded.

[0013] In some embodiments of the present application, the through main line, the first coupling branch, and the second coupling branch are C-shaped, L-shaped, or S-shaped.

[0014] The embodiments of the present application further provide a radio frequency front-end module, and the radio frequency front-end module includes the directional coupler in the above solution.

[0015] It can be understood that by setting the bonding wires, the connection between the first coupling branch line and the second coupling branch line can be realized, and a large coupling degree can be achieved with a short through main line and coupling branch lines. In this way, the occupation of the substrate is reduced; on the one hand, the occupation of the area of the substrate is reduced; on the other hand, the through main line, the first coupling branch line and the second coupling branch line can only occupy one metal layer on the surface of the substrate, without the need to occupy other metal layers. At the same time, the through main line and the coupling branch lines are short, reducing the insertion loss. Brief Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 Structural Schematic Diagram of the Directional Coupler Provided by the Embodiment of the Present Application Figure 1 ;

[0018] Figure 2A Structural Schematic Diagram II of the Directional Coupler Provided by the Embodiment of the Present Application;

[0019] Figure 2B Structural Schematic Diagram of the Directional Coupler Provided by the Embodiment of the Present Application Figure 3 ;

[0020] Figure 2C Structural Schematic Diagram of the Directional Coupler Provided by the Embodiment of the Present Application Figure 4 ;

[0021] Figure 2D Structural Schematic Diagram of the Directional Coupler Provided by the Embodiment of the Present Application Figure 5 ;

[0022] Figure 3 Circuit Schematic Diagram of the Directional Coupler Provided by the Embodiment of the Present Application Figure 1 ;

[0023] Figure 4 Circuit Schematic Diagram II of the Directional Coupler Provided by the Embodiment of the Present Application;

[0024] Figure 5 Structural Schematic Diagram of the RF Front-End Module Provided by the Embodiment of the Present Application. Detailed Embodiments

[0025] Exemplary embodiments disclosed in the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the specific embodiments set forth herein. On the contrary, these embodiments are provided so that the present application can be more thoroughly understood and the scope of the present application disclosed can be fully communicated to those skilled in the art.

[0026] In the following description, numerous specific details are given to provide a more thorough understanding of the present application. However, it will be apparent to one of ordinary skill in the art that the present application may be practiced without one or more of these details. In other instances, some well-known technical features are not described in order to avoid obscuring the present application; that is, not all features of the actual embodiments are described here, and the well-known functions and structures are not described in detail.

[0027] In the drawings, for clarity, the dimensions of layers, regions, elements, and their relative dimensions may be exaggerated. Like reference numerals throughout the drawings denote like elements.

[0028] It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Thus, without departing from the teachings of the present application, the first element, component, region, layer, or portion discussed below may be referred to as the second element, component, region, layer, or portion. And when discussing the second element, component, region, layer, or portion, it does not necessarily imply the existence of a first element, component, region, layer, or portion in the present application.

[0029] The purpose of the terms used herein is only to describe specific embodiments and is not a limitation of the present application. As used herein, the singular forms "a", "an", and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. As used herein, the term "and / or" includes any and all combinations of the associated listed items. All numerical ranges herein include the endpoint values.

[0030] As Figure 1As shown in the figure, the directional coupler includes a through main line and a coupling branch line. The through main line is located between the RFin and RFout ports, and the radio frequency signal is transmitted through the through main line. The coupling branch line is located beside the through main line. The coupling branch line is used to follow the signal change on the through main line, couple a part of the radio frequency signal to the CPLout terminal (coupling output terminal), and output it to the detection module for detection. Among them, the coupling branch line needs to minimize the influence on the through main line as much as possible, and the coupling branch line cannot be interfered by other high-power signals.

[0031] Figure 2A 、 Figure 2B 、 Figure 2C and Figure 2D show the external structure of the directional coupler provided by the embodiment of the present application. Among them, Figure 2A is the top view, Figure 2B is the left view, Figure 2C and Figure 2D are three-dimensional views from different angles.

[0032] Referring to Figure 2A , the directional coupler includes: a through main line 301, a first coupling branch line 401 and a second coupling branch line 402. The through main line 301, the first coupling branch line 401 and the second coupling branch line 402 are all arranged on the substrate 10. Among them, the first coupling branch line 401 and the second coupling branch line 402 are respectively arranged on both sides of the through main line 301.

[0033] Continuing to refer to Figure 2A , between the first coupling branch line 401 and the second coupling branch line 402, they are connected by a plurality of bonding lines 501. The first coupling branch line 401, the second coupling branch line 402 and the plurality of bonding lines 501 can couple the energy of the through main line 301.

[0034] It should be noted that the substrate (LMT) includes multiple metal layers. Using the metal layers, metal lines can be formed to construct a circuit structure. For example, referring to Figure 2B , the first substrate 10 includes a top metal layer 101 and a bottom metal layer 102. Among them, the through main line 301, the first coupling branch line 401 and the second coupling branch line 402 can be formed in the top metal layer 101, and the bottom metal layer 102 can be used as the ground layer (i.e., the grounding terminal).

[0035] It can be understood that by setting the bonding wire 501, the electrical connection between the first coupling branch line 401 and the second coupling branch line 402 can be realized, and a large coupling degree can be achieved with a shorter through main line and coupling branch lines. In this way, the occupation of the substrate 10 is reduced; on the one hand, the occupation of the area of the substrate 10 is reduced; on the other hand, the through main line 301, the first coupling branch line 401 and the second coupling branch line 402 can only occupy one metal layer on the surface of the substrate 10, without the need to occupy other metal layers. At the same time, the through main line and the coupling branch lines are short, reducing the insertion loss.

[0036] In addition, the shape of the bonding wire 501 is easy to adjust. For example, the length, height and direction of the bonding wire 501 can be adjusted. Thus, the coupling degree of the directional coupler can be adjusted more conveniently, that is, the energy at the CPLout end can be adjusted.

[0037] In some embodiments of the present application, referring to Figure 2A , multiple bonding wires 501 are arranged in sequence along the extending direction of the through main line 301. Each bonding wire 501 straddles the through main line 301, and both ends of each bonding wire 501 are bonded and connected to the first coupling branch line 401 and the second coupling branch line 402 respectively. In this way, the coupling of the energy of the through main line 301 can be strengthened.

[0038] In some embodiments of the present application, continuing to refer to Figure 2A , multiple bonding wires 501 can be divided into at least one coupling zone; in each coupling zone, the shape and position of the bonding wire 501 are determined based on a corresponding frequency band. That is to say, one or more coupling zones can be divided, and each coupling zone corresponds to a frequency band; furthermore, the shape and position of the bonding wire 501 in each coupling zone can be designed based on the required frequency band, for example, the height or spacing of the bonding wire is designed. In this way, the energy coupling of one or more frequency bands can be realized, thereby improving the flexibility and expanding the application range of the directional coupler.

[0039] It should be noted that the number of CPLout ends in the directional coupler needs to be set correspondingly according to the number of coupling frequency bands (that is, the number of coupling zones divided by the bonding wire 501); for example, if the bonding wire 501 is divided into two coupling zones and the coupling of signals of two frequency bands can be realized, then the number of CPLout ends also needs to be set to two correspondingly, and the two CPLout ends are respectively used to output the coupling signals of the two frequency bands.

[0040] In some embodiments of the present application, referring to Figure 2A , the directional coupler further includes: a flatness adjustment module 601, an isolation adjustment module 602 and an impedance adjustment module 603.

[0041] In the embodiments of the present application, the flatness adjustment module 601 may be connected to the first end of the first coupling branch 401, or the flatness adjustment module 601 may also be connected to the first end of the second coupling branch 402. The isolation adjustment module 602 may be connected to the second end of the first coupling branch 401, or the isolation adjustment module 602 may also be connected to the second end of the second coupling branch 402. The impedance adjustment module 603 may be connected to the first end of the first coupling branch 401, or the impedance adjustment module 603 may also be connected to the first end of the second coupling branch 402.

[0042] Among them, the first end of the first coupling branch 401 and the first end of the second coupling branch 402 are close to the input end of the through main line 301; the second end of the first coupling branch 401 and the second end of the second coupling branch 402 are close to the output end of the through main line 301.

[0043] It can be understood that by setting the flatness adjustment module 601 and the impedance adjustment module 603, the reflection coefficient and coupling flatness at the CPLout end can be conveniently adjusted, so that the coupled energy can be well output to the detection module. At the same time, by setting the isolation adjustment module 602, good isolation can be achieved.

[0044] In some embodiments of the present application, the devices (such as resistor devices, capacitor devices, and inductor devices) in the flatness adjustment module 601, the isolation adjustment module 602, and the impedance adjustment module 603 are surface-mounted devices (Surface Mounted Devices, SMD).

[0045] It can be understood that using surface-mounted devices improves flexibility, and is easy to process and easy to adjust the frequency band and bandwidth.

[0046] In some embodiments of the present application, as Figure 3 shown, the flatness adjustment module 601 includes: a first capacitor C1. The first end of the first capacitor C1 is connected to the first end of the first coupling branch 401, or is connected to the first end of the second coupling branch 402. The second end of the first capacitor C1 is grounded.

[0047] Continuing to refer to Figure 3 the isolation adjustment module 602 includes: a first resistor R1. The first end of the first resistor R1 is connected to the second end of the first coupling branch 401, or is connected to the second end of the second coupling branch 402. The second end of the first resistor R1 is grounded.

[0048] Continuing to refer to Figure 3, the impedance adjustment module 603 includes: a second resistor R2 and a first inductor L1. The second resistor R2 and the first inductor L1 are connected in parallel; and one end of the parallel connection is connected to the first end of the first coupling branch 401, or connected to the first end of the second coupling branch 402.

[0049] In some embodiments of the present application, as Figure 4 shown, the isolation adjustment module 602 further includes: a second capacitor C2. The first end of the second capacitor C2 is connected to the second end of the first coupling branch 401, or connected to the second end of the second coupling branch 402. The second end of the second capacitor C2 is grounded.

[0050] In some embodiments of the present application, referring to Figure 2A , the through main line 301, the first coupling branch 401, and the second coupling branch 402 can be C-shaped. Compared with the straight shape, the C-shaped through main line and coupling branches can reduce the occupation of the area of the substrate 10.

[0051] In other embodiments of the present application, the through main line 301, the first coupling branch 401, and the second coupling branch 402 can be L-shaped or S-shaped. Compared with the straight shape, the L-shaped or S-shaped through main line and coupling branches can also reduce the occupation of the area of the substrate 10.

[0052] The embodiments of the present application also provide a radio frequency front-end module, as Figure 5 shown, the radio frequency front-end module 90 includes a directional coupler 80. Among them, the directional coupler 80 includes the technical features in the above embodiments.

[0053] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the element.

[0054] The serial numbers of the above embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments. The methods disclosed in several method embodiments provided by the present application can be arbitrarily combined without conflict to obtain new method embodiments. The features disclosed in several product embodiments provided by the present application can be arbitrarily combined without conflict to obtain new product embodiments. The features disclosed in several method or device embodiments provided by the present application can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0055] As described above, it 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, which should all be covered within the protection scope of the present application.

Claims

1. A directional coupler, applied to a radio frequency front-end module, characterized in that: The directional coupler comprises: a straight-through main line, a first coupling branch line and a second coupling branch line; The through main line, the first coupling branch line and the second coupling branch line are all arranged on a substrate; wherein the first coupling branch line and the second coupling branch line are respectively arranged on both sides of the through main line; The first coupling branch line and the second coupling branch line are connected via a plurality of bonding lines.

2. The directional coupler according to claim 1, characterized in that The plurality of bonding lines are arranged in sequence along the extension direction of the through main line; Each of the bonding lines spans the through main line; and both ends of each of the bonding lines are bonded and connected to the first coupling branch line and the second coupling branch line, respectively.

3. The directional coupler according to claim 2, characterized in that: The plurality of bonding lines are divided into at least one coupling zone; In each of the coupling regions, the shape and position of the bonding line are determined based on a corresponding frequency band.

4. The directional coupler according to claim 1, characterized in that: The directional coupler further comprises: a flatness adjustment module, an isolation adjustment module and an impedance adjustment module; The flatness adjustment module is connected to the first end of the first coupling branch line, or connected to the first end of the second coupling branch line; The isolation adjustment module is connected to the second end of the first coupling branch line, or connected to the second end of the second coupling branch line; The impedance adjustment module is connected to the first end of the first coupling branch line, or connected to the first end of the second coupling branch line; The first end of the first coupling branch line and the first end of the second coupling branch line are close to the input end of the straight-through main line; the second end of the first coupling branch line and the second end of the second coupling branch line are close to the output end of the straight-through main line.

5. The directional coupler according to claim 4, characterized in that: The devices in the flatness adjustment module, the isolation adjustment module and the impedance adjustment module are surface mount devices.

6. The directional coupler according to claim 4, characterized in that The flatness adjustment module comprises: a first capacitor; a first end of the first capacitor is connected to a first end of the first coupling branch line, or connected to a first end of the second coupling branch line; a second end of the first capacitor is grounded; The isolation adjustment module comprises: a first resistor; a first end of the first resistor is connected to the second end of the first coupling branch line, or connected to the second end of the second coupling branch line; a second end of the first resistor is grounded; The impedance adjustment module includes: a second resistor and a first inductor; the second resistor and the first inductor are connected in parallel; and one end of the parallel connection is connected to the first end of the first coupling branch line, or is connected to the first end of the second coupling branch line.

7. The directional coupler according to claim 6, characterized in that The isolation adjustment module further includes: a second capacitor; A first end of the second capacitor is connected to a second end of the first coupling branch, or connected to a second end of the second coupling branch; a second end of the second capacitor is grounded.

8. The directional coupler according to any one of claims 1 to 7, characterized in that: The through main line, the first coupling branch line and the second coupling branch line are C-shaped, L-shaped or S-shaped.

9. A radio frequency front-end module, characterized in that: The radio frequency front-end module includes the directional coupler according to any one of claims 1 to 8.

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