A directional coupler and radio frequency front end module

Abstract

The application relates to the field of radio frequency communication, and discloses a directional coupler. The directional coupler comprises 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 arranged on a substrate. The first coupling branch line and the second coupling branch line are arranged on the two sides of the 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] The present application relates to the field of radio frequency communication, in particular to a directional coupler and a radio frequency front-end module. BACKGROUND

[0002] The radio frequency front-end module is a core component of a radio frequency communication device, which is mainly responsible for receiving and transmitting wireless signals. Power detection needs to be performed in the radio frequency front-end module, and the design of the coupler directly relates to the accuracy and stability of the power detection.

[0003] With the frequency coverage range of the radio frequency mobile terminal becoming wider, a wideband directional coupler needs to be used. Since the signal wavelength corresponding to the low frequency band is relatively long, compared with the directional coupler covering only the high frequency band, the wideband directional coupler covering the low frequency band needs a longer through main line and coupling branch line, which will occupy a larger substrate area, and meanwhile, the insertion loss at the high frequency band is large. SUMMARY

[0004] Therefore, the embodiments of the present 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 scheme of the embodiments of the present application is implemented as follows:

[0006] The embodiments of the present application provide a directional coupler applied to a radio frequency front-end module, which comprises 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; the first coupling branch line and the second coupling branch line are arranged on two sides of the through main line respectively; and the first coupling branch line and the second coupling branch line are connected by a plurality of bonding lines.

[0007] In some embodiments of the present application, the plurality of bonding lines are arranged in sequence along the extension direction of the through main line; each bonding line crosses the through main line; and the two ends of each bonding line are respectively bonded to the first coupling branch line and the second coupling branch line.

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

[0009] In some embodiments of the present application, 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 coupled branch or the first end of the second coupled branch; the isolation adjustment module is connected to the second end of the first coupled branch or the second end of the second coupled branch; the impedance adjustment module is connected to the first end of the first coupled branch or the first end of the second coupled branch; wherein the first end of the first coupled branch and the first end of the second coupled branch are close to the input end of the through main line; the second end of the first coupled branch and the second end of the second coupled 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 comprises a first capacitor; the first end of the first capacitor is connected to the first end of the first coupled branch or the first end of the second coupled branch; the second end of the first capacitor is grounded; the isolation adjustment module comprises a first resistor; the first end of the first resistor is connected to the second end of the first coupled branch or the second end of the second coupled branch; the second end of the first resistor is grounded; the impedance adjustment module comprises 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 coupled branch or the first end of the second coupled branch.

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

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

[0014] Embodiments of the present application also provide a radio frequency front end module, which comprises the directional coupler in the above-mentioned scheme.

[0015] It can be understood that the connection between the first coupling branch and the second coupling branch can be realized by setting the bonding line, so that a larger coupling degree can be realized by shorter straight-through main line and coupling branch. 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 straight-through main line, the first coupling branch and the second coupling branch can only occupy one metal layer on the surface of the substrate, without occupying other metal layers. At the same time, the straight-through main line and the coupling branch are shorter, which reduces the insertion loss. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0017] Figure 1 Structure diagram of the directional coupler provided by the embodiments of the present application Figure 1 ;

[0018] Figure 2A Structure diagram of the directional coupler provided by the embodiments of the present application

[0019] Figure 2B Structure diagram of the directional coupler provided by the embodiments of the present application Figure 3 ;

[0020] Figure 2C Structure diagram of the directional coupler provided by the embodiments of the present application Figure 4 ;

[0021] Figure 2D Structure diagram of the directional coupler provided by the embodiments of the present application Figure 5 ;

[0022] Figure 3 Circuit diagram of the directional coupler provided by the embodiments of the present application Figure 1 ;

[0023] Figure 4 Circuit diagram of the directional coupler provided by the embodiments of the present application

[0024] Figure 5 Structure diagram of the radio frequency front end module provided by the embodiments of the present application. DETAILED DESCRIPTION

[0025] Example embodiments of the present application will now be described in detail with reference to the drawings. Although specific embodiments of the application are shown in the drawings, it should be understood that the application can be implemented in various forms and should not be limited to the specific embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0026] In the following description, numerous specific details are given to provide a thorough understanding of the application. However, it will be apparent that the application can be practiced without one or more of the specific details. In other instances, well-known features are not described in detail in order to avoid obscuring the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein was chosen to best describe the

[0027] In the drawings, the size of layers, regions, elements, and the like can be exaggerated for clarity. Like reference numerals refer to like elements throughout.

[0028] It is to be understood that the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections but do not to be construed as limiting the application to three elements or components. The terms are used merely as labels to distinguish elements having similar or related characteristics from each other. Therefore, discussion of a first element, component, region, layer or section below can be discussed as a second element, component, region, layer or section without departing from the teachings of the present application. Similarly, discussion of a second element, component, region, layer or section below can be discussed as a first element, component, region, layer or section without departing from the teachings of the present application.

[0029] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of 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 thereof. As used herein the term "and / or" includes any and all combinations of one or more of the associated listed items. All numerical ranges herein should be read as "from about the lower limit to about the upper limit of the stated range."

[0030] As Figure 1As shown, the directional coupler includes a through main line and a coupling branch line. The through main line is located between the two ports of RFin and RFout, and the radio frequency signal is transmitted from the through main line. The coupling branch line is located beside the through main line, and the coupling branch line is used to follow the signal change on the through main line, and the coupling part of the radio frequency signal is output to the CPLout end (coupling output end) and is output to the detection module for detection. Among them, the coupling branch line needs to reduce the influence on the through main line as much as possible, and the coupling branch line cannot be disturbed by the rest of the high-power signal.

[0031] Figure 2A 、 Figure 2B 、 Figure 2C and Figure 2D The external structure of the directional coupler provided by the embodiment of the application is shown, wherein, Figure 2A is a top view, Figure 2B is a left view, Figure 2C and Figure 2D are three-dimensional views of 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 arranged on both sides of the through main line 301.

[0033] Referring to Figure 2A , the first coupling branch line 401 and the second coupling branch line 402 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 a plurality of metal layers. By using the metal layer, a metal line 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, wherein 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 a ground layer (i.e. ground end).

[0035] It can be understood that by arranging the bonding line 501, the electrical connection between the first coupling branch 401 and the second coupling branch 402 can be achieved, and a larger coupling degree can be achieved by a shorter straight-through main line and coupling branch. 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 straight-through main line 301, the first coupling branch 401 and the second coupling branch 402 can only occupy one metal layer on the surface of the substrate 10, without occupying other metal layers. At the same time, the straight-through main line and the coupling branch are shorter, and the insertion loss is reduced.

[0036] In addition, the shape of the bonding line 501 is easy to adjust. For example, the length, height and direction of the bonding line 501 can be adjusted, so that 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 , a plurality of bonding lines 501 are arranged in sequence along the extension direction of the straight-through main line 301. Each bonding line 501 spans the straight-through main line 301, and the two ends of each bonding line 501 are respectively bonded and connected to the first coupling branch 401 and the second coupling branch 402. In this way, the energy of the straight-through main line 301 can be coupled and strengthened.

[0038] In some embodiments of the present application, continuing to refer to Figure 2A , the plurality of bonding lines 501 can be divided into at least one coupling region; in each coupling region, the shape and position of the bonding line 501 are determined based on a corresponding frequency band. That is, one or more coupling regions can be divided, and each coupling region corresponds to a frequency band. Then, the shape and position of the bonding line 501 in each coupling region can be designed based on the required frequency band, for example, the height or spacing of the bonding line can be designed. In this way, the energy coupling of one or more frequency bands can be achieved, 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 correspondingly set according to the number of coupling frequency bands (i.e. the number of coupling regions into which the bonding line 501 is divided). For example, if the bonding line 501 is divided into two coupling regions, the signals of two frequency bands can be coupled, and the number of CPLout ends also needs to be correspondingly set to two, and the two CPLout ends are respectively used to output the coupled signals of the two frequency bands.

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

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

[0042] 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 straight-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 straight-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 of the CPLout end and the coupling flatness can be conveniently adjusted, so that the coupling 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 the use of surface mounted devices improves flexibility and is easy to process and adjust the frequency band and bandwidth.

[0046] In some embodiments of the present application, as shown in Figure 3 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 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 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 3The 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 after the parallel connection is connected to the first end of the first coupling branch 401, or the first end of the second coupling branch 402.

[0049] In some embodiments of the present application, as shown in Figure 4 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 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 straight-through main branch 301, the first coupling branch 401 and the second coupling branch 402 can be C-shaped. Compared with a straight line shape, the C-shaped straight-through main branch and the coupling branch can reduce the occupation of the area of the substrate 10.

[0051] In some other embodiments of the present application, the straight-through main branch 301, the first coupling branch 401 and the second coupling branch 402 can be L-shaped or S-shaped. Compared with a straight line shape, the L-shaped or S-shaped straight-through main branch and the coupling branch 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 shown in Figure 5 The radio frequency front-end module 90 includes the directional coupler 80. The directional coupler 80 includes the technical features in the above embodiments.

[0053] It should be noted that, in this document, the terms "comprising", "containing", or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles, or devices that include a series of elements not only include those elements, but also include other elements not explicitly listed, or inherent to such processes, methods, articles, or devices. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article, or device that includes the element.

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

[0055] The above description is only the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in 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 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 arranged on a substrate; the first coupling branch line and the second coupling branch line are arranged on two sides of the through main line, respectively; The first coupling branch line and the second coupling branch line are connected by a plurality of bonding lines; The directional coupler is used for coupling signals of at least one frequency band; the plurality of bonding lines are divided into at least one coupling area; the shape and position of the bonding lines in each coupling area are determined based on a corresponding frequency band.

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

3. The directional coupler of claim 1, wherein, 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 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 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 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 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 through main line.

4. The directional coupler of claim 3, wherein The devices in the flatness adjustment module, the isolation adjustment module and the impedance adjustment module are surface mount devices.

5. The directional coupler of claim 3, wherein The flatness adjustment module comprises a first capacitor; the first end of the first capacitor is connected to the first end of the first coupling branch line or the first end of the second coupling branch line; and the second end of the first capacitor is grounded; The isolation adjustment module comprises a first resistor; the first end of the first resistor is connected to the second end of the first coupling branch line or the second end of the second coupling branch line; and the second end of the first resistor is grounded; The impedance adjustment module comprises 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 the first end of the second coupling branch line.

6. The directional coupler of claim 5, wherein, The isolation adjustment module further comprises a second capacitor; The first end of the second capacitor is connected to the second end of the first coupling branch line or the second end of the second coupling branch line; and the second end of the second capacitor is grounded.

7. The directional coupler of any one of claims 1 to 6, wherein The through main line, the first coupling branch line and the second coupling branch line are C-shaped, L-shaped or S-shaped.

8. A radio frequency front-end module, characterized in that, The radio frequency front end module comprises the directional coupler according to any one of claims 1 to 7.

Images