Branch coupler

Abstract

A branch coupler comprises: a first branch arranged on a first surface of a substrate, comprising an input end, an isolation end, a first transmission line, a first branch line and a second branch line, the input end is connected with the isolation end through the first transmission line, the first branch line is electrically connected to the input end, and the second branch line is electrically connected to the isolation end; a second branch arranged on a second surface of the substrate, comprising a first output end, a second output end, a second transmission line, a third branch line and a fourth branch line, the first output end is connected with the second output end through the second transmission line, the third branch line is electrically connected to the first output end, and the fourth branch line is electrically connected to the second output end; wherein the first branch line is electrically connected with the third branch line through a first via, and the second branch line is electrically connected with the fourth branch line through a second via, so as to reduce the area of the branch coupler, and meet the miniaturization requirement of communication products under the premise of ensuring performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of couplers, in particular to a branch coupler. BACKGROUND

[0002] With the development of communication technology, various communication products are increasingly developing towards miniaturization. However, the current branch coupler has a large area and occupies a large area of the PCB, which is not conducive to the miniaturization of communication products. SUMMARY

[0003] Therefore, it is necessary to provide a branch coupler to reduce the size to meet the miniaturization of communication products.

[0004] An embodiment of the present application provides a branch coupler, comprising:

[0005] a first branch arranged on a first surface of the substrate, comprising an input end, an isolation end, a first transmission line, a first branch line and a second branch line, the input end and the isolation end being connected by the first transmission line, the first branch line being electrically connected to the input end, and the second branch line being electrically connected to the isolation end;

[0006] a second branch arranged on a second surface of the substrate, comprising a first output end, a second output end, a second transmission line, a third branch line and a fourth branch line, the first output end and the second output end being connected by the second transmission line, the third branch line being electrically connected to the first output end, and the fourth branch line being electrically connected to the second output end;

[0007] wherein the first branch line is electrically connected to the third branch line through a first via hole, and the second branch line is electrically connected to the fourth branch line through a second via hole.

[0008] Preferably, the first branch and the second branch are structurally identical and reversely symmetrical, the first branch line and the second branch line are structurally identical and mutually symmetrical, and the third branch line and the fourth branch line are structurally identical and mutually symmetrical.

[0009] Preferably, the first branch line of the first branch comprises:

[0010] a first microstrip line having one end electrically connected to the input end;

[0011] a first U-shaped structure having one end electrically connected to the first microstrip line and the other end suspended towards the first microstrip line;

[0012] a first L-shaped structure having one end electrically connected to one end of the first U-shaped structure and the other end suspended and semi-surrounding the first U-shaped structure;

[0013] a first inverted L-shaped structure having one end electrically connected to one end of the first U-shaped structure and the other end being free;

[0014] the second branch line of the first branch comprises:

[0015] a second microstrip line having one end electrically connected to the input terminal;

[0016] a second U-shaped microstrip line having one end electrically connected to the second microstrip line and the other end being free and facing the first microstrip line;

[0017] a second L-shaped structure having one end electrically connected to one end of the second U-shaped microstrip line and the other end being free and semi-enclosing the second U-shaped microstrip line;

[0018] a second inverted L-shaped microstrip line having one end electrically connected to one end of the second U-shaped microstrip line and the other end being free.

[0019] Preferably, the third branch line of the second branch comprises:

[0020] a third microstrip line having one end electrically connected to the input terminal;

[0021] a third U-shaped microstrip line having one end electrically connected to the third microstrip line and the other end being free and facing the first microstrip line;

[0022] a third L-shaped microstrip line having one end electrically connected to one end of the third U-shaped microstrip line and the other end being free and semi-enclosing the third U-shaped microstrip line;

[0023] a third inverted L-shaped microstrip line having one end electrically connected to one end of the third U-shaped microstrip line and the other end being free.

[0024] the fourth branch line of the second branch comprises:

[0025] a fourth microstrip line having one end electrically connected to the input terminal;

[0026] a fourth U-shaped microstrip line having one end electrically connected to the fourth microstrip line and the other end being free and facing the first microstrip line;

[0027] a fourth L-shaped microstrip line having one end electrically connected to one end of the fourth U-shaped microstrip line and the other end being free and semi-enclosing the fourth U-shaped microstrip line;

[0028] a fourth inverted L-shaped microstrip line having one end electrically connected to one end of the fourth U-shaped microstrip line and the other end being free.

[0029] Preferably, the first inverted L-shaped microstrip line is electrically connected to the third inverted L-shaped microstrip line through a first via hole;

[0030] the second inverted L-shaped microstrip line is electrically connected to the fourth inverted L-shaped microstrip line through a second via hole.

[0031] Preferably, the first branch line of the first branch comprises:

[0032] a fifth microstrip line electrically connected to the input terminal;

[0033] a sixth microstrip line having one end vertically electrically connected to the fifth microstrip line;

[0034] a fifth U-shaped microstrip line having a bottom portion vertically connected to the fifth microstrip line;

[0035] the second branch line of the first branch comprises:

[0036] a seventh microstrip line electrically connected to the isolation terminal;

[0037] an eighth microstrip line having one end vertically electrically connected to the seventh microstrip line;

[0038] a sixth U-shaped microstrip line having a bottom portion vertically connected to the seventh microstrip line.

[0039] Preferably, the third branch line of the second branch comprises:

[0040] a ninth microstrip line electrically connected to the first output terminal;

[0041] a tenth microstrip line having one end vertically electrically connected to the ninth microstrip line;

[0042] a seventh U-shaped microstrip line having a bottom portion vertically connected to the ninth microstrip line;

[0043] the fourth branch line of the second branch comprises:

[0044] an eleventh microstrip line electrically connected to the second output terminal;

[0045] a twelfth microstrip line having one end vertically electrically connected to the eleventh microstrip line;

[0046] an eighth U-shaped microstrip line having a bottom portion vertically connected to the eleventh microstrip line.

[0047] Preferably, the sixth microstrip line and the tenth microstrip line are electrically connected through the first via hole;

[0048] the eighth microstrip line and the twelfth microstrip line are electrically connected through the second via hole.

[0049] Preferably, the first branch and the second branch are structurally identical and inversely symmetric;

[0050] the first branch line and the second branch line are structurally identical and symmetric to each other, and the third branch line and the fourth branch line are structurally identical and symmetric to each other;

[0051] The input end and the isolation end are parallel, and the first output end and the second output end are parallel.

[0052] Preferably, the first branch line and the second branch line are structurally identical and mutually symmetrical, and the third branch line and the fourth branch line are structurally identical and mutually symmetrical.

[0053] The input end and the isolation end extend along two ends of the first transmission line respectively, and the first output end and the second output end are parallel.

[0054] Compared with the prior art, the branch coupler provided by the embodiment of the present application comprises a first branch and a second branch arranged on different planes of a substrate, and the first branch and the second branch are electrically connected through a via hole, thereby reducing the area of the branch coupler and meeting the miniaturization requirement of a communication product. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 It is a perspective structural schematic diagram of the branch coupler of an embodiment of the present application.

[0056] Figure 2 It is a structural schematic diagram of the branch coupler of an embodiment of the present application.

[0057] Figure 3 It is a structural schematic diagram of the first branch and the second branch of the branch coupler of an embodiment of the present application.

[0058] Figure 4 It is a structural schematic diagram of the branch coupler of another embodiment of the present application.

[0059] Figure 5 It is a structural schematic diagram of the first branch and the second branch of the branch coupler of another embodiment of the present application.

[0060] Figure 6 It is an S parameter simulation diagram of the branch coupler 10 according to an embodiment of the present application.

[0061] Figure 7 It is an output port isolation degree S parameter simulation diagram of the branch coupler 10 according to an embodiment of the present application.

[0062] Figure 8 It is a phase difference diagram of the branch coupler 10 according to an embodiment of the present application.

[0063] Figure 9 It is an amplitude difference diagram of the branch coupler 10 according to an embodiment of the present application.

[0064] Explanation of main element symbols

[0065] Coupling brancher 10

[0066] Substrate 11

[0067] First surface 110

[0068] Second surface 112

[0069] GND 111

[0070] First branch 100

[0071] Second branch 101

[0072] First transmission line L1

[0073] Second transmission line L2

[0074] Input end P1

[0075] Isolation end P2

[0076] First output end P3

[0077] Second output end P4

[0078] First via via1

[0079] Second via via2

[0080] First to twelfth microstrip lines T1-T12

[0081] First to eighth U-shaped microstrip lines U1-U8

[0082] First to fourth L-shaped microstrip lines Tr1-Tr4

[0083] First to fourth inverted L-shaped microstrip lines Tp1-Tp4

[0084] The following specific embodiments will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0085] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0086] It should be noted that the terms "first", "second", and the like in the description of embodiments of the present application are intended to indicate or specify particular aspects of the claimed application, and are not intended to imply or warrant that the recited order or combination of features will necessarily be employed. Thus, features defined with "first", "second" and the like may be employed in either order or simultaneously, or may be substituted with one another. Additionally, technical solutions of various embodiments can be combined with each other, but it must be based on the fact that a person skilled in the art can realize the combination, and when the combination of technical solutions contradicts each other or cannot be realized, it is considered that the combination of technical solutions does not exist, and is not within the protection scope of the present application.

[0087] Referring to Figures 1-3 As shown in the drawings, Figure 1 Fig. 1 is a perspective view of an embodiment of the branch coupler 10 of the present application, Figure 2 Fig. 2 is a structural schematic view of an embodiment of the branch coupler 10 of the present application, Figure 3 Fig. 3 is a schematic view of the first branch 100 and the second branch 101 of the branch coupler 10 of the present application. In the embodiment, the branch coupler 10 is applied to a communication product, such as a wireless communication device, as shown in Fig. 4. Figure 1 As shown in the drawings, the branch coupler 10 includes the first branch 100 and the second branch 101. The first branch 100 and the second branch 101 are arranged on different layers of the substrate 11. In the embodiment, the first branch 100 is arranged on the first surface 110 of the substrate 11, and the second branch 101 is arranged on the second surface 112 of the substrate 11 and electrically connected through a via. The first branch 100 and the second branch 101 are the same in structure and are reverse symmetric to each other. In the embodiment, the reverse symmetry means that the first branch 100 is rotated by 180 degrees and is symmetric to the second branch. The projection of the first branch 100 on the second surface of the substrate 11 partially overlaps the second branch 101. Specifically, the first branch 100 includes an input port P1, an isolation port P2, a first transmission line L1, a first branch line S1, and a second branch line S2. The input port P1 and the isolation port P2 are connected through the first transmission line L1. The first branch line S1 is electrically connected to the input port P1, and the second branch line S2 is electrically connected to the isolation port P2. Similarly, the second branch 101 includes a first output port P3, a second output port P4, a second transmission line L2, a third branch line S3, and a fourth branch line S4. The first output port P3 and the second output port P4 are connected through the second transmission line L2. The third branch line S3 is electrically connected to the first output port P3, and the fourth branch line S4 is electrically connected to the second output port P4. The first branch line S1 is electrically connected to the third branch line S3 through a first via via1, and the second branch line S2 is electrically connected to the fourth branch line S4 through a second via via2. A GND layer 111 is further arranged between the first surface and the second surface of the substrate 11. It can be understood that the arrangement of the ports is not intended to limit the present application, and the arrangement of the ports can be designed according to actual needs.

[0088] In the embodiment, the first branch line S1 and the second branch line S2 are identical in structure and symmetrical to each other, and the third branch line S3 and the fourth branch line S4 are identical in structure and symmetrical to each other.

[0089] In the embodiment, the first branch line S1 of the first branch 100 includes a first microstrip line T1, a first U-shaped microstrip line U1, a first L-shaped microstrip line Lr1, and a first inverted L-shaped microstrip line Lp1. One end of the first microstrip line T1 is electrically connected to the input end P1. One end of the first U-shaped microstrip line U1 is electrically connected to the first microstrip line T1, and the other end thereof is suspended towards the first microstrip line T1. One end of the first L-shaped microstrip line Lr1 is electrically connected to one end of the first U-shaped microstrip line U1, and the other end thereof is suspended and half-encloses the first U-shaped microstrip line U1. One end of the first inverted L-shaped microstrip line Lp1 is electrically connected to one end of the first U-shaped microstrip line U1, and the other end thereof is suspended. The second branch line S2 of the first branch 100 includes a second microstrip line T2, a second U-shaped microstrip line U2, a second L-shaped microstrip line Lr2, and a second inverted L-shaped microstrip line Lp2. One end of the second microstrip line T2 is electrically connected to the isolation end P2. One end of the second U-shaped microstrip line U2 is electrically connected to the second microstrip line T2, and the other end thereof is suspended towards the second microstrip line T2. One end of the second L-shaped microstrip line Lr2 is electrically connected to one end of the second U-shaped microstrip line U2, and the other end thereof is suspended and half-encloses the second U-shaped microstrip line U2. One end of the second inverted L-shaped microstrip line Lp2 is electrically connected to one end of the second U-shaped microstrip line U2, and the other end thereof is suspended.

[0090] Similarly, the second branch 101 is identical in structure to the first branch 100, that is, the third branch line S3 of the second branch 101 includes a third microstrip line T3, a third U-shaped microstrip line U3, a third L-shaped microstrip line Lr3, and a third inverted L-shaped microstrip line Lp3. One end of the third microstrip line T3 is electrically connected to the first output end P3. The connections of the other microstrip lines of the third branch line S3 are similar to those of the first branch line S1 of the first branch 100, and are not described herein again.

[0091] Similarly, the fourth branch line S4 of the second branch 101 is identical in structure to the second branch line S2 of the first branch 100, that is, the fourth branch line S4 of the second branch 101 includes a fourth microstrip line T4, a fourth U-shaped microstrip line U4, a fourth L-shaped microstrip line Lr4, and a fourth inverted L-shaped microstrip line Lp4. One end of the fourth microstrip line T3 is electrically connected to the second output end P4. The connections of the other microstrip lines of the fourth branch line S4 are similar to those of the second branch line S2 of the first branch 100, and are not described herein again.

[0092] In the embodiment, the first inverted L-shaped microstrip line Lr1 is electrically connected to the third inverted L-shaped microstrip line Lr3 through a first via via1, and the second inverted L-shaped microstrip line Lr2 is electrically connected to the fourth inverted L-shaped microstrip line Lp4 through a second via via2. Figure 1As shown, the projection of the first inverted L-shaped microstrip line Lr1 on the second surface of the substrate 11 is connected with the third inverted L-shaped microstrip line Lr3, and the projection of the second inverted L-shaped microstrip line Lr2 on the second surface of the substrate 11 is connected with the fourth inverted L-shaped microstrip line Lp4.

[0093] In an embodiment, the distance between the projection of the first transmission line L1 on the second surface of the substrate 11 and the second transmission line L2 is 1.88 mm, and the distance between the first inverted L-shaped microstrip line Lr1 and the third inverted L-shaped microstrip line Lr3 is 9.14 mm. The size is small, which meets the miniaturization requirement of communication products. It can be understood that the distance is adjusted according to actual requirements, which is only an example and does not limit the present application.

[0094] In other embodiments of the present application, the first branch 100 and the second branch 101 can have other structures. For example, Figures 4-5 As shown, Figure 4 FIG. 4 is a structural schematic diagram of a branch coupler 10 according to another embodiment of the present application, Figure 5 FIG. 5 is a structural schematic diagram of the first branch 100 and the second branch 101 of the branch coupler 10 according to another embodiment of the present application. In this embodiment, the first branch line S1 of the first branch 100 can include a fifth microstrip line T5, a sixth microstrip line T6, and a fifth U-shaped microstrip line U5, wherein the fifth microstrip line T5 is electrically connected to the input end P1; the sixth microstrip line T6 has one end vertically electrically connected to the fifth microstrip line T5; and the fifth U-shaped microstrip line U5 has a bottom vertically connected to the fifth microstrip line T5. As shown, the two extension lines of the fifth U-shaped microstrip line U5 perpendicular to the bottom are not of the same length. The second branch line S2 of the first branch 100 can include a seventh microstrip line T7, an eighth microstrip line T8, and a sixth U-shaped microstrip line U6, wherein the seventh microstrip line T7 is electrically connected to the isolation end P2; the eighth microstrip line T8 has one end vertically electrically connected to the seventh microstrip line T7; and the sixth U-shaped microstrip line U6 has a bottom vertically connected to the seventh microstrip line T7. As shown, the two extension lines of the sixth U-shaped microstrip line U6 perpendicular to the bottom are not of the same length.

[0095] Similarly, the second branch 101 has the same structure as the first branch 100. The third branch line S3 of the second branch 101 includes a ninth microstrip line T9, a tenth microstrip line T10, and a seventh U-shaped microstrip line U7. The fourth branch line S4 of the second branch 101 includes an eleventh microstrip line T11, a twelfth microstrip line T12, and an eighth U-shaped microstrip line U8. The connection of the above-mentioned microstrip lines is the same as that of the first branch line S1 and the second branch line S2 of the first branch 100, which will not be described here.

[0096] In the embodiment, the first branch 100 and the second branch 101 are structurally identical and reverse symmetric; the first branch line S1 and the second branch line S2 are structurally identical and symmetric to each other, and the third branch line S3 and the fourth branch line S4 are structurally identical and symmetric to each other; the input end P1 and the isolation end P2 are parallel, and the first output end P3 and the second output end P4 are parallel.

[0097] In another embodiment of the present application, the first branch line S1 and the second branch line S2 are structurally identical and symmetric to each other, and the third branch line S3 and the fourth branch line S4 are structurally identical and symmetric to each other. The projection of the first branch line S1 on the second surface of the substrate 11 coincides with the third branch line S3, and the projection of the second branch line S2 on the second surface of the substrate 11 coincides with the fourth branch line S4. The projection of the first transmission line L1 on the second surface of the substrate 11 coincides with the second transmission line L2. The input end P1 and the isolation end P2 extend along the two ends of the first transmission line L1, and the first output end P2 and the second output end P4 are parallel. It can be understood that in other embodiments, the port arrangement can also have other ways, which are not limited herein.

[0098] Referring to Figure 6 , it can be seen that Figure 6 , the S11, S21 and S31 parameter simulation diagram of the branch coupler 10 described in an embodiment of the present application is shown. As shown in the figure, the branch coupler parameter S11 has a frequency band of about 4.8GHz-6.3GHz with an attenuation greater than 10dB, and the center frequency is 5.6GHz.

[0099] Referring to Figure 7 , it can be seen that Figure 7 , the output port isolation S parameter simulation diagram of the branch coupler 10 described in an embodiment of the present application is shown. As shown in the figure, the two output ends of the branch coupler 10 have good isolation in the frequency band of 4.6GHz-6.6GHz.

[0100] Referring to Figure 8 , it can be seen that Figure 8 , the phase difference diagram of the branch coupler 10 described in an embodiment of the present application is shown. As shown in the figure, the first output end P3 and the second output end P4 have a smaller output phase difference in the frequency band of 4.9GHz-6.2GHz, and the phase difference is less than 10°.

[0101] Referring to Figure 9 , it can be seen that Figure 9 , the amplitude difference diagram of the branch coupler 10 described in an embodiment of the present application is shown. As shown in the figure, the first output end P3 and the second output end P4 have a smaller amplitude output difference in the frequency band of 4.9GHz-6.2GHz, and the amplitude difference is less than 2dB.

[0102] Compared with the prior art, the branch coupler provided by the embodiment of the application comprises a first branch and a second branch arranged on different planes of a substrate, and the first branch and the second branch are electrically connected through a via hole, so that the area of the branch coupler is reduced, and the miniaturization requirement of a communication product is met under the premise of ensuring performance.

[0103] Those skilled in the art should understand that the above embodiments are only used to illustrate the application, and are not used as a limitation to the application, and any appropriate changes and modifications made to the above embodiments within the spirit and principle of the application fall within the scope of the application.

Claims

1. A branch coupler provided on a substrate, characterized by, The application relates to a microstrip filter, which comprises: a first branch arranged on a first surface of a substrate, comprising an input end, an isolation end, a first transmission line, a first branch line and a second branch line, the input end being connected to the isolation end through the first transmission line, the first branch line being electrically connected to the input end, the first branch line comprising a first U-shaped microstrip line, one end of which is electrically connected to the input end and the other end of which is suspended towards the first transmission line, the second branch line being electrically connected to the isolation end, the second branch line comprising a second U-shaped microstrip line, one end of which is electrically connected to the isolation end and the other end of which is suspended towards the first transmission line; a second branch arranged on a second surface of the substrate, comprising a first output end, a second output end, a second transmission line, a third branch line and a fourth branch line, the first output end being connected to the second output end through the second transmission line, the third branch line being electrically connected to the first output end, and the fourth branch line being electrically connected to the second output end; wherein the first branch line is electrically connected to the third branch line through a first via hole, and the second branch line is electrically connected to the fourth branch line through a second via hole; the first branch line of the first branch further comprises: a first microstrip line, one end of which is electrically connected to the input end and one end of the first U-shaped microstrip line; a first L-shaped microstrip line, one end of which is electrically connected to one end of the first U-shaped microstrip line and the other end of which is suspended and half-encloses the first U-shaped microstrip line; a first inverted L-shaped microstrip line, one end of which is electrically connected to one end of the first U-shaped microstrip line and the other end of which is suspended; the second branch line of the first branch further comprises: a second microstrip line, one end of which is electrically connected to the isolation end and one end of the second U-shaped microstrip line; a second L-shaped microstrip line, one end of which is electrically connected to one end of the second U-shaped microstrip line and the other end of which is suspended and half-encloses the second U-shaped microstrip line; a second inverted L-shaped microstrip line, one end of which is electrically connected to one end of the second U-shaped microstrip line and the other end of which is suspended; the third branch line of the second branch further comprises: a third microstrip line, one end of which is electrically connected to the input end; a third U-shaped microstrip line, one end of which is electrically connected to the third microstrip line and the other end of which is suspended towards the first microstrip line; a third L-shaped microstrip line, one end of which is electrically connected to one end of the third U-shaped microstrip line and the other end of which is suspended and half-encloses the third U-shaped microstrip line; a third inverted L-shaped microstrip line, one end of which is electrically connected to one end of the third U-shaped microstrip line and the other end of which is suspended; the fourth branch line of the second branch further comprises: a fourth microstrip line, one end of which is electrically connected to the input end; a fourth U-shaped microstrip line, one end of which is electrically connected to the fourth microstrip line and the other end of which is suspended towards the first microstrip line; a fourth L-shaped microstrip line, one end of which is electrically connected to one end of the fourth U-shaped microstrip line and the other end of which is suspended and half-encloses the fourth U-shaped microstrip line; a fourth inverted L-shaped microstrip line, one end of which is electrically connected to one end of the fourth U-shaped microstrip line and the other end of which is suspended.

2. The branch coupler of claim 1, wherein The first branch and the second branch are identical in structure and reverse symmetrical, the first branch line and the second branch line are identical in structure and symmetrical to each other, and the third branch line and the fourth branch line are identical in structure and symmetrical to each other.

3. The branch coupler of claim 2, wherein, The first inverted L-shaped microstrip line is electrically connected with the third inverted L-shaped microstrip line through a first via hole; The second inverted L-shaped microstrip line is electrically connected with the fourth inverted L-shaped microstrip line through a second via hole.

4. A branch coupler provided on a substrate, characterized by Comprise: The first branch is arranged on the first surface of the substrate and comprises an input end, an isolation end, a first transmission line, a first branch line and a second branch line. The input end is connected with the isolation end through the first transmission line. The first branch line is electrically connected with the input end. The first branch line comprises a first U-shaped microstrip line, one end of which is electrically connected with the input end, and the other end thereof is suspended towards the first transmission line. The second branch line is electrically connected with the isolation end. The second branch line comprises a second U-shaped microstrip line, one end of which is electrically connected with the isolation end, and the other end thereof is suspended towards the first transmission line. The second branch is arranged on the second surface of the substrate and comprises a first output end, a second output end, a second transmission line, a third branch line and a fourth branch line. The first output end is connected with the second output end through the second transmission line. The third branch line is electrically connected with the first output end. The fourth branch line is electrically connected with the second output end. The first branch line of the first branch is electrically connected with the third branch line through a first via hole. The second branch line is electrically connected with the fourth branch line through a second via hole. The first branch line of the first branch comprises: The fifth microstrip line is electrically connected with the input end. The sixth microstrip line is vertically electrically connected with the fifth microstrip line at one end. The fifth U-shaped microstrip line is vertically connected with the fifth microstrip line at the bottom. The second branch line of the first branch comprises: The seventh microstrip line is electrically connected with the isolation end. The eighth microstrip line is vertically electrically connected with the seventh microstrip line at one end. The sixth U-shaped microstrip line is vertically connected with the seventh microstrip line at the bottom. The third branch line of the second branch comprises: The ninth microstrip line is electrically connected with the first output end. The tenth microstrip line is vertically electrically connected with the ninth microstrip line at one end. The seventh U-shaped microstrip line is vertically connected with the ninth microstrip line at the bottom. The fourth branch line of the second branch comprises: The eleventh microstrip line is electrically connected with the second output end. The twelfth microstrip line is vertically electrically connected with the eleventh microstrip line at one end. The eighth U-shaped microstrip line is vertically connected with the eleventh microstrip line at the bottom.

5. The branch coupler of claim 4, wherein, The sixth microstrip line is electrically connected with the tenth microstrip line through the first via hole. The eighth microstrip line is electrically connected with the twelfth microstrip line through the second via hole.

6. The branch coupler of claim 4, wherein: The first branch and the second branch are structurally identical and reversely symmetrical. The first branch line and the second branch line are structurally identical and mutually symmetrical. The third branch line and the fourth branch line are structurally identical and mutually symmetrical. The input end and the isolation end are parallel. The first output end and the second output end are parallel.

7. The branch coupler of claim 4, wherein: The first branch line and the second branch line are structurally identical and mutually symmetrical. The third branch line and the fourth branch line are structurally identical and mutually symmetrical. The input and the isolation end extend along two ends of the first transmission line, respectively, and the first output and the second output are parallel.

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