TW202310486A - Branch line coupler - Google Patents

Abstract

The disclosure provides a branch line coupler including a first transmission line, a second transmission line, a first bent transmission line and a second bent transmission line. The first transmission line includes a first elongated transmission line, a first branch transmission line and a second branch transmission line. The first elongated transmission line extends along a predetermined direction, the first branch transmission line has a first slot, and the second branch transmission line has a second slot. The first branch transmission line and the second branch transmission line are in an axisymmetric relationship with respect to a first axis. The first transmission line and the second transmission line are in an axisymmetric relationship with respect to a second axis orthogonal to the first axis. The first bent transmission line is electrically connected to the ends of the first transmission line and the second transmission line on the same side, and the second bent transmission line is electrically connected to the ends of the first transmission line and the second transmission line on the other side.

Description

branch line coupler

This application relates to a coupler, especially a 3dB branch line coupler.

It is well known that in many microwave circuits, directional couplers are often used to solve the related problems caused by distributing power. With the development of mobile communication technology and satellite communication technology, in order to facilitate portability and mobility, the miniaturization of communication equipment is becoming more and more important. Branch line couplers are widely used in microwave integrated circuits and monolithic integrated circuits. A traditional branch line coupler, such as a 3dB branch line coupler, is composed of four quarter-wavelength transmission lines. However, the structure of the conventional branch line coupler occupies a considerable area of the printed circuit board (PCB).

In view of this, in an embodiment of the present application, a miniaturized branch line coupler structure is provided.

An embodiment of the present application discloses a branch line coupler, including: a first port, a second port, a third port, and a fourth port, serving as an input end, a straight-through end, a coupling end, and an isolation end respectively; the first transmission line includes: The first elongated transmission line has a first first end electrically connected to the first port and a first second end electrically connected to the second port, and the first elongated transmission line is along a predetermined direction Extension; the first branch transmission line is electrically connected to the first first end and has a first slit; the second branch transmission line is electrically connected to the first and second ends and has a second slit, wherein the above The first branch transmission line and the above-mentioned second branch transmission line are in an axisymmetric relationship with respect to a first axis; the second transmission line includes: a second elongated transmission line having a second first end electrically connected to the above-mentioned third port and Electrically connected to the second second end of the fourth port, the second elongated transmission line extends along the predetermined direction; the third branch transmission line is electrically connected to the second first end, and has a third narrow Slit; the fourth branch transmission line is electrically connected to the second second end, and has a fourth slit, wherein the third branch transmission line and the fourth branch transmission line are in an axisymmetric relationship with respect to the first axis axis; A bent transmission line electrically connected between the first port and the fourth port; and a second bent transmission line electrically connected between the second port and the third port.

According to an embodiment of the present application, the first branch transmission line includes a helical branch, and the first slit is located between the helical branch and the first bent transmission line.

According to an embodiment of the present application, the first branch transmission line further includes an elongated branch, and a fifth slit located between the helical branch and the elongated branch.

According to an embodiment of the present application, the first branch transmission line further includes an L-shaped branch, and a fifth slit located between the spiral branch and the L-shaped branch.

According to an embodiment of the present application, the above-mentioned first bent transmission line includes a fifth branch transmission line, and the above-mentioned fifth branch transmission line includes: a fifth first branch extending along the predetermined direction; a fifth second branch extending along the predetermined direction direction; and the fifth and third branch, connecting the fifth first branch and the fifth second branch close to the terminal of the second meander transmission line.

According to an embodiment of the present application, the fifth branch transmission line further includes fifth and fourth branches extending along the predetermined direction, and the fifth and fourth branches are connected to the fifth and third branches near the terminal of the second bent transmission line .

According to an embodiment of the present application, the second bent transmission line includes a sixth branch transmission line, and the sixth branch transmission line includes: a sixth first branch extending along the predetermined direction; a sixth second branch extending along the predetermined direction The sixth and third branches are connected to the terminal of the sixth first branch and the sixth second branch close to the first bent transmission line; and the sixth and fourth branches are extended along the predetermined direction. The terminals of the six fourth branches close to the first bent transmission line are connected to the sixth and third branches.

According to an embodiment of the present application, the above-mentioned first transmission line and the above-mentioned second transmission line are in an axisymmetric relationship with respect to a second axis orthogonal to the above-mentioned first axis.

According to an embodiment of the present application, the branch line coupler further includes: a first connecting portion electrically connected to the first port, the first transmission line, and the first bent transmission line; a second connecting portion electrically connected to the first Two ports, the above-mentioned first transmission line and the above-mentioned second bent transmission line; the third connection part is electrically connected to the above-mentioned third port, the above-mentioned second transmission line and the above-mentioned second bent transmission line; the fourth connection part is electrically connected The fourth port, the second transmission line, and the first bent transmission line.

According to an embodiment of the present application, the first connection part, the second connection part, the third connection part and the fourth connection part are transmission lines.

The branch line coupler provided according to an embodiment of the present application can effectively reduce the small coupler area.

Compared with the prior art, the beneficial effect of the present invention is obvious. The branch line coupler designed by the present invention has better performance and smaller occupied area, and is very suitable for application in mobile communication products.

In order to facilitate those skilled in the art to understand and implement the present application, the following further describes the present application in detail with reference to the accompanying drawings and embodiments. It should be understood that the present application provides many applicable inventive concepts, which can be implemented in various specific forms. Those skilled in the art can use the details described in these embodiments or other embodiments and other applicable structural, logical and electrical changes to practice the invention without departing from the spirit and scope of the application.

The specification of this application provides different embodiments to illustrate the technical features of different implementations of this application. Wherein, the arrangement of each element in the embodiment is for illustration purposes, and is not intended to limit the present application. In addition, the partial repetition of the symbols in the figures in the embodiments is for the purpose of simplifying the description, and does not imply the relationship between different embodiments. Wherein, the same reference numerals used in the illustrations and descriptions represent the same or similar components. The illustrations in this specification are in simplified form and have not been drawn to precise scale. For clarity and ease of illustration, directional terms (eg, top, bottom, up, down, and diagonal) refer to accompanying illustrations. The directional terms used in the following description are not used to limit the scope of the application when they are not clearly used in the scope of the patent application attached below.

Furthermore, in describing some embodiments of the present application, the specification describes the method and (or) procedure of the present application in a specific order of steps. However, since the methods and procedures are not necessarily implemented according to the specific order of steps described, they are not limited to the specific order of steps described. Those skilled in the art will recognize that other sequences are also possible implementations. Therefore, the specific sequence of steps described in the specification is not intended to limit the scope of the patent application. Furthermore, the patent scope of this application for methods and (or) procedures is not limited by the order of execution steps written by it, and those skilled in this art can understand that adjusting the order of execution steps does not escape the spirit and scope of this application .

FIG. 1 shows a schematic structural diagram of a branch line coupler according to an embodiment of the present application. Referring to FIG. 1 , according to an embodiment of the present application, a branch line coupler is provided including a first port P1, a second port P2, a third port P3, and a fourth port P4, as well as a first transmission line T1, a second transmission line T2, a first The meander transmission line T3 and the second meander transmission line T4.

The first port P1 is an input port for inputting electromagnetic wave signals. The second port P2 is a through terminal, which is used for outputting through electromagnetic wave signals. The third port P3 is a coupling end for outputting a coupled electromagnetic wave signal. The fourth port P4 is an isolation port. It should be noted that the setting of each port here is not intended to limit the present invention, and those skilled in the technical field of the present invention can design the functions of each port according to actual use.

The first transmission line T1 includes a first elongated transmission line T11 , a first branch transmission line T12 and a second branch transmission line T13 . The first elongated transmission line T11 has an end point P111 electrically connected to the first port P1 and an end point P112 electrically connected to the second port P2. The first elongated transmission line T11 is along a predetermined direction (in the figure). for the X-direction). The first branch transmission line T12 is electrically connected to the terminal P111 and includes a helical branch T121 and a strip branch T122 . There is a slit St11 between the helical branch T121 and the first meander transmission line T3 , and a slit St12 between the helical branch T122 and the elongated branch T122 . The second branch transmission line T13 is electrically connected to the terminal P112 and includes a helical branch T131 and a strip branch T132 . There is a slit St21 between the helical branch T131 and the second meander transmission line T4 , and a slit St22 between the helical branch T132 and the elongated branch T132 .

FIG. 2 is an enlarged schematic diagram of the first transmission line T1 of the branch line coupler shown in FIG. 1 . Referring to FIG. 2 , the first transmission line T1 according to an embodiment of the present application includes a first elongated transmission line T11 , a first branch transmission line T12 and a second branch transmission line T13 . The first branch transmission line T12 includes a spiral branch T121 and a strip branch T122. The helical branch T121 includes branch segments T1210, T1211, T1213, T1215, T1217, T1219. The branch section T1210 extends from the end point P111 in the direction of the second branch transmission line T13, the branch section T1211 extends from the branch section T1210 in a direction away from the first elongated transmission line T11, and the branch section T1213 extends from the branch section T1211 in a direction away from the second branch transmission line The branch section T1215 extends from the branch section T1213 to the direction of the first elongated transmission line T11, the branch section T1217 extends from the branch section T1215 to the direction of the second branch transmission line T13, and the branch section T1219 extends from the branch section T1217 to It extends in a direction away from the first elongated transmission line T11. It must be noted that the number of branch segments of the helical branch T121 shown in the figure is only an example, and those skilled in the art can select an appropriate number of branch segments to form the helical branch T121 according to the characteristics of the coupler. The elongated branch T122 may be L-shaped, including a branch segment T1221 and a branch segment T1223. Likewise, those skilled in the art can select an appropriate length of the branch section T1223 according to the characteristics of the coupler. In configuration, the first elongated transmission line T11 is parallel to the branch sections T1210 , T1213 , T1217 and T1223 , and perpendicular to the branch sections T1211 , T1215 , T1219 and T1221 . In addition, as shown in the figure, the first branch transmission line T12 and the second branch transmission line T13 have an axisymmetric relationship with respect to the axis Y, so the specific structure of the second branch transmission line T13 is omitted for brevity.

Returning to FIG. 1 , the first meander transmission line T3 is electrically connected between the first port P1 and the fourth port P4 , and includes a fifth branch transmission line T31 including branch sections T311 , T313 , and T315 . The branch section T311 extends toward the second meander-type transmission line T4 along a predetermined direction (X direction in the figure), the branch section T313 connects the branch segment T311 and the branch segment T315 close to the terminal of the second meander-type transmission line T4, and along A direction (Y direction in the figure) perpendicular to the predetermined direction extends toward the second transmission line T2, and the branch section T315 extends along the X direction away from the second meander transmission line T4. In this embodiment, the branch sections T311, T313, T315 constitute the fifth branch transmission line T31. In other embodiments, the fifth branch transmission line T31 may further include a branch segment T317. In configuration, the first elongated transmission line T11 is parallel to the branch sections T311 , T315 and T317 , and perpendicular to the branch section T313 . In addition, as shown in the figure, the first meander transmission line T3 and the second meander transmission line T4 are axisymmetric with respect to the axis Y, so the specific structure of the second meander transmission line T4 is omitted for brevity. Likewise, the first transmission line T1 and the second transmission line T2 are axisymmetric with respect to the axis X, so the specific structure of the second transmission line T2 will not be repeated for brevity. According to the embodiment of the present application, through the multi-branch design of the first branch transmission line T12 and the second branch transmission line T13 and adding a bending design to the first meander transmission line T3 and the second meander transmission line T4, the coupler can be effectively reduced. area.

In addition, in other embodiments, the branch line coupler 100 may further include a connecting portion J1, a connecting portion J2, a connecting portion J3, and a connecting portion J4, which are respectively used to electrically connect the first port P1, the second port P2, the second port Three ports P3 and a fourth port P4. For example, the first transmission line T1 and the first bent transmission line T3 are electrically connected to the first port P1 through the connecting portion J1, and the first transmission line T1 and the second bent transmission line T4 are connected to the second port P2 through the connecting portion J2. Electrically connected, the second transmission line T2 and the second bent transmission line T4 are electrically connected to the third port P3 through the connection part J3, and the second transmission line T2 and the first bent transmission line T3 are connected to the fourth port P4 through the connection part J4 electrical connection. According to an embodiment of the present application, the connection part J1 , the connection part J2 , the connection part J3 and the connection part J4 are all transmission lines. In other embodiments, the connection part J1 , the connection part J2 , the connection part J3 and the connection part J4 may be microstrip lines or other types of transmission lines.

According to an embodiment of the present application, the length L of the branch line coupler 100 is 4.08 millimeters (mm), and the width H is 6.52 millimeters (mm). It should be noted that the size of the branch line coupler 100 is determined according to the frequency used, which does not limit the present invention. Those skilled in the art can choose branch line couplers of different sizes according to specific conditions to adapt to different frequencies. Require.

Referring to FIG. 3 , FIG. 3 is a simulation graph of S parameters of the branch line coupler 100 according to an embodiment of the present application. From the curve C1 in FIG. 3, it can be seen that the frequency band in which the parameter S11 of the branch line coupler 100 of the present application has an attenuation greater than 10 dB is approximately 4.8 GHz-6.3 GHz, corresponding to a center frequency of 5.6 GHz. It can be seen from the curves C2 and C3 in Fig. 3 that the parameters S12 and S13 have a power loss of 3 dB in the frequency band. The parameters S22, S33 and S44 of the second port, the third port and the fourth port are similar to the parameter S11 of the first port, which are not listed in the drawings.

Referring to FIG. 4 , FIG. 4 is a simulation curve diagram of S-parameters of isolation between two output ports of a branch line coupler according to an embodiment of the present application. It can be seen from the curve C4 in FIG. 4 that the two output ports of the branch line coupler according to an embodiment of the present application have better isolation in the 4.6GHz-6.6GHz frequency band.

Please refer to FIG. 5 . Curve C5 in FIG. 5 is a phase difference diagram between the output phases of the second port P2 and the third port P3 of the branch line coupler according to an embodiment of the present application. It can be seen from FIG. 5 that the second port P2 and the third port P3 of the branch line coupler according to an embodiment of the present application have a small output phase difference in the frequency band 4.9 GHz-6.2 GHz. Specifically, the second port P2 The phase difference with the output of the third port P3 is less than 10°.

Please refer to FIG. 6 . Curve C6 in FIG. 6 is a graph showing the output amplitude difference between the second port P2 and the third port P3 of the branch line coupler according to an embodiment of the present application. It can be seen from FIG. 6 that the second port P2 and the third port P3 of the branch line coupler according to an embodiment of the present application have a small amplitude output difference in the frequency band 4.9 GHz-6.2 GHz. Specifically, the second port The output amplitude difference between P2 and the third port P3 is less than 2 dB.

FIG. 7 is a schematic structural diagram of a conventional branch line coupler. The length L of the conventional branch line coupler is 7.4 millimeters (mm), and the width H is 9.14 millimeters (mm). According to the branch line coupler 100 described in the embodiment of the present application, through the multi-branch design of the first branch transmission line T12 and the second branch transmission line T13 and adding bends to the first bent transmission line T3 and the second bent transmission line T4 Design, the length L of the branch line coupler 100 is 4.08 millimeters (mm), and the width H is 6.52 millimeters (mm). Compared with traditional branch line couplers, the area of the couplers is significantly reduced.

Figure 8 is the S-parameter simulation curve of the traditional branch line coupler. As shown in Figure 8, the parameter S11 of the traditional branch line coupler has a bandwidth of 4.6 GHz-6.6 GHz when the attenuation is greater than 10 dB, and the corresponding center frequency is 5.6 GHz . Parameters S12, S13 have a 3 dB power loss in the frequency band. Comparing FIG. 3 and FIG. 8 , it can be known that the branch line coupler 100 according to the embodiment of the present application is similar to the traditional branch line coupler in achieving effects.

The area of the branch line coupler 100 according to the embodiment of the present application is 60.67% smaller than that of the traditional branch line coupler. In addition, the branch line coupler 100 has better performance in the frequency band 4.6 GHz-6.6 GHz, and the parameter S11 attenuation is greater than 10 dB , and the output amplitude and phase difference of the two output ports are small. After overcoming the disadvantage of occupying a large PCB area in the prior art, it has better characteristics and is very suitable for application in mobile communication products.

To sum up, this application meets the requirements of an invention patent, and a patent application is filed in accordance with the law. However, the above is only a preferred implementation mode of the present application, and the scope of the application is not limited to the above-mentioned implementation modes. For those who are familiar with the technology of this case, any equivalent modification or change made according to the spirit of the application should be Covered in the scope of the following patent applications.

100: branch line coupler C1, C2, C3, C4, C5, C6: curves J1, J2, J3, J4: connecting part P1: first port P2: second port P3: third port P4: the fourth port P111, P112: endpoint St11, St12, St21, St22: slits T1: the first transmission line T2: the second transmission line T3: The first bent transmission line T4: Second bent transmission line T11: The first long strip transmission line T12: The first branch transmission line T13: second branch transmission line T121, T131: Spiral branches T122, T132: long strip branch T1210, T1211, T1213, T1215, T1217, T1219, T1221, T1223, T311, T313, T315, T317: branch section X, Y: axis

FIG. 1 is a schematic structural diagram of a branch line coupler according to an embodiment of the present application. FIG. 2 is an enlarged schematic diagram of a first transmission line of the branch line coupler shown in FIG. 1 . FIG. 3 is an S-parameter simulation curve diagram of the branch line coupler according to an embodiment of the present application. FIG. 4 is a simulation curve diagram of S-parameters of isolation between two output ports of a branch line coupler according to an embodiment of the present application. FIG. 5 is a diagram of output phase differences between two output ports of a branch line coupler according to an embodiment of the present application. FIG. 6 is a graph showing the difference in output amplitude between two output terminals of the branch line coupler according to an embodiment of the present application. FIG. 7 is a schematic structural diagram of a conventional branch line coupler. Fig. 8 is an S-parameter simulation curve diagram of a traditional branch line coupler.

none

100: branch line coupler

P1: first port

P2: second port

P3: third port

P4: the fourth port

P111, P112: endpoint

St11, St12, St21, St22: slits

T1: the first transmission line

T2: the second transmission line

T3: The first bent transmission line

T4: Second bent transmission line

T11: The first long strip transmission line

T12: The first branch transmission line

T13: second branch transmission line

T121, T131: Spiral branches

T122, T132: long strip branch

T311, T313, T315, T317: branch section

X, Y: axis

Claims (10)

A branch line coupler comprising: The first port, the second port, the third port and the fourth port are respectively used as an input terminal, a straight-through terminal, a coupled terminal and an isolated terminal; The first transmission line, including: The first elongated transmission line has a first first end electrically connected to the first port and a first second end electrically connected to the second port, and the first elongated transmission line is along a predetermined direction extend; a first branch transmission line electrically connected to the first first end and having a first slit; The second branch transmission line is electrically connected to the first and second ends and has a second slit, wherein the first branch transmission line and the second branch transmission line are in an axisymmetric relationship with respect to a first axis; Second transmission line, including: The second elongated transmission line has a second first end electrically connected to the third port and a second second end electrically connected to the fourth port, and the second elongated transmission line is along the predetermined direction extend; a third branch transmission line electrically connected to the second first end and having a third slit; The fourth branch transmission line is electrically connected to the second second end and has a fourth slit, wherein the third branch transmission line and the fourth branch transmission line are in an axisymmetric relationship with respect to the first axis; a first bent transmission line electrically connected between the first port and the fourth port; and The second bent transmission line is electrically connected between the second port and the third port. The branch line coupler according to claim 1, wherein the first branch transmission line includes a helical branch, and the first slit is located between the helical branch and the first bent transmission line. The branch line coupler as claimed in claim 2, wherein the first branch transmission line further includes a long branch, and a fifth slit between the spiral branch and the long branch. The branch line coupler as claimed in claim 2, wherein the first branch transmission line further includes an L-shaped branch, and a fifth slit located between the spiral branch and the L-shaped branch. The branch line coupler as described in claim 2, wherein the first bent transmission line includes a fifth branch transmission line, and the fifth branch transmission line includes: The fifth first branch extends along the predetermined direction; a fifth second branch extending along the aforementioned predetermined direction; and The fifth and third branch is connected to a terminal of the fifth first branch and the fifth second branch close to the second meander transmission line. The branch line coupler according to claim 5, wherein the fifth branch transmission line further includes fifth and fourth branches extending along the predetermined direction, and the fifth and fourth branches are connected close to the terminals of the second bent transmission line The fifth and third branches above. The branch line coupler as described in claim 2, wherein the second bent transmission line includes a sixth branch transmission line, and the sixth branch transmission line includes: The sixth first branch extends along the predetermined direction; The sixth second branch extends along the predetermined direction; The sixth third branch is connected to the terminal of the sixth first branch and the sixth second branch close to the first meander transmission line; and The sixth and fourth branches extend along the predetermined direction, and the terminals of the sixth and fourth branches close to the first meander transmission line are connected to the sixth and third branches. The branch line coupler as claimed in claim 1, wherein the first transmission line and the second transmission line are axisymmetric with respect to a second axis perpendicular to the first axis. The branch line coupler as described in claim 1, further comprising: The first connection part is electrically connected to the first port, the first transmission line, and the first bent transmission line; a second connection part electrically connected to the second port, the first transmission line, and the second bent transmission line; The third connection part is electrically connected to the third port, the second transmission line, and the second bent transmission line; and The fourth connection part is electrically connected to the fourth port, the second transmission line, and the first bent transmission line. The branch line coupler according to claim 9, wherein the first connection part, the second connection part, the third connection part and the fourth connection part are transmission lines.

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