Asymmetric directional coupler and radio frequency chip

Abstract

The utility model provides an asymmetric directional coupler and a radio frequency chip, the asymmetric directional coupler comprises a first microstrip line, a second microstrip line coupled with the first microstrip line and a resistor, two ends of the first microstrip line are respectively provided with a radio frequency input port and an antenna output port, two ends of the second microstrip line are respectively provided with an isolation port and a coupling output port, and the isolation port is grounded after passing through a series resistor; the first microstrip line and the second microstrip line are arranged in an asymmetric multi-section structure. The first microstrip line comprises a radio frequency input section, a first section, a second section, a third section and an antenna output section; the second microstrip line comprises a coupling output section, a fourth section, a fifth section, a sixth section and an isolation section; the clearance between the second section and the fifth section is smaller than that between the first section and the fourth section; and the clearance between the first section and the fourth section is smaller than that between the third section and the sixth section. According to the utility model, the coupling degree and directivity of the coupler can be improved.

Description

Technical Field

[0001] This utility model relates to the field of wireless communication technology, and in particular to an asymmetric directional coupler and a radio frequency chip. Background Technology

[0002] With the rapid development of China's economy, the demand for consumer electronics is increasing. As a core component of consumer electronics, the performance of radio frequency (RF) front-end chips directly impacts the user experience. Microstrip directional couplers are important RF and microwave components, widely used in signal distribution, coupling, and monitoring. While microstrip line couplers offer numerous advantages in RF and microwave applications, their design and performance also face some shortcomings and challenges. First, the performance of microstrip line couplers is highly dependent on their geometry and manufacturing process; even minor manufacturing errors can lead to significant performance degradation, such as inaccurate coupling or insufficient bandwidth. Furthermore, the transmission characteristics of microstrip lines are affected by the substrate material and thickness; different dielectric constants can cause signal reflection and loss, thus affecting the overall efficiency of the coupler. Second, microstrip line couplers may exhibit frequency selectivity in high-frequency applications, resulting in good performance within a specific frequency range but poor performance at other frequencies, limiting their use in broadband applications. Third, the isolation of microstrip line couplers may be insufficient in some cases, potentially leading to unwanted signal interference and affecting system stability and signal quality.

[0003] Currently, couplers in consumer electronics products typically use microstrip line couplers, such as... Figure 1 As shown, Port1 is the signal input port. Port2 is the signal output port, connected to the antenna. Port3 is the coupling port, used to monitor signal power. Port4 is the isolation port, typically connected to a 50Ω resistor and then grounded. Couplers usually have three important specifications: coupling coefficient, isolation coefficient, and directivity. The coupling coefficient is the ratio of the power at the coupling port to the power at the input port; the isolation coefficient is the ratio of the power at the isolation port to the power at the input port; and directivity is the difference between the coupling coefficient and the isolation coefficient. Directivity is a crucial indicator of coupler performance. Traditional microstrip lines typically have poor directivity, and once fabricated, their performance cannot be changed through adjustments.

[0004] Therefore, the aforementioned asymmetric directional coupler has a poor effect on improving directionality. Utility Model Content

[0005] To address the shortcomings of the existing technologies, this invention proposes an asymmetric directional coupler and an RF chip to solve the problem of poor directionality improvement in existing asymmetric directional couplers.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] In a first aspect, this utility model provides an asymmetric directional coupler, which includes a first microstrip line, a second microstrip line coupled to the first microstrip line, and a resistor. The first microstrip line has a radio frequency input port and an antenna output port at its two ends, and the second microstrip line has an isolation port and a coupling output port at its two ends, respectively. The isolation port is grounded after being connected in series with the resistor. Both the first microstrip line and the second microstrip line adopt an asymmetric multi-section structure.

[0008] The first microstrip line includes an RF input segment connected to the RF input port, a first segment extending vertically from the end of the RF input segment away from the RF input port, a second segment extending from the end of the first segment away from the RF input segment, a third segment extending from the end of the second segment away from the RF input segment, and an antenna output segment extending vertically from the end of the third segment away from the RF input segment; the end of the antenna output segment away from the third segment is connected to the antenna output port; the sides of the first segment, the second segment, and the third segment away from the second microstrip line are located in different planes;

[0009] The second microstrip line includes a coupling output segment connected to the coupling output port, a fourth segment extending vertically from one end of the coupling output segment away from the coupling output port, a fifth segment extending from one end of the fourth segment away from the coupling output segment, a sixth segment extending from one end of the fifth segment away from the coupling output segment, and an isolation segment extending vertically from one end of the sixth segment away from the coupling output segment. The end of the isolation segment away from the sixth segment is connected to the isolation port. The sides of the fourth segment, the fifth segment, and the sixth segment away from the first microstrip line are located in different planes.

[0010] The net space between the second segment and the fifth segment is smaller than the net space between the first segment and the fourth segment; the net space between the first segment and the fourth segment is smaller than the net space between the third segment and the sixth segment.

[0011] Preferably, the first segment, the second segment, and the third segment are respectively positioned opposite the fourth segment, the fifth segment, and the sixth segment.

[0012] Preferably, the third segment includes a first parallel segment, a second parallel segment extending from the end of the first parallel segment away from the second segment, and a third parallel segment extending from the end of the second parallel segment away from the second segment. The end of the first parallel segment near the second segment is fixed to the second segment. The end of the third parallel segment away from the second segment is connected to the antenna output segment. The widths of the first parallel segment, the second parallel segment, and the third parallel segment are different.

[0013] The sixth segment includes a fourth parallel segment, a fifth parallel segment extending from the end of the fourth parallel segment away from the fifth segment, and a sixth parallel segment extending from the end of the fifth parallel segment away from the fifth segment. The end of the fourth parallel segment near the fifth segment is fixed to the fifth segment. The end of the sixth parallel segment away from the fifth segment is connected to the isolation segment. The widths of the fourth parallel segment, the fifth parallel segment, and the sixth parallel segment are different.

[0014] The first parallel segment, the second parallel segment, and the third parallel segment are respectively arranged opposite to the fourth parallel segment, the fifth parallel segment, and the sixth parallel segment.

[0015] Preferably, the RF input segment and the coupled output segment extend in a direction away from each other, and the antenna output segment and the isolation segment extend in a direction away from each other; the RF input segment and the antenna output segment are parallel, and the coupled output segment and the isolation segment are parallel.

[0016] Secondly, this utility model provides a radio frequency chip, which includes the aforementioned asymmetric directional coupler.

[0017] Compared with related technologies, in the embodiments of this utility model, the first microstrip line is provided with an RF input port and an antenna output port at both ends, and the second microstrip line is provided with an isolation port and a coupling output port at both ends, with the isolation port grounded after being connected in series with a resistor; both the first and second microstrip lines adopt an asymmetrical multi-segment structure; the first microstrip line includes an RF input segment connected to the RF input port, a first segment extending vertically from the end of the RF input segment away from the RF input port, a second segment extending from the end of the first segment away from the RF input segment, a third segment extending from the end of the second segment away from the RF input segment, and an antenna output segment extending vertically from the end of the third segment away from the RF input segment; the end of the antenna output segment away from the third segment is connected to the antenna output port; the sides of the first, second, and third segments away from the second microstrip line are located on different planes; the second microstrip line includes a coupling output segment connected to the coupling output port, a coupling output segment extending vertically from the end of the coupling output segment away from the coupling output port, and an antenna output segment extending vertically from the end of the coupling output segment away from the coupling output port. The microstrip line consists of a fourth segment extending vertically, a fifth segment extending from the end of the fourth segment away from the coupled output segment, a sixth segment extending from the end of the fifth segment away from the coupled output segment, and an isolation segment extending vertically from the end of the sixth segment away from the coupled output segment. The end of the isolation segment away from the sixth segment is connected to the isolation port. The sides of the fourth, fifth, and sixth segments away from the first microstrip line are located on different planes. The net space gap between the second and fifth segments is smaller than the net space gap between the first and fourth segments. The net space gap between the first and fourth segments is smaller than the net space gap between the third and sixth segments. In this way, by splitting the single-section first and second microstrip lines, they are transformed into a multi-section microstrip line structure. The multi-section microstrip line structure is not a gradual transition process, but rather improves the coupling of the coupled output segment by approaching the middle sections and increasing the spacing between the middle and the isolation ports to hinder energy from reaching the isolation ports. Without changing the coupling degree, isolation is provided, thereby improving directivity. Attached Figure Description

[0018] The present invention will now be described in detail with reference to the accompanying drawings. The above and other aspects of the present invention will become clearer and easier to understand through the detailed description in conjunction with the following drawings. (Appendix)

[0019] In the picture:

[0020] Figure 1 This is a schematic diagram of a traditional asymmetric directional coupler.

[0021] Figure 2 for Figure 1 A schematic diagram of the simulation results for the coupling coefficient and isolation coefficient;

[0022] Figure 3 A schematic diagram of the structure of the asymmetric directional coupler provided in the embodiment of this utility model;

[0023] Figure 4 for Figure 3 A schematic diagram of the simulation results for the coupling coefficient and isolation coefficient.

[0024] Among them, 100, asymmetric directional coupler; 1, first microstrip line; 11, radio frequency input segment; 12, first segment; 13, second segment; 14, third segment; 141, first parallel segment; 142, second parallel segment; 143, third parallel segment; 15, antenna output segment; 2, second microstrip line; 21, coupling output segment; 22, fourth segment; 23, fifth segment; 24, sixth segment; 241, fourth parallel segment; 242, fifth parallel segment; 243, sixth parallel segment; 25, isolation segment. Detailed Implementation

[0025] 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 pertains; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application, are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0026] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] Example 1

[0029] Please see Figures 3-4As shown, this embodiment of the present invention provides an asymmetric directional coupler 100, which includes a first microstrip line 1, a second microstrip line 2 coupled to the first microstrip line 1, and a resistor R1. The first microstrip line 1 has a radio frequency input port (Port1) and an antenna output port (Port2) at its two ends, and the second microstrip line 2 has an isolation port (Port4) and a coupling output port (Port3) at its two ends, respectively. The isolation port is grounded by connecting the resistor R1 in series. Both the first microstrip line 1 and the second microstrip line 2 adopt an asymmetric multi-section structure.

[0030] The first microstrip line 1 includes an RF input segment 11 connected to the RF input port, a first segment 12 extending vertically from the end of the RF input segment 11 away from the RF input port, a second segment 13 extending from the end of the first segment 12 away from the RF input segment 11, a third segment 14 extending from the end of the second segment 13 away from the RF input segment 11, and an antenna output segment 15 extending vertically from the end of the third segment 14 away from the RF input segment 11; the end of the antenna output segment 15 away from the third segment 14 is connected to the antenna output port; the sides of the first segment 12, the second segment 13, and the third segment 14 away from the second microstrip line 2 are located in different planes.

[0031] The second microstrip line 2 includes a coupling output segment 21 connected to the coupling output port, a fourth segment 22 extending vertically from the end of the coupling output segment 21 away from the coupling output port, a fifth segment 23 extending from the end of the fourth segment 22 away from the coupling output segment 21, a sixth segment 24 extending from the end of the fifth segment 23 away from the coupling output segment 21, and an isolation segment 25 extending vertically from the end of the sixth segment 24 away from the coupling output segment 21. The end of the isolation segment 25 away from the sixth segment 24 is connected to the isolation port. The sides of the fourth segment 22, the fifth segment 23, and the sixth segment 24 away from the first microstrip line 1 are located in different planes.

[0032] The net space gap between the second segment 13 and the fifth segment 23 is smaller than the net space gap between the first segment 12 and the fourth segment 22; the net space gap between the first segment 12 and the fourth segment 22 is smaller than the net space gap between the third segment 14 and the sixth segment 24. By approximating the intermediate sections of the first microstrip line 1 and the second microstrip line 2, the energy of the RF input port is more easily coupled to the coupled output port. Furthermore, by adjusting the length and width of each microstrip line segment, the impedance transformation during microstrip line transmission is controlled, resulting in better coupler matching and reduced transmission loss. Additionally, the end segments of the coupler are pulled outwards. This significantly improves the directivity of the coupler; the high directivity results in a larger bandwidth; the microstrip line routing structure is simple and easy to manufacture; the asymmetric directional coupler 100 is small in size, making it easier to control processing costs later; and the multi-strip line configuration offers greater flexibility.

[0033] Specifically, the original integrated structure of the first microstrip line 1 and the second microstrip line 2 is segmented, which enhances the flexibility of debugging to a certain extent. The length and width of each microstrip line segment also allow for better control of the coupler's matching, resulting in lower transmission loss. Approximation processing of the middle segment of the microstrip line makes it easier for energy from the RF input port to couple to the output port, thus reducing the coupling coefficient. Furthermore, the outward pulling of the end segment of the coupler confines more energy between the two microstrip transmission lines, reducing the energy reaching the isolation port and lowering the isolation coefficient. While maintaining the same coupling coefficient, reducing the isolation coefficient improves the coupler's directivity in the high-frequency band, since directivity is the difference between the coupling coefficient and the isolation coefficient. This asymmetric directional coupler 100 exhibits a directivity of approximately 38dB in the high-frequency band, compared to... Figure 2 The directivity of the traditional coupler in the process is improved by 24 dB.

[0034] In this embodiment, the first segment 12, the second segment 13, and the third segment 14 are respectively positioned opposite the fourth segment 22, the fifth segment 23, and the sixth segment 24. This makes the overall structure formed by the first microstrip line 1 and the second microstrip line 2 compact.

[0035] In this embodiment, the third segment 14 includes a first parallel segment 141, a second parallel segment 142 extending from the end of the first parallel segment 141 away from the second segment 13, and a third parallel segment 143 extending from the end of the second parallel segment 142 away from the second segment 13. The end of the first parallel segment 141 near the second segment 13 is fixed to the second segment 13. The end of the third parallel segment 143 away from the second segment 13 is connected to the antenna output segment 15. The widths of the first parallel segment 141, the second parallel segment 142, and the third parallel segment 143 are different from each other.

[0036] The sixth segment 24 includes a fourth parallel segment 241, a fifth parallel segment 242 extending from the end of the fourth parallel segment 241 away from the fifth segment 23, and a sixth parallel segment 243 extending from the end of the fifth parallel segment 242 away from the fifth segment 23. The end of the fourth parallel segment 241 near the fifth segment 23 is fixed to the fifth segment 23. The end of the sixth parallel segment 243 away from the fifth segment 23 is connected to the isolation segment 25. The widths of the fourth parallel segment 241, the fifth parallel segment 242, and the sixth parallel segment 243 are different from each other.

[0037] The first parallel segment 141, the second parallel segment 142 and the third parallel segment 143 are respectively arranged opposite to the fourth parallel segment 241, the fifth parallel segment 242 and the sixth parallel segment 243.

[0038] The first parallel segment 141, the second parallel segment 142, and the third parallel segment 143 are respectively arranged opposite to the fourth parallel segment 241, the fifth parallel segment 242, and the sixth parallel segment 243. This enhances the flexibility of debugging to a certain extent, and the microstrip line routing structure is simple and easy to manufacture.

[0039] Preferably, the length of the third segment 14 is greater than the length of the first segment 12 and the second segment 13, and the length of the sixth segment 24 is greater than the length of the fourth segment 22 and the fifth segment 23, so as to better control the matching of the coupler by the length and width of the microstrip line of each segment, thereby achieving lower transmission loss.

[0040] In this embodiment, the RF input segment 11 and the coupled output segment 21 extend in a direction away from each other, and the antenna output segment 15 and the isolation segment 25 extend in a direction away from each other; the RF input segment 11 and the antenna output segment 15 are parallel, and the coupled output segment 21 and the isolation segment 25 are parallel. By designing the first microstrip line 1 and the second microstrip line 2 as a multi-segment structure, and by approximating the structure of the middle segment, and by pulling outwards the RF input segment 11 and the coupled output segment 21, the antenna output segment 15 and the isolation segment 25 at the ends, the performance of the microstrip coupler can be significantly improved, and flexible debugging can be performed, reducing the risk of redesign.

[0041] Example 2

[0042] This utility model provides a radio frequency (RF) chip, which includes the asymmetric directional coupler 100 described in Embodiment 1 above. The technical problem solved and the technical effects produced by the RF chip are the same as those of the asymmetric directional coupler 100 described above, and will not be repeated here.

[0043] It should be noted that the various embodiments described above with reference to the accompanying drawings are only illustrative of the present invention and not intended to limit its scope. Those skilled in the art should understand that any modifications or equivalent substitutions made to the present invention without departing from its spirit and scope should be covered within the scope of the present invention. Furthermore, unless the context otherwise requires, singular terms include plural forms, and vice versa. Additionally, unless specifically stated otherwise, all or part of any embodiment may be used in conjunction with all or part of any other embodiment.

Claims

1. An asymmetric directional coupler, the asymmetric directional coupler comprising a first microstrip line, a second microstrip line coupled to the first microstrip line, and a resistor, wherein the first microstrip line has a radio frequency input port and an antenna output port at its two ends, and the second microstrip line has an isolation port and a coupling output port at its two ends, wherein the isolation port is grounded through the resistor in series; characterized in that, Both the first microstrip line and the second microstrip line adopt an asymmetric multi-segment structure. The first microstrip line includes an RF input segment connected to the RF input port, a first segment extending vertically from the end of the RF input segment away from the RF input port, a second segment extending from the end of the first segment away from the RF input segment, a third segment extending from the end of the second segment away from the RF input segment, and an antenna output segment extending vertically from the end of the third segment away from the RF input segment; the end of the antenna output segment away from the third segment is connected to the antenna output port; the sides of the first segment, the second segment, and the third segment away from the second microstrip line are located in different planes; The second microstrip line includes a coupling output segment connected to the coupling output port, a fourth segment extending vertically from one end of the coupling output segment away from the coupling output port, a fifth segment extending from one end of the fourth segment away from the coupling output segment, a sixth segment extending from one end of the fifth segment away from the coupling output segment, and an isolation segment extending vertically from one end of the sixth segment away from the coupling output segment. The end of the isolation segment away from the sixth segment is connected to the isolation port. The sides of the fourth segment, the fifth segment, and the sixth segment away from the first microstrip line are located in different planes. The net space between the second segment and the fifth segment is smaller than the net space between the first segment and the fourth segment; the net space between the first segment and the fourth segment is smaller than the net space between the third segment and the sixth segment.

2. The asymmetric directional coupler according to claim 1, characterized in that, The first segment, the second segment, and the third segment are respectively positioned opposite the fourth segment, the fifth segment, and the sixth segment.

3. The asymmetric directional coupler according to claim 1, characterized in that, The third segment includes a first parallel segment, a second parallel segment extending from the end of the first parallel segment away from the second segment, and a third parallel segment extending from the end of the second parallel segment away from the second segment. The end of the first parallel segment near the second segment is fixed to the second segment. The end of the third parallel segment away from the second segment is connected to the antenna output segment. The widths of the first parallel segment, the second parallel segment, and the third parallel segment are different. The sixth segment includes a fourth parallel segment, a fifth parallel segment extending from the end of the fourth parallel segment away from the fifth segment, and a sixth parallel segment extending from the end of the fifth parallel segment away from the fifth segment. The end of the fourth parallel segment near the fifth segment is fixed to the fifth segment. The end of the sixth parallel segment away from the fifth segment is connected to the isolation segment. The widths of the fourth parallel segment, the fifth parallel segment, and the sixth parallel segment are different. The first parallel segment, the second parallel segment, and the third parallel segment are respectively arranged opposite to the fourth parallel segment, the fifth parallel segment, and the sixth parallel segment.

4. The asymmetric directional coupler according to claim 1, characterized in that, The radio frequency input segment and the coupled output segment extend in a direction away from each other, and the antenna output segment and the isolation segment extend in a direction away from each other; the radio frequency input segment and the antenna output segment are parallel, and the coupled output segment is parallel to the isolation segment.

5. A radio frequency chip, characterized in that, The radio frequency chip includes the asymmetric directional coupler as described in any one of claims 1-4.

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