High-directivity ultra-wideband coupler

Abstract

The invention discloses a high-directivity ultra-wideband coupler which comprises a main microstrip line and an auxiliary microstrip line which are coupled with each other, and a sawtooth structure is arranged on the coupling side between the main microstrip line and the auxiliary microstrip line and used for increasing the coupling distance between the main microstrip line and the auxiliary microstrip line, so that the impedance of the main microstrip line and the impedance of the auxiliary microstrip line are adjusted; the isolation port is connected with a matching load of a zigzag structure and then is grounded, and the energy flow direction of the matching load is opposite to the energy flow direction of the main microstrip line. The sawtooth structure is arranged on the coupling side between the main microstrip line and the auxiliary microstrip line, the matching load of the zigzag structure connected with the isolation port is combined, parasitic parameters introduced by the matching load can be utilized, the performance of the high-directivity ultra-wideband coupler can be improved in the forward direction, joint optimization between the main microstrip line and the auxiliary microstrip line in the high-directivity ultra-wideband coupler is achieved, and the coupling performance of the high-directivity ultra-wideband coupler is improved. The directional coupler effectively optimizes the impedance consistency of odd and even modes, improves the directivity, and is small in overall size, simple in structure and convenient to process.

Description

Technical Field

[0001] This application relates to the technical field of directional couplers, and particularly to a high-directivity ultra-wideband coupler. Background Art

[0002] A directional coupler is a four-port passive component used for power distribution and is widely applied in systems such as radio frequency and microwave systems. It plays an indispensable role in electronic countermeasures, communication systems, radar systems, and test and measurement instruments. Its main uses include synthesizing and distributing power, expanding the power range, monitoring power and spectrum, etc. In some important microwave measurement instruments such as vector network analyzers and reflectometers, the directional coupler determines their performance and is an important device in the circuit.

[0003] Currently, the requirements for directional couplers are large bandwidth, miniaturization, and integrability. However, the increase in bandwidth and the reduction in volume will both cause deterioration in their directivity, seriously affecting the performance of the coupler. Therefore, how to improve the directivity as much as possible on the basis of realizing miniaturization and ultra-wideband is the key point and difficulty of the research.

[0004] In the face of the requirement for ultra-wideband of directional couplers, researchers basically adopt transmission line structures, and the common ones are microstrip lines and strip lines. Among them, the microstrip line structure is convenient for processing and manufacturing, so it has the widest application range. For example, adding stubs to the coupler can achieve a directivity of 25 dB within the bandwidth of 45 - 85 GHz. Another example is adding interdigital capacitors to the coupler, which can achieve a directivity of 25 dB within the bandwidth of 1.5 - 3.5 GHz. Most of the currently reported ultra-wideband directional couplers with high directivity have relatively low operating frequencies, and the directivity mostly concentrates between 20 - 25 dB. Therefore, how to achieve a higher directivity above 25 dB within an ultra-wide operating frequency band above 100 GHz is a problem that needs to be solved. Summary of the Invention

[0005] The purpose of this application is to provide a high-directivity ultra-wideband coupler to solve the technical problem of low directivity of ultra-wideband couplers in the prior art. The many technical effects that can be produced by the preferred technical solutions provided in this application are described in detail below.

[0006] To achieve the above purpose, this application provides the following technical solutions: A high-directivity ultra-wideband coupler provided in this application includes a main microstrip line and a secondary microstrip line that are mutually coupled. One end of the main microstrip line is configured as the input port of the coupler for receiving electromagnetic wave signals, and the other end is configured as the through output port for outputting signals; one end of the secondary microstrip line is configured as the coupled output port of the coupler, and the other end is configured as the isolation port; A sawtooth structure is provided on the coupling side between the main microstrip line and the secondary microstrip line, which is used to increase the coupling distance between the main microstrip line and the secondary microstrip line, thereby adjusting the impedance of the main microstrip line and the secondary microstrip line. The isolation port is grounded after being connected to the matching load of the zigzag structure, and the energy flow direction of the matching load is opposite to that of the main microstrip line.

[0007] In some embodiments, a first platform-shaped sawtooth structure is provided on the coupling side of the main microstrip line and the secondary microstrip line, and a second platform-shaped sawtooth structure is provided on the coupling side of the secondary microstrip line and the main microstrip line. The height of the first platform-shaped sawtooth structure is higher than that of the second platform-shaped sawtooth structure.

[0008] In some embodiments, the first platform-shaped sawtooth structure includes a plurality of alternately arranged first recesses and first protrusions, the second platform-shaped sawtooth structure includes a plurality of alternately arranged second recesses and second protrusions, the first recesses are aligned with the second protrusions, the first protrusions are aligned with the second recesses, and the height of the first protrusions is higher than that of the second protrusions.

[0009] In some embodiments, the shapes of the first recesses, first protrusions, second recesses, and second protrusions are all trapezoidal.

[0010] In some embodiments, the tops of the first protrusions and the second protrusions are both platforms, and the platforms of the first protrusions and the second protrusions are on the same straight line.

[0011] In some embodiments, the matching load is a thin film resistor of a zigzag structure. One end of the thin film resistor is connected to the isolation port, and several positions of the thin film resistor are grounded.

[0012] In some embodiments, symmetric conductive bands are distributed on both sides of the thin film resistor. The conductive bands are provided with symmetric circular vias, and the thin film resistor is grounded through the conductive bands connected to the circular vias.

[0013] In some embodiments, the zigzag structure includes a bent part and a straight part. The bent part and the straight part are alternately connected end to end, and the energy flow directions of two adjacent straight parts are opposite.

[0014] In some embodiments, the isolation port is connected to the first straight part, and the end face of the last straight part is connected to the conductive band.

[0015] In some embodiments, each bent part is connected to the conductive band.

[0016] Implementing one of the above technical solutions of the present application has the following advantages or beneficial effects: The highly directional ultra-wideband coupler of the present application can, by arranging a sawtooth structure on the coupling side between the main microstrip line and the secondary microstrip line and combining the matching load with a zigzag structure connected to the isolation port, utilize the parasitic parameters introduced by the matching load to positively improve the performance of the highly directional ultra-wideband coupler, break the conventional thinking of the role of the traditional matching load, realize the joint optimization between the main microstrip line and the secondary microstrip line inside the highly directional ultra-wideband coupler, effectively optimize the odd and even mode impedance consistency of the highly directional ultra-wideband coupler, achieve the improvement of the directivity of the highly directional ultra-wideband coupler, and has a small overall size, a simple structure and is convenient for processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings. In the drawings: Figure 1 is a schematic block diagram of the highly directional ultra-wideband coupler according to the embodiment of the present application; Figure 2 is a schematic structural diagram of the highly directional ultra-wideband coupler according to the embodiment of the present application; Figure 3 is a schematic structural diagram of the sawtooth structure according to the embodiment of the present application; Figure 4 is a schematic structural diagram of the matching load according to the embodiment of the present application; Figure 5 is a diagram of the energy flow direction of the matching load according to the embodiment of the present application; Figure 6 is a schematic diagram of the simulation result of the highly directional ultra-wideband coupler according to the embodiment of the present application.

[0018] In the figures: 1, main microstrip line; 2, secondary microstrip line; 3, conducting strip; 4, matching load; 5, dielectric layer; 6, circular via; 10, input port; 20, through output port; 30, isolation port; 40, coupling output port; 11, sawtooth structure; 12, first platform-shaped sawtooth structure; 21, second platform-shaped sawtooth structure; 41, straight part; 42, bent part; 121, first protrusion; 122, first recess; 211, second protrusion; 212, second recess. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] To make the objectives, technical solutions and advantages of this application more clear and understandable, various exemplary embodiments to be described below will refer to the corresponding drawings, which form a part of the exemplary embodiments and describe various exemplary embodiments that may be adopted to implement this application. Unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. It should be understood that they are merely examples of processes, methods, devices, etc. consistent with some aspects of the disclosure of this application as detailed in the appended claims. Other embodiments may also be used, or structural and functional modifications may be made to the embodiments listed herein without departing from the scope and essence of this application.

[0020] In the description of this application, it should be understood that terms such as "center", "longitudinal", "lateral", etc. indicate the orientation or positional relationship based on the drawings shown, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the elements referred to must have a specific orientation, be constructed and operated in a specific orientation. Terms such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the technical features indicated. The meaning of the term "plurality" is two or more. The terms "connected" and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, a communication connection, a direct connection, an indirect connection through an intermediate medium, and may be the communication inside two elements or the interaction relationship between two elements. The term "and / or" includes any and all combinations of one or more of the related listed items. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0021] To illustrate the technical solutions described in this application, the following will be described through specific embodiments, and only the parts related to the embodiments of this application are shown.

[0022] As Figures 1 to 2 shown, this application provides a highly directional ultra-wideband coupler, which includes a main microstrip line 1 and a secondary microstrip line 2 that are mutually coupled. One end of the main microstrip line 1 is configured as the input port 10 of the coupler for receiving electromagnetic wave signals, and the other end is configured as the through output port 20 for outputting signals; one end of the secondary microstrip line 2 is configured as the coupled output port 40 of the coupler, and the other end is configured as the isolation port 30; A sawtooth structure 11 is provided on the coupling side between the main microstrip line 1 and the secondary microstrip line 2, which is used to increase the coupling distance between the main microstrip line 1 and the secondary microstrip line 2, so as to adjust the impedance of the main microstrip line 1 and the secondary microstrip line 2; The isolation port 30 is connected to the matching load 4 and then grounded, and the energy flow direction of the matching load 4 is opposite to that of the main microstrip line 1.

[0023] Specifically, the high-directivity ultra-wideband coupler of the embodiment of the present invention adopts a single-layer coupled microstrip line structure of one section, including a main microstrip line 1, a secondary microstrip line 2, and a conductive strip 3. The conductive strip 3 is a metal conductive strip layer, and the main microstrip line 1, the secondary microstrip line 2, and the conductive strip 3 are all arranged on the dielectric layer 5. The through output port 20 and the coupled output port 40 have a 90° phase difference, and the isolation port 30 is connected to the matching load 4 and then grounded. The overall size of the high-directivity ultra-wideband coupler can be 2.2mm * 1.8mm * 0.13mm, the working bandwidth is 50 - 120Ghz, the directivity reaches 26db - 30db at 50 - 60Ghz, and the directivity reaches more than 30db at 60 - 120Ghz.

[0024] By adding a sawtooth structure 11 to the coupling side between the main microstrip line 1 and the secondary microstrip line 2, the coupling distance between the coupled main microstrip line 1 and the secondary microstrip line 2 can be increased, the coupling between the main body structure of the coupled microstrip lines (the coupled main microstrip line 1 and the secondary microstrip line 2) is weakened, and more energy can be guided to be coupled through the sawtooth structure 11. The sawtooth structure 11 can more effectively adjust the impedance of the main microstrip line 1 and the secondary microstrip line 2.

[0025] Furthermore, by controlling the height of the sawtooth structure 11, the impedance of the main microstrip line 1 and the secondary microstrip line 2 can be effectively regulated, so that the parasitic parameters of the matching load 4 connected to the isolation port 30 form a favorable resonance, which can improve the directivity of the high-directivity ultra-wideband coupler.

[0026] The working principle of the high-directivity ultra-wideband coupler is as follows: An electromagnetic wave signal is input at the input port 10, and most of the electromagnetic wave signals are output from the through output port 20, that is, the energy flow direction of the main microstrip line 1 is from the input port 10 to the through output port 20. A small part of the electromagnetic wave signals are coupled to the secondary microstrip line 2 through the coupling effect between the main microstrip line 1 and the secondary microstrip line 2. At this time, the energy flow direction of the secondary microstrip line 2 is opposite to that of the main microstrip line 1. A part of the energy coupled to the secondary microstrip line 2 is output from the coupled output port 40, and another part of the energy forms a reflection due to impedance mismatch and is thus output through the isolation port 30.

[0027] In some embodiments, as Figure 3 shown, a first platform-shaped sawtooth structure 12 is provided on the coupling side of the main microstrip line 1 and the secondary microstrip line 2, and a second platform-shaped sawtooth structure 21 is provided on the coupling side of the secondary microstrip line 2 and the main microstrip line 1. The height of the first platform-shaped sawtooth structure 12 is higher than that of the second platform-shaped sawtooth structure 21.

[0028] Specifically, the sawtooth structure 11 includes a first platform-shaped sawtooth structure 12 located on the main microstrip line 1 and a second platform-shaped sawtooth structure 21 located on the secondary microstrip line 2. The height of the first platform-shaped sawtooth structure 12 is higher than that of the second platform-shaped sawtooth structure 21, indicating that the height change of the first platform-shaped sawtooth structure 12 on the main microstrip line 1 is relatively larger than that of the second platform-shaped sawtooth structure 21 on the secondary microstrip line 2. This makes the first platform-shaped sawtooth structure 12 and the second platform-shaped sawtooth structure 21 asymmetric up and down. Such a sawtooth design can increase the coupling distance between the coupled microstrip lines and weaken the coupling between the main structures of the coupled microstrip lines, and can more effectively adjust the impedance of the main microstrip line 1 and the secondary microstrip line 2.

[0029] In some embodiments, the first platform-shaped sawtooth structure 12 includes a plurality of alternately arranged first recesses 122 and first protrusions 121, and the second platform-shaped sawtooth structure 21 includes a plurality of alternately arranged second recesses 212 and second protrusions 211. The first recesses 122 are aligned with the second protrusions 211, the first protrusions 121 are aligned with the second recesses 212, and the height of the first protrusions 121 is higher than that of the second protrusions 211.

[0030] Specifically, the first recesses 122 and the first protrusions 121 form the first platform-shaped sawtooth structure 12. Correspondingly, the second recesses 212 and the second protrusions 211 form the second platform-shaped sawtooth structure 21. The height of the first protrusions 121 is higher than that of the second protrusions 211, making the first protrusions 121 and the second protrusions 211 asymmetric, and making the height of the first platform-shaped sawtooth structure 12 higher than that of the second platform-shaped sawtooth structure 21. Thus, the first platform-shaped sawtooth and the second platform-shaped sawtooth structure 21 are asymmetric up and down, which is beneficial to regulating the impedance of the coupled main microstrip line 1 and secondary microstrip line 2, making the parasitic parameters of the matching load 4 connected to the isolation port 30 form a favorable resonance, and improving the directivity of the high-directivity ultra-wideband coupler.

[0031] The sawtooth structure 11 formed by the first recesses 122, the first protrusions 121, the second recesses 212, and the second protrusions 211 increases the interval between the main microstrip line 1 and the secondary microstrip line 2. The energy flow can be guided through the sawtooth structure 11. The height of the first protrusions 121 and the second protrusions 211 is mainly responsible for ensuring the coupling strength, while the height of the first recesses 122 and the second recesses 212 can adjust the impedance of the main microstrip line 1 and the secondary microstrip line 2 and has no significant impact on the coupling strength.

[0032] In some embodiments, the shapes of the first concave position 122, the first convex position 121, the second concave position 212, and the second convex position 211 are all trapezoidal. The trapezoidal first concave position 122 and first convex position 121 form the first platform-like serrated structure 12; correspondingly, the trapezoidal second concave position 212 and second convex position 211 form the second platform-like serrated structure 21.

[0033] In some embodiments, the tops of the first convex position 121 and the second convex position 211 are both platforms, and the platform 1211 of the first convex position 121 and the platform 2111 of the second convex position 211 are on the same straight line. This enables the main microstrip line 1 and the secondary microstrip line 2 to be coupled, and a coupling distance between the main microstrip line 1 and the secondary microstrip line 2 is achieved through the first concave position 122 and the second concave position 212.

[0034] Compared with the case where the top is a tip, at high frequencies, the tip is prone to causing resonance, resulting in performance deterioration. Compared with the case where the shapes of the first convex position 121 and the second convex position 211 are rectangular, the rectangle has right angles and is also prone to causing interference at high frequencies.

[0035] Therefore, the trapezoidal first concave position 122, first convex position 121, second concave position 212, and second convex position 211 can have a bevel transition, eliminating the resonance and interference of the tip and right angles at high frequencies.

[0036] In some embodiments, as Figure 2 , shown in FIG. 4, the matching load 4 is a thin-film resistor with a zigzag structure. One end of the thin-film resistor is connected to the isolation port 30, and several positions of the thin-film resistor are grounded.

[0037] The thin-film resistor with a zigzag structure can force the current in the thin-film resistor to flow in a staggered manner, thereby weakening the influence of parasitic parameters, enabling the matching load 4 to maintain a low reflection coefficient below -29 dB in an ultra-wide operating frequency band of 50 GHz - 120 GHz. By combining and adjusting the height difference of the serrated structure 11 on the main microstrip line 1 and the secondary microstrip line 2 designed, the parasitic parameters introduced by the matching load 4 can produce a positive resonance effect, further compensating for the odd-even mode impedance difference of the highly directional ultra-wideband coupler, and further improving the directivity of the highly directional ultra-wideband coupler.

[0038] In some embodiments, symmetric conductive bands 3 are distributed on both sides of the thin-film resistor. The conductive bands 3 are provided with symmetric circular vias 6, and the thin-film resistor is grounded after being connected to the circular vias 6 through the conductive bands 3.

[0039] Specifically, there is a conductive band 3 on the left side of the thin-film resistor, and there is also the same conductive band 3 on the right side. Each conductive band 3 has a circular via 6, and the circular vias 6 on the left and right sides of the thin-film resistor are symmetrically distributed with respect to the thin-film resistor. Then, multiple positions where the thin-film resistor contacts the conductive bands 3 are respectively grounded through these circular vias 6.

[0040] In some embodiments, the zigzag structure includes a bent portion 42 and a straight portion 41. The bent portions 42 and the straight portions 41 are alternately connected end to end, and the energy flow directions of two adjacent straight portions 41 are opposite.

[0041] Specifically, the head end of the first straight portion 41 is connected to the right conduction band 3, the tail end of the first straight portion 41 is connected to the head end of the first bent portion 42, the tail end of the first bent portion 42 is connected to the head end of the second straight portion 41, the tail end of the second straight portion 41 is connected to the head end of the second bent portion 42, the tail end of the second bent portion 42 is connected to the head end of the third straight portion 41, the tail end of the third straight portion 41 is connected to the head end of the third bent portion 42, the tail end of the third bent portion 42 is connected to the head end of the fourth straight portion 41, and so on, until the tail end of the last straight portion 41 is connected to the adjacent conduction band 3. Figure 4 Taking 5 straight portions 41 and 4 bent portions 42 as an example, a thin-film resistor is formed.

[0042] Too few straight portions 41 will result in too short an energy flow length, and the energy cannot be completely absorbed by the matching load 4; too many straight portions 41 will also result in too many bent portions 42, thus leading to too large parasitic parameters and weakening the absorption efficiency of the matching load 4.

[0043] As Figure 5 shown, Figure 5 is the energy flow direction of the thin-film resistor. Obviously, the energy flow direction of the first straight portion 41 is opposite to that of the second straight portion 41, and the energy flow direction of the second straight portion 41 is opposite to that of the third straight portion 41. By alternately connecting the bent portions 42 and the straight portions 41 end to end, the current between adjacent straight portions 41 can be forced to be out of phase, thereby reducing the influence of parasitic parameters.

[0044] In some embodiments, the isolation port 30 is connected to the first straight portion 41, and the end face of the last straight portion 41 is connected to the conduction band 3.

[0045] Since the isolation port 30 is not used in practice, therefore, the matching load 4 is connected, specifically to the first straight portion 41 of the thin-film resistor. Then, the end face of the tail end of the last straight portion 41 is actually connected to the conduction band 3.

[0046] In some embodiments, each bent portion 42 is connected to the conduction band 3. In contrast, only the head end and the tail end of the straight portion 41 are connected to the conduction band 3. The bent portion 42 is integrally connected to the conduction band 3, and there are several circular vias 6 provided on the conduction band 3 to facilitate the bent portion 42 to be grounded through the circular vias 6.

[0047] The high-directivity ultra-wideband coupler of the present application can improve the performance of the high-directivity ultra-wideband coupler in the forward direction by setting a sawtooth structure 11 on the coupling side between the main microstrip line 1 and the secondary microstrip line 2, and combining with the matching load 4 of the zigzag structure connected to the isolation port 30. It breaks the conventional thinking of the function of the traditional matching load 4, realizes the joint optimization between the main microstrip line 1 and the secondary microstrip line 2 inside the high-directivity ultra-wideband coupler, effectively optimizes the odd and even mode impedance consistency of the high-directivity ultra-wideband coupler, realizes the improvement of the directivity of the high-directivity ultra-wideband coupler, and has a small overall size, a simple structure, and is convenient for processing.

[0048] At the same time, the high-directivity ultra-wideband coupler of the present application propagates quasi-TEM waves. Compared with the TEM waves of the rectangular waveguide structure, the structure of this high-directivity ultra-wideband coupler supports multi-mode transmission, so that a larger frequency range can be covered, and an ultra-wide operating frequency band of 50 - 120 GHz can be realized.

[0049] As Figure 6 shown, the abscissa represents frequency, and the ordinate represents the scattering parameter. The scattering parameter, that is, the S parameter, is an important parameter in microwave transmission. The directivity within the bandwidth is equal to . Obviously, the directivity of this high-directivity ultra-wideband coupler reaches more than 26 dB at 50 GHz - 60 GHz, and further reaches more than 30 dB at 60 - 120 GHz, successfully achieving high directivity at high frequencies and large bandwidths. Compared with the same type of couplers, the high-directivity ultra-wideband coupler designed by the present invention has a higher frequency, a larger bandwidth, and better directivity.

[0050] The above are only the preferred embodiments of the present application. Those skilled in the art know that without departing from the spirit and scope of the present application, various changes or equivalent replacements can be made to these features and embodiments. In addition, under the teaching of the present application, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present application. Therefore, the present application is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application belong to the protection scope of the present application.

Claims

1. A highly directional ultra-wideband coupler, characterized in that, It includes a main microstrip line and a secondary microstrip line that are coupled to each other. One end of the main microstrip line is configured as the input port of the coupler for receiving an electromagnetic wave signal, and the other end is configured as the through output port for outputting a signal; One end of the secondary microstrip line is configured as the coupled output port of the coupler, and the other end is configured as the isolation port; A sawtooth structure is provided on the coupling side between the main microstrip line and the secondary microstrip line for increasing the coupling distance between the main microstrip line and the secondary microstrip line, thereby adjusting the impedance of the main microstrip line and the secondary microstrip line; The isolation port is grounded after being connected to a matching load of a meandering structure, and the energy flow direction of the matching load is opposite to the energy flow direction of the main microstrip line.

2. The highly directional ultra-wideband coupler according to claim 1, wherein A first platform-shaped sawtooth structure is provided on the coupling side of the main microstrip line and the secondary microstrip line, and a second platform-shaped sawtooth structure is provided on the coupling side of the secondary microstrip line and the main microstrip line. The height of the first platform-shaped sawtooth structure is higher than the height of the second platform-shaped sawtooth structure.

3. The highly directional ultra-wideband coupler according to claim 2, characterized in that, The first platform-shaped sawtooth structure includes a plurality of alternately arranged first recesses and first protrusions. The second platform-shaped sawtooth structure includes a plurality of alternately arranged second recesses and second protrusions. The first recesses are aligned with the second protrusions, the first protrusions are aligned with the second recesses, and the height of the first protrusions is higher than the height of the second protrusions.

4. The highly directional ultra-wideband coupler according to claim 3, wherein The shapes of the first recesses, first protrusions, second recesses, and second protrusions are all trapezoidal.

5. The highly directional ultra-wideband coupler according to claim 3, characterized in that, The tops of the first protrusions and the second protrusions are both platforms, and the platforms of the first protrusions and the platforms of the second protrusions are on the same straight line.

6. The high-directivity ultra-wideband coupler according to claim 1, wherein, The matching load is a meandering thin film resistor. One end of the thin film resistor is connected to the isolation port, and several positions of the thin film resistor are grounded.

7. The highly directional ultra-wideband coupler according to claim 6, wherein Symmetrical conductive bands are distributed on both sides of the thin film resistor. The conductive bands are provided with symmetrical circular vias. The thin film resistor is grounded after being connected to the circular vias through the conductive bands.

8. The highly directional ultra-wideband coupler according to claim 7, characterized in that, The meandering structure includes a bent part and a straight part. The bent part and the straight part are alternately connected end to end, and the energy flow directions of two adjacent straight parts are opposite.

9. The highly directional ultra-wideband coupler according to claim 8, wherein The isolation port is connected to the first straight part, and the end face of the last straight part is connected to the conductive band.

10. The highly directional ultra-wideband coupler according to claim 8, characterized in that, Each bent part is connected to the conductive band.

Images