Ultra-wideband bi-directional coupler

Abstract

The invention discloses an ultra wide band bi-directional coupler, which aims at solving the problems that the frequency range, the loss characteristic, the bandwidth, the power processing capability, the structure complexity, the manufacturing cost and the anti-interference performance are difficult to optimize at the same time, and comprises an input port and an output port which are respectively arranged at two ends of a shell, the input port and the output port are respectively connected with the input and the output of the coupling units, the at least two coupling units are arranged in the shell, one coupling unit is connected with the coupling port, the other coupling unit is connected with the isolation port, and the coupling port and the isolation port are both mounted on the shell; wherein the input and the output of the coupling unit are connected to the input port and the output port through a coaxial conductor. According to the invention, enhanced isolation and noise suppression, flexible coupling degree adjustment, wide working frequency range, simplified structure, low-cost manufacturing and high-power processing capability are realized, so that excellent performance and reliability are provided in various application environments.

Description

Technical Field

[0001] This document relates to the field of radio frequency microwave technology, and in particular to an ultra-wideband dual directional coupler. Background Art

[0002] A directional coupler is a device for measuring electromagnetic fields. It can couple the energy of an electromagnetic field from one transmission line (main line) to another transmission line (auxiliary line). In electromagnetic compatibility experiments, directional couplers are used to couple electromagnetic fields from a signal generator to the device under test to simulate real electromagnetic radiation conditions. In the design of a directional coupler, many factors need to be considered, such as frequency range, insertion loss, reflection loss, etc. In order to improve the performance and accuracy of directional couplers. It is necessary to study some background technologies. There are many different forms of couplers now. Common coupler types include structural RF couplers, transformer couplers, monolithic integration-based couplers, and optical-based couplers. Among them, the structural coupler is characterized by a simple structure, but the bandwidth and power handling capacity are limited. Transformer-based couplers have higher bandwidth and power handling capacity, but the structure is relatively complex. Monolithic integration-based couplers have higher bandwidth and power, compact structure, but higher manufacturing cost. Optical-based couplers have higher bandwidth and power handling capacity and anti-interference ability, but the manufacturing and debugging costs are very high.

[0003] Therefore, it is necessary to provide an ultra-wideband dual directional coupler. Summary of the invention

[0004] This specification provides an ultra-wideband dual directional coupler to solve the problem of difficulty in simultaneously optimizing frequency range, loss characteristics, bandwidth, power handling capability, structural complexity, manufacturing cost and anti-interference performance, including: a housing, an input port, an output port, a coupling unit, a coupling port, an isolation port and a coaxial conductor;

[0005] An input port and an output port are installed at both ends of the housing, respectively, the input port and the output port are connected to the input and output of the coupling unit respectively, at least two coupling units are arranged inside the housing, one of the coupling units is connected to the coupling port, and the other coupling unit is connected to the isolation port, and both the coupling port and the isolation port are installed on the housing;

[0006] The input and output of the coupling unit are connected to the input port and the output port through a coaxial conductor.

[0007] Further, the coupling unit includes a resistor R1, a resistor R2, a resistor R31, a resistor R32, a capacitor C1, a capacitor C2, a terminal term1, a terminal term2 and a terminal term3;

[0008] A first node Q1 is provided at one end of the resistor R1, and the first node Q1 is connected to a terminal term1 and a terminal term2, the terminal term1 is connected to an input port, and the terminal term2 is connected to an output port;

[0009] A second node Q2 is provided at the other end of the resistor R1, the second node Q2 is connected to one end of the resistor R31 and the resistor R32, the other end of the resistor R31 is connected to the other end of the resistor R32, a third node Q3 is connected between one end of the resistor R31 and one end of the resistor R32, the third node Q3 is connected to the capacitor C2 and the terminal term3 respectively, the other end of the capacitor C2 is grounded, and the terminal term3 is connected to the coupling port;

[0010] One end of the resistor R32 is also connected to one end of the resistor R2, the other end of the resistor R2 is grounded, one end of the capacitor C1 is connected between the other end of the resistor R31 and the other end of the resistor R32, the other end of the capacitor C1 is grounded;

[0011] The resistor R2 is equivalent to a chip resistor disc, and the chip resistor disc is fixed on the housing through a metal resistor disc bracket.

[0012] Furthermore, the terminal term1 and the terminal term2 are connected via a coaxial conductor, specifically:

[0013] The coaxial conductor includes a ferrite ring, a bracket and a coaxial cable; the coaxial cable is used to connect the terminal term1 and the terminal term2, and a ferrite ring is sleeved in the middle of the coaxial cable, and the ferrite ring is fixed to the housing through the bracket.

[0014] Furthermore, the bracket is a polytetrafluoroethylene bracket.

[0015] Furthermore, the ferrite in the ferrite magnetic ring is nickel zinc and / or manganese zinc.

[0016] Furthermore, the bracket is of the same length as the ferrite ring.

[0017] Furthermore, both the input port and the output port are N-type interfaces.

[0018] Furthermore, the resistor R1 is fixed to the housing via a heat conducting plate.

[0019] Furthermore, the interface form of the coupling port and the isolation port is a through-wall SMA radio frequency coaxial connector with a flange.

[0020] Furthermore, a heat sink is provided on the housing.

[0021] At least one of the above technical solutions adopted in the embodiments of this specification can achieve the following beneficial effects:

[0022] Enhanced isolation and noise suppression: By selecting ferrite rings of different materials (such as nickel-zinc and manganese-zinc), the coupler can significantly improve the isolation of the circuit and effectively suppress noise. This design can be dynamically adjusted according to the specific operating frequency to ensure optimal performance in different application environments.

[0023] Flexible coupling adjustment: The introduction of adjustable coupling circuit allows users to adjust coupling parameters according to actual needs to achieve matching effects of different coupling degrees. This feature greatly expands the application range of the coupler, making it not only suitable for conventional testing, but also meeting special requirements in specific experiments or industrial environments.

[0024] Significantly expanded operating frequency range: The coupler covers a wide frequency band from 5KHz to 1GHz, far exceeding existing domestic similar products, and maintains excellent performance with a flatness of 40dB and an error within 1dB throughout the frequency band. This provides a wider range of options for electromagnetic compatibility testing and other high-frequency applications.

[0025] Simplified structure and low-cost manufacturing: Despite its excellent technical indicators, the design of the coupler still maintains structural simplicity, using standardized N-type interfaces and lightweight materials to reduce manufacturing costs. At the same time, its compact design facilitates integration into various systems, and is particularly suitable for application scenarios such as electromagnetic compatibility experiments.

[0026] High power handling capability: The stable coaxial conductor structure ensures that the coupler can withstand high power up to 200W, and its stability has been verified by full-band copy machine testing. This makes it suitable for occasions that need to handle high-power signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0028] Figure 1 A schematic diagram of the structure of an ultra-wideband dual directional coupler provided in one embodiment of this specification;

[0029] Figure 2 A structural connection diagram of a coupling unit in an ultra-wideband dual-directional coupler provided in an embodiment of this specification;

[0030] Figure 3 A schematic diagram of the measured coupling results of an ultra-wideband dual-directional coupler provided in an embodiment of this specification;

[0031] Figure 4 A schematic diagram of the measured isolation results of an ultra-wideband dual directional coupler provided in an embodiment of this specification;

[0032] Figure 5 A schematic diagram of the standing wave measurement results of an ultra-wideband dual directional coupler provided in one embodiment of this specification.

[0033] Figure 6 This is a structural diagram of a chip resistor disk in an ultra-wideband dual directional coupler provided in one embodiment of this specification. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0035] The technical solutions provided by various embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0036] Figure 1 This is a schematic diagram of the structure of an ultra-wideband dual directional coupler provided in an embodiment of this specification, see Figure 1 , the coupler comprises a housing 1, an input port 2, an output port 3, a coupling unit 4, a coupling port 5, an isolation port 6 and a coaxial conductor 7;

[0037] An input port 2 and an output port 3 are installed at both ends of the housing 1, respectively. The input port 2 and the output port 3 are connected to the input and output of a coupling unit 4, respectively. At least two coupling units 4 are arranged inside the housing 1, one of the coupling units 4 is connected to a coupling port 5, and the other coupling unit 4 is connected to an isolation port 6. Both the coupling port 5 and the isolation port 6 are installed on the housing 1;

[0038] The input and output of the coupling unit 4 are connected to the input port 2 and the output port 3 via a coaxial conductor 7 .

[0039] The housing 1 is a protective structure of the entire coupler, and is used to accommodate and fix the internal components. It is made of high-strength materials, can provide electromagnetic shielding, prevent external interference, and ensure the stable operation of the internal circuit. Specifically, in this embodiment, the dimensions of the housing 1 are: 129mm long × 73mm wide × 40mm high, and the weight is ≤500g;

[0040] In order to make the coupler easier to use, the size of the housing 1 should be as small as possible while ensuring that sufficient space is reserved in the internal design of the coupler and that the strength is guaranteed. A thin-wall structure plus an external heat sink structure and an internal circuit structure can effectively reduce the weight of the coupler to less than 500g.

[0041] In this embodiment, the signal form is an AC signal, and the signal input and output are input port 2 and output port 3, which are preferably N-type interfaces; the coupling port 5 and the isolation port are SMA interfaces, with an impedance of 50 ohms and a standing wave ratio of ≤1.5;

[0042] The signal input form uses AC signal. In order to ensure the standing wave ratio and minimize interference, the interface needs to have good impedance matching. The input and output ports use N-type connectors. In order to facilitate the subsequent circuit connection, the core wire of the N-type interface needs to be divided into two paths during design and specially customized; the coupling port and isolation port interface form directly use SMA RF coaxial connectors with flanges.

[0043] During the assembly process of this embodiment, all components must be installed in accordance with strict tolerance requirements to ensure the working performance of the coupler. After assembly, the coupler needs to undergo a series of tests and calibrations, including frequency response, coupling ratio, insertion loss and other parameters, to ensure that it meets the expected design specifications.

[0044] like Figure 2 As shown, as a further explanation of the present invention, the coupling unit 4 includes a resistor R1, a resistor R2, a resistor R31, a resistor R32, a capacitor C1, a capacitor C2, a terminal term1, a terminal term2 and a terminal term3;

[0045] A first node Q1 is provided at one end of the resistor R1, the first node Q1 is connected to a terminal term1 and a terminal term2, the terminal term1 is connected to an input port 2, and the terminal term2 is connected to an output port 3;

[0046] A second node Q2 is provided at the other end of the resistor R1, the second node Q2 is connected to one end of the resistor R31 and the resistor R32, the other end of the resistor R31 is connected to the other end of the resistor R32, a third node Q3 is connected between one end of the resistor R31 and one end of the resistor R32, the third node Q3 is connected to the capacitor C2 and the terminal term3 respectively, the other end of the capacitor C2 is grounded, and the terminal term3 is connected to the coupling port 5;

[0047] One end of the resistor R32 is also connected to one end of the resistor R2, the other end of the resistor R2 is grounded, one end of the capacitor C1 is connected between the other end of the resistor R31 and the other end of the resistor R32, the other end of the capacitor C1 is grounded.

[0048] Wherein, the resistor R1 is fixed to the housing 1 through a heat conducting plate;

[0049] Among them, Figure 6 As shown, the resistor R2 is equivalent to a chip resistor disc, specifically a dispersed chip resistor disc, and the chip resistor disc is fixed on the housing 1 through a metal resistor disc bracket.

[0050] Among them, the distributed chip resistor disc is a parallel connection structure of multiple circular array resistors R2, which are connected and fixed on the housing 1 through a metal resistor disc bracket. The resistance values ​​of the multiple resistors R2 in the circular array are different. Technical personnel in this field can choose to connect resistors R2 with different resistance values ​​according to actual needs.

[0051] The connection terminal term1 and the connection terminal term2 are connected via a coaxial conductor 7, specifically:

[0052] The coaxial conductor 7 includes a ferrite ring, a bracket and a coaxial cable; the coaxial cable is used to connect the terminal term1 and the terminal term2, and a ferrite ring is sleeved in the middle of the coaxial cable, and the ferrite ring is fixed to the housing 1 through the bracket.

[0053] The working frequency of the coupling unit 4 in this embodiment is: 5kHz~1GHz, and the coupling degree is: 40dB+1dB;

[0054] Currently, there are structural couplers, transformer couplers, etc. that can meet the requirements of different operating frequencies and coupling degrees. Since this design focuses on ultra-wideband, improvements are made on the basis of the above-mentioned couplers. A circuit voltage divider coupler is used, and innovative improvements are made. Twisted pair coupling is used to reduce interference in high-frequency states. A distributed chip resistor disk design is used to better achieve low-frequency grounding and high-frequency isolation. The design is optimized through simulation to meet the requirements of wide-band and high-flatness indicators.

[0055] Among them, a ferrite ring is set in the middle of the coaxial cable. The function of the ferrite ring is to provide good electromagnetic interference (EMI) suppression effect under high frequency conditions, reduce the impact of external electromagnetic interference on signal transmission between terminals, and reduce the radiation noise generated by the cable itself. The ferrite material should be selected according to the working frequency band to ensure the best filtering effect.

[0056] like Figure 3-Figure 5 As shown, Figure 3The schematic diagram of the isolation measurement results is shown. It can be seen from the figure that the coupling degree is within the range of 40±1dB and the flatness is good; Figure 4 The diagram shows the isolation measurement results. It can be seen from the figure that the isolation is ≤50dB and the directivity meets the use requirements. Figure 5 A schematic diagram of the standing wave measurement results is shown, from which it can be seen that the standing wave is less than 1.5.

[0057] As a further explanation of the present invention, the bracket is a polytetrafluoroethylene bracket, the ferrite in the ferrite magnetic ring is nickel zinc and / or manganese zinc, and the bracket is the same length as the ferrite magnetic ring.

[0058] Among them, the ferrite material in the ferrite magnetic ring is nickel zinc (NiZn) or manganese zinc (MnZn). These two materials show good electromagnetic interference (EMI) suppression effect under high frequency conditions. NiZn ferrite is suitable for higher frequency bands and has a lower loss tangent; MnZn ferrite is more suitable for medium and low frequency bands and provides higher saturation flux density. Choose the appropriate ferrite type according to actual application requirements.

[0059] Among them, the bracket is made of polytetrafluoroethylene (PTFE), which not only has excellent mechanical strength and chemical stability, but also has extremely low dielectric constant and loss factor, which is very suitable for high-frequency signal transmission environment.

[0060] The bracket is designed to be the same length as the ferrite ring, ensuring that the two can be installed perfectly aligned. This design helps maintain structural consistency and stability while simplifying the assembly process.

[0061] The ferrite magnetic ring is sleeved in the middle of the coaxial cable, and the polytetrafluoroethylene bracket tightly wraps the ferrite magnetic ring, which not only plays a fixing role but also does not cause adverse effects on the received or sent signals.

[0062] The assembly steps in this embodiment are as follows:

[0063] Connect one end of the coaxial cable to terminal Term1 and the other end to terminal Term2.

[0064] Precisely loop the ferrite magnet around the middle of the coaxial cable, ensuring it is centered along the length of the cable.

[0065] A specially designed polytetrafluoroethylene bracket is used to fix the ferrite ring on the housing 1. Since the bracket is the same length as the ferrite ring, it can be easily positioned and fixed through a fixing point (such as a screw hole) preset on the housing.

[0066] A space is reserved at an appropriate position inside the housing 1 to accommodate the bracket and the ferrite ring to avoid interference with other components.

[0067] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. An ultra-wideband dual directional coupler, characterized in that: include: A housing (1), an input port (2), an output port (3), a coupling unit (4), a coupling port (5), an isolation port (6) and a coaxial conductor (7); An input port (2) and an output port (3) are respectively installed at both ends of the housing (1); the input port (2) and the output port (3) are respectively connected to the input and output of a coupling unit (4); at least two coupling units (4) are arranged inside the housing (1); one of the coupling units (4) is connected to a coupling port (5), and the other coupling unit (4) is connected to an isolation port (6); and both the coupling port (5) and the isolation port (6) are installed on the housing (1); The input and output of the coupling unit (4) are connected to the input port (2) and the output port (3) via a coaxial conductor (7).

2. The ultra-wideband dual directional coupler according to claim 1, characterized in that: The coupling unit (4) comprises a resistor R1, a resistor R2, a resistor R31, a resistor R32, a capacitor C1, a capacitor C2, a terminal term1, a terminal term2 and a terminal term3; A first node Q1 is provided at one end of the resistor R1, the first node Q1 is connected to a terminal term1 and a terminal term2, the terminal term1 is connected to an input port (2), and the terminal term2 is connected to an output port (3); A second node Q2 is provided at the other end of the resistor R1, the second node Q2 is connected to one end of the resistor R31 and the resistor R32, the other end of the resistor R31 is connected to the other end of the resistor R32, a third node Q3 is connected between one end of the resistor R31 and one end of the resistor R32, the third node Q3 is connected to the capacitor C2 and the terminal term3 respectively, the other end of the capacitor C2 is grounded, and the terminal term3 is connected to the coupling port (5); One end of the resistor R32 is also connected to one end of the resistor R2, the other end of the resistor R2 is grounded, one end of the capacitor C1 is connected between the other end of the resistor R31 and the other end of the resistor R32, the other end of the capacitor C1 is grounded; The resistor R2 is equivalent to a chip resistor disc, and the chip resistor disc is fixed on the housing (1) via a metal resistor disc bracket.

3. The ultra-wideband dual directional coupler according to claim 2, characterized in that: The connection terminal term1 and the connection terminal term2 are connected via a coaxial conductor (7), specifically: The coaxial conductor (7) comprises a ferrite magnetic ring, a bracket and a coaxial cable; the coaxial cable is used to connect the terminal term1 and the terminal term2, the middle part of the coaxial cable is sleeved with a ferrite magnetic ring, and the ferrite magnetic ring is fixed to the housing (1) through the bracket.

4. The ultra-wideband dual directional coupler according to claim 3, characterized in that: The bracket is a polytetrafluoroethylene bracket.

5. The ultra-wideband dual directional coupler according to claim 3, characterized in that: The ferrite in the ferrite magnetic ring is nickel zinc and / or manganese zinc.

6. The ultra-wideband dual directional coupler according to claim 3, characterized in that: The bracket is equal in length to the ferrite ring.

7. The ultra-wideband dual directional coupler according to claim 1, characterized in that: The input port (2) and the output port (3) are both N-type interfaces.

8. The ultra-wideband dual directional coupler according to claim 2, characterized in that: The resistor R1 is fixed to the housing (1) via a heat conducting plate.

9. The ultra-wideband dual directional coupler according to claim 1, characterized in that: The interface form of the coupling port (5) and the isolation port (6) is a through-wall SMA radio frequency coaxial connector with a flange.

10. The ultra-wideband dual directional coupler according to claim 1, characterized in that: The housing (1) is provided with a heat sink.

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