Megawatt broadband weak directional coupler

Abstract

The megawatt broadband weak directional coupler comprises an outer conductor, an inner conductor and a plurality of coupling heads, the outer conductor is of a cavity structure, the inner conductor is installed in the outer conductor through a supporting assembly, the coupling heads are installed on an installation seat, the installation seat is installed on the outer side face of the outer conductor, and the outer surface of the installation seat is provided with a plurality of installation planes; the coupling head comprises a shell, the shell is of a bottomless cavity structure, the shell is formed by splicing two half shells arranged in a mirror image mode, the splicing faces of the half shells are located on the side faces, the shell is embedded in a clamping hoop, a connecting flange is arranged at the bottom of the outer side of the clamping hoop, and the connecting flange is fixedly connected with an installation plane through a bolt. A bolt penetrates through the paired flanges located on one side of the hoop to achieve locking, the bottom of the inner side of the hoop is provided with an inner circle, a base is arranged between the bottom of the shell and the inner circle and inserted into the outer conductor, the outer side of the base is provided with an outer circle, the outer circle is in lap joint with the inner circle, and the upper end face of the shell is provided with a load port and a coupling port.

Description

Technical Field

[0001] The utility model is a megawatt-level broadband weak directional coupler. Background Art

[0002] Directional coupler is an important RF passive device. It extracts the power signal in the RF path according to a certain ratio, and then detects and analyzes the obtained power signal. Directional couplers are widely used in various RF microwave systems to monitor the working status of the entire RF system. According to the degree of coupling, directional couplers can be divided into strong directional couplers (coupling degree in the range of 0 to -10dB), medium directional couplers (coupling degree in the range of -10 to -20dB) and weak directional couplers (coupling degree less than -20dB). Generally, weak directional couplers are used for RF system detection and monitoring.

[0003] Coaxial weak directional couplers are used in RF systems connected by coaxial lines. The main line interface has the same specifications as the coaxial line of the RF system and can be connected to the system. The main line port of the coaxial weak directional coupler can adopt a straight port structure or a flange port structure. The weak directional coupler can be designed with multiple coupling ports, each of which can take out a part of the power signal from the main line channel for detection and monitoring. The coupling ports have different directions and can monitor the forward power and reverse power of the main line respectively.

[0004] The coupling degree of a coupled stripline weak directional coupler of general structure increases with the increase of operating frequency, and the coupling degree increases by 6dB for each frequency doubling. That is to say, in the frequency domain coordinate system, the coupling degree of a coupled stripline weak directional coupler of general structure is an upward sloping line with a slope of 6dB / 2 frequency doubling. For systems operating in narrowband or point frequency, there is no problem using a coupler of this structure. However, if the RF system used by the coupler is broadband, if the coupling degree is different over the entire operating frequency band, it will cause trouble for detection and data statistical analysis. Therefore, for a weak directional coupler operating in a wideband, it is necessary to find a way to "level" the coupling degree of the coupler over the entire operating frequency band. Utility Model Content

[0005] The purpose of the utility model is to solve the above deficiencies in the prior art and provide a megawatt-class broadband weak directional coupler.

[0006] A megawatt-class broadband weak directional coupler comprises an outer conductor, an inner conductor and a plurality of coupling heads, wherein the outer conductor is a cavity structure, the inner conductor is installed in the outer conductor through a supporting assembly, the coupling head is installed on a mounting seat, the mounting seat is installed on the outer side surface of the outer conductor, and the outer surface of the mounting seat is provided with a plurality of mounting planes;

[0007] The coupling head includes a shell, which is a bottomless cavity structure. The shell is formed by splicing two half shells in mirror-image arrangement. The splicing surface of the half shells is located on the side. The shell is embedded in the clamp. A connecting flange is provided at the bottom of the outer side of the clamp. The connecting flange is fixedly connected to the mounting plane by bolts. The clamp is locked by bolts passing through a matching flange located on one side of the clamp. An inner circle is provided at the bottom of the inner side of the clamp. A base is provided between the bottom of the shell and the inner circle. The base is inserted into the outer conductor. An outer circle is provided on the outer side of the base. The outer circle is overlapped on the inner circle. A load port and a coupling port are provided on the upper end face of the shell.

[0008] Preferably, a water cooling structure is provided on the inner conductor.

[0009] Preferably, a radial adjustment mechanism is provided on the coupling head, and the radial adjustment mechanism is used to control the radial adjustment of the coupling head along the outer conductor structure.

[0010] Preferably, the coupling heads are each provided with a rotation adjustment mechanism, and the rotation adjustment mechanism is used to control the forward coupling head and the reverse coupling head to perform 360° rotation adjustment along their own central axis.

[0011] Preferably, the number of coupling heads is two, namely a forward coupling head and a reverse coupling head.

[0012] Preferably, the outer conductor is made of aluminum alloy in one piece.

[0013] Preferably, the support assembly includes a plurality of flanges and insulating supports, the flanges are fixed at ports at both ends of the outer conductor, the insulating supports are embedded in the flanges, and a through hole for passing the inner conductor is provided at the center of the insulating support.

[0014] Preferably, the insulating support is made of polytetrafluoroethylene.

[0015] Preferably, heat dissipation teeth are provided on the outer side wall of the coupling head that is exposed from the clamp.

[0016] Beneficial effects: Compared with the prior art, the coupling degree of the utility model meets 63.7±0.2dB in the working frequency range (25~75MHz, high-low frequency ratio is 3), the directivity is better than 30dB, and the coupling degree of the coupler is very "flat" in the entire working frequency band. The processing cost is low, the appearance is beautiful, and the debugging is convenient. The rated power of the coupler is 1.5MW, and this power level of broadband weak directional coupler is still blank in the country.

[0017] At the same time, in order to meet the ultra-high power requirements of the coupler, the coupler is designed with a water cooling structure. The cooling water flows inside the main line conductor, which greatly improves the heat dissipation efficiency of the coupler and increases the rated power capacity. The coupling head and the built-in balancing circuit can withstand high power requirements and have excellent heat dissipation performance. The coupling head is installed through a specific installation structure to ensure that the coupling head is tightly connected to the outer conductor and will not fall off. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of a megawatt-class broadband weak directional coupler;

[0019] Figure 2 is a cross-sectional view of a megawatt-class broadband weak directional coupler;

[0020] Figure 3 is a schematic diagram of the coupling head;

[0021] In the figure, 1, coupling head, 2, outer conductor, 3, mounting seat, 4, inner conductor, 5, insulating support, 6, clamp, 7, base, 8, outer circle, 9, inner circle, 10, coupling port, 11, load port, 12, half shell. DETAILED DESCRIPTION

[0022] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with embodiments and drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0023] like Figure 1-3 As shown, coupling head 1, outer conductor 2, mounting seat 3, inner conductor 4, insulating support 5, clamp 6, base 7, outer circle 8, inner circle 9, coupling port 10, load port 11, half shell 12;

[0024] A megawatt-class broadband weak directional coupler comprises an outer conductor 2, an inner conductor 4, and two coupling heads 1. The outer conductor 2 is a cavity structure. The inner conductor 4 is installed in the outer conductor 2 through a supporting assembly. The supporting assembly comprises a plurality of flanges and insulating supports 5. The flanges are fixed at ports at both ends of the outer conductor 2. The insulating supports 5 are embedded in the flanges. A through hole for passing the inner conductor 4 is provided at the center of the insulating support 5. A plurality of through holes are provided on the surface of the insulating support 5. The insulating support 5 is made of polytetrafluoroethylene. A water cooling structure is provided on the inner conductor 4.

[0025] Specifically, the inner conductor 4 is arranged inside the outer conductor 2, and an insulating support 5 made of polytetrafluoroethylene is arranged between the outer conductor 2 and the inner conductor 4. The main line conductor structure is provided with a main line input port and a main line output port, both of which are non-standard flange interfaces. There are two insulating supports 5 in the main line conductor structure, which are respectively located at the flange cores of the flange interfaces at both ends. A through hole is arranged in the middle of the insulating support 5. The insulating support 5 is embedded in the main line outer conductor 2, and the main line inner conductor 4 is embedded in the through hole in the middle of the insulating support 5, which not only ensures that the inner and outer conductors 2 of the main line are coaxial, but also ensures that the main line inner conductor 4 will not move along the axial direction. In order to meet the ultra-high power use requirements of the coupler, the coupler is designed with a water cooling structure, and the cooling water flows inside the main line inner conductor 4, which greatly improves the heat dissipation efficiency of the coupler and improves the rated power capacity.

[0026] The coupling heads 1 are respectively a forward coupling head 1 and a reverse coupling head 1. The coupling heads 1 are mounted on a mounting seat 3. The mounting seat 3 is mounted on the outer surface of the outer conductor 2. The outer surface of the mounting seat 3 is provided with a plurality of mounting planes. The coupling head 1 comprises a shell. The shell is a bottomless cavity structure. The shell is formed by splicing two mirror-set half shells 12. The splicing surface of the half shells 12 is located on the side. The shell is embedded in the clamp 6. The outer side wall of the coupling head 1 exposed from the clamp 6 is provided with heat dissipation teeth.

[0027] A connecting flange is provided at the bottom of the outer side of the clamp 6, and the connecting flange is fixedly connected to the mounting plane by bolts. The clamp 6 is locked by bolts passing through a matching flange located on one side of the clamp 6. An inner circle 9 is provided at the bottom of the inner side of the clamp 6, and a base 7 is provided between the bottom of the shell and the inner circle 9. The base 7 is inserted into the outer conductor 2, and an outer circle 8 is provided on the outer side of the base 7. The outer circle 8 is overlapped on the inner circle 9, and a load port 11 and a coupling port 10 are provided on the upper end surface of the shell.

[0028] The coupling head 1 is provided with a radial adjustment mechanism, which is used to control the radial adjustment of the coupling head 1 along the outer conductor 2 structure. The coupling head 1 is also provided with a rotation adjustment mechanism, which is used to control the forward coupling head 1 and the reverse coupling head 1 to perform 360° rotation adjustment along their own central axis.

[0029] Specifically, in order to lock the coupling head that has been adjusted to the appropriate position, a locking device is provided on the forward coupling head and the reverse coupling head. The locking device is used to lock and fix the positions of the adjusted forward coupling head and the reverse coupling head. The locking method is to split a seam at the top of the locking device, and then screw the two separated parts together to hold and fix the coupling head. The locking method has little effect on the position of the coupling head during the locking process. There is no need to reserve the change caused by locking during debugging. Compared with the traditional locking method, debugging is more convenient and more efficient.

[0030] In addition, the coupler structure has excellent RF indicators (such as reflection loss, insertion loss, directivity, etc.). The outer conductor cavity of the coupler main line adopts the process of integrated processing of aluminum alloy. Compared with the process of round tube welding, it has higher processing accuracy, better coupler indicators, lower processing cost and more beautiful appearance.

[0031] The built-in equalizing circuit of the coupler is composed of several capacitors, inductors, and resistors, among which the resistors are all double-lead flange resistors to ensure that the selected ones can withstand sufficiently large power. Since the two ports of the equalizing circuit have excellent reflection loss, the coupling port and load port of the coupler in the utility model also have excellent reflection loss. Compared with the traditional method in which the coupling port and the load port are connected to the coupling board through the equalizing circuit board, the load port and the coupling board in the coupling head structure are directly connected with a 50-ohm cable, and the reflection loss of the connecting line all the way to the load port will be better, which can ensure that the directionality of the coupler will not change after being connected to the equalizing circuit. The equalizing circuit has excellent RF indicators, and the coupler after being connected to the equalizing circuit has excellent flatness of coupling within the operating frequency range.

[0032] The components (capacitors, inductors, resistors) used in the balancing circuit are all models that can withstand high power. The circuit board uses a plate that can withstand high power and has good thermal conductivity. The back of the balancing circuit board is in full contact with the coupling head. The part of the coupling head exposed outside the locking device is covered with heat dissipation teeth to ensure a sufficiently large heat dissipation area. The entire coupling head and the built-in balancing circuit can meet the ultra-high power usage requirements of the coupler and have excellent heat dissipation performance.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A megawatt-class broadband weak directional coupler, characterized in that: It includes an outer conductor, an inner conductor, and a plurality of coupling heads, wherein the outer conductor is a cavity structure, the inner conductor is installed in the outer conductor through a supporting assembly, the coupling head is installed on a mounting seat, the mounting seat is installed on the outer side of the outer conductor, and the outer surface of the mounting seat is provided with a plurality of mounting planes; The coupling head includes a shell, which is a bottomless cavity structure. The shell is formed by splicing two mirror-imaged half shells, and the splicing surface of the half shells is located on the side. The shell is embedded in the clamp, and a connecting flange is provided at the outer bottom of the clamp. The connecting flange is fixedly connected to the mounting plane by bolts. The clamp is locked by bolts passing through a matching flange located on one side of the clamp. An inner circle is provided at the inner bottom of the clamp, and a base is provided between the bottom of the shell and the inner circle. The base is inserted into the outer conductor, and an outer circle is provided on the outer side of the base. The outer circle is overlapped on the inner circle. The upper end surface of the shell is provided with a load port and a coupling port.

2. The megawatt-class broadband weak directional coupler according to claim 1, characterized in that: A water cooling structure is provided on the inner conductor.

3. The megawatt-class broadband weak directional coupler according to claim 1, characterized in that: The coupling head is provided with a radial adjustment mechanism, and the radial adjustment mechanism is used to control the radial adjustment of the coupling head along the outer conductor structure.

4. The megawatt-class broadband weak directional coupler according to claim 1, characterized in that: The coupling heads are all provided with a rotation adjustment mechanism, and the rotation adjustment mechanism is used to control the forward coupling head and the reverse coupling head to perform 360° rotation adjustment along their own central axis.

5. The megawatt-class broadband weak directional coupler according to claim 1, characterized in that: The number of the coupling heads is two, namely a forward coupling head and a reverse coupling head.

6. The megawatt-class broadband weak directional coupler according to claim 1, characterized in that: The outer conductor is made of aluminum alloy in one piece.

7. The megawatt-class broadband weak directional coupler according to claim 1, characterized in that: The support assembly includes multiple flanges and insulating supports. The flanges are fixed at the ports at both ends of the outer conductor, the insulating supports are embedded in the flanges, and a through hole for passing the inner conductor is provided at the center of the insulating support.

8. The megawatt-class broadband weak directional coupler according to claim 7, characterized in that: The material of the insulating support is polytetrafluoroethylene.

9. The megawatt-class broadband weak directional coupler according to claim 1, characterized in that: The outer side wall of the coupling head that is exposed from the clamp is provided with heat dissipation teeth.

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