DC-AC Isolator and Microwave Active Circuit

Abstract

The present invention provides a DC-AC isolator and a microwave active circuit. The first ground housing and the second ground housing of the DC-AC isolator are arranged opposite to each other. The first coaxial connector of the coaxial connector is arranged on the first ground housing, and the second coaxial connector is arranged on the second ground housing. The first coaxial connector and the second coaxial connector are connected through a first DC-blocking capacitor. One end of the first ground housing facing the second ground housing is recessed to form a groove, and one side of the second ground housing opposite to the first ground housing protrudes to form a protrusion. The protrusion is embedded in the groove, and the protrusion and the groove are arranged at intervals to form a choke structure. The length of the choke structure is an odd multiple of a quarter of the operating wavelength of the DC-AC isolator. The present invention can increase the relative area between the first ground housing and the second ground housing, improve the power capacity and withstand voltage value of the isolator, and suppress the transmission of electromagnetic fields in the ground housing, effectively improving the electromagnetic shielding performance of the isolator and solving the problem of electromagnetic leakage.

Description

Technical Field

[0001] The present invention relates to the technical field of isolators, and particularly to a DC-AC isolator and a microwave active circuit. Background Art

[0002] At present, an isolator can block DC and low-frequency AC signals while not affecting the transmission of radio frequency signals, and is an essential component of a microwave active circuit. The isolators in the prior art usually achieve the function of blocking the DC path by isolating the inner and outer conductors. However, this method has the following deficiencies: (1) small power capacity, unable to be applied to high-power and low-loss microwave transmission applications; (2) low withstand voltage value, unable to effectively avoid the problem of arc discharge caused by breakdown of media such as air in high-voltage applications; (3) no shielding structure, resulting in electromagnetic leakage problems. Summary of the Invention

[0003] In order to overcome the deficiencies of the prior art, the present invention proposes a DC-AC isolator and a microwave active circuit. A groove and a protrusion are respectively provided on the first ground shell and the second ground shell. The first ground shell and the second ground shell are opposed by embedding the protrusion into the groove, and a choke structure is formed between the first ground shell and the second ground shell. The length of the choke structure is an odd multiple of a quarter of the operating wavelength, which can increase the relative area between the first ground shell and the second ground shell, improve the power capacity and withstand voltage value of the isolator, and suppress the transmission of electromagnetic fields in the ground shell by setting the choke structure, effectively improving the electromagnetic shielding performance of the isolator and solving the problem of electromagnetic leakage.

[0004] To solve the above problems, a technical solution adopted by the present invention is: a DC-AC isolator, the DC-AC isolator comprising: a coaxial connector, a first ground shell, and a second ground shell, the first ground shell and the second ground shell being oppositely arranged; the coaxial connector comprising a first coaxial connector and a second coaxial connector, the first coaxial connector being arranged on the first ground shell, the second coaxial connector being arranged on the second ground shell, the first coaxial connector and the second coaxial connector being connected by a first DC-blocking capacitor; one end of the first ground shell facing the second ground shell is recessed to form a groove, and a protrusion is formed on a side of the second ground shell opposite to the first ground shell. The protrusion is embedded into the groove, and the protrusion and the groove are arranged at intervals to form a choke structure, and the length of the choke structure is an odd multiple of a quarter of the operating wavelength of the DC-AC isolator.

[0005] Further, the first coaxial connector and the second coaxial connector are respectively fixed on the first ground shell and the second ground shell by screws.

[0006] Further, the choke structure includes a second DC-blocking capacitor, which is arranged circumferentially along the protrusion and has two ends respectively connected to the first ground housing and the second ground housing.

[0007] Further, the first DC-blocking capacitor and the second DC-blocking capacitor are lumped capacitor elements.

[0008] Further, the DC-AC isolator includes an elastic conductive component, which is arranged at two ends of the first DC-blocking capacitor and the second DC-blocking capacitor.

[0009] Further, the elastic conductive component includes any one of conductive rubber and conductive spring pieces.

[0010] Further, both the first coaxial connector and the second coaxial connector include inner conductors, and the inner conductor of the first coaxial connector is connected to the inner conductor of the second coaxial connector through the first DC-blocking capacitor.

[0011] Further, the inner conductor of the first coaxial connector penetrates through the first ground housing and extends into the groove; the protrusion of the second ground housing is hollow to form a through hole, and the inner conductor of the second coaxial connector is arranged in the through hole and is opposite to the inner conductor of the first coaxial connector extending into the groove.

[0012] Further, the choke structure further includes an insulator, which is arranged around the protrusion and has two sides respectively connected to the first ground housing and the second ground housing.

[0013] Based on the same inventive concept, the present invention also provides a microwave active circuit, which includes the DC-AC isolator as described above.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: grooves and protrusions are respectively arranged on the first ground housing and the second ground housing. The first ground housing and the second ground housing are opposed by embedding the protrusion into the groove, and a choke structure is formed between the first ground housing and the second ground housing, so that the length of the choke structure is an odd multiple of a quarter of the operating wavelength. The relative area between the first ground housing and the second ground housing can be increased, the power capacity and the withstand voltage value of the isolator are improved, and the transmission of the electromagnetic field in the ground housing is suppressed by arranging the choke structure, effectively improving the electromagnetic shielding performance of the isolator and solving the problem of electromagnetic leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a flowchart of an embodiment of the DC-AC isolator of the present invention;

[0016] Figure 2 is a cross-sectional view of an embodiment of the DC-AC isolator of the present invention;

[0017] Figure 3 Schematic diagram of an embodiment of the DC-AC isolator for suppressing electromagnetic leakage of the present invention;

[0018] Figure 4 Structural diagram of an embodiment of the microwave active circuit of the present invention.

[0019] In the figure: 1. First coaxial connector; 2. Second coaxial connector; 3. First ground housing; 4. Second ground housing; 5. Insulator; 6. First DC-blocking capacitor; 7. Second DC-blocking capacitor. Detailed implementation manners

[0020] Next, in combination with the accompanying drawings and specific implementation manners, the present invention will be further described. It should be noted that, on the premise of no conflict, the following-described embodiments or technical features can be arbitrarily combined to form new embodiments.

[0021] Please refer to Figure 1 , 2 , 3, wherein, Figure 1 Flowchart of an embodiment of the DC-AC isolator of the present invention; Figure 2 Cross-sectional view of an embodiment of the DC-AC isolator of the present invention; Figure 3 Schematic diagram of an embodiment of the DC-AC isolator for suppressing electromagnetic leakage of the present invention, wherein, Figure 2 is Figure 1 Cross-sectional view of the DC-AC isolator after being axially cut along the first coaxial connector and the second coaxial connector. In combination with the attached Figures 1-3 The DC-AC isolator of the present invention will be described in detail.

[0022] In this embodiment, the DC-AC isolator includes: coaxial connectors, a first ground housing 3, and a second ground housing 4. The first ground housing 3 and the second ground housing 4 are disposed opposite to each other; the coaxial connectors include a first coaxial connector 1 and a second coaxial connector 2. The first coaxial connector 1 is disposed on the first ground housing 3, and the second coaxial connector 2 is disposed on the second ground housing 4. The first coaxial connector 1 and the second coaxial connector 2 are connected through a first DC-blocking capacitor 6; one end of the first ground housing 3 facing the second ground housing 4 is recessed to form a groove, and one side of the second ground housing 4 opposite to the first ground housing 3 protrudes to form a protrusion. The protrusion is embedded in the groove, and the protrusion and the groove are spaced apart to form a choke structure. The length of the choke structure is an odd multiple of a quarter of the operating wavelength of the DC-AC isolator.

[0023] In this embodiment, by the way of the protrusion being embedded in the groove, the relative area between the first ground housing 3 and the second ground housing 4 is increased, the withstand voltage value of the DC-AC isolator is improved, and the power loss is reduced by using the electromagnetic leakage suppression characteristic of the choke structure.

[0024] In a specific embodiment, the DC-AC isolator of the present invention can withstand voltages of AC 4000V and DC 4500V, meeting the requirements for medical and other high-voltage applications.

[0025] In this embodiment, the first ground housing 3 and the second ground housing 4 are cylindrical. In other embodiments, the first ground housing 3 and the second ground housing 4 can also be prismatic, square, or other shapes, which are not limited herein.

[0026] In this embodiment, the top of the protrusion is arranged parallel to the bottom of the groove, the outer side is parallel to the inner wall of the groove, and the platform surrounding the protrusion on the second ground housing 4 is parallel to the end of the groove facing the second ground housing 4.

[0027] In other embodiments, in order to increase the relative area between the first ground housing 3 and the second ground housing 4, the surfaces of the first ground housing 3 and the second ground housing 4 that face each other, i.e., the surfaces of the choke structure, can also be corrugated or have multiple gentle protrusions.

[0028] In this embodiment, the first coaxial connector 1 and the second coaxial connector 2 are respectively fixed to the first ground housing 3 and the second ground housing 4 by screws. In other embodiments, the first coaxial connector 1 and the second coaxial connector 2 can also be fixed to the first ground housing 3 and the second ground housing 4 by clamping, screwing, welding, or other means.

[0029] In this embodiment, the first DC-blocking capacitor 6 is a signal-line DC-blocking capacitor. The first coaxial connector 1 and the second coaxial connector 2 can be connected to one or more signal-line DC-blocking capacitors, and the working frequency, insertion loss, and other indicators are adjusted through the cooperation of the signal-line DC-blocking capacitors. Among them, according to the requirements of withstand voltage and power capacity, signal-line DC-blocking capacitors with appropriate capacitance values and capacitor package sizes are selected.

[0030] In this embodiment, the choke structure includes a second DC-blocking capacitor 7. The second DC-blocking capacitor 7 is arranged circumferentially along the protrusion and is connected to the first ground housing 3 and the second ground housing 4 at both ends. Among them, the second DC-blocking capacitor 7 is a ground-line DC-blocking capacitor.

[0031] In this embodiment, for the convenience of processing and assembling the isolator, the first DC-blocking capacitor 6 and the second DC-blocking capacitor 7 of the present invention are lumped capacitor elements, and the first coaxial connector 1 and the second coaxial connector 2 are standard-type coaxial connectors, making the overall structure of the isolator simple, easy to process, and reducing the assembly difficulty.

[0032] In this embodiment, to ensure the stability of installation, the DC-AC isolator includes an elastic conductive component, which is arranged at both ends of the first DC-blocking capacitor 6 and the second DC-blocking capacitor 7. The first DC-blocking capacitor 6 and the second DC-blocking capacitor 7 are connected to the first ground housing 3 and the second ground housing 4 through the elastic conductive component.

[0033] In this embodiment, the elastic conductive component includes any one of conductive rubber and conductive spring pieces. In other embodiments, the elastic conductive component further includes conductive springs, conductive foams, and other elastic materials capable of conducting electricity.

[0034] In this embodiment, both the first coaxial connector 1 and the second coaxial connector 2 include inner conductors. The inner conductor of the first coaxial connector 1 is connected to the inner conductor of the second coaxial connector 2 through the first DC-blocking capacitor 6. Among them, the inner conductor of the first coaxial connector 1 penetrates through the first ground housing 3 and extends into the groove; the protrusion of the second ground housing 4 is hollow to form a through hole, and the inner conductor of the second coaxial connector 2 is arranged along the through hole and is opposite to the inner conductor of the first coaxial connector 1 extending into the groove.

[0035] In this embodiment, the choke structure further includes an insulator 5, which is arranged around the protrusion on the second ground housing 4 and is connected to the first ground housing 3 and the second ground housing 4 on both sides respectively.

[0036] In this embodiment, the insulator 5 can also fill the gap between the first ground housing 3 and the second ground housing 4, and can also be arranged outside the second DC-blocking capacitor 7.

[0037] In this embodiment, the insulator 5 is provided with mounting holes along the circumference of the protrusion, and the second DC-blocking capacitor 7 is placed in the mounting holes. The capacitance coupling between the first ground housing 3 and the second ground housing 4 of the two coaxial connectors is realized through the second DC-blocking capacitor 7.

[0038] The first ground housing 3 and the second ground housing 4 of the DC-AC isolator of the present invention are cooperated with a choke structure, and the choke structure is as Figure 3 shown (the area where the arrow is located in the figure is the choke structure. The microwave transmitted by the isolator leaks out and propagates along the arrow direction, and will be continuously reduced during the transmission process). The overall length of the choke structure is about an odd multiple of 1 / 4 of the working wavelength. This structure can effectively improve the electromagnetic shielding performance and reduce the electromagnetic leakage value. It can be obtained by referring to electromagnetic simulation that the electromagnetic field is suppressed after passing through the choke structure, and the leakage electric field intensity is reduced by about two orders of magnitude compared with the traditional isolator.

[0039] By adjusting the parameters of the lumped capacitance elements, the operating frequency, insertion loss and other indicators of the DC-AC isolator can be flexibly optimized. In the embodiment, the operating frequency band of the isolator is adjusted to 2.4 - 2.5 GHz, the in-band reflection is less than -20 dB, and the in-band insertion loss is less than 0.2 dB. It can ensure that under extremely low power loss, it meets the requirements of ultra-high voltage and high-power radio frequency applications for medical purposes.

[0040] Advantageous effects: In the DC-AC isolator of the present invention, grooves and protrusions are respectively provided on the first ground shell and the second ground shell. By embedding the protrusion into the groove, the first ground shell and the second ground shell are opposed to each other, and a choke structure is formed between the first ground shell and the second ground shell, so that the length of the choke structure is an odd multiple of a quarter of the operating wavelength, which can increase the relative area between the first ground shell and the second ground shell, improve the power capacity and withstand voltage value of the isolator, and suppress the transmission of electromagnetic fields in the ground shell by setting the choke structure, effectively improving the electromagnetic shielding performance of the isolator and solving the problem of electromagnetic leakage.

[0041] Based on the same inventive concept, the present invention also proposes a microwave active circuit. Please refer to Figure 4 , Figure 4 which is a structural diagram of an embodiment of the microwave active circuit of the present invention. In combination with Figure 4 the microwave active circuit of the present invention will be further described.

[0042] In this embodiment, the DC-AC isolator includes: a coaxial connector, a first ground shell, and a second ground shell, and the first ground shell and the second ground shell are disposed opposite to each other; the coaxial connector includes a first coaxial connector and a second coaxial connector, the first coaxial connector is disposed on the first ground shell, the second coaxial connector is disposed on the second ground shell, and the first coaxial connector and the second coaxial connector are connected by a first DC-blocking capacitor; one end of the first ground shell facing the second ground shell is recessed to form a groove, and a protrusion is formed on the side of the second ground shell opposite to the first ground shell, and the protrusion is embedded in the groove, and the protrusion and the groove are spaced apart to form a choke structure, and the length of the choke structure is an odd multiple of a quarter of the operating wavelength of the DC-AC isolator.

[0043] In this embodiment, by the way of embedding the protrusion into the groove, the relative area between the first ground shell and the second ground shell is increased, the withstand voltage value of the DC-AC isolator is improved, and the power loss is reduced by using the electromagnetic leakage suppression characteristic of the choke structure.

[0044] In a specific embodiment, the DC-AC isolator of the present invention can withstand voltages of AC 4000V and DC 4500V, meeting the requirements of medical and other high-voltage fields.

[0045] In this embodiment, the first ground housing and the second ground housing are cylindrical. In other embodiments, the first ground housing and the second ground housing can also be prisms, squares, and other shapes, which are not limited herein.

[0046] In this embodiment, the top end of the protrusion is arranged parallel to the bottom of the groove, the outer side is parallel to the inner wall of the groove, and the platform surrounding the protrusion on the second ground housing is parallel to one end of the groove facing the second ground housing.

[0047] In other embodiments, in order to increase the relative area between the first ground housing and the second ground housing, the surfaces of the first ground housing and the second ground housing facing each other, that is, the surface of the choke structure, can also be a corrugated surface structure or multiple gentle protrusions.

[0048] In this embodiment, the first coaxial connector and the second coaxial connector are respectively fixed on the first ground housing and the second ground housing by screws. In other embodiments, the first coaxial connector and the second coaxial connector can also be fixed on the first ground housing and the second ground housing by clamping, screwing, welding, and other methods.

[0049] In this embodiment, the first DC-blocking capacitor is a signal line DC-blocking capacitor. The first coaxial connector and the second coaxial connector can be connected to one or more signal line DC-blocking capacitors, and the working frequency, insertion loss, and other indicators are adjusted through the cooperation of the signal line DC-blocking capacitors. Among them, according to the requirements of withstand voltage and power capacity, a signal line DC-blocking capacitor with a suitable capacitance value and capacitor package size is selected.

[0050] In this embodiment, the choke structure includes a second DC-blocking capacitor. The second DC-blocking capacitor is arranged circumferentially along the protrusion, and both ends are respectively connected to the first ground housing and the second ground housing. Among them, the second DC-blocking capacitor is a ground wire DC-blocking capacitor.

[0051] In this embodiment, for the convenience of the processing and assembly of the isolator, the first DC-blocking capacitor and the second DC-blocking capacitor of the present invention are lumped capacitor elements, and the first coaxial connector and the second coaxial connector are coaxial connectors of standard models, making the overall structure of the isolator simple and easy to process, and reducing the assembly difficulty.

[0052] In this embodiment, to ensure the installation stability, the DC-AC isolator includes an elastic conductive component, and the elastic conductive component is arranged at both ends of the first DC-blocking capacitor and the second DC-blocking capacitor. The first DC-blocking capacitor and the second DC-blocking capacitor are connected to the first ground housing and the second ground housing through the elastic conductive component.

[0053] In this embodiment, the elastic conductive component includes any one of conductive rubber and conductive spring pieces. In other embodiments, the elastic conductive component also includes conductive springs, conductive foam, and other elastic materials capable of conducting electricity.

[0054] In this embodiment, both the first coaxial connector and the second coaxial connector include inner conductors, and the inner conductor of the first coaxial connector is connected to the inner conductor of the second coaxial connector through a first DC-blocking capacitor. Among them, the inner conductor of the first coaxial connector penetrates through the first ground housing and extends into the groove; the protrusion of the second ground housing is hollow to form a through hole, and the inner conductor of the second coaxial connector is arranged along the through hole and is opposite to the inner conductor of the first coaxial connector extending into the groove.

[0055] In this embodiment, the choke structure further includes an insulator, which is arranged around the protrusion on the second ground housing and is connected to the first ground housing and the second ground housing on both sides respectively.

[0056] In this embodiment, the insulator can also fill the gap between the first ground housing and the second ground housing, and can also be arranged outside the second DC-blocking capacitor.

[0057] In this embodiment, the insulator is provided with mounting holes along the circumference of the protrusion, and the second DC-blocking capacitor is placed in the mounting holes, and capacitive coupling between the first ground housing and the second ground housing of the two coaxial connectors is achieved through the second DC-blocking capacitor.

[0058] The first ground housing and the second ground housing of the DC-AC isolator of the present invention are cooperated with a choke structure, and the choke structure is as Figure 3 shown (the area where the arrow is located in the figure is the choke structure, and the microwave transmitted by the isolator leaks out and propagates along the arrow direction, and will be continuously reduced during the transmission process). The overall length of the choke structure is about an odd multiple of 1 / 4 of the operating wavelength. This structure can effectively improve the electromagnetic shielding performance and reduce the electromagnetic leakage value. It can be obtained by referring to electromagnetic simulation that the electromagnetic field is suppressed after passing through the choke structure, and the leakage electric field intensity is reduced by about two orders of magnitude compared with the traditional isolator.

[0059] By adjusting the parameters of the lumped capacitance element, the working frequency, insertion loss and other indexes of the DC-AC isolator can be flexibly optimized. In the embodiment, the working frequency band of the isolator is adjusted to 2.4 - 2.5 GHz, the in-band reflection is less than -20 dB, and the in-band insertion loss is less than 0.2 dB. It can ensure that under extremely low power loss, it meets the medical applications of ultra-high voltage and high-power radio frequency.

[0060] Beneficial effects: The microwave active circuit of the present invention is provided with grooves and protrusions on the first ground housing and the second ground housing of the DC-AC isolator respectively. The first ground housing and the second ground housing are opposed by embedding the protrusions into the grooves, and a choke structure is formed between the first ground housing and the second ground housing. The length of the choke structure is an odd multiple of a quarter of the operating wavelength, which can increase the relative area between the first ground housing and the second ground housing, improve the power capacity and withstand voltage value of the isolator, and suppress the transmission of electromagnetic fields in the ground housing by setting the choke structure, effectively improving the electromagnetic shielding performance of the isolator and solving the problem of electromagnetic leakage.

[0061] Among them, the various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0062] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A DC-AC isolator, characterized in that, the DC-AC isolator includes: a coaxial connector, a first ground housing, and a second ground housing, and the first ground housing and the second ground housing are oppositely arranged; the coaxial connector includes a first coaxial connector and a second coaxial connector. The first coaxial connector is arranged on the first ground housing, and the second coaxial connector is arranged on the second ground housing. The first coaxial connector and the second coaxial connector are connected by a first DC-blocking capacitor; one end of the first ground housing facing the second ground housing is recessed to form a groove, and one side of the second ground housing opposite to the first ground housing protrudes to form a protrusion. The protrusion is embedded in the groove, and the protrusion and the groove are arranged at intervals to form a choke structure. The length of the choke structure is an odd multiple of a quarter of the operating wavelength of the DC-AC isolator; the first coaxial connector and the second coaxial connector both include inner conductors. The inner conductor of the first coaxial connector and the inner conductor of the second coaxial connector are connected by the first DC-blocking capacitor; the inner conductor of the first coaxial connector penetrates through the first ground housing and extends into the groove; the protrusion of the second ground housing is hollowed out to form a through hole, and the inner conductor of the second coaxial connector is arranged in the through hole and is opposite to the inner conductor of the first coaxial connector extending into the groove; the first DC-blocking capacitor is located in the choke structure, and the microwave generated during the transmission of the DC-AC isolator propagates outward along the choke structure by the first DC-blocking capacitor; the choke structure includes a second DC-blocking capacitor, and the second DC-blocking capacitor is arranged along the circumference of the protrusion and is respectively connected to the first ground housing and the second ground housing at both ends; the choke structure further includes an insulator, and the insulator surrounds the protrusion and is respectively connected to the first ground housing and the second ground housing on both sides.

2. The DC-AC isolator according to claim 1, characterized in that, the first coaxial connector and the second coaxial connector are respectively fixed on the first ground housing and the second ground housing by screws.

3. The DC-AC isolator according to claim 1, characterized in that, the first DC-blocking capacitor and the second DC-blocking capacitor are lumped capacitance elements.

4. The DC-AC isolator according to claim 1, characterized in that, the DC-AC isolator includes an elastic conductive component, and the elastic conductive component is arranged at both ends of the first DC-blocking capacitor and the second DC-blocking capacitor.

5. The DC-AC isolator according to claim 4, characterized in that, the elastic conductive component includes any one of conductive rubber and conductive spring pieces.

6. A microwave active circuit, characterized in that, the microwave active circuit includes the DC-AC isolator according to any one of claims 1-5.

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