A magnetic tuning method and device suitable for electromagnetic hybrid coupled coaxial cavity filter

Abstract

A magnetic tuning method and device suitable for an electromagnetic hybrid coupling coaxial cavity filter, comprising: an electromagnetic hybrid coupling coaxial cavity filter composed of a metal resonant cavity, a cover plate, and a metal resonant rod; a gap is left between the upper end of the metal resonant rod and the metal resonant cavity, forming an open-circuit end; the lower end of the metal resonant rod is directly connected to the metal resonant cavity, forming a short-circuit end; a slot or hole is opened near the magnetic coupling dominant region of the electromagnetic hybrid coupling coaxial cavity filter, and a magnetic tuning device extends from the slot or hole position into the resonant cavity through a mechanical structure. The total coupling coefficient of the electromagnetic hybrid coupling coaxial cavity filter is determined by the ratio of the electric coupling coefficient to the magnetic coupling coefficient; adjusting the magnetic coupling coefficient can adjust the total coupling coefficient of the electromagnetic hybrid coupling coaxial cavity filter. The present invention enriches the tuning of the electromagnetic hybrid coupling coaxial cavity filter.

Description

Technical Field

[0001] The present invention belongs to the field of microwave communication technology and filter technology, and in particular relates to a magnetic tuning method and device suitable for an electromagnetic hybrid coupled coaxial cavity filter. Background Art

[0002] A filter is a frequency-selective device that can select the desired signal and suppress useless and interfering signals. Cavity filters have the characteristics of good stability, moderate Q value (in-band loss / input power), and good heat dissipation, and are widely used in modern microwave and millimeter wave communications. Out-of-band suppression performance is an important parameter of cavity filters, and the out-of-band suppression performance is generally improved by introducing a transmission zero point. Among them, the electromagnetic hybrid coupled cavity filter developed in recent years can introduce a transmission zero point with a simple physical structure, and has the characteristics of compact structure and superior performance. However, cavity filters, including electromagnetic hybrid coupled cavity filters, are very sensitive to manufacturing tolerances. In order to achieve the pre-designed electrical performance indicators, performance testing and adjustment are required during the final assembly process.

[0003] Conventional cavity coaxial filters rely on electrical adjustment. This involves introducing a tuning screw in the dense electric field area (above the cover) and adjusting the filter's resonant frequency and coupling bandwidth by manipulating the screw's movement. However, this adjustment method only affects the electrically dominant coupling in electromagnetic hybrid-coupled coaxial cavity filters, making it difficult to achieve the desired electrical performance. Currently, there are no reports on magnetic coupling adjustment methods for electromagnetic hybrid-coupled coaxial cavity filters. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above technical deficiencies and provide a magnetic tuning method suitable for electromagnetic hybrid coupled coaxial cavity filters, aiming to enrich the tuning methods and devices of electromagnetic hybrid coupled coaxial cavity filters.

[0005] The present invention adopts the following technical solution: a tuning method for an electromagnetic hybrid coupled coaxial cavity filter, based on an electromagnetic hybrid coupled coaxial cavity filter, the electromagnetic hybrid coupled coaxial cavity filter comprising: a metal resonant cavity, a cover plate, and a metal resonant rod; the metal resonant cavity is a three-dimensional (cylindrical, rectangular, etc.) geometric shape, the cover plate is located on the top of the metal resonant cavity, making the metal resonant cavity a closed space; a metal resonant rod is provided inside the metal resonant cavity, and the metal resonant rod is not limited to cylindrical, cubic, or irregular shapes. A gap is left between the upper end of the metal resonant rod and the metal resonant cavity, forming an open-circuit end; the lower end of the metal resonant rod is directly connected to the metal resonant cavity, forming a short-circuit end;

[0006] In the electromagnetic hybrid coupled coaxial cavity filter, one or more groups of adjacent metal resonant rods form coexisting electric coupling dominant regions and magnetic coupling dominant regions;

[0007] The electric coupling-dominant region of the electromagnetic hybrid coupling coaxial cavity filter is formed by coupling the open-circuit ends between adjacent cavities, and the magnetic coupling-dominant region is formed by coupling the short-circuit ends between adjacent cavities.

[0008] The implementation of the open-circuit end coupling and the short-circuit end coupling is not limited to the resonant cavity itself being provided with or introducing an additional electromagnetic hybrid coupling circuit.

[0009] The electric coupling dominant region strength and the magnetic coupling dominant region strength of the electromagnetic hybrid coupling coaxial cavity filter can be respectively expressed by the electric coupling coefficient k e and the magnetic coupling coefficient k m Numerical representation.

[0010] The electrical coupling coefficient k e By formula Extraction, magnetic coupling coefficient k m By formula extract.

[0011] The transmission zero point position of the electromagnetic hybrid coupling coaxial cavity filter can be determined by the ratio of the electric coupling coefficient to the magnetic coupling coefficient. To regulate.

[0012] When the electromagnetic hybrid coupling coaxial cavity filter is tuned using the magnetic tuning method of the present invention, the magnetic coupling coefficient change ratio is large, while the electric coupling coefficient change ratio is small or basically does not change.

[0013] The magnetic tuning method of the electromagnetic hybrid coupled coaxial cavity filter is as follows:

[0014] The electromagnetic hybrid coupling coaxial cavity filter is prepared, and a groove or a hole is opened in the magnetic coupling dominant area of the coaxial cavity filter, and the groove depth or the hole depth penetrates the cavity wall.

[0015] The slot or hole position is not limited to the lower bottom plate of the cavity, and the slot or hole can be made near the magnetic coupling dominant area. The magnetic tuning device extends from the slot or hole position into the interior of the resonant cavity through a mechanical structure. The larger the area of the magnetic tuning device extending into the interior of the resonant cavity, the more obvious the effect on the magnetic coupling dominant area, and the greater the change in the magnetic coupling coefficient. The total coupling coefficient of the electromagnetic hybrid coupling coaxial cavity filter is determined by the ratio of the electric coupling coefficient to the magnetic coupling coefficient; adjusting the magnetic coupling coefficient can adjust the total coupling coefficient of the electromagnetic hybrid coupling coaxial cavity filter. The present invention aims to enrich the tuning method and device of the electromagnetic hybrid coupling coaxial cavity filter.

[0016] Prepare a tuning device. The tuning device is not limited to various tuning devices such as a tuning metal plate or a tuning screw. The following description takes the tuning metal plate as an example.

[0017] Prepare a metal plate, which is not limited to rectangular, semicircular and other shapes. The thickness of the metal plate is required to be as small as possible under the existing process and must be smaller than the width of the slot in the magnetic coupling dominant area of the above-mentioned coaxial cavity filter cavity.

[0018] The form of the metal plate is not limited to a metal plane plate structure, and may also be other three-dimensional geometric shapes.

[0019] The metal plate is driven by a fixed structure and a screw-in pushing structure. The fixed structure ensures that the metal plate is supported during the adjustment process and does not fall; the screw-in pushing structure sends the metal plate into the coaxial cavity filter and acts on the magnetic coupling dominant area in the cavity. At this time, the larger the area where the metal plate enters, the smaller the magnetic field coupling intensity, thereby achieving the magnetic tuning effect of the electromagnetic hybrid coupling coaxial cavity filter.

[0020] The fixing structure is not limited to fixing methods such as screws, nuts, glue, and welding.

[0021] The screwing structure is not limited to the propulsion methods of screw, hand push, piston, etc. The hardware of the method of the present invention constitutes a tuning device.

[0022] Beneficial effects: Compared with the existing technology, the present invention has the following advantages:

[0023] 1. The tuning methods of electromagnetic hybrid coupled coaxial cavity filters are enriched.

[0024] 2. Due to limitations in machining precision, mass-produced coaxial cavity filters may exhibit suboptimal electrical performance due to large errors. Previously, this was achieved through electrical coupling adjustment, but this is no longer applicable to electromagnetic hybrid-coupled coaxial cavity filters, forcing them to be reworked or scrapped. The present invention enables a wider range of magnetic coupling tuning methods, achieving the desired effect.

[0025] 3. The present invention can be used in conjunction with the electric tuning screw method to greatly improve the tuning range of the electromagnetic hybrid coupled coaxial cavity filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of a classic electromagnetic hybrid coupling filter provided by the present invention.

[0027] Figure 2 This is a top view of a classic electromagnetic hybrid coupling filter provided by the present invention.

[0028] Figure 3 Graph 1 shows the changes in the electric coupling coefficient and the magnetic coupling coefficient when the metal plate H is raised in Example 1 of the present invention.

[0029] Figure 41 and 2 are S parameters of the electromagnetic hybrid coupling filter of Example 1 of the present invention at different metal plate heights H.

[0030] Figure 5 This is a schematic diagram of an electromagnetic hybrid coupling filter with a special-shaped metal resonant rod provided by the present invention.

[0031] Figure 6 This is a top view of an electromagnetic hybrid coupling filter with a special-shaped metal resonant rod provided by the present invention.

[0032] Figure 7 This is the change in the electric coupling coefficient and the magnetic coupling coefficient when the metal plate H is raised in Example 2.

[0033] Figure 8 1 and 2 are the S parameters of the electromagnetic hybrid coupling filter of Example 2 at different metal plate heights H.

[0034] Figure 9 This is a magnetically tuned mechanical mechanism exemplified in the present invention.

[0035] Figure 10 This is a structural diagram of magnetic tuning using other magnetic tuning devices and tuning screws as an example of the present invention. DETAILED DESCRIPTION

[0036] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the technical solutions of the present invention are described in detail below in conjunction with the embodiments of the present invention and the accompanying drawings. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] The electromagnetic hybrid coupling coaxial cavity filter to which the method of the present invention is applicable has one or more groups of adjacent metal resonance rods forming coexisting electric coupling dominant regions and magnetic coupling dominant regions.

[0038] The electric coupling-dominant region is formed by coupling the open-circuit ends between adjacent cavities, and the magnetic coupling-dominant region is formed by coupling the short-circuit ends between adjacent cavities.

[0039] The implementation of the open-circuit end coupling and the short-circuit end coupling is not limited to the resonant cavity itself being provided with or introducing an additional electromagnetic hybrid coupling circuit.

[0040] The electric coupling dominant region strength and the magnetic coupling dominant region strength can be respectively expressed by the electric coupling coefficient k e and the magnetic coupling coefficient k m Numerical representation.

[0041] The electrical coupling coefficient k e By formula Extraction, magnetic coupling coefficient k mBy formula extract.

[0042] The ratio of the electric coupling coefficient to the magnetic coupling coefficient is The position of the transmission zero point of the electromagnetic hybrid coupled coaxial cavity filter can be adjusted.

[0043] A slot or hole is formed in the magnetic coupling dominant region of the metal resonant cavity, and the slot or hole depth penetrates the cavity wall. A mechanical structure is used to extend the tuning device into the magnetic coupling dominant region inside the electromagnetic hybrid coupled coaxial cavity filter.

[0044] During magnetic tuning, the change ratio of the magnetic coupling coefficient is large, while the change ratio of the electric coupling coefficient is small or basically does not change.

[0045] Magnetic tuning is performed using the area of the tuning device inserted into the electromagnetic hybrid coupled coaxial cavity filter cavity, which is not limited to various tuning devices such as tuning metal plates and tuning screws.

[0046] SMA connectors are provided on both sides of the input and output of the coaxial cavity bandpass filter. The coaxial cavity bandpass filter is connected to an external circuit and matched with the external circuit through the SMA connector and a 50Ω characteristic impedance transmission line.

[0047] Example 1

[0048] The present invention exemplifies a second-order electromagnetic hybrid coupled cavity filter that requires the introduction of additional structures, such as Figure 1 、 Figure 2 As shown. It includes: an SMA connector 1, a metal resonant cavity 2, a cover plate 3, a metal resonant rod 4, a metal resonant rod 5, and a metal plate 6; the metal resonant cavity is a three-dimensional geometric shape (30 cm long, 15 cm wide, and 17 cm high); the cover plate 3 is located on the top of the metal resonant cavity 2, making the resonant cavity a closed space; the main bodies of the metal resonant rods 4 and 5 are cylindrical, and the upper ends of the two resonant rods have opposing square geometric protrusions, which are separated by a certain distance; a gap is left between the upper ends of the metal resonant rods 4 and 5 and the cover plate 3, forming an open-circuit end; the lower ends of the metal resonant rods 4 and 5 are connected to the metal resonant cavity 2, forming a short-circuit end; the SMA connector 1 is placed on both sides of the input and output of the electromagnetic hybrid coupling cavity filter, and the coaxial cavity bandpass filter is connected to the external circuit and matched with the external circuit through the SMA connector and 50Ω characteristic impedance transmission line. Like the SMA connector, the present invention is applicable to applications in the microwave field with a frequency range up to 26.5 GHz. The open-circuit ends at the relative positions above the metal resonance rod 4 and the metal resonance rod 5 are coupled to form an electric coupling dominant area, and the short-circuit ends at the relative positions below the metal resonance rod 4 and the metal resonance rod 5 are coupled to form a magnetic coupling dominant area; as the insertion height of the lower metal plate 6 increases, Figure 1As the “H” in the figure increases, the area where the metal plate enters increases, the magnetic coupling coefficient decreases rapidly, while the electric coupling coefficient decreases slowly. Figure 3 The k of Example 1 is given e 、k m The relationship between the insertion height H and the change diagram. Using simulation software, and measuring the relevant data at different insertion heights H, the formula Extract the electrical coupling coefficient k e , through the formula Extracted magnetic coupling coefficient k m (ω odd is the odd mode frequency, ω even is the even mode frequency, ω0 is the pole frequency between f1 and f2 in the group delay, ω Z is the transmission zero frequency, which can be obtained through simulation software). Since the transmission zero position varies with the ratio of the magnetic coupling coefficient to the electric coupling coefficient, The transmission zero point moves from the high frequency band to the low frequency band. Figure 4 A graph showing the variation of S parameters with frequency f at different metal plate heights H in the simulation software is given; this result verifies the effectiveness of the magnetic tuning of the present invention.

[0049] Example 2

[0050] The present invention exemplifies a second-order electromagnetic hybrid coupling cavity filter that has electromagnetic hybrid coupling. Figure 5 、 Figure 6The invention comprises an SMA connector 7, a metal resonant cavity 8, a cover plate 9, a metal resonant rod 10, a metal resonant rod 11, and a metal plate 12. The metal resonant cavity is a three-dimensional geometric shape (30 cm long, 17 cm wide, and 15 cm high). The cover plate 9 is located on the top of the metal resonant cavity 8, making the resonant cavity a closed space. The upper sides of the metal resonant rods 10 and 11 are square geometric bodies with one side cut into an arc surface, and the lower sides are square curved bases bent to both sides. The metal resonant rods are separated by a certain distance. A gap is left between the upper ends of the metal resonant rods 10 and 11 and the cover plate 9, forming an open-circuit end. The lower ends of the metal resonant rods 10 and 11 are connected to the metal resonant cavity 8, forming a short-circuit end. The SMA connector 7 is placed on the input and output sides of the electromagnetic hybrid coupled cavity filter. The coaxial cavity bandpass filter is connected to the external circuit and matched with the external circuit through the SMA connector and a 50Ω characteristic impedance transmission line. The present invention is similar to the SMA connector and can be applied to microwave applications with a frequency range up to 26.5 GHz. The metal resonant rod 10 is relatively located at the upper open-circuit end of the resonant rod 11, and the metal resonant rod 10 and the metal resonant rod 11 are relatively located at the lower short-circuit end, forming a magnetic coupling-dominated area. As the lower metal plate 12 is inserted, the lower short-circuit end of the metal resonant rod 10 and the metal resonant rod 11 are relatively located, and the lower short-circuit end of the metal resonant rod 10 and the metal resonant rod 11 are relatively located, forming a magnetic coupling-dominated area. Figure 5 As the "H" in the figure increases, the area where the metal plate enters increases, the magnetic coupling coefficient decreases rapidly, while the electric coupling coefficient decreases slowly. Figure 7 The k of Example 2 is given e 、k m The relationship between the insertion height H and the change diagram. Using simulation software, and measuring the relevant data at different insertion heights H, the formula Extract the electrical coupling coefficient k e , through the formula Extracted magnetic coupling coefficient k m (ω odd is the odd mode frequency, ω even is the even mode frequency, ω0 is the pole frequency between f1 and f2 in the group delay, ω Z is the transmission zero frequency, which can be obtained through simulation software). Since the transmission zero position varies with the ratio of the magnetic coupling coefficient to the electric coupling coefficient, The transmission zero point moves from the high frequency band to the low frequency band. Figure 8 A graph showing the variation of S parameters with frequency f at different metal plate heights H in the simulation software is given; this result verifies the effectiveness of the magnetic tuning of the present invention.

[0051] Example 3

[0052] like Figure 9As shown, this example is a magnetic tuning mechanical structure, including a metal resonant cavity 13, a cover plate 14, a tuning metal plate 15, an M2 screw 16, an M2 fixing nut 17, a fixing plate 18, and an M2 support nut 19; the metal resonant cavity is a three-dimensional geometric shape, and a groove is opened on the bottom surface, and the groove depth runs through the cavity; M2 threaded holes are drilled on both sides of the bottom, the threaded holes are located in the cavity wall, and the depth of the threaded holes is determined by the length of the screw, but cannot exceed the height of the cavity. When using this magnetic tuning structure, first screw the M2 fixing nut 17 close to the countersunk side of the M2 screw 16, that is, the top of the thread of the M2 screw 16, then extend the M2 screw 16 into the fixing plate 18, screw in the M2 support nut 19, and then extend the M2 screw 16 into the top of the threaded hole of the metal resonance cavity 13, and extend the tuning metal plate 15 into the cavity from the slot of the metal resonance cavity 13. Then use the corresponding flat-blade screwdriver to align with the flat-blade countersunk head of the M2 screw 16 and rotate it to adjust the length of the tuning metal plate 15 extending into the metal resonance cavity 13 to the desired position. After completing the magnetic tuning, use a small wrench or other tool to rotate the M2 fixing nut 17 and the M2 support nut 19 to tighten them to complete the fixation and complete the entire magnetic tuning process. The magnetic tuning mechanical structure is a symmetrical structure, with an M2 screw 16, an M2 fixing nut 17, a fixing plate 18, and an M2 support nut 19 on each side of the tuning metal plate 15. When using a flat-blade screwdriver to tune, both sides need to be tuned sequentially or simultaneously to prevent the mechanical structure from getting stuck.

[0053] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

[0054] Example 4

[0055] like Figure 10 As shown, the present invention exemplifies another tuning device based on Example 1, namely, a tuning screw 20 for magnetic tuning. By adjusting the height H of the tuning screw 20, the second-order electromagnetic hybrid coupling cavity filter of Example 1 can also be magnetically tuned.

[0056] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A magnetic tuning method for an electromagnetic hybrid coupled coaxial cavity filter, used for tuning an electromagnetic hybrid coupled coaxial cavity filter, characterized in that: Based on the electromagnetic hybrid coupled coaxial cavity filter described below, the electromagnetic hybrid coupled coaxial cavity filter includes: a metal resonant cavity, a cover plate, and a metal resonant rod; the metal resonant cavity is cylindrical in shape, and the cover plate is located on the top of the metal resonant cavity, making the metal resonant cavity a closed space; a metal resonant rod is provided inside the metal resonant cavity, and a gap is left between the upper end of the metal resonant rod and the metal resonant cavity to form an open-circuit end; the lower end of the metal resonant rod is directly connected to the metal resonant cavity to form a short-circuit end; In the electromagnetic hybrid coupled coaxial cavity filter, one or more groups of adjacent metal resonant rods form coexisting electric coupling dominant regions and magnetic coupling dominant regions; The electric coupling-dominant region of the electromagnetic hybrid coupled coaxial cavity filter is formed by coupling between the open-circuit ends of adjacent cavities, and the magnetic coupling-dominant region is formed by coupling between the short-circuit ends of adjacent cavities; When the electromagnetic hybrid coupled coaxial cavity filter is tuned, the ratio of change of the magnetic coupling coefficient is large, while the ratio of change of the electric coupling coefficient is small or substantially unchanged; The magnetic tuning method of the electromagnetic hybrid coupled coaxial cavity filter is as follows: Prepare the electromagnetic hybrid coupling coaxial cavity filter, and make a groove or a hole in the magnetic coupling dominant area of the coaxial cavity filter, wherein the groove depth or the hole depth penetrates the metal resonant cavity wall; The slots or holes are located on the bottom plate of the cavity or near the magnetic coupling dominant area; The tuning device includes a tuning metal plate; the tuning metal plate includes a rectangular or semicircular shape, and the thickness of the tuning metal plate is required to be less than the width of the slot in the magnetic coupling dominant region of the coaxial cavity filter cavity; The form of the tuning metal plate includes a metal plane plate structure or a solid geometric shape; The tuning metal plate is driven by a fixed structure and a screw-in pushing structure. The fixed structure ensures that the tuning metal plate is supported during the adjustment process and does not fall. The screw-in pushing structure sends the tuning metal plate into the coaxial cavity filter and acts on the magnetic coupling dominant area in the cavity. At this time, the larger the area where the tuning metal plate enters, the smaller the magnetic field coupling intensity, thereby achieving the magnetic tuning effect of the electromagnetic hybrid coupling coaxial cavity filter.

2. The magnetic tuning method for an electromagnetic hybrid coupled coaxial cavity filter according to claim 1, characterized in that: The fixing structure includes screws, nuts, glue, and welding fixing methods; the screw-in pushing structure includes screws, hand pushers, or pistons.

3. The magnetic tuning method for an electromagnetic hybrid coupled coaxial cavity filter according to claim 1 or 2, characterized in that: The open-circuit end coupling and the short-circuit end coupling are realized by the resonant cavity itself being provided with or introducing an additional electromagnetic hybrid coupling circuit; the electric coupling dominant region strength and the magnetic coupling dominant region strength of the electromagnetic hybrid coupling coaxial cavity filter are respectively characterized by the electric coupling coefficient and the magnetic coupling coefficient numerical value.

4. The magnetic tuning method for an electromagnetic hybrid coupled coaxial cavity filter according to claim 1 or 2, characterized in that: The electrical coupling coefficient k e By formula Extraction, magnetic coupling coefficient k m By formula extract; The transmission zero point position of the electromagnetic hybrid coupling coaxial cavity filter is determined by the ratio of the electric coupling coefficient to the magnetic coupling coefficient. To regulate; odd is the odd mode frequency, ω even is the even mode frequency, ω0 is the pole frequency between f1 and f2 in the group delay, ω Z is the transmission zero frequency.

5. The tuning device according to any one of claims 1 to 4, wherein the tuning device is suitable for the magnetic tuning method of the electromagnetic hybrid coupled coaxial cavity filter. include: A metal resonant cavity, a cover plate, and a metal resonant rod; the metal resonant cavity has a cylindrical geometric shape, and the cover plate is located on the top of the metal resonant cavity, making the metal resonant cavity a closed space; a metal resonant rod is provided inside the metal resonant cavity, and the metal resonant rod includes cylindrical, cubic, and irregular shapes; a gap is left between the upper end of the metal resonant rod and the metal resonant cavity, forming an open-circuit end; the lower end of the metal resonant rod is directly connected to the metal resonant cavity, forming a short-circuit end; the size of the filter cavity depends on the specific frequency requirements; a slot or hole is opened in the magnetic coupling dominant area of the coaxial cavity filter, and the slot depth or hole depth penetrates the cavity wall of the metal resonant cavity; The slots or holes are located on the bottom plate of the cavity, or near the magnetic coupling dominant area; The tuning device is a tuning metal plate; The tuning metal plate includes rectangular and semicircular shapes, and the thickness of the tuning metal plate is required to be smaller than the width of the slot in the magnetic coupling dominant region of the coaxial cavity filter cavity; The tuning metal plate is driven by a fixed structure and a screw-in push structure. The fixed structure ensures that the tuning metal plate is supported during the adjustment process and does not fall. The screw-in pushing structure sends the tuning metal plate into the coaxial cavity filter and acts on the magnetic coupling dominant area in the cavity. At this time, the larger the area where the tuning metal plate enters, the smaller the magnetic field coupling intensity, thereby achieving the magnetic tuning effect of the electromagnetic hybrid coupling coaxial cavity filter.

6. The magnetic tuning device for an electromagnetic hybrid coupled coaxial cavity filter according to claim 5, characterized in that: SMA connectors are provided on both sides of the input and output of the coaxial cavity filter. The coaxial cavity filter is connected to an external circuit and matched with the external circuit through the SMA connector and a 50Ω characteristic impedance transmission line.

7. The magnetic tuning device for an electromagnetic hybrid coupled coaxial cavity filter according to claim 5 or 6, characterized in that: Magnetic tuning is performed by tuning the protruding area in the electromagnetic hybrid coupling coaxial cavity filter.

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