Structure for solving synchronous tuning of coaxial mechanical tuned filter

Abstract

The invention discloses a structure for solving synchronous tuning of a coaxial mechanically tuned filter, which belongs to the technical field of microwave filters and comprises five coaxial cavities arranged in parallel, tuning rods in the coaxial cavities, double-coupling hole structures between adjacent cavities and input and output structures. The cavity bodies of the five row coaxial cavities are the same in size and are symmetrically distributed, the number of the cavity bodies can be N, and the coaxial cavity bodies can be arranged in a row, side by side or other flexible forms. The tuning rods in the coaxial cavity are symmetrically distributed, the diameters of the tuning rods are different, the middle of the tuning rods is thick, and the two sides of the tuning rods are thin. The double-coupling junction hole structure between the adjacent cavities is formed by forming two regular coupling holes in the common wall of the adjacent cavities, and the coupling between the whole cavities is symmetrically distributed. By changing the diameter of the resonance rod in the coaxial cavity, the problem of asynchronous high-frequency mechanical tuning is solved, and meanwhile, the bandwidth difference in the whole tuning range can be reduced by adopting the double coupling holes.

Description

Technical Field

[0001] The invention relates to a structure for solving the synchronous tuning of a coaxial mechanical tuning filter, and belongs to the technical field of microwave filters. Background Art

[0002] As the frequency of communication equipment increases, the demand for high-frequency mechanical tuning filters increases. One problem that high-frequency mechanical tuning filters need to solve is to find a structural method that can meet the high-frequency synchronous tuning problem, and this structure is easy to process and debug.

[0003] In the prior art, the Chinese invention patent with patent number CN201410763893.5 discloses "a wide tuning coaxial electrically tunable filter and its debugging method", which uses an adjustable compensation screw arranged outside the resonant cavity to achieve full-band frequency compensation. This method is applied to high-frequency mechanical tuning filters. The Chinese invention patent with patent number CN201910110641.5 discloses "a high-selectivity electrically tunable coaxial filter with constant absolute bandwidth", which uses one end of the coaxial tuning rod to connect with the frequency adjustment circuit to realize a frequency-adjustable resonator, which is suitable for low-frequency bands. In the high-frequency band, the volume is reduced and the space does not meet the requirements. In addition, the high-frequency mechanical tunable filter has the problem of frequency asynchronism, which cannot be solved by this structure. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a method for solving the synchronous tuning of a mechanically tuned filter. The feature of the present invention is that synchronous tuning is achieved by changing the size of the tuning rod in the cavity, thereby achieving synchronous adjustability and easy processing.

[0005] The technical solution adopted by the present invention is:

[0006] A structure for solving the synchronous tuning of a coaxial mechanical tuning filter comprises five coaxial cavities in a row; adjacent coaxial cavities are coupled to each other through double coupling holes; each coaxial cavity is provided with a tuning rod, which penetrates from the bottom wall of the coaxial cavity into the coaxial cavity.

[0007] A filter input end is provided on the cavity wall of the first end coaxial cavity; a filter output end is provided on the cavity wall of the terminal coaxial cavity;

[0008] The inner side of the cavity wall where the filter input end and the filter output end are located is provided with a coupling ring.

[0009] Furthermore, the dual coupling hole includes a main coupling hole and a secondary coupling hole; the main coupling hole and the secondary coupling hole are arranged up and down, and the secondary coupling hole is located above the main coupling hole; the secondary coupling hole is a rectangular hole; and the main coupling hole is a right-angle trapezoidal hole.

[0010] Further, the coupling loop is in a U-shaped structure, and both ends thereof are connected to the corresponding cavity wall.

[0011] Further, the bottom side of the right trapezoidal hole is adjacent to the secondary coupling hole; the right-angled side of the right trapezoidal hole and one of the short sides of the rectangular hole are on the same vertical line.

[0012] Further, the row of coaxial cavities is symmetric about the central axis, and the diameter of the tuning rod decreases from the middle to both sides.

[0013] Further, the output end of the filter is a coaxial port or a waveguide port.

[0014] Further, the 5 coaxial cavities are arranged in a row.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention solves the problem of asynchronization of the high-frequency mechanical tuning filter by changing the structure of the diameter of the tuning rod in the cavity. At the same time, double coupling holes are adopted between the cavities, which can reduce the bandwidth difference in the whole tuning range, making the high-frequency mechanical tunable filter easy to process and realize. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is the front view of the internal structure of the coaxial mechanical tuning filter of the present invention

[0018] Figure 2 is Figure 1 the cross-sectional view taken along B-B in

[0019] Figure 3 is the axonometric view of the coaxial mechanical tuning filter of the present invention;

[0020] Wherein 1 is the filter cavity, 2 is the tuning rod, 2_1 is the tuning rod of the first cavity, 2_2 is the tuning rod of the second cavity, 2_3 is the tuning rod of the third cavity, 2_4 is the tuning rod of the fourth cavity, 2_5 is the tuning rod of the fifth cavity, 3 is the secondary coupling hole, 4 is the main coupling hole, 5 is the filter coupling loop, and 6 is the filter input / output end. DETAILED DESCRIPTION OF THE INVENTION

[0021] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Of course, the described content is only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0022] A structure for solving the synchronous tuning problem of a coaxial mechanical tuning filter, the structure comprising five coaxial cavities in a row, the frequency change is achieved by linking the tuning rods of the coaxial cavities together, and the inter-cavity coupling is achieved between adjacent coaxial cavities through double coupling holes. The inter-cavity coupling between adjacent cavities of the coaxial mechanical tuning filter is achieved through double coupling holes, and the inter-cavity coupling is symmetrically distributed. The tuning rods in the coaxial cavity can be symmetrical or asymmetrical according to the arrangement structure, and the diameter of the tuning rods can be adjusted according to the synchronization requirements. The number of coaxial cavities can be N, and the arrangement of the coaxial cavities can be in a row, side by side, or other flexible forms. The output end of the coaxial mechanical tuning filter can be a coaxial port or a waveguide port.

[0023] Figure 1 The right picture shows the cavity structure of the five-cavity coaxial mechanical tuning filter, which has five coaxial cavities in a row. 2_1 is the tuning column of the first cavity, 2_2 is the tuning column of the second cavity, 2_3 is the tuning column of the third cavity, 2_4 is the tuning column of the fourth cavity, and 2_5 is the tuning column of the fifth cavity. The frequency is changed by linking the tuning columns of the first cavity, the second cavity, the third cavity, the fourth cavity, and the fifth cavity together. 3 is the secondary coupling hole, 4 is the main coupling hole, 5 is the filter coupling ring, and 6 is the filter input and output terminal. Inter-cavity coupling is achieved between adjacent coaxial cavities through 3 and 4. Figure 1 2_1 and 2_5 have the same radius, 2_2 and 2_4 have the same radius, the diameter of 2_3 is larger than the diameters of 2_1, 2_2, 2_4, and 2_5, the five-cavity mechanical tuning filter cavity has the same size, the tuning rod is bilaterally symmetrical, and the double coupling holes 3 and 4 between the filter cavities are bilaterally symmetrical relative to the entire filter. Figure 1 The left picture is a cross-sectional view of the mechanically tuned filter cavity. Figure 2 It is a 45-degree axonometric drawing.

Claims

1. A structure for solving the synchronous tuning of a coaxial mechanically tuned filter, characterized in that: It includes five juxtaposed coaxial cavities; the adjacent coaxial cavities are coupled to each other through double coupling holes; a tuning rod is arranged in each coaxial cavity, and the tuning rod penetrates from the bottom wall of the coaxial cavity into the coaxial cavity. A filter input end is arranged on the cavity wall of the first coaxial cavity; a filter output end is arranged on the cavity wall of the last coaxial cavity. Coupling rings are arranged on the inner sides of the cavity walls where the filter input end and the filter output end are located.

2. A structure for solving synchronous tuning of a coaxial mechanically tuned filter according to claim 1, characterized in that: The double coupling holes include a main coupling hole and a secondary coupling hole; the main coupling hole and the secondary coupling hole are arranged vertically, and the secondary coupling hole is located above the main coupling hole; the secondary coupling hole is a rectangular hole; the main coupling hole is a right-angled trapezoidal hole.

3. A structure for solving synchronous tuning of a coaxial mechanically tuned filter according to claim 1, characterized in that: The coupling ring is in a U-shaped structure, and both ends thereof are connected to the corresponding cavity wall.

4. A structure for solving synchronous tuning of a coaxial mechanically tuned filter according to claim 2, characterized in that: The bottom side of the right-angled trapezoidal hole is adjacent to the secondary coupling hole; one of the right-angled sides of the right-angled trapezoidal hole and one of the short sides of the rectangular hole are on the same vertical line.

5. The structure for solving the synchronous tuning of the coaxial mechanically tuned filter according to claim 1, characterized in that: The juxtaposed coaxial cavities are symmetric about the central axis, and the diameter of the tuning rod decreases from the middle to both sides.

6. The structure for solving the synchronous tuning of the coaxial mechanically tuned filter according to claim 1, characterized in that: The filter output end and the filter output end are coaxial ports or waveguide ports.

7. A structure for solving synchronous tuning of a coaxial mechanical tuning filter according to claim 1, wherein the 5 coaxial cavities are juxtaposed.

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