Filter and communication device using the filter

Abstract

The present invention relates to a filter and a communication device using the filter, comprising a cavity of the filter, a resonator located in the cavity and a cover plate covering the cavity, wherein the resonator can be rotatably mounted on the cover plate around its axis and suspended in the cavity; the resonator coupling surface at the bottom of the resonator is opposite to the cavity coupling surface at the bottom of the cavity; when the resonator is rotated, the distance between the resonator coupling surface and the cavity coupling surface remains unchanged, and the effective coupling area of ​​the two coupling surfaces changes accordingly. Compared with the prior art, the filter of the present invention removes the adjustment screw, reduces the height of the filter, has a compact structure, a smaller volume and simple debugging operation.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, in particular to a waveguide device, and more particularly to a filter. Background Art

[0002] Filters used in communication equipment can effectively suppress useless signals, and play a role in selecting signals, attenuating noise, and filtering interference. With the development of mobile communication devices and equipment base stations becoming smaller and lighter, the filters used in them are also required to be able to fit into the narrow internal assembly space and meet the needs of smaller structure and better performance. Figure 1 The filter of the prior art includes a filter cavity 93, a resonator 95 installed in the cavity, a cover plate 94 covering the cavity, and an adjusting screw 99 erected on the cover plate through a locking nut 91; the depth of the adjusting screw is adjusted to change the coupling area and coupling distance of the resonator to achieve the purpose of adjusting the coupling amount. The screw locking operation is not only cumbersome, but also the adjusting screw and the locking nut are much higher than the cover plate, and the raised space is wasted space. The height of the filter cannot be minimized, which is not suitable for the miniaturization of the use environment. The screw adjustment mode is prone to thread slippage when the screw is repeatedly tightened and loosened, and part of the screw thread extends into the cavity, which will deteriorate the performance of the filter. Summary of the invention

[0003] The technical problem to be solved by the present invention is to propose a filter with a reduced height and convenient adjustment of the coupling amount in view of the above-mentioned defects of the prior art.

[0004] The technical solution adopted by the present invention to solve the technical problem is:

[0005] A filter comprises a cavity of the filter, a resonator located in the cavity and a cover plate covering the cavity, in particular, the resonator is mounted on the cover plate and suspended in the cavity so as to be rotatable around its axis; the resonator coupling surface at the bottom of the resonator is opposite to the cavity coupling surface at the bottom of the cavity; when the resonator is rotated, the distance between the resonator coupling surface and the cavity coupling surface remains unchanged, and the effective coupling areas of the two coupling surfaces change accordingly.

[0006] Further:

[0007] The resonator coupling surface may be any shape other than a circle rotated about the axis of the resonator.

[0008] The cavity coupling surface may be any shape other than a circle rotated about the axis of the resonator.

[0009] The shapes of the resonator coupling surface and the cavity coupling surface may be the same or different.

[0010] The resonator coupling surface includes a flat surface or a curved surface.

[0011] The cavity coupling surface includes a plane or a curved surface, and is arranged at a convex position or a concave position on the bottom surface of the cavity, and includes a plane or a curved surface.

[0012] The resonator is riveted onto the cover plate through an elastic device, the resonator is in close contact with the cover plate surface and the resonator can rotate around its axis.

[0013] The elastic device includes a disc spring, a spring washer or a rubber washer.

[0014] The filter includes one or more resonators. When there are more than one resonator, the resonators are arranged in each cavity of the filter in a one-to-one correspondence.

[0015] The present invention also proposes a communication device, which uses the above-mentioned filter. The communication device includes an outer cover, an antenna array, a filter, a shielding cover, a PCB board and a radiator arranged in sequence. One external connection pin of the filter is connected to the antenna, and the other external connection pin is connected to the PCB board through the shielding cover.

[0016] Compared with the prior art, the filter of the present invention removes the adjusting screw, reduces the height of the filter, has a compact structure, a smaller volume, and simpler debugging operation, and is more suitable for miniaturization requirements of mobile communication devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of the components in the cavity of the prior art filter;

[0018] Figure 2 A schematic cross-sectional view of the orthographic projection of the components in the cavity of the first preferred embodiment of the filter of the present invention;

[0019] Figure 3 A schematic diagram of the effective coupling of two coupling surfaces of the filter of the present invention;

[0020] Figure 4 A schematic diagram of an axonometric projection of a resonator of a filter of the present invention;

[0021] Figure 5 An orthographic cross-sectional schematic diagram of the components in the cavity of the second preferred embodiment of the filter of the present invention;

[0022] Figure 6 An orthographic cross-sectional schematic diagram of the components in the cavity of the third preferred embodiment of the filter of the present invention;

[0023] Figure 7 A schematic diagram of an axonometric projection of a filter in a fourth preferred embodiment of the filter of the present invention. DETAILED DESCRIPTION

[0024] Now, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0025] Embodiment 1, a filter, such as Figures 2 to 4 As shown, the filter includes a resonator 35 of the filter, which is riveted onto a cover plate 34 through an elastic device 303, such as a disc spring, and is suspended in a cavity 31 of the filter. The elastic element 303 can ensure that the resonator is in close contact with the cover plate surface without being riveted to the point that the resonator cannot rotate, that is, the resonator can rotate around its own central axis. The bottom surface of the resonator 35 is a resonator coupling surface 300; the shape of the coupling surface of the resonator is any shape other than a circle rotating with the axis of the resonator as the center, such as a triangle, a polygon, a star, any shape with an irregular outer edge, an ellipse, or a circle with the axis of the resonator as the center.

[0026] A cavity coupling surface is provided on the bottom surface of the cavity opposite to the resonator coupling; see Figure 3 , the overlapping part of the two coupling surfaces is the effective coupling area.

[0027] The cavity coupling surface is located at the convex part of the cavity bottom opposite to the coupling surface of the resonator 35, or it can be a concave part. In this example, it is set at the convex part. The coupling surface cavity 31 can be a plane or a curved surface, and its shape can be any shape except a circle rotating with the axis of the resonator as the center, such as a triangle, a polygon, a star, any shape with irregular outer edges, an ellipse, or a circle with the axis of the non-resonator as the center. The cavity coupling surface and the resonator coupling surface can also be the same shape, or they can be different.

[0028] The coupling amount of the filter depends on the distance between the two coupling surfaces and the effective coupling area of ​​the two coupling surfaces; the coupling amount is inversely proportional to the distance and directly proportional to the area; after the resonator and the cover are riveted, the distance between the resonator coupling surface and the cavity coupling surface is fixed.

[0029] When the direction of the resonator is adjusted, the effective coupling area of ​​the two can be changed, thereby achieving the adjustment function. This effectively eliminates the adjustment screw of the traditional filter extending outside the resonant cavity, effectively reducing the height of the filter, reducing the installation space, and reducing the manufacturing cost; at the same time, the filter has fewer structural parts and simple debugging operations (just adjust the direction of the resonator), and there is no thread locking mechanism, so there is no risk of thread slippage causing the product to fail, and it will not loosen. In the existing screw adjustment mode, the thread is prone to slippage when the screw is repeatedly tightened and loosened, and part of the screw thread extends into the cavity, which will deteriorate the performance of the filter.

[0030] The structure of the filter in this embodiment can provide a countersunk hole on the cover plate so that the adjustment part of the resonator is not higher than the cover plate surface at all, which is more convenient for assembly and meets the needs of a smaller use space.

[0031] Example 2, see Figure 5 The structure of the filter in this example is basically similar to that in Example 1, except that the resonator coupling surface 300 of the filter in this example is a curved surface.

[0032] Example 3, see Figure 6 The structure of the filter in this example is basically similar to that in the second example, except that the resonator coupling surface 300 of the filter in this example is a curved surface different from that in the second example.

[0033] Of course, the resonator coupling surface may be a curved surface, a flat surface or a combination of the two.

[0034] Example 4, see Figure 7 The filter in this embodiment is a filter composed of multiple resonators, each resonator is arranged in a cavity in the filter housing in a one-to-one correspondence, and the structure in each cavity is as described in the above embodiment. It will not be repeated here; according to the requirements, the filter can have one or more resonators.

[0035] A communication device using the filters in the aforementioned embodiments comprises an outer cover, an antenna array, a filter, a shielding cover, a PCB board and a heat sink arranged in sequence, one external connection pin of the filter is connected to the antenna, and another external connection pin is connected to the PCB board through the shielding cover.

[0036] This effectively eliminates the need for the adjustment screw of the traditional filter extending outside the resonant cavity, effectively reduces the height of the filter, reduces installation space and manufacturing costs, and meets the needs of small and light communication equipment.

[0037] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. For those skilled in the art, the technical solutions described in the above embodiments can be modified, or some of the technical features therein can be replaced by equivalents; and these modifications and replacements should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A filter, comprising a cavity of the filter, a resonator located in the cavity and a cover plate covering the cavity, characterized in that: The resonator can be rotatably mounted on the cover plate around its axis and suspended in the cavity; the resonator coupling surface at the bottom of the resonator is opposite to the cavity coupling surface at the bottom of the cavity; when the resonator is rotated, the distance between the resonator coupling surface and the cavity coupling surface remains unchanged, and the effective coupling areas of the two coupling surfaces change accordingly; The shape of the resonator coupling surface is any shape other than a circle rotating around the axis of the resonator; The shape of the cavity coupling surface is any shape except a circle rotating around the axis of the resonator; The resonator is riveted into the countersunk hole on the cover plate through an elastic device, so that the adjustment part of the resonator is not higher than the cover plate surface at all, the resonator is in close contact with the cover plate surface and the resonator can rotate around its axis.

2. The filter according to claim 1, characterized in that: The shapes of the resonator coupling surface and the cavity coupling surface are the same or different.

3. The filter according to claim 1, characterized in that: The resonator coupling surface includes a flat surface or a curved surface.

4. The filter according to claim 1, characterized in that: The cavity coupling surface includes a plane or a curved surface, and is arranged at a convex position or a concave position of the cavity bottom surface.

5. The filter according to claim 1, characterized in that: The elastic device includes a disc spring, a spring washer or a rubber washer.

6. The filter according to claim 1, characterized in that: The filter includes one or more resonators. When there are more than one resonator, the resonators are arranged in each cavity of the filter in a one-to-one correspondence.

7. A communication device using the filter according to any one of claims 1 to 6, characterized in that: The communication device comprises an outer cover, an antenna array, a filter, a shielding cover, a PCB board and a radiator arranged in sequence. One external connection pin of the filter is connected to the antenna, and another external connection pin passes through the shielding cover and is connected to the PCB board.

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