Ku wave band U-shaped cavity filter

Abstract

The invention discloses a Ku-band U-shaped cavity filter, and belongs to the technical field of communication. The box comprises a box body and a cover plate, the cover plate is arranged at the top of the box body to form a box body cavity; the box body cavity comprises eight sub-cavities, and the eight sub-cavities are arranged in a 2 * 4 rectangular array mode; a resonance rod is arranged in each sub-cavity; the cover plate is provided with a plurality of tuning screw holes, the resonance rod, the inter-stage coupling window, the middle-end coupling window, the first zero-point window and the second zero-point window all correspond to one tuning screw hole, and a tuning screw is arranged in each tuning screw hole. Zero windowing is added twice, the U-shaped design is adopted, and the cover plate is grooved, so that the rectangular coefficient is improved, the size of the filter is reduced, and the number of resonant cavities is also reduced.

Description

Technical Field

[0001] The invention relates to the field of communications, and in particular to a Ku-band U-shaped cavity filter. Background Art

[0002] Reality requires that all communication equipment develop in the direction of low power consumption, small size, light weight, high efficiency and high reliability. Microwave filters are devices used to selectively pass or block microwave signals in a specific frequency range. Microwave filters play a vital role in wireless communications, radar systems and satellite technology. They ensure that the system can work stably in a complex electromagnetic environment while improving the signal quality and the system's anti-interference ability. The design and construction of microwave filters are usually based on various resonant structures, such as cavity resonators, microstrip lines, coplanar waveguides, etc.

[0003] A cavity filter is a device that uses a metal cavity as a resonant unit and achieves selective passage of microwave frequencies through a specific structural design. This filter is usually composed of one or more coupled resonant cavities, each of which has a specific resonant frequency, which determines the passband and stopband of the filter. As a key component in wireless communication systems, the performance of cavity filters directly affects the communication quality of the entire system. With the continuous advancement of wireless technology, the design of cavity filters is also being continuously optimized to meet higher performance requirements and a wider range of application scenarios.

[0004] With the continuous development of modern wireless communication technology, the requirements for the rectangular coefficient of RF products are getting higher and higher, and the volume is required to be miniaturized, especially in the high-frequency band. In general, in order to meet the high rectangular coefficient, the theoretical design leads to a large number of resonant cavities, while the structure required by the product is very small. How to achieve a high matrix coefficient with a small overall size of the component has become a difficult problem for designers.

[0005] In actual engineering applications, in order to meet the high rectangular coefficient requirements of the Ku band, if conventional design methods are used, the number of resonant cavities of the filter must be large and the dielectric thickness must be thin, which greatly reduces product reliability. Summary of the invention

[0006] The object of the present invention is to provide a Ku-band U-shaped cavity filter to solve the problems raised in the above background technology.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A Ku-band U-shaped cavity filter comprises a box body and a cover plate; the cover plate is arranged on the top of the box body to form a box body cavity; the box body cavity comprises 8 sub-cavities, and the 8 sub-cavities are arranged in a 2×4 rectangular array;

[0009] Two adjacent sub-cavities located on one short side are each provided with a signal transmission end, one of which is used as a signal input and the other as a signal output; the signal transmission end is located on the outer wall of the box body, and a tap penetrating the box body wall is provided at the center thereof, and the tap is welded to the resonant rod located in the sub-cavity;

[0010] Each adjacent sub-cavity among the four sub-cavities on the long side is connected through an inter-stage coupling window, and two adjacent sub-cavities on the other short side are connected through a middle-end coupling window;

[0011] The adjacent sub-cavities of the two middle groups of short sides are provided with windows at the first zero point and the second zero point respectively;

[0012] A resonant rod is provided in each sub-cavity; a plurality of tuning screw holes are provided on the cover plate, and each of the resonant rod, the inter-stage coupling window, the mid-end coupling window, the first zero point window and the second zero point window corresponds to a tuning screw hole, and each tuning screw hole is provided with a tuning screw.

[0013] Furthermore, a skirt (11) is provided on the cover plate, and the outer area of ​​the skirt (11) is higher than the area inside the skirt where the tuning screw is located.

[0014] Compared with the background technology, the present invention has the following beneficial effects:

[0015] The present invention adds a secondary zero-point windowing technology and adopts a U-shaped design, which not only achieves the characteristic of small size, but also meets the design requirements in terms of performance. It has a high suppression effect on both the second and third harmonics, and solves the problem of cavity filters due to their large size, poor rectangular coefficient, and unclear high harmonic suppression effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the Ku-band U-shaped cavity filter box of the present invention;

[0017] Figure 2 It is a structural schematic diagram of the Ku-band U-shaped cavity filter cover plate of the present invention.

[0018] In the figure: 1. Tap in the box cavity; 2. Resonant rod; 3. Inter-stage coupling window; 4. First zero point window; 5. Second zero point window; 6. Mid-end coupling window; 7. Resonant rod tuning screw hole; 8. Coupling window tuning screw hole; 9. First zero point window tuning screw hole; 10. Second zero point window tuning screw hole; 11. Skirt. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0020] A Ku-band U-shaped cavity filter comprises a box body and a cover plate; the cover plate is arranged on the top of the box body to form a box body cavity; the box body cavity comprises 8 sub-cavities, and the 8 sub-cavities are arranged in a 2×4 rectangular array;

[0021] Two adjacent sub-cavities located on one short side are each provided with a signal transmission end, one of which is used as a signal input and the other as a signal output; the signal transmission end is located on the outer wall of the box body, and a tap penetrating the box body wall is provided at the center thereof, and the tap is welded to the resonant rod located in the sub-cavity;

[0022] Each adjacent sub-cavity among the four sub-cavities on the long side is connected through an inter-stage coupling window, and two adjacent sub-cavities on the other short side are connected through a middle-end coupling window;

[0023] The adjacent sub-cavities of the two middle groups of short sides are provided with windows at the first zero point and the second zero point respectively;

[0024] A resonant rod is provided in each sub-cavity; a plurality of tuning screw holes are provided on the cover plate, and each of the resonant rod, the inter-stage coupling window, the mid-end coupling window, the first zero point window and the second zero point window corresponds to a tuning screw hole, and each tuning screw hole is provided with a tuning screw.

[0025] Furthermore, a skirt (11) is provided on the cover plate, and the outer area of ​​the skirt (11) is higher than the area inside the skirt where the tuning screw is located.

[0026] See also Figure 1 Figure 2 The present invention provides a technical solution: a Ku-band U-shaped cavity filter, comprising a box body, a signal transmission end arranged at one side of the end of the box body, and a tap 1 and a resonance rod 2 arranged in the box body cavity, wherein one end of the tap is welded to the signal transmission end, and the other end of the tap is welded to the resonance rod 2.

[0027] In this embodiment, the cover plate is provided with a tuning screw hole 7 and a tuning screw hole 8 corresponding to the stator rod 2 and the coupling window 3 .

[0028] In this embodiment, the resonant rod 2 and the tuning screw hole 7 are arranged concentrically, and the coupling window 3 and the tuning screw hole 8 are arranged concentrically.

[0029] In this embodiment, during installation, one end of the tap 1 is welded to the signal transmission end, and the other end is welded to the resonance rod 2 .

[0030] In this embodiment, since the tap 1 is welded to the signal transmission end and is close to the ground of the cavity, care should be taken to prevent short circuit during operation.

[0031] In this embodiment, two taps 1 are provided, and the taps 1 have the same height from the bottom.

[0032] The invention has a high suppression effect on both the second and third harmonics and is also based on the tuning distance of the tuning screw hole (9) and the tuning screw hole (10) corresponding to the first zero point window (4) and the second zero point window (5). The suppression effect is better when the distance is appropriate.

[0033] In the design of the microwave filter of the present invention, the U-shaped cavity filter adopting the secondary window design has a high rectangular coefficient and a small volume, which meets modern needs. The secondary zero-point window design meets the rules:

[0034]

[0035] C N (ω) represents the Nth order filter function, x is the name of the complex frequency function corresponding to the transmission zero point, and ω is a variable.

[0036] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A Ku-band U-shaped cavity filter, characterized in that: It comprises a box body and a cover plate; the cover plate is arranged on the top of the box body to form a box body cavity; the box body cavity comprises 8 sub-cavities, and the 8 sub-cavities are arranged in a 2×4 rectangular array; Two adjacent sub-cavities located on one short side are each provided with a signal transmission end, one of which is used as a signal input and the other as a signal output; the signal transmission end is located on the outer wall of the box body, and a tap penetrating the box body wall is provided at the center thereof, and the tap is welded to the resonant rod located in the sub-cavity; Each adjacent sub-cavity among the four sub-cavities on the long side is connected through an inter-stage coupling window, and two adjacent sub-cavities on the other short side are connected through a middle-end coupling window; The adjacent sub-cavities of the two middle groups of short sides are provided with windows at the first zero point and the second zero point respectively; A resonant rod is provided in each sub-cavity; a plurality of tuning screw holes are provided on the cover plate, and each of the resonant rod, the inter-stage coupling window, the mid-end coupling window, the first zero point window and the second zero point window corresponds to a tuning screw hole, and each tuning screw hole is provided with a tuning screw.

2. A Ku-band U-shaped cavity filter according to claim 1, characterized in that: The cover plate is provided with a skirt (11), and the outer area of ​​the skirt (11) is higher than the area inside the skirt where the tuning screw is located.

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