阅读说明：本技术 介质滤波器的电容耦合结构 (Capacitance coupling structure of dielectric filter ) 是由 徐华 于 2019-10-29 设计创作，主要内容包括：本发明公开一种介质滤波器的电容耦合结构,包括介质滤波器本体以及位于介质滤波器本体上的第一调试孔和第二调试孔,所述第一调试孔和第二调试孔之间设有至少一个负耦合孔,所述负耦合孔的开口方向与第一调试孔和第二调试孔的开口方向相同；所述负耦合孔为阶梯孔,包括上部通孔和下部盲孔,此阶梯孔的上部通孔一端延伸至滤波器本体外侧,另一端位于滤波器本体内部,与下部盲孔连接,所述下部盲孔远离上部通孔的一端为封闭端,所述第一调试孔、第二调试孔和下部盲孔的内壁均设有导电层。本发明可以在实现电容耦合的同时,实现了对于远端寄生通带频率的控制。(The invention discloses a capacitive coupling structure of a dielectric filter, which comprises a dielectric filter body, and a first debugging hole and a second debugging hole which are positioned on the dielectric filter body, wherein at least one negative coupling hole is arranged between the first debugging hole and the second debugging hole, and the opening direction of the negative coupling hole is the same as the opening direction of the first debugging hole and the second debugging hole; the negative coupling hole is a stepped hole and comprises an upper through hole and a lower blind hole, one end of the upper through hole of the stepped hole extends to the outer side of the filter body, the other end of the upper through hole is located inside the filter body and connected with the lower blind hole, one end, far away from the upper through hole, of the lower blind hole is a closed end, and the inner walls of the first debugging hole, the second debugging hole and the lower blind hole are provided with conducting layers. The invention can realize the control of the frequency of the far-end parasitic passband while realizing the capacitive coupling.)

1. A capacitive coupling structure for a dielectric filter, characterized by: the medium filter comprises a medium filter body (1) and a first debugging hole (2) and a second debugging hole (3) which are positioned on the medium filter body (1), wherein at least one negative coupling hole (4) is arranged between the first debugging hole (2) and the second debugging hole (3), and the opening direction of the negative coupling hole (4) is the same as that of the first debugging hole (2) and the second debugging hole (3); negative coupling hole (4) are the shoulder hole, including upper portion through-hole and lower part blind hole, and the upper portion through-hole one end of this shoulder hole extends to the wave filter body (1) outside, and the other end is located inside wave filter body (1), is connected with the lower part blind hole, the one end that the upper portion through-hole was kept away from to the lower part blind hole is the blind end, the inner wall of first debugging hole (2), second debugging hole (3) and lower part blind hole all is equipped with the conducting layer.

2. The capacitive coupling structure of a dielectric filter according to claim 1, wherein: the depth of the upper through hole of the negative coupling hole (4) is smaller than the depths of the first debugging hole (2) and the second debugging hole (3).

3. The capacitive coupling structure of a dielectric filter according to claim 1, wherein: the total depth of the negative coupling hole (4) is respectively greater than the depth of the first debugging hole (2) and the depth of the second debugging hole (3).

4. The capacitive coupling structure of a dielectric filter according to claim 1, wherein: the number of the negative coupling holes (4) is 2.

5. The capacitive coupling structure of a dielectric filter according to claim 2, wherein the total depth of the negative coupling holes (4) is 1.1 ~ 1.3.3 times the depth of the first tuning holes (2).

6. The capacitive coupling structure of a dielectric filter according to claim 1, wherein: the first debugging hole (2) and the second debugging hole (3) are blind holes.

7. The capacitive coupling structure of a dielectric filter according to claim 1, wherein: the dielectric filter body (1) is made of non-metal materials.

Technical Field

The invention relates to a capacitive coupling structure of a dielectric filter, belonging to the technical field of communication.

Background

With the increasing development of wireless communication technology, wireless communication base stations are distributed more and more densely, the volume requirement of the base stations is smaller and smaller, wherein the volume ratio of a radio frequency front-end filter module in the base stations is larger, and therefore the volume requirement of the filter is smaller and smaller. However, when the volume of the metal coaxial cavity filter is reduced, it is found that: the smaller the filter volume, the higher the surface current, the higher the losses and the lower the power carrying capacity, i.e. the smaller the power capacity. That is, as the volume of the metal coaxial cavity filter is reduced, its performance index is deteriorated. At present, a miniaturized filter, that is, a solid dielectric filter is widely used, but a structure for realizing capacitive coupling (or called negative coupling) in the solid dielectric filter is complex, the process realization difficulty is high, and a parasitic passband is easily generated at a frequency close to the passband, so that how to provide a dielectric filter with a simple structure and low process difficulty becomes a research direction of a person skilled in the art.

Disclosure of Invention

The invention aims to provide a capacitive coupling structure of a dielectric filter, which can realize the control of the frequency of a far-end parasitic passband while realizing the capacitive coupling.

In order to achieve the purpose, the invention adopts the technical scheme that: a capacitive coupling structure of a dielectric filter comprises a dielectric filter body, a first debugging hole and a second debugging hole, wherein the first debugging hole and the second debugging hole are positioned on the dielectric filter body; the negative coupling hole is a stepped hole and comprises an upper through hole and a lower blind hole, one end of the upper through hole of the stepped hole extends to the outer side of the filter body, the other end of the upper through hole is located inside the filter body and connected with the lower blind hole, one end, far away from the upper through hole, of the lower blind hole is a closed end, and the inner walls of the first debugging hole, the second debugging hole and the lower blind hole are provided with conducting layers.

The further improved scheme in the technical scheme is as follows:

1. in the above scheme, the depth of the upper through hole of the negative coupling hole is smaller than the depths of the first debugging hole and the second debugging hole.

2. In the above scheme, the total depth of the negative coupling hole is greater than the depths of the first debugging hole and the second debugging hole respectively.

3. In the above scheme, there are 2 negative coupling holes.

4. In the scheme, the total depth of the negative coupling holes is 1.1 ~ 1.3.3 times of the depth of the first debugging hole.

5. In the above scheme, the first debugging hole and the second debugging hole are blind holes.

6. In the above scheme, the dielectric filter body is made of a non-metallic material.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

1. the capacitive coupling structure of the dielectric filter realizes the capacitive coupling and the control of the frequency of a far-end parasitic passband, can be used for realizing smaller negative coupling which can reach below 50MHz generally by adjusting the diameter of the through hole, the diameter of the lower blind hole and the depth ratio of the through hole and the lower blind hole, and can be convenient for practical production and processing, which is particularly important for narrow-band filters.

2. According to the capacitive coupling structure of the dielectric filter, the negative coupling hole is a stepped hole, namely a combined structure of the through hole and the blind hole, one end of the blind hole is a closed end, and the depth of the negative coupling hole is 1.1 ~ 1.3.3 times of the depth of the first debugging hole.

3. According to the capacitive coupling structure of the dielectric filter, only the blind hole part in the negative coupling hole is provided with the conducting layer, the conducting layer is not arranged on the through hole and the transition step of the through hole and the blind hole, the structure controls the strength of negative coupling by adjusting the area of the conducting layer on the negative coupling hole and the position of the conducting layer, and the deeper the through hole is, the stronger the negative coupling is; the deeper the blind hole the weaker the negative coupling.

Drawings

Fig. 1 is a schematic diagram of a capacitive coupling structure of a dielectric filter according to the present invention.

In the above drawings: 1. a dielectric filter body; 2. a first pilot hole; 3. a second pilot hole; 4. a negative coupling aperture.

Detailed Description

In the description of this patent, it is noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention; the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; furthermore, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, as they may be fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The meaning of the above terms in this patent may be specifically understood by those of ordinary skill in the art.