A negative coupling structure of dielectric filter

Abstract

The present invention provides a negative coupling structure of a dielectric filter. The present invention can selectively set an adjustment hole that penetrates a dielectric block between any two resonant cavities. The two resonant cavities are connected through the adjustment hole, so that the capacitive coupling structure between the resonant cavities can be transformed into an inductive structure to form a negative coupling structure. At the same time, the present invention sets an adjustment groove on the back of the filter input port. The far-end suppression performance of the dielectric filter can be further improved by adjusting the depth and width of the adjustment groove. Moreover, the present invention has a simple structure and strong applicability, and can be applied to all dielectric filters to optimize their far-end performance.

Description

Technical Field

[0001] The invention belongs to the technical field of dielectric filter coupling structures, and in particular relates to a negative coupling structure of a dielectric filter. Background Art

[0002] In the 5G era, due to the requirements of Massive MIMO (massive antenna technology) for large-scale antenna integration, filters need to be more miniaturized and integrated. Under the condition of limited cavity size, due to the loss of their own materials, metal coaxial cavity filters and metal cavity dielectric filters cannot achieve very high Q values, which leads to limitations on various performance indicators of the filters.

[0003] The electromagnetic wave resonance in the ceramic dielectric filter occurs inside the dielectric material. The traditional metal cavity is replaced by a metal coating, so the volume will be smaller and the weight will be lighter. In addition, the ceramic dielectric filter has the advantages of high Q value, good frequency selection characteristics, good operating frequency stability, low insertion loss, and low high and low temperature drift characteristics. Therefore, in order to meet the miniaturization requirements of 5G base station filters, the ceramic dielectric filter, which is easier to miniaturize, has become the mainstream solution. Summary of the invention

[0004] The purpose of the present invention is to provide a negative coupling structure suitable for a ceramic dielectric filter, which can transform the capacitive coupling structure between resonant cavities into an inductive one, so as to improve the out-of-band suppression performance of the dielectric filter.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a negative coupling structure of a dielectric filter, the dielectric filter includes a dielectric block, an ANT port, a TX port and a plurality of resonant cavities, any two of the resonant cavities can be selectively connected through an adjustment hole set through the dielectric block, and the far-end suppression performance of the dielectric filter can be adjusted by adjusting the size of the adjustment hole and the distance between the two connected resonant cavities.

[0006] Furthermore, an adjustment slot is provided between the ANT port and the TX port, and the far-end suppression performance of the dielectric filter is improved by adjusting the width and depth of the adjustment slot.

[0007] Furthermore, the ANT port and the TX port are jointly arranged on one end surface of the dielectric block, and the adjustment slot is arranged on the other end surface of the dielectric block.

[0008] Furthermore, the adjustment slot and the multiple resonant cavities are all blind slot structures.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention can selectively set an adjustment hole penetrating the dielectric block between any two resonant cavities, and the two resonant cavities are connected through the adjustment hole, so that the capacitive coupling structure between the resonant cavities can be transformed into an inductive structure, forming a negative coupling structure. At the same time, the present invention sets an adjustment groove on the back of the filter input port, and the far-end suppression performance of the dielectric filter can be further improved by adjusting the depth and width of the adjustment groove. Moreover, the present invention has a simple structure and strong applicability, and can be applied to all dielectric filters to optimize their far-end performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of a negative coupling structure of a dielectric filter of the present invention;

[0011] Figure 2 A simulated frequency response curve of a dielectric filter using the negative coupling structure of the present invention;

[0012] Markings in the figure: 1, ANT port, 2, TX port, 3, adjustment slot, 4, first resonant cavity, 5, second resonant cavity, 6, adjustment hole. DETAILED DESCRIPTION

[0013] In order to make the purpose, 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 in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0014] like Figure 1 As shown, a negative coupling structure of a dielectric filter comprises a dielectric block, an ANT port 1, a TX port 2 and a plurality of resonant cavities, any two of the resonant cavities can be selectively connected through an adjustment hole 6 provided through the dielectric block, so that the capacitive coupling structure between the resonant cavities can be transformed into an inductive structure to form a negative coupling structure, and the far-end suppression performance of the dielectric filter can be adjusted by adjusting the size of the adjustment hole 6 and the distance between the two connected resonant cavities.

[0015] In this embodiment, the first resonant cavity 4 and the second resonant cavity 5 are used to illustrate the scheme of the present invention: the first resonant cavity 4 and the second resonant cavity 5 are both blind groove structures, and the opening ends of the two are respectively opened on the two end surfaces of the dielectric block, and the adjustment hole 6 is a through hole set through the dielectric block. The two resonant cavities are connected through the adjustment hole 6, so that the capacitive coupling structure between the two resonant cavities can be transformed into inductive, forming a negative coupling structure.

[0016] In order to achieve the best use effect, an adjustment groove 3 is opened between the ANT port 1 and the TX port 2. The adjustment groove 3 is a blind groove structure. The ANT port and the TX port are jointly arranged on one end surface of the dielectric block, and the adjustment groove 3 is arranged on the other end surface of the dielectric block. The far-end suppression performance of the dielectric filter is improved by adjusting the width and depth of the adjustment groove 3.

[0017] A simulation experiment was conducted on the dielectric filter using the negative coupling structure of the present invention. The simulation frequency response curve obtained after the simulation is as follows: Figure 2 As shown in the figure, there are two curves S11 and S21, wherein the curve S11 is a reflection characteristic curve, and the curve S21 is a transmission characteristic curve. The curve S11 is located above the curve S21. Figure 2 It can be seen that by adopting the negative coupling structure of the present invention, the secondary slope peak that should be generated at about 4.3G can be pushed to after 5.7G. Obviously, the dielectric filter adopting the negative coupling structure of the present invention has good far-end suppression performance. Moreover, the present invention has a simple structure and strong applicability, and can be applied to all dielectric filters to optimize their far-end performance.

[0018] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A negative coupling structure of a dielectric filter, the dielectric filter comprising a dielectric block, an ANT port, a TX port and a plurality of resonant cavities, characterized in that: Any two of the resonant cavities can be selectively connected through an adjustment hole set through the dielectric block, and the two resonant cavities are connected through the adjustment hole, so that the capacitive coupling structure between the resonant cavities is transformed into an inductive negative coupling structure; the far-end suppression performance of the dielectric filter is adjusted by adjusting the size of the adjustment hole and the distance between the two connected resonant cavities; An adjustment slot is provided between the ANT port and the TX port, and the far-end suppression performance of the dielectric filter is improved by adjusting the width and depth of the adjustment slot.

2. The negative coupling structure of a dielectric filter according to claim 1, characterized in that: The ANT port and the TX port are jointly arranged on one end surface of the dielectric block, and the adjustment groove is arranged on the other end surface of the dielectric block.

3. The negative coupling structure of a dielectric filter according to claim 2, characterized in that: The adjustment slot and the multiple resonant cavities are all blind slot structures.

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