A dielectric-filled high-selectivity waveguide filter

Abstract

The present invention discloses a dielectric-filled high-selectivity waveguide filter, which is metallized by silver plating on the surface of a dielectric shell. A coupling diaphragm is arranged along the wide side of the dielectric shell. The coupling diaphragm divides the space inside the dielectric shell into a first resonator and a second resonator that are symmetrical on the left and right, and the two resonators constitute a dual-mode resonator. A plurality of metal blind holes are evenly arranged in the first resonator and the second resonator. The metal blind holes are used to excite the dual-mode resonator or tune the resonant frequencies of the two working modes. The coupling diaphragm is used to control the inter-cavity coupling between the first resonator and the second resonator. The present invention can realize TE 102 Mould and TE 201 The resonant frequency of the mode is controlled and the dual-mode resonator is used, which reduces the volume by about 30% and has the advantage of miniaturization. The metal blind hole of the coupling probe can excite the TE 101 The coupling diaphragm is coupled to realize the source-load coupling structure, which improves the out-of-band suppression of the filter. The coupling diaphragm adopts a three-section structure, with high yield and strong practicality.

Description

Technical Field

[0001] The present invention belongs to the field of radio frequency and microwave filters, and in particular relates to a dielectric-filled high-selectivity waveguide filter. Background Art

[0002] Filters are a critical component of RF modules. RF communication systems require filters before and after each frequency step in the transceiver system to frequency-select signals and remove noise interference, ensuring accurate and efficient communication. With the rapid development of mobile communications, 5G base station technology is placing demands on lightweight and miniaturized filters. Massive MIMO technology, on the one hand, exponentially increases the number of antenna elements, leading to increased base station weight and the need for lighter filters. On the other hand, Massive MIMO technology expands the original 2 / 4 / 8 channels to 64 / 128 / 256 or even more. Therefore, accommodating more channels in a limited space requires smaller filters. Summary of the Invention

[0003] The technical purpose of the present invention is to provide a dielectric-filled high-selectivity waveguide filter to solve the technical problems in the background technology.

[0004] In order to solve the above problems, the technical solution of the present invention is:

[0005] A dielectric-filled high-selectivity waveguide filter comprising:

[0006] A dielectric shell with a silver-plated surface, and a plurality of metal blind holes, a dual-mode resonator, and a coupling diaphragm arranged in the dielectric shell;

[0007] The coupling diaphragm is arranged along the wide side of the dielectric housing, and the coupling diaphragm divides the space inside the dielectric housing into a first resonator and a second resonator that are symmetrical on the left and right, and the first resonator and the second resonator constitute a dual-mode resonator; a plurality of metal blind holes are evenly arranged in the first resonator and the second resonator;

[0008] The metal blind hole is used to excite the dual-mode resonator or tune the resonant frequencies of the two working modes in the first resonator or the second resonator; and the coupling diaphragm is used to control the inter-cavity coupling between the first resonator and the second resonator.

[0009] Specifically, the metal blind hole includes a coupling probe metal blind hole and a resonance control metal blind hole;

[0010] There are two metal blind holes of the coupling probe, which are respectively arranged in the first resonator and the second resonator, for exciting the dual-mode resonator;

[0011] There are eight resonance control metal blind holes, which are evenly distributed in the first resonator and the second resonator in a diamond-shaped symmetry, and are used to control the TE 102 Mould and TE 201 The resonant frequency of the mode is tuned and controlled.

[0012] Specifically, the coupling probe metal blind hole includes a first coupling probe metal blind hole and a second coupling probe metal blind hole. The first coupling probe metal blind hole and the second coupling probe metal blind hole have the same height and are symmetrically arranged about the center of the dielectric shell.

[0013] Among them, the end face of the metal blind hole of the coupling probe is annular, and the inner ring diameter Din and the outer ring diameter Dout of the ring satisfy the following formula: Dout = 2.3*Din; it is used to connect with the coaxial connector to feed the dual-mode filter, and the height of the metal blind hole of the coupling probe inserted into the dielectric shell controls the coupling strength of the input and output.

[0014] The outer surface of the dielectric shell, except for the annular portion at the end face of the metal blind hole of the coupling probe, is plated with silver to achieve metallization.

[0015] Specifically, the resonance control metal blind vias include a first metal blind via, a second metal blind via, a third metal blind via and a fourth metal blind via provided in the first resonator, and a fifth metal blind via, a sixth metal blind via, a seventh metal blind via and an eighth metal blind via provided in the second resonator;

[0016] The first metal blind hole, the second metal blind hole, the third metal blind hole and the fourth metal blind hole are evenly distributed in the first resonator in a diamond shape;

[0017] The fifth metal blind via, the sixth metal blind via, the seventh metal blind via and the eighth metal blind via are evenly distributed in the second resonator in a diamond shape;

[0018] The first metal blind hole and the second metal blind hole are provided on both sides of the midline along the long side direction of the first resonator, and are used to 102 The resonant frequency of the mode is controlled;

[0019] The third metal blind hole and the fourth metal blind hole are arranged on both sides of the midline along the width direction of the first resonator, and are used to 201 The resonant frequency of the mode is controlled;

[0020] The fifth metal blind hole and the sixth metal blind hole are provided on both sides of the midline along the long side direction of the second resonator, and are used to 102 The resonant frequency of the mode is controlled;

[0021] The seventh metal blind hole and the eighth metal blind hole are provided on both sides of the midline along the width direction of the second resonator, and are used to 201 The resonant frequency of the mode is controlled.

[0022] The first metal blind via, the second metal blind via, the fifth metal blind via and the sixth metal blind via are of the same height;

[0023] The third metal blind via, the fourth metal blind via, the seventh metal blind via and the eighth metal blind via have the same height.

[0024] The coupling diaphragm is the space connecting the first resonator and the second resonator, is parallel to the wide side direction of the dual-mode resonator, and includes a first coupling section, a second coupling section, and a third coupling section;

[0025] The first coupling section and the third coupling section are symmetrically arranged along the midline of the long side direction of the dual-mode resonator; the second coupling section is located between the first coupling section and the third coupling section;

[0026] The direct coupling between the first resonator and the second resonator is controlled by the length of the second coupling section, and the cross coupling between the first resonator and the second resonator is controlled by the offset of the second coupling section toward the first coupling section or the third coupling section.

[0027] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0028] The present invention realizes the orthogonal TE by loading four resonance control metal blind holes on both sides of the dielectric shell. 102 Mould and TE 201 The resonant frequency of the mode is controlled, and at the same time, the metal blind hole has a capacitive loading effect, which can realize the miniaturization of the resonator.

[0029] The present invention utilizes dual-mode resonators, achieving a fourth-order filter response with just two resonators. Its right-side suppression is comparable to that of a filter designed using eight single-mode resonators. Consequently, this design eliminates six single-mode resonators and reduces volume by approximately 30%, offering the advantage of miniaturization.

[0030] The metal blind hole of the coupling probe of the present invention can excite the TE in the dual-mode resonator 101 The source-load coupling structure is realized by coupling the mode and coupling through the coupling diaphragm. In addition to obtaining four transmission poles, four transmission zeros can also be obtained, thereby improving the out-of-band suppression of the filter.

[0031] The coupling diaphragm of the present invention adopts a three-section structure, has a high yield and strong practicality during dielectric block processing and filter testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Various other advantages and benefits will become apparent to those skilled in the art by reading the following detailed description of the preferred embodiment.The accompanying drawings are only for the purpose of illustrating the preferred embodiment and are not to be considered as limiting the present invention.

[0033] Figure 1 A top view of a dielectric-filled high-selectivity waveguide filter of the present invention Figure 1 ;

[0034] Figure 2 A top view of a dielectric-filled high-selectivity waveguide filter of the present invention Figure 2 ;

[0035] Figure 3 A three-dimensional structural diagram of a dielectric-filled high-selectivity waveguide filter according to the present invention;

[0036] Figure 4 is an S-parameter curve diagram of a dielectric-filled high-selectivity waveguide filter of the present invention;

[0037] Figure 5 This is an S-parameter simulation curve diagram of the input and output ports offsetting the y-axis center of the resonator of the present invention.

[0038] Description of Reference Numerals

[0039] 1: First metal blind hole; 2: Second metal blind hole; 3: Third metal blind hole; 4: Fourth metal blind hole; 5: Fifth metal blind hole; 6: Sixth metal blind hole; 7: Seventh metal blind hole; 8: Eighth metal blind hole; 9: First coupling section; 10: Third coupling section; 11: Second coupling section; 12: First coupling probe metal blind hole; 13: Second coupling probe metal blind hole. DETAILED DESCRIPTION

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific embodiments of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings and other embodiments can be obtained based on these drawings without inventive work.

[0041] To simplify the drawings, only the parts relevant to the present invention are schematically shown in each figure. They do not represent the actual structure of the product. Furthermore, to simplify the drawings and facilitate understanding, in some figures, only one of the components with the same structure or function is schematically depicted or labeled. As used herein, "one" not only means "only one" but also "more than one."

[0042] The following is a detailed description of a dielectric-filled high-selectivity waveguide filter proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims.

[0043] Example

[0044] See Figures 1 to 3 This embodiment provides a dielectric-filled, highly selective waveguide filter. This embodiment utilizes silver plating on the outer surface of the dielectric housing to achieve metallization. Consequently, this circuit structure offers the advantages of low cost, low insertion loss, and lightweight. Frequency tuning in this embodiment is achieved through varying the height of metal blind vias, which exhibit a capacitive loading effect, resulting in a compact design.

[0045] Specifically, it comprises a dielectric housing, a plurality of metal blind holes, a dual-mode resonator, and a coupling diaphragm disposed within the dielectric housing. The coupling diaphragm is disposed at the center of the dielectric housing along its width. The coupling diaphragm divides the space within the dielectric housing into a first resonator and a second resonator that are symmetrical on the left and right. The first and second resonators together constitute a dual-mode resonator. A plurality of metal blind holes are evenly distributed between the first and second resonators. The metal blind holes can excite the dual-mode resonator or tune the resonant frequencies of the two operating modes. The coupling diaphragm can control the inter-cavity coupling between the first and second resonators.

[0046] Specifically, the metal blind vias include coupling probe metal blind vias and resonance control metal blind vias.

[0047] See Figures 1 to 3 There are two metal blind holes of the coupling probe, which are respectively arranged in the first resonator and the second resonator, for exciting the dual-mode resonator and connecting with the coaxial connector for testing.

[0048] Specifically, the coupling probe metal blind hole includes a first coupling probe metal blind hole 12 and a second coupling probe metal blind hole 13. The first coupling probe metal blind hole 12 and the second coupling probe metal blind hole 13 have the same height, and their positions are symmetrical about the center of the dielectric shell. The end face of the coupling probe metal blind hole is an input / output port, and its port is arranged in a ring shape, and the inner ring diameter Din and the outer ring diameter Dout of the ring satisfy the following formula: Dout = 2.3*Din, which is used to ensure 50Ω port matching. The outer surface of the dielectric shell is silver-plated except for the annular end face of the input and output ports to achieve surface metallization. Furthermore, the coupling probe metal blind hole is located at a distance of (0.64mm, 0.7mm) from the center of the resonator, and the height of the metal blind hole controls the strength of the input and output coupling. The first coupling probe metal blind hole 12 and the second coupling probe metal blind hole 13 can respectively excite the TE in the first resonator and the second resonator. 101mode, and couples it through the coupling diaphragm to achieve source-load coupling and obtain the full-scale filter design.

[0049] Specifically, there are eight resonance control metal blind holes, which are evenly distributed and set in the first resonator and the second resonator to control the TE 102 Mould and TE 201 The resonant frequency of the mode is tuned and controlled. The two metal blind holes in each resonator are loaded with TE 102 The strong electric field region of the mode, namely TE 201 The zero electric field region of the die; the other two metal blind holes are loaded on the TE 201 The strong electric field region of the mode, namely TE 102 The zero electric field region of the module.

[0050] See Figure 1 and Figure 3 The resonance control metal blind vias can be divided into a first metal blind via 1, a second metal blind via 2, a third metal blind via 3 and a fourth metal blind via 4 arranged in the first resonator, and a fifth metal blind via 5, a sixth metal blind via 6, a seventh metal blind via 7 and an eighth metal blind via 8 arranged in the second resonator.

[0051] The first metal blind hole 1, the second metal blind hole 2, the third metal blind hole 3 and the fourth metal blind hole 4 are evenly distributed in the second resonator in a diamond shape. The first metal blind hole 1 and the second metal blind hole 2 are arranged on both sides of the midline along the long side direction of the first resonator, which can 102 The resonant frequency of the mode is controlled so that its TE 102 The mode resonates at an operating frequency of about 3.5 GHz. The third metal blind hole 3 and the fourth metal blind hole 4 are provided on both sides of the midline along the width direction of the first resonator, and are used to 201 The resonant frequency of the mode is controlled so that its TE 201 The mode resonates at an operating frequency of approximately 3.5 GHz.

[0052] The fifth metal blind via 5, the sixth metal blind via 6, the seventh metal blind via 7 and the eighth metal blind via 8 are evenly distributed in the second resonator in a diamond shape. The fifth metal blind via 5 and the sixth metal blind via 6 are arranged on both sides of the midline along the long side direction of the second resonator to control the TE 102 The resonant frequency of the mode is controlled so that its TE 102 The mode resonates at an operating frequency of about 3.5 GHz. The seventh metal blind hole 7 and the eighth metal blind hole 8 are provided on both sides of the midline along the width direction of the second resonator to control the TE 201 The resonant frequency of the mode is controlled so that its TE 201 The mode resonates at an operating frequency of approximately 3.5 GHz.

[0053] The first metal blind via 1, the second metal blind via 2, the fifth metal blind via 5 and the sixth metal blind via 6 have the same height; the third metal blind via 3, the fourth metal blind via 4, the seventh metal blind via 7 and the eighth metal blind via 8 have the same height.

[0054] In this embodiment, the offset oy of the input and output ports relative to the resonator center controls the position of the transmission zero on the left side of the passband. Figure 2 and Figure 3 As shown, the geometric dimensions of the filter in this embodiment are as follows (unit: mm): ox = 0.7, oy = 0.64, Din = 1.7, Dout = 4, H1 = H2 = 1.8, H3 = H4 = 1.77, H12 = 6.15, L9 = L10 = 2, L11 = 4.76.

[0055] See Figures 1 to 3 The coupling diaphragm forms the space between the first and second resonators and consists of three sections: a first coupling section 9, a second coupling section 11, and a third coupling section 10. The length of each coupling section is parallel to the width of the dual-mode resonator: the first coupling section 9 is L9, the second coupling section 11 is L11, and the third coupling section 10 is L10. The first and third coupling sections 9, 10 are symmetrically arranged along the midline of the long side of the dual-mode resonator, making them of equal length. The second coupling section 11 is located between the first and third coupling sections 9, 10.

[0056] The direct coupling between the first resonator and the second resonator is controlled by changing the length of the second coupling section 11. The cross coupling between the first resonator and the second resonator is controlled by shifting the second coupling section 11 toward the first coupling section 9 or the second coupling section 11.

[0057] like Figure 4 As shown, in this embodiment, the rectangular dielectric block is entirely silver-plated except for the annular outer surface between Din and Dout at the port. During testing, the dielectric block is connected to a coaxial connector to feed the filter.

[0058] like Figure 5 As shown in the figure, when the input and output ports are offset from the y-axis, the transmission zero on the left moves toward the far end of the passband as the offset increases. Therefore, the transmission zero on the left moves from 3.36 GHz and 3.38 GHz to 3.33 GHz and 3.35 GHz.

[0059] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the scope of protection of the present invention.

Claims

1. A dielectric-filled high-selectivity waveguide filter, characterized in that: include: A dielectric shell with a silver-plated surface, and a plurality of metal blind holes, a dual-mode resonator, and a coupling diaphragm arranged in the dielectric shell; The coupling diaphragm is arranged along the wide side direction of the dielectric housing, and the coupling diaphragm divides the space inside the dielectric housing into a first resonator and a second resonator that are symmetrical in the left and right directions, and the first resonator and the second resonator constitute the dual-mode resonator; A plurality of the metal blind holes are evenly arranged in the first resonator and the second resonator; The metal blind hole is used to excite the dual-mode resonator or tune the resonant frequencies of the two working modes of the first resonator or the second resonator; the coupling diaphragm is used to control the inter-cavity coupling between the first resonator and the second resonator; The coupling diaphragm is a space connecting the first resonator and the second resonator, is parallel to the wide side direction of the dual-mode resonator, and includes a first coupling section, a second coupling section, and a third coupling section; The first coupling section and the third coupling section are symmetrically arranged along the midline of the long side direction of the dual-mode resonator; the second coupling section is located between the first coupling section and the third coupling section; The direct coupling between the first resonator and the second resonator is controlled by the length of the second coupling section, and the cross coupling between the first resonator and the second resonator is controlled by the offset of the second coupling section toward the first coupling section or the third coupling section.

2. The dielectric-filled high-selectivity waveguide filter according to claim 1, characterized in that: The metal blind holes include coupling probe metal blind holes and resonance control metal blind holes; There are two metal blind holes of the coupling probe, which are respectively arranged in the first resonator and the second resonator, for exciting the dual-mode resonator; There are eight resonance control metal blind holes, including a first metal blind hole, a second metal blind hole, a third metal blind hole and a fourth metal blind hole provided in the first resonator, and a fifth metal blind hole, a sixth metal blind hole, a seventh metal blind hole and an eighth metal blind hole provided in the second resonator; the first metal blind hole, the second metal blind hole, the third metal blind hole and the fourth metal blind hole are evenly distributed in a diamond shape in the first resonator; the fifth metal blind hole, the sixth metal blind hole, the seventh metal blind hole and the eighth metal blind hole are evenly distributed in a diamond shape in the second resonator, and are used to control the TE 102 Mould and TE 201 The resonant frequency of the mode is tuned and controlled.

3. The dielectric-filled high-selectivity waveguide filter according to claim 2, wherein: The coupling probe metal blind hole includes a first coupling probe metal blind hole and a second coupling probe metal blind hole. The first coupling probe metal blind hole and the second coupling probe metal blind hole have the same height and are symmetrically arranged about the center of the dielectric shell.

4. The dielectric-filled high-selectivity waveguide filter according to claim 3, characterized in that: The end face of the metal blind hole of the coupling probe is annular, and the inner ring diameter Din and the outer ring diameter Dout of the annular portion satisfy the following formula: Dout=2.3*Din; it is used to connect to a coaxial connector to feed the waveguide filter.

5. The dielectric-filled high-selectivity waveguide filter according to claim 4, characterized in that: The outer surface of the dielectric shell, except for the annular portion at the end surface of the metal blind hole of the coupling probe, is plated with silver to achieve metallization.

6. The dielectric-filled high-selectivity waveguide filter according to claim 3, wherein: The first metal blind hole and the second metal blind hole are provided on both sides of the midline along the long side direction of the first resonator, and are used to 102 The resonant frequency of the mode is controlled; The third metal blind hole and the fourth metal blind hole are provided on both sides of the midline along the width direction of the first resonator, and are used to 201 The resonant frequency of the mode is controlled; The fifth metal blind hole and the sixth metal blind hole are provided on both sides of the midline along the long side direction of the second resonator, and are used to control the TE 102 The resonant frequency of the mode is controlled; The seventh metal blind hole and the eighth metal blind hole are provided on both sides of the midline along the width direction of the second resonator, and are used to control the TE 201 The resonant frequency of the mode is controlled.

7. The dielectric-filled high-selectivity waveguide filter according to claim 6, characterized in that: The first metal blind via, the second metal blind via, the fifth metal blind via and the sixth metal blind via have the same height; The third metal blind via, the fourth metal blind via, the seventh metal blind via, and the eighth metal blind via have the same height.

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