阅读说明：本技术 高抑制高通滤波器 (High-suppression high-pass filter ) 是由 钱可伟 田忠 于 2020-07-27 设计创作，主要内容包括：本发明公开了一种高抑制高通滤波器,涉及微波通信技术领域,其包括设置有多层电路的滤波器主体,所述多层电路为无过孔的电路结构；所述多层电路包括输入等效电感、输出等效电感、第一等效电容、第二等效电容、第三等效电容、第四等效电容和第五等效电容、第一带状线支节谐振单元、第二带状线支节谐振单元、第三带状线支节谐振单元、第四带状线支节谐振单元和第五带状线支节谐振单元。本发明利用带状线支节谐振单元代替传统高通滤波器中的接地电感,可最大限度降低微带传输线在等效为集总元件时引入的寄生参数；多层电路采用无过孔叠层设计,不仅简化了工艺,有利于量产的稳定性和一致性,还能进一步降低过孔引入的寄生电感对电路Q值的影响。(The invention discloses a high-suppression high-pass filter, which relates to the technical field of microwave communication and comprises a filter main body provided with a multilayer circuit, wherein the multilayer circuit is of a circuit structure without a through hole; the multilayer circuit comprises an input equivalent inductor, an output equivalent inductor, a first equivalent capacitor, a second equivalent capacitor, a third equivalent capacitor, a fourth equivalent capacitor, a fifth equivalent capacitor, a first strip line branch node resonance unit, a second strip line branch node resonance unit, a third strip line branch node resonance unit, a fourth strip line branch node resonance unit and a fifth strip line branch node resonance unit. The invention uses the strip line branch node resonance unit to replace the grounding inductance in the traditional high-pass filter, and can reduce the parasitic parameters introduced when the microstrip transmission line is equivalent to a lumped element to the maximum extent; the multilayer circuit adopts a non-via laminated design, so that the process is simplified, the stability and consistency of mass production are facilitated, and the influence of parasitic inductance introduced by via holes on the Q value of the circuit can be further reduced.)

1. A high-suppression high-pass filter comprises a filter main body provided with a multilayer circuit, wherein the multilayer circuit comprises an input equivalent inductor, an output equivalent inductor, a first equivalent capacitor, a second equivalent capacitor, a third equivalent capacitor, a fourth equivalent capacitor and a fifth equivalent capacitor,

the multilayer circuit is a circuit structure without a via hole;

the multilayer circuit further comprises a first strip line branch resonance unit, a second strip line branch resonance unit, a third strip line branch resonance unit, a fourth strip line branch resonance unit and a fifth strip line branch resonance unit;

the second equivalent capacitor is cascaded between the first strip line branch node resonance unit and the second strip line branch node resonance unit; the third equivalent capacitor is cascaded between the second stripline stub resonance unit and the third stripline stub resonance unit; the fourth equivalent capacitor is cascaded between the third strip line stub resonance unit and the fourth strip line stub resonance unit; the fifth equivalent capacitor is cascaded between the fourth strip line stub resonance unit and the fifth strip line stub resonance unit.

2. The high rejection high pass filter according to claim 1, wherein said multilayer circuit comprises ten layers of circuits, wherein,

the input equivalent inductance is distributed on a second layer of the multilayer circuit;

the output equivalent inductance is distributed in a first layer of the multilayer circuit;

the first equivalent capacitance is distributed in a first layer and a second layer of the multilayer circuit;

the second equivalent capacitance is distributed on a sixth layer, a seventh layer and a ninth layer of the multilayer circuit;

the third equivalent capacitance is distributed in a third layer, a fourth layer and a fifth layer of the multilayer circuit;

the fourth equivalent capacitance is distributed on a seventh layer, an eighth layer and a ninth layer of the multilayer circuit;

the fifth equivalent capacitance is distributed in a third layer, a fifth layer and a sixth layer of the multilayer circuit;

the first strip line stub resonant units are distributed on a sixth layer and a ninth layer of the multilayer circuit;

the second strip line stub resonant units are distributed on a third layer, a sixth layer and a ninth layer of the multilayer circuit;

the third strip line stub resonance units are distributed on the fifth layer, the sixth layer and the seventh layer of the multilayer circuit;

the fourth strip line stub resonance units are distributed on a third layer, a sixth layer and a ninth layer of the multilayer circuit;

and the fifth strip line stub resonance units are distributed on the third layer and the sixth layer of the multilayer circuit.

3. The high-rejection high-pass filter according to claim 2,

the first equivalent capacitor comprises a first polar plate positioned on the second layer and a second polar plate positioned on the first layer, and the first polar plate and the second polar plate form the first equivalent capacitor through interlayer coupling;

the second equivalent capacitor comprises a third polar plate and an eighth polar plate which are positioned on the sixth layer, and a fourth polar plate and a ninth polar plate which are positioned on the seventh layer, and the third polar plate, the fourth polar plate, the eighth polar plate and the ninth polar plate are coupled through layers to form the second equivalent capacitor;

the third equivalent capacitor comprises a sixth polar plate positioned on the third layer, a seventh polar plate and an eleventh polar plate positioned on the fourth layer, and a twelfth polar plate positioned on the fifth layer, wherein the sixth polar plate, the seventh polar plate, the eleventh polar plate and the twelfth polar plate form the third equivalent capacitor through interlayer coupling;

the fourth equivalent capacitor comprises a fourteenth polar plate positioned on the seventh layer, a fifteenth polar plate and a nineteenth polar plate positioned on the eighth layer, and a twentieth polar plate positioned on the ninth layer, wherein the fourteenth polar plate, the fifteenth polar plate, the nineteenth polar plate and the twentieth polar plate form the fourth equivalent capacitor through interlayer coupling; and

the fifth equivalent capacitor comprises a seventeenth polar plate and a twenty-twelve polar plate which are positioned on the fifth layer, and an eighteenth polar plate and a twenty-third polar plate which are positioned on the sixth layer, wherein the seventeenth polar plate, the eighteenth polar plate, the twenty-twelve polar plate and the twenty-third polar plate form the fifth equivalent capacitor through interlayer coupling.

4. The high-rejection high-pass filter according to claim 2,

the first strip line stub resonance unit comprises a third polar plate positioned on the sixth layer and a fifth polar plate positioned on the ninth layer;

the second strip line stub resonance unit comprises a sixth polar plate positioned on the third layer, an eighth polar plate positioned on the sixth layer and a tenth polar plate positioned on the ninth layer;

the third strip line stub resonance unit comprises a twelfth polar plate positioned on the fifth layer, a thirteenth polar plate positioned on the sixth layer and a fourteenth polar plate positioned on the seventh layer;

the fourth strip line stub resonance unit comprises a sixteenth polar plate positioned on the third layer, an eighteenth polar plate positioned on the sixth layer and a twentieth polar plate positioned on the ninth layer; and

the fifth strip line stub resonance unit comprises a twenty-first polar plate positioned on the third layer and a twenty-third polar plate positioned on the sixth layer;

and the third polar plate, the fifth polar plate, the sixth polar plate, the eighth polar plate, the tenth polar plate, the twelfth polar plate, the thirteenth polar plate, the fourteenth polar plate, the sixteenth polar plate, the eighteenth polar plate, the twentieth polar plate, the twenty-first polar plate and the twenty-third polar plate are respectively connected with the ground through side external electrodes.

5. The high-pass filter with high rejection of claim 2, further comprising a ground plate disposed on the tenth layer of said multilayer circuit and connected to ground through a side external electrode.

6. The high-rejection high-pass filter according to claim 2,

the thickness from the first layer circuit to the top layer of the filter body is 120 um;

the thickness from the second layer circuit to the first layer circuit is 60 um;

the thickness from the third layer circuit to the second layer circuit is 180 um;

the thickness from the fourth layer circuit to the third layer circuit is 60 um;

the thickness from the fifth layer circuit to the fourth layer circuit is 60 um;

the thickness of the sixth layer circuit to the fifth layer circuit is 60 um;

the thickness of the seventh layer circuit to the sixth layer circuit is 60 um;

the thickness of the eighth layer circuit to the seventh layer circuit is 60 um;

the thickness of the ninth layer circuit to the eighth layer circuit is 60 um;

the thickness of the tenth layer circuit to the ninth layer circuit is 150 um; and

the thickness of the filter body bottom layer to the tenth layer circuit is 120 um.

7. The high-rejection high-pass filter according to claim 1, wherein said multilayer circuit is fabricated based on a low temperature co-fired ceramic process.

8. The high-rejection high-pass filter according to claim 7, wherein the embedded metal material used in said multilayer circuit is palladium silver.

9. The high-rejection high-pass filter according to claim 7, wherein the substrate material of said multilayer circuit has a dielectric constant of 9.8.

10. The high-rejection high-pass filter according to claim 7, wherein the substrate material of said multilayer circuit has a dielectric loss tangent angle of 0.004.

Technical Field

The invention relates to the technical field of microwave communication, in particular to a high-rejection high-pass filter.

Background

In microwave and millimeter wave systems such as communication and radar, filters have been one of the most important devices. The method plays a key role in screening and extracting useful signals for a wireless communication system and improving the signal quality. Therefore, the performance of the filter directly affects the communication quality of the entire wireless communication system. The high-pass filter is one of microwave filters, and has the function of allowing high-frequency signals to pass through and attenuating low-frequency signals to be cut off. A high-pass filter with excellent performance has larger out-of-band attenuation, lower insertion loss and smaller return loss. Achieving higher out-of-band rejection is generally achieved by increasing the number of filter stages, but this introduces more insertion loss and increases the difficulty of impedance matching, and the increase of the number of stages is not only detrimental to the miniaturization of the size, but also increases the complexity of the design and the processing cost.

In recent years, the emergence of new materials and process technologies such as Micro Electro Mechanical Systems (MEMS) technology, high temperature superconducting technology, low temperature co-fired ceramic (LTCC) technology, photonic band gap structure, microwave monolithic integrated circuit, etc. has promoted the continuous improvement of the filter from performance to volume. With the continuous development of wireless communication systems and microwave millimeter wave components, smaller size, lighter weight, lower cost, and higher performance have become inevitable trends and requirements for the development of modern high-pass filters.

The high-pass filter prepared by the traditional LTCC technology is composed of lumped elements, and connection between different circuit layers is realized by utilizing via holes, so that large parasitic capacitance and inductance exist, the electrical property is poor, the preparation process structure is complex, the process stability and consistency are difficult to guarantee, and the high-pass filter is not beneficial to mass production. In addition, the introduction of these parasitic parameters can also deteriorate the Q value of the filter circuit, resulting in large insertion loss and low out-of-band rejection level.

Disclosure of Invention

The present invention aims to provide a high-rejection high-pass filter which alleviates the above problems.

In order to alleviate the above problems, the technical scheme adopted by the invention is as follows:

a high-suppression high-pass filter comprises a filter main body provided with a multilayer circuit, wherein the multilayer circuit comprises an input equivalent inductor, an output equivalent inductor, a first equivalent capacitor, a second equivalent capacitor, a third equivalent capacitor, a fourth equivalent capacitor and a fifth equivalent capacitor; the multilayer circuit is a circuit structure without a via hole; the multilayer circuit further comprises a first strip line branch resonance unit, a second strip line branch resonance unit, a third strip line branch resonance unit, a fourth strip line branch resonance unit and a fifth strip line branch resonance unit; the second equivalent capacitor is cascaded between the first strip line branch node resonance unit and the second strip line branch node resonance unit; the third equivalent capacitor is cascaded between the second stripline stub resonance unit and the third stripline stub resonance unit; the fourth equivalent capacitor is cascaded between the third strip line stub resonance unit and the fourth strip line stub resonance unit; the fifth equivalent capacitor is cascaded between the fourth strip line stub resonance unit and the fifth strip line stub resonance unit.

Optionally, the multi-layer circuit comprises ten layers of circuits, wherein the input equivalent inductance is distributed in a second layer of the multi-layer circuit; the output equivalent inductance is distributed in a first layer of the multilayer circuit; the first equivalent capacitance is distributed in a first layer and a second layer of the multilayer circuit; the second equivalent capacitance is distributed on a sixth layer, a seventh layer and a ninth layer of the multilayer circuit; the third equivalent capacitance is distributed in a third layer, a fourth layer and a fifth layer of the multilayer circuit; the fourth equivalent capacitance is distributed on a seventh layer, an eighth layer and a ninth layer of the multilayer circuit; the fifth equivalent capacitance is distributed in a third layer, a fifth layer and a sixth layer of the multilayer circuit; the first strip line stub resonant units are distributed on a sixth layer and a ninth layer of the multilayer circuit; the second strip line stub resonant units are distributed on a third layer, a sixth layer and a ninth layer of the multilayer circuit; the third strip line stub resonance units are distributed on the fifth layer, the sixth layer and the seventh layer of the multilayer circuit; the fourth strip line stub resonance units are distributed on a third layer, a sixth layer and a ninth layer of the multilayer circuit; and the fifth strip line stub resonance units are distributed on the third layer and the sixth layer of the multilayer circuit.

Optionally, the first equivalent capacitor includes a first plate located in the second layer and a second plate located in the first layer, and the first plate and the second plate form the first equivalent capacitor through interlayer coupling; the second equivalent capacitor comprises a third polar plate and an eighth polar plate which are positioned on the sixth layer, and a fourth polar plate and a ninth polar plate which are positioned on the seventh layer, and the third polar plate, the fourth polar plate, the eighth polar plate and the ninth polar plate are coupled through layers to form the second equivalent capacitor; the third equivalent capacitor comprises a sixth polar plate positioned on the third layer, a seventh polar plate and an eleventh polar plate positioned on the fourth layer, and a twelfth polar plate positioned on the fifth layer, wherein the sixth polar plate, the seventh polar plate, the eleventh polar plate and the twelfth polar plate form the third equivalent capacitor through interlayer coupling; the fourth equivalent capacitor comprises a fourteenth polar plate positioned on the seventh layer, a fifteenth polar plate and a nineteenth polar plate positioned on the eighth layer, and a twentieth polar plate positioned on the ninth layer, wherein the fourteenth polar plate, the fifteenth polar plate, the nineteenth polar plate and the twentieth polar plate form the fourth equivalent capacitor through interlayer coupling; and the fifth equivalent capacitor comprises a seventeenth polar plate and a twenty-twelfth polar plate which are positioned on the fifth layer, and an eighteenth polar plate and a twenty-third polar plate which are positioned on the sixth layer, wherein the seventeenth polar plate, the eighteenth polar plate, the twenty-twelfth polar plate and the twenty-third polar plate form the fifth equivalent capacitor through interlayer coupling.

Optionally, the first stripline stub resonant unit comprises a third plate located on the sixth layer and a fifth plate located on the ninth layer; the second strip line stub resonance unit comprises a sixth polar plate positioned on the third layer, an eighth polar plate positioned on the sixth layer and a tenth polar plate positioned on the ninth layer; the third strip line stub resonance unit comprises a twelfth polar plate positioned on the fifth layer, a thirteenth polar plate positioned on the sixth layer and a fourteenth polar plate positioned on the seventh layer; the fourth strip line stub resonance unit comprises a sixteenth polar plate positioned on the third layer, an eighteenth polar plate positioned on the sixth layer and a twentieth polar plate positioned on the ninth layer; the fifth strip line stub resonance unit comprises a twenty-first polar plate positioned on the third layer and a twenty-third polar plate positioned on the sixth layer; and the third polar plate, the fifth polar plate, the sixth polar plate, the eighth polar plate, the tenth polar plate, the twelfth polar plate, the thirteenth polar plate, the fourteenth polar plate, the sixteenth polar plate, the eighteenth polar plate, the twentieth polar plate, the twenty-first polar plate and the twenty-third polar plate are respectively connected with the ground through side external electrodes.

Optionally, the filter further comprises a ground plate disposed on the tenth layer of the multilayer circuit and connected to ground through a side external electrode.

Optionally, the thickness of the first layer of circuitry to the top layer of the filter body is 120 um; the thickness from the second layer circuit to the first layer circuit is 60 um; the thickness from the third layer circuit to the second layer circuit is 180 um; the thickness from the fourth layer circuit to the third layer circuit is 60 um; the thickness from the fifth layer circuit to the fourth layer circuit is 60 um; the thickness of the sixth layer circuit to the fifth layer circuit is 60 um; the thickness of the seventh layer circuit to the sixth layer circuit is 60 um; the thickness of the eighth layer circuit to the seventh layer circuit is 60 um; the thickness of the ninth layer circuit to the eighth layer circuit is 60 um; the thickness of the tenth layer circuit to the ninth layer circuit is 150 um; and the thickness of the filter body bottom layer to the tenth layer circuit is 120 um.

Optionally, the multilayer circuit is manufactured based on a low temperature co-fired ceramic process.

Optionally, the embedded metal material adopted by the multilayer circuit is palladium silver.

Optionally, the substrate material of the multilayer circuit has a dielectric constant of 9.8.

Optionally, the substrate material of the multilayer circuit has a dielectric loss tangent angle of 0.004.

Compared with the prior art, the invention has the beneficial effects that:

1) two equivalent inductors, five equivalent capacitors and five groups of strip line branch node resonance units are integrated on ten conductor layers of the multilayer circuit, so that the transmission and suppression characteristics of the fifth-order high-pass filter are realized;

2) the strip line branch node resonance unit is used for replacing a grounding inductor in the traditional high-pass filter, so that parasitic parameters introduced when the microstrip transmission line is equivalent to a lumped element can be reduced to the maximum extent, and the quality factor of the whole circuit is improved;

3) the multilayer circuit of the whole filter adopts a non-via laminated design, so that the process is simplified, the stability and consistency of mass production are facilitated, and the influence of parasitic inductance introduced by via holes on the Q value of the circuit can be further reduced;

4) the filter has compact structure and good repeatability by adopting the low-temperature co-fired ceramic technology, and is suitable for wireless communication terminals and radio frequency front ends with strict requirements on volume, such as mobile phones, data cards and the like. Meanwhile, a vertical coupling mode is used, so that a large capacitance value can be realized in a small volume;

5) the insertion loss is small;

6) the high suppression degree, the filter can realize the out-of-band suppression of up to 30dB at the stop band which is very close to each other, can effectively filter various low-frequency noises and stray signals, and is favorable for reducing the interference among various communication channels.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic external view of a high-pass filter according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of an internal structure of a high-pass filter according to an embodiment of the present invention.

Fig. 3 is an equivalent schematic diagram of a high pass filter of an embodiment of the invention.

FIG. 4 is a first layer circuit diagram of a high pass filter according to an embodiment of the invention.

Fig. 5 is a schematic diagram of a second layer circuit of the high-pass filter according to the embodiment of the invention.

FIG. 6 is a third circuit diagram of the high pass filter according to the embodiment of the invention.

FIG. 7 is a fourth layer circuit diagram of the high pass filter according to the embodiment of the invention.

Fig. 8 is a fifth layer circuit diagram of the high pass filter according to the embodiment of the invention.

Fig. 9 is a sixth layer circuit diagram of the high pass filter according to the embodiment of the invention.

Fig. 10 is a seventh layer circuit diagram of the high pass filter according to the embodiment of the invention.

Fig. 11 is a circuit diagram of an eighth layer of the high pass filter according to the embodiment of the invention.

Fig. 12 is a ninth layer circuit diagram of the high pass filter according to the embodiment of the invention.

Fig. 13 is a circuit diagram of the tenth layer of the high-pass filter according to the embodiment of the invention.

Fig. 14 is a schematic frequency response characteristic graph of a high pass filter of an embodiment of the present invention.

Description of reference numerals:

1-input equivalent inductance; 2-output equivalent inductance; 3-a first polar plate; 4-a second polar plate; 5-a third polar plate; 6-a fourth polar plate; 7-a fifth polar plate; 8-a sixth polar plate; 9-a seventh polar plate; 10-an eighth polar plate; 11-a ninth polar plate; 12-tenth plate; 13-eleventh plate; 14-twelfth polar plate; 15-a thirteenth polar plate; 16-a fourteenth plate; 17-a fifteenth plate; 18-sixteenth polar plate; 19-a seventeenth plate; 20-eighteenth polar plate; 21-nineteenth plate; 22-twentieth plate; 23-the twenty-first plate; 24-a second twelve pole plate; 25-the twenty-third polar plate; 26-ground plate.

Detailed Description

In order to make the objects, 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 with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, the high-pass filter with high rejection according to the embodiment of the present invention includes a filter main body a and four external electrodes, where the four external electrodes are an input external electrode B, an output external electrode C, and two side external electrodes D, respectively, the filter main body a is an LTCC ceramic substrate, and an identifier E on the top of the filter is used to identify the input/output end direction of the filter. The multilayer circuit of the filter is built in a filter body A of 2.5mm 2.0mm 1.0mm, which is based on a low temperature co-fired ceramic (LTCC) process and is sintered at a temperature of 870 ℃. + -. 10 ℃. By the process, all passive devices of the multilayer circuit are buried in the ceramic medium, integration of various equivalent elements on the three-dimensional circuit substrate is realized, and miniaturization and high density of the circuit are realized.

In this embodiment, a high-conductivity metal material, such as silver or copper, may be used as the conductor material, which is beneficial to improve the quality factor of the circuit system. For example, palladium silver can be used as the embedded metal material, and the embedded metal material is not oxidized in the sintering process and can not need electroplating protection. The dielectric constant of the LTCC material can be changed in a large range, the length of the resonant unit is inversely proportional to the square root of the dielectric constant of the LTCC material, in order to meet the requirements of high frequency and high speed, the dielectric constant of the ceramic substrate material can be 9.8, and the dielectric loss tangent angle is 0.004.

Referring to fig. 2, 4-13, the multi-layer circuit includes ten layers of circuits, which are respectively a first layer, a second layer, a third layer, a fourth layer, a fifth layer, a sixth layer, a seventh layer, an eighth layer, a ninth layer, and a tenth layer, and the connection between the circuit layers is realized by interlayer coupling and external electrodes, so that the parasitic effect caused by using via holes is avoided, and the process flow is simplified.

The multilayer circuit comprises an input equivalent inductor 1, an output equivalent inductor 2, five equivalent capacitors and five strip line branch node resonance units.

The input equivalent inductor 1 is distributed on the second layer of the multilayer circuit; the output equivalent inductor 2 is distributed on the first layer of the multilayer circuit; the first equivalent capacitor comprises a first polar plate 3 positioned on the second layer and a second polar plate 4 positioned on the first layer, and the first polar plate 3 and the second polar plate 4 form the first equivalent capacitor through interlayer coupling; the second equivalent capacitor comprises a third polar plate 5 and an eighth polar plate 10 which are positioned on the sixth layer and a fourth polar plate 6 and a ninth polar plate 11 which are positioned on the seventh layer, and the third polar plate 5, the fourth polar plate 6, the eighth polar plate 10 and the ninth polar plate 11 form the second equivalent capacitor through interlayer coupling; the third equivalent capacitor comprises a sixth polar plate 8 positioned on the third layer, a seventh polar plate 9 and an eleventh polar plate 13 positioned on the fourth layer, and a twelfth polar plate 14 positioned on the fifth layer, wherein the sixth polar plate 8, the seventh polar plate 9, the eleventh polar plate 13 and the twelfth polar plate 14 form the third equivalent capacitor through interlayer coupling; the fourth equivalent capacitor comprises a fourteenth polar plate 16 positioned on the seventh layer, a fifteenth polar plate 17 and a nineteenth polar plate 21 positioned on the eighth layer, and a twentieth polar plate 22 positioned on the ninth layer, wherein the fourteenth polar plate 16, the fifteenth polar plate 17, the nineteenth polar plate 21 and the twentieth polar plate 22 form the fourth equivalent capacitor through interlayer coupling; and the fifth equivalent capacitor comprises a seventeenth polar plate 19 and a twentieth polar plate 24 which are positioned at the fifth layer, and an eighteenth polar plate 20 and a twenty-third polar plate 25 which are positioned at the sixth layer, wherein the seventeenth polar plate 19, the eighteenth polar plate 20, the twentieth polar plate 24 and the twenty-third polar plate 25 form the fifth equivalent capacitor through interlayer coupling.

The first strip line stub resonance unit comprises a third polar plate 5 positioned on a sixth layer and a fifth polar plate 7 positioned on a ninth layer; the second strip line stub resonance unit comprises a sixth polar plate 8 positioned on the third layer, an eighth polar plate 10 positioned on the sixth layer and a tenth polar plate 12 positioned on the ninth layer; the third strip line stub resonance unit comprises a twelfth polar plate 14 positioned at the fifth layer, a thirteenth polar plate 15 positioned at the sixth layer and a fourteenth polar plate 16 positioned at the seventh layer; the fourth strip line stub resonance unit comprises a sixteenth polar plate 18 positioned on the third layer, an eighteenth polar plate 20 positioned on the sixth layer and a twentieth polar plate 22 positioned on the ninth layer; and the fifth stripline stub resonant unit includes a twenty-first plate 23 at the third layer and a twenty-third plate 25 at the sixth layer.

In this embodiment, the first terminal of the input equivalent inductor 1 is connected to the input external electrode B, and the second terminal is connected to the first electrode plate 3. The first end of the output equivalent inductor 2 is connected with the output outer electrode C, and the second end is connected with the second plate 4. The first end of the third polar plate 5 is open-circuit, the second end is grounded through the external electrode, and a small segment of microstrip lead-out wire is arranged in the middle of the two ends and connected with the input external electrode. The eighth electrode plate 10 has a first end open and a second end grounded through an external electrode. The fourth plate 6 and the ninth plate 11 are connected by a small segment of microstrip line. The sixth electrode plate 8 has a first end open and a second end grounded through the external electrode. The seventh plate 9 and the eleventh plate 13 are connected by a small length of microstrip line. The twelfth pole plate 14 has a first end open and a second end grounded through the external electrode. The fourteenth electrode plate 16 has a first end open and a second end grounded through the external electrode. The fifteenth plate 17 and the nineteenth plate 21 are connected by a small length of microstrip line. The twentieth plate 22 has a first end open and a second end grounded through the external electrode. The seventeenth plate 19 and the twelfth plate 24 are connected by a small length of microstrip line. The eighteenth polar plate 20 is open at a first end and grounded at a second end through an external electrode. The first end of the twenty-third polar plate 25 is open-circuit, the second end is grounded through the external electrode, and a small segment of microstrip lead-out wire is arranged in the middle of the two ends and connected with the output external electrode.

In this embodiment, the third electrode plate 5 and the fifth electrode plate 7 have the same length and width, and are both open at one end and grounded at the other end through the external electrode, and the two electrode plates are connected in parallel to form the first strip line stub resonant unit. After the two inductors with the same inductance value are connected in parallel, the total inductance value is half of the original single inductance value, so that after the third polar plate 5 and the fifth polar plate 7 are connected in parallel, the total parasitic inductance can be greatly reduced, the circuit Q value of the first strip line stub resonance unit is improved, and the performance of the filter is further optimized. Similarly, the sixth polar plate 8, the eighth polar plate 10 and the tenth polar plate 12 have the same length and width, and are open at one end and grounded at the other end through an external electrode, and the three polar plates form a second strip line stub resonant unit together in a parallel connection manner; the twelfth polar plate 14, the thirteenth polar plate 15 and the fourteenth polar plate 16 have the same length and width, one end of each polar plate is open, the other end of each polar plate is grounded through an external electrode, and the three polar plates form a third strip line branched resonant unit together in a parallel connection mode; the sixteenth polar plate 18, the eighteenth polar plate 20 and the twentieth polar plate 22 are the same in length and width, one ends of the sixteenth polar plate, the eighteenth polar plate and the twentieth polar plate are open, the other ends of the sixteenth polar plate, the eighteenth polar plate and the twentieth polar plate are grounded through an external electrode, and the sixteenth polar plate, the eighteenth polar plate and the twentieth polar plate form a fourth strip; the twenty-first polar plate 23 and the twenty-third polar plate 25 have the same length and width, and one end of each of the twenty-first polar plate and the twenty-third polar plate is open-circuited, and the other end of each of the twenty-third polar plate and the twenty-third polar plate is grounded through an external electrode.

In this embodiment, the thickness from the first layer circuit to the top layer of the filter body is 120 um; the thickness from the second layer circuit to the first layer circuit is 60 um; the thickness from the third layer circuit to the second layer circuit is 180 um; the thickness from the fourth layer circuit to the third layer circuit is 60 um; the thickness from the fifth layer circuit to the fourth layer circuit is 60 um; the thickness from the sixth layer circuit to the fifth layer circuit is 60 um; the thickness from the seventh layer circuit to the sixth layer circuit is 60 um; the thickness of the eighth layer circuit to the seventh layer circuit is 60 um; the thickness from the ninth layer circuit to the eighth layer circuit is 60 um; the thickness of the tenth layer circuit to the ninth layer circuit is 150 um; and the thickness of the filter body bottom layer to the tenth layer circuit is 120 um.

In the present embodiment, the tenth layer of the multilayer circuit is provided with a ground plate 26, which is connected to the ground through a side external electrode, and the coupling capacitance values of the fifth plate 7, the tenth plate 12 and the twentieth plate 22 in the ninth layer to the ground layer can be changed by changing the area of the ground plate 26. Since the distance between the ninth layer and the tenth layer is large and the coupling is weak, these coupling capacitance values are low, and therefore, they are not identified in the equivalent schematic diagram of fig. 3 and are only used for fine tuning the position of the transmission frequency point of the filter and the out-of-band rejection depth.

Referring to fig. 3, in the equivalent circuit of the filter of the present embodiment, a first equivalent capacitor C1 is cascaded between an input equivalent inductor L1 and an output equivalent inductor L2, and a second equivalent capacitor C2, a third equivalent capacitor C3, a fourth equivalent capacitor C4, and a fifth equivalent capacitor C5 are cascaded between the input end and the output end in sequence. One end of the first stripline stub resonant cell U1 is connected between the input terminal and the second equivalent capacitor C2, and the other end is grounded. One end of the second stripline stub resonant unit U2 is connected between the second equivalent capacitor C2 and the third equivalent capacitor C3, and the other end is grounded. One end of the third stripline stub resonant unit U3 is connected between the third equivalent capacitor C3 and the fourth equivalent capacitor C4, and the other end is grounded. One end of the fourth stripline stub resonant unit U4 is connected between the fourth equivalent capacitor C4 and the fifth equivalent capacitor C5, and the other end is grounded. One end of the fifth stripline stub resonant unit U5 is connected between the fifth equivalent capacitor C5 and the output terminal, and the other end is grounded.

Fig. 14 is a schematic frequency response characteristic graph of a high pass filter in an embodiment of the invention. As can be seen, the insertion loss of the high-pass filter in the 5.15-5.95GHz frequency band is 1.5dB, the return loss is better than 20dB, and the whole Wi-Fi 5G working frequency band is effectively covered. Meanwhile, the out-of-band rejection of nearly 50dB can be realized at low-frequency DC-4 GHz, and the out-of-band rejection of up to 35dB can be realized at 4.9GHz which is only 5% of the relative bandwidth away from the passband, so that the excellent near-end rejection performance of the filter is embodied.

In summary, the present invention provides a high-rejection high-pass filter based on multilevel interconnection technology. The high-Q-value high-power-factor band-pass filter has the excellent performances of high Q value, small volume, low insertion loss, high out-of-band rejection and the like. Meanwhile, the manufacturing process flow is relatively simple, the mass production stability and consistency are high, the circuit module is easy to integrate with other circuit modules, and the circuit module has wide application prospect in the field of new generation wireless communication.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.