CN211089617U

CN211089617U - Band-pass filter

Info

Publication number: CN211089617U
Application number: CN202020091292.5U
Authority: CN
Inventors: 林亚梅; 肖倩; 黎燕林; 王东; 王志华; 朱建华; 邓兵
Original assignee: Guizhou Zhenhua Electronic Information Industry Technology Research Institute Co ltd; Shenzhen Zhenhua Ferrite and Ceramic Electronics Co Ltd
Current assignee: Guizhou Zhenhua Electronic Information Industry Technology Research Institute Co ltd; Shenzhen Zhenhua Ferrite and Ceramic Electronics Co Ltd
Priority date: 2020-01-15
Filing date: 2020-01-15
Publication date: 2020-07-24
Anticipated expiration: 2030-01-15

Abstract

A band-pass filter is characterized in that a first resonant circuit, a second resonant circuit, a third resonant circuit, a fourth resonant circuit, a fifth resonant circuit and a sixth resonant circuit are added, so that the attenuation of the band-pass filter is improved, the resonant circuits are connected together in an inductive coupling and capacitive coupling relationship, the inductive coupling resonant circuits are respectively arranged on a first plane of a base body and a second plane parallel to the first plane, and the capacitive coupling resonant circuits are jointly arranged on the first plane or the second plane of the base body, so that the occupied volume of the band-pass filter is reduced, namely the band-pass filter solves the problems of large occupied volume and insufficient attenuation in a stop band in the traditional technical scheme.

Description

Band-pass filter

Technical Field

The invention belongs to the technical field of filters, and particularly relates to a band-pass filter.

Background

At present, the conventional band-pass filter occupies a large volume and generally has only 4 electrically connected resonators, so that it is often difficult to suppress spurious frequencies near the pass band due to insufficient attenuation in the stop band.

Therefore, the traditional technical scheme has the problems of large occupied volume and insufficient attenuation in the stop band.

Disclosure of Invention

In view of this, the embodiment of the present invention provides a band-pass filter, which aims to solve the problems of large occupied volume and insufficient attenuation in a stop band in the conventional technical scheme.

A first aspect of an embodiment of the present invention provides a band-pass filter, including: the inner electrode comprises a first resonant circuit, a second resonant circuit, a third resonant circuit, a fourth resonant circuit, a fifth resonant circuit and a sixth resonant circuit, the first resonant circuit, the second resonant circuit, the fifth resonant circuit and the sixth resonant circuit are arranged in parallel on a first plane of the base body, the third resonant circuit and the fourth resonant circuit are arranged on a second plane of the base body, the first plane of the base body is parallel and opposite to the second plane of the base body, the first resonant circuit is connected with the input end electrode, and the sixth resonant circuit is connected with the output end electrode.

In one embodiment, the first resonant circuit comprises a first capacitor and a first inductor, the second resonant circuit comprises a second capacitor and a second inductor, the third resonant circuit comprises a third capacitor and a third inductor, the fourth resonant circuit comprises a fourth capacitor and a fourth inductor, the fifth resonant circuit comprises a fifth capacitor and a fifth inductor, the sixth resonant circuit comprises a sixth capacitor and a sixth inductor, the second resonant circuit and the third resonant circuit are coupled through the second inductor and the third inductor, and the fourth resonant circuit and the fifth resonant circuit are coupled through the fourth inductor and the fifth inductor.

In one embodiment, the first inductor and the first capacitor are placed in parallel or the first capacitor is placed on the first inductor, the second inductor and the second capacitor are placed in parallel or the second capacitor is placed on the second inductor, the third inductor and the third capacitor are placed in parallel or the third capacitor is placed on the third inductor, the fourth inductor and the fourth capacitor are placed in parallel or the fourth capacitor is placed on the fourth inductor, the fifth inductor and the fifth capacitor are placed in parallel or the fifth capacitor is placed on the fifth inductor, and the sixth inductor and the sixth capacitor are placed in parallel or the sixth capacitor is placed on the sixth inductor.

In one embodiment, the inner electrode further comprises: the first resonant circuit and the second resonant circuit are coupled through the seventh capacitor, the third resonant circuit and the fourth resonant circuit are coupled through the eighth capacitor, and the fifth resonant circuit and the sixth resonant circuit are coupled through the ninth capacitor.

In one embodiment, the method comprises the following steps:

the first resonant circuit and the sixth resonant circuit are mirror symmetric, the second resonant circuit and the fifth resonant circuit are mirror symmetric, and the third resonant circuit and the fourth resonant circuit are mirror symmetric.

In one embodiment, the second resonant circuit and the third resonant circuit are diametrically opposed; the fourth resonant circuit and the fifth resonant circuit are diametrically opposed.

In one embodiment, the distance between the second resonant circuit and the third resonant circuit is adjustable, and the distance between the fourth resonant circuit and the fifth resonant circuit is adjustable.

In one embodiment, the second resonant circuit and the fifth resonant circuit are disposed adjacent in a parallel row, and the second resonant circuit and the fifth resonant circuit form a cross-coupling therebetween and generate an out-of-band zero.

In one embodiment, the substrate is a low-loss low-temperature co-fired ceramic dielectric with a relative dielectric constant of 10-40 and a dielectric loss tan α ≦ 0.001.

In one embodiment, the input terminal electrode and the output terminal electrode include a silver layer, a nickel layer, and a tin layer, respectively.

According to the band-pass filter, the first resonant circuit, the second resonant circuit, the third resonant circuit, the fourth resonant circuit, the fifth resonant circuit and the sixth resonant circuit are added, so that the attenuation of the band-pass filter is improved, the resonant circuits are connected together in an inductive coupling and capacitive coupling relationship, the inductive coupling resonant circuits are respectively arranged on the first plane of the base body and the second plane parallel to the first plane, and the capacitive coupling resonant circuits are jointly arranged on the first plane or the second plane of the base body, so that the occupied volume of the band-pass filter is reduced, namely the band-pass filter solves the problems of large occupied volume and insufficient attenuation in a stop band in the traditional technical scheme.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic structural diagram of a bandpass filter circuit according to an embodiment of the invention;

FIG. 2 is an exemplary circuit schematic of the bandpass filter circuit shown in FIG. 1;

fig. 3 is an exemplary circuit schematic of the bandpass filter circuit shown in fig. 2.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, a schematic structural diagram of a bandpass filter according to an embodiment of the present invention only shows portions related to the embodiment for convenience of description, and the details are as follows:

the band pass filter in this embodiment includes: the internal electrode 30 comprises a first resonant circuit 100, a second resonant circuit 200, a third resonant circuit 300, a fourth resonant circuit 400, a fifth resonant circuit 500 and a sixth resonant circuit 600, the first resonant circuit 100, the second resonant circuit 200, the fifth resonant circuit 500 and the sixth resonant circuit 600 are arranged in a parallel manner on a first plane 11 of the substrate 10, the third resonant circuit 300 and the fourth resonant circuit 400 are arranged on a second plane 12 of the substrate 10, the first plane 11 of the substrate 10 and the second plane 12 of the substrate 10 are in parallel and opposite, the first resonant circuit 100 is connected with the input end electrode 21, and the sixth resonant circuit 600 is connected with the output end electrode 22.

Alternatively, the capacitive coupling may be implemented by connecting one or more coupling capacitors between the two resonant circuits, and the inductive coupling may be implemented by adding an inductor to each of the two resonant circuits or by using an inductor in the resonant circuit itself.

It should be understood that the structure of the band pass filter in this embodiment can be realized by adopting L TCC (L ow-temperature Co-fired Ceramic) laminated structure, and it should be understood that the size of the band pass filter in this embodiment can be 4.8mm × 2.5.5 mm × 1.5.5 mm.

It should be understood that the input terminal electrode 21 is used for inputting a signal, the output terminal electrode 22 is used for outputting a filtered signal, and a plurality of ground terminal electrodes may be further included, each of which is respectively connected to each of the resonant circuits, and each of which is used for grounding.

In the bandpass filter of the embodiment, the first resonant circuit 100, the second resonant circuit 200, the third resonant circuit 300, the fourth resonant circuit 400, the fifth resonant circuit 500, and the sixth resonant circuit 600 are added, so that the attenuation of the bandpass filter is improved, the resonant circuits are connected together in two coupling relationships of inductive coupling and capacitive coupling, the inductive coupling resonant circuits are respectively arranged on the first plane 11 of the substrate 10 and the second plane 12 parallel to the first plane 11, and the two capacitive coupling resonant circuits are jointly arranged on the first plane 11 or the second plane 12 of the substrate 10, so that the volume occupied by the bandpass filter is reduced, that is, the bandpass filter of the present application solves the problems of large occupied volume and insufficient attenuation in the stop band in the conventional technical scheme.

Referring to fig. 2, in an embodiment, the first resonant circuit 100 includes a first capacitor C1 and a first inductor L1, the second resonant circuit 200 includes a second capacitor C2 and a second inductor L2, the third resonant circuit 300 includes a third capacitor C3 and a third inductor L3, the fourth resonant circuit 400 includes a fourth capacitor C4 and a fourth inductor L4, the fifth resonant circuit 500 includes a fifth capacitor C5 and a fifth inductor L5, the sixth resonant circuit 600 includes a sixth capacitor C6 and a sixth inductor L6, the second resonant circuit 200 and the third resonant circuit 300 are coupled to each other through the second inductor L2 and the third inductor L3, and the fourth resonant circuit 400 and the fifth resonant circuit 500 are coupled to each other through the fourth inductor L4 and the fifth inductor L5.

It should be understood that the capacitances of the resonant units are different in size, that is, the capacitance values of the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5 and the sixth capacitor C6 are different in size, so that the parasitic passband of the band-pass filter is eliminated, and the target frequency doubling inner-far-end rejection is further achieved.

In one embodiment, the first inductor L1 and the first capacitor C1 are placed in parallel or the first capacitor C1 is placed on the first inductor L1, the second inductor L02 and the second capacitor C2 are placed in parallel or the second capacitor C2 is placed on the second inductor L12, the third inductor L3 and the third capacitor C3 are placed in parallel or the third capacitor C3 is placed on the third inductor L3, the fourth inductor L4 and the fourth capacitor C4 are placed in parallel or the fourth capacitor C4 is placed on the fourth inductor L4, the fifth inductor L5 and the fifth capacitor C5 are placed in parallel or the fifth capacitor C5 is placed on the fifth inductor L5, and the sixth inductor L6 and the sixth capacitor C6 are placed in parallel or the sixth capacitor C6 is placed on the sixth inductor L6.

When the inductances and capacitances of the resonant units are connected through the vertical via holes, that is, the first inductance L1 and the first capacitance C1 are connected through the vertical via holes, the second inductance L2 and the second capacitance C2 are connected through the vertical via holes, the third inductance L3 and the third capacitance C3 are connected through the vertical via holes, the fourth inductance L4 and the fourth capacitance C4 are connected through the vertical via holes, the fifth inductance L5 and the fifth capacitance C5 are connected through the vertical via holes, the sixth inductance L6 and the sixth capacitance C6 are connected through the vertical via holes, and the inductances and capacitances in the resonant units are connected through the vertical via holes, so that the capacitances and the inductances are isolated from each other, and thus parasitic effects are avoided.

It should be understood that when the capacitor of each resonant circuit is disposed on the inductor, the capacitor may be built directly above or directly below the inductor, for example, the first capacitor C1 may be built directly above or directly below the first inductor L1.

Referring to fig. 3, in one embodiment, the inner electrode 30 further includes: a seventh capacitor C7, an eighth capacitor C8, and a ninth capacitor C9, wherein the first resonant circuit 100 and the second resonant circuit 200 are coupled and connected by the seventh capacitor C7, the third resonant circuit 300 and the fourth resonant circuit 400 are coupled and connected by the eighth capacitor C8, and the fifth resonant circuit 500 and the sixth resonant circuit 600 are coupled and connected by the ninth capacitor C9.

Alternatively, the seventh capacitor C7, the eighth capacitor C8, and the ninth capacitor C9 may be respectively formed by two capacitors connected in series.

In one embodiment, the method comprises the following steps: the first 100 and sixth 600 resonance circuits are mirror symmetric, the second 200 and fifth 500 resonance circuits are mirror symmetric, and the third 300 and fourth 400 resonance circuits are mirror symmetric.

In one embodiment, the second resonant circuit 200 and the third resonant circuit 300 are diametrically opposed; the fourth resonant circuit 400 and the fifth resonant circuit 500 are diametrically opposed.

In one embodiment, the spacing between the second resonant circuit 200 and the third resonant circuit 300 is adjustable, and the spacing between the fourth resonant circuit 400 and the fifth resonant circuit 500 is adjustable.

In one embodiment, the substrate 10 is a low loss low temperature co-fired ceramic dielectric having a relative dielectric constant of 10-40 and a dielectric loss tan α ≦ 0.001.

Alternatively, in an embodiment, when the band pass filter is a band pass filter with a center frequency of 130MHz, the substrate 10 may be made of a ceramic substrate 10 material with a dielectric constant of 40 ± 1 and a material dielectric loss factor tan α ≤ 0.001, and in an embodiment, when the band pass filter is a band pass filter with a center frequency of 130MHz, the substrate 10 may be made of a ceramic substrate 10 material with a dielectric constant of 13 ± 1 and a material dielectric loss factor tan α ≤ 0.001.

In one embodiment, the input terminal electrode 21 and the output terminal electrode 22 include a silver layer, a nickel layer, and a tin layer, respectively.

Various embodiments are described herein for various devices, circuits, apparatuses, systems, and/or methods. Numerous specific details are set forth in order to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments as described in the specification and illustrated in the accompanying drawings. However, it will be understood by those skilled in the art that the embodiments may be practiced without such specific details. In other instances, well-known operations, components and elements have been described in detail so as not to obscure the embodiments in the description. It will be appreciated by those of ordinary skill in the art that the embodiments herein and shown are non-limiting examples, and thus, it can be appreciated that the specific structural and functional details disclosed herein may be representative and do not necessarily limit the scope of the embodiments.

Reference throughout the specification to "various embodiments," "in an embodiment," "one embodiment," or "an embodiment," etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in various embodiments," "in some embodiments," "in one embodiment," or "in an embodiment," or the like, in places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, a particular feature, structure, or characteristic illustrated or described in connection with one embodiment may be combined, in whole or in part, with features, structures, or characteristics of one or more other embodiments without presuming that such combination is not an illogical or functional limitation. Any directional references (e.g., plus, minus, upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above …, below …, vertical, horizontal, clockwise, and counterclockwise) are used for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of the embodiments.

Although certain embodiments have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this disclosure. Joinder references (e.g., attached, coupled, connected, and the like) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. Thus, connection references do not necessarily imply that two elements are directly connected/coupled and in a fixed relationship to each other. The use of "for example" throughout this specification should be interpreted broadly and used to provide non-limiting examples of embodiments of the disclosure, and the disclosure is not limited to such examples. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the disclosure.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A bandpass filter, comprising: the inner electrode comprises a first resonant circuit, a second resonant circuit, a third resonant circuit, a fourth resonant circuit, a fifth resonant circuit and a sixth resonant circuit, the first resonant circuit, the second resonant circuit, the fifth resonant circuit and the sixth resonant circuit are arranged in parallel on a first plane of the base body, the third resonant circuit and the fourth resonant circuit are arranged on a second plane of the base body, the first plane of the base body is parallel and opposite to the second plane of the base body, the first resonant circuit is connected with the input end electrode, and the sixth resonant circuit is connected with the output end electrode.

2. The bandpass filter according to claim 1, wherein the first resonant circuit comprises a first capacitor and a first inductor, the second resonant circuit comprises a second capacitor and a second inductor, the third resonant circuit comprises a third capacitor and a third inductor, the fourth resonant circuit comprises a fourth capacitor and a fourth inductor, the fifth resonant circuit comprises a fifth capacitor and a fifth inductor, the sixth resonant circuit comprises a sixth capacitor and a sixth inductor, the second resonant circuit and the third resonant circuit are coupled through the second inductor and the third inductor, and the fourth resonant circuit and the fifth resonant circuit are coupled through the fourth inductor and the fifth inductor.

3. The bandpass filter according to claim 2, wherein the first inductor and the first capacitor are placed in parallel or the first capacitor is placed on the first inductor, the second inductor and the second capacitor are placed in parallel or the second capacitor is placed on the second inductor, the third inductor and the third capacitor are placed in parallel or the third capacitor is placed on the third inductor, the fourth inductor and the fourth capacitor are placed in parallel or the fourth capacitor is placed on the fourth inductor, the fifth inductor and the fifth capacitor are placed in parallel or the fifth capacitor is placed on the fifth inductor, and the sixth inductor and the sixth capacitor are placed in parallel or the sixth capacitor is placed on the sixth inductor.

4. The bandpass filter according to claim 1, wherein the inner electrode further comprises: the first resonant circuit and the second resonant circuit are coupled through the seventh capacitor, the third resonant circuit and the fourth resonant circuit are coupled through the eighth capacitor, and the fifth resonant circuit and the sixth resonant circuit are coupled through the ninth capacitor.

5. The bandpass filter according to claim 1, comprising:

6. The bandpass filter according to claim 1, wherein the second resonant circuit and the third resonant circuit are diametrically opposed; the fourth resonant circuit and the fifth resonant circuit are diametrically opposed.

7. The bandpass filter according to claim 6, wherein a spacing between the second resonant circuit and the third resonant circuit is adjustable, and a spacing between the fourth resonant circuit and the fifth resonant circuit is adjustable.

8. The bandpass filter according to any one of claims 1-7, wherein the second resonant circuit and the fifth resonant circuit are placed in parallel adjacent to each other, the second resonant circuit and the fifth resonant circuit forming a cross-coupling therebetween and creating an out-of-band zero.

9. The bandpass filter according to any one of claims 1 to 7, wherein the substrate is a low-loss low-temperature co-fired ceramic dielectric having a relative dielectric constant of 10 to 40 and a dielectric loss tan α ≦ 0.001.

10. The bandpass filter according to any one of claims 1 to 7, wherein the input terminal electrode and the output terminal electrode comprise a silver layer, a nickel layer, and a tin layer, respectively.