CN220106858U - High-rejection cavity band-pass filter with frequency band of 2.5GHz - Google Patents

Abstract

The utility model belongs to the technical field of filters, and discloses a 2.5 GHz-frequency-band high-rejection cavity band-pass filter, which comprises a hollow rectangular shell and a plurality of cylindrical cavities arranged in the shell, wherein the cylindrical cavities are arranged side by side along the length direction of the shell; the two end surfaces of the shell along the length direction are respectively provided with a feed port, and a feed line core in the feed port penetrates into the shell and is connected with the adjacent cylindrical cavity; a tuning screw which is in insulating and movable connection with the cylindrical cavity is further arranged outside the shell, and the tuning screw is provided with a rod part which is inserted into the cylindrical cavity. According to the bandpass filter structure designed by the utility model, the shell is internally provided with the plurality of equidistant side-by-side cylindrical cavities with adjustable insertion depth, so that a better high-frequency inhibition effect is provided on the premise of realizing high-precision adjustability by using the adjustable tuning screw, and meanwhile, the bandpass filter structure has lower insertion loss.

Description

High-rejection cavity band-pass filter with frequency band of 2.5GHz

Technical Field

The utility model belongs to the technical field of filters, and particularly relates to a high-rejection cavity band-pass filter with a frequency band of 2.5 GHz.

Background

With the development of the fifth generation mobile communication technology, the carrier frequency of wireless communication tends to be concentrated towards ultrahigh frequency, so that the absolute bandwidth of a higher frequency band is wider under the condition of a certain relative bandwidth, and faster data communication and larger data throughput can be realized theoretically. The 2.5GHz band has become an important band for 5G network communications. In order to prevent the communication itself from interfering with other frequency bands, a radio frequency filter needs to be added to a transmitter and a receiver of the communication device, and the current mobile communication devices all need to achieve high integration and miniaturization, so that the miniaturized high-performance high-rejection low-insertion-loss filter is very high in demand.

Typical 2.5GHz filters are typically LC band reject low pass filters, which require the use of a variety of discrete devices, each of which has a direct impact on the filter characteristics, and LC band pass filters tend to have undesirable high frequency rejection effects due to device parasitics. In the prior art, a cavity band-pass filter is adopted for signal processing, such as a low-frequency band cavity band-pass filter with the patent application number of CN201610833115.8, and the filter realizes the suppression capacity of a large frequency band range and the large power bearing capacity of a suppression degree through a special structure, but the structure adopts the coaxial cavity structural design of an outer square and an inner round and does not adopt the structural design of a spiral tuning cavity. Meanwhile, the patent does not give an actual interpolation loss value, in order to realize high suppression and low interpolation loss and to realize the structural design of a filter with a specific frequency band, the adjustment precision of a spiral tuning cavity is higher, but the interpolation loss needs to be optimized, and the prior art does not give related design ideas.

Disclosure of Invention

In order to solve the problems in the prior art, the utility model provides the high-rejection cavity band-pass filter with the frequency band of 2.5GHz, and the structural design of the high-rejection cavity band-pass filter is optimized, so that the high adjustment precision of the high-rejection cavity band-pass filter is ensured by adopting the spiral tuning cavity, and the interpolation loss of the high-rejection cavity band-pass filter can be effectively reduced.

The technical scheme adopted by the utility model is as follows:

the utility model discloses a 2.5 GHz-frequency-band high-rejection cavity band-pass filter, which comprises a hollow rectangular shell and a plurality of cylindrical cavities arranged in the shell, wherein the cylindrical cavities are arranged side by side along the length direction of the shell;

the two end surfaces of the shell along the length direction are respectively provided with a feed port, and a feed line core in the feed port penetrates into the shell and is connected with the adjacent cylindrical cavity;

a tuning screw which is in insulating and movable connection with the cylindrical cavity is further arranged outside the shell, and the tuning screw is provided with a rod part which is inserted into the cylindrical cavity.

With reference to the first aspect, the present utility model provides a first implementation manner of the first aspect, the inner layer of the housing has a silver plating layer, the shielding layer outside the feed port is connected with the silver plating layer, the cylindrical cavity is an integral cylindrical structure formed by extending the bottom of the inner layer of the housing upwards, a gap is formed between the top of the cylindrical cavity and the inner wall of the housing, and the housing is provided with an opening corresponding to the cylindrical cavity.

With reference to the first aspect, the present utility model provides a second implementation manner of the first aspect, wherein the housing has a row of five cylindrical cavities arranged along a length direction.

With reference to the first embodiment of the first aspect, the present utility model provides a third embodiment of the first aspect, wherein the length, width and height of the housing are divided into 69mm, 16mm and 18mm, wherein the radius of the cylindrical cavity is 3mm, the height is 15mm, and the radius of the cavity is 2mm;

the length of the tuning screws in the two cylindrical cavities at the two ends of the length of the shell is 4.8mm, and the length of the three tuning screws in the middle is 4mm.

With reference to the first aspect or the several embodiments of the first aspect, the present utility model provides a fourth embodiment of the first aspect, where the cylindrical cavity is an independent copper pipe structure, and an end surface on one side of the housing is provided with a plurality of holes, and the cylindrical cavity is disposed in the holes and is fixedly connected with the housing.

With reference to the fourth implementation manner of the first aspect, the present utility model provides a fifth implementation manner of the first aspect, wherein a stop collar is disposed at an opening of the cylindrical cavity, and the stop collar has an internal thread and is in threaded fit connection with the tuning screw.

With reference to the fifth implementation manner of the first aspect, the present utility model provides a sixth implementation manner of the first aspect, where the stop collar is fixed at the opening of the housing, and the cylindrical cavity is sunk into the opening, and the stop collar is fixedly connected to the housing and aligned with the opening of the cylindrical cavity.

With reference to the sixth implementation manner of the first aspect, the present utility model provides a seventh implementation manner of the first aspect, where the tuning screw has a shaft portion and an expansion end, and the expansion end and the stop collar rotate relatively by operating;

the rod part is provided with an external thread matched with the internal thread of the limit sleeve, the rod part is also provided with a limit nut in a threaded mode, the expansion end is operated to enable the tuning screw to move to a corresponding position, and the tuning screw is locked by rotating the limit nut to abut against the end part of the limit sleeve.

The beneficial effects of the utility model are as follows:

(1) According to the bandpass filter structure designed by the utility model, the shell is internally provided with the plurality of equidistant side-by-side cylindrical cavities with adjustable insertion depth, so that a better high-frequency inhibition effect is provided on the premise of realizing high-precision adjustability by using the adjustable tuning screw, and meanwhile, the bandpass filter structure has lower insertion loss;

(2) According to the utility model, the shielding effect is improved by optimizing the conductive characteristics of the shell structure, the feed port structure and the inside of the cylindrical cavity;

(3) According to the utility model, through optimizing the cylindrical cavity and the limiting sleeve structure, the limiting nut can be used for limiting on the premise of ensuring good bolt adjusting precision between the cylindrical cavities of the tuning screws, so that the influence on the filtering effect caused by rotation of the tuning screws due to shaking is avoided.

Drawings

FIG. 1 is a schematic front view of an overall bandpass filter according to embodiments of the utility model;

FIG. 2 is a top view of an entire bandpass filter in an embodiment of the utility model;

FIG. 3 is a schematic cross-sectional view of the present utility model taken along section line A-A in FIG. 2;

FIG. 4 is an isometric view of an entire bandpass filter in an embodiment of the utility model;

FIG. 5 is a perspective isometric view of an entire bandpass filter in an embodiment of the utility model;

FIG. 6 is a schematic diagram of a band pass filter in simulation software in an embodiment of the utility model;

FIG. 7 is a parametric diagram of a band pass filter dB (S21) in an embodiment of the utility model;

fig. 8 is a table of specific dimensions of the present utility model in an embodiment.

In the figure: the antenna comprises a 1-shell, a 2-feed port, a 3-tuning screw, a 4-limit nut, a 5-limit sleeve, a 6-cylindrical cavity and a 7-feed core.

Detailed Description

The utility model is further illustrated by the following description of specific embodiments in conjunction with the accompanying drawings.

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. The components of the embodiments of the present utility model 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 utility model, as presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the description of the present utility model, it should be noted that, if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate an azimuth or a positional relationship based on that shown in the drawings, or an azimuth or a positional relationship in which a product of the application is conventionally put in use, it is merely for convenience of describing the present utility model and simplifying the description, and it is not indicated or implied that the referred device or element must have a specific azimuth, be constructed and operated in a specific azimuth, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and the like in the description of the present utility model, if any, are used for distinguishing between the descriptions and not necessarily for indicating or implying a relative importance.

Furthermore, the terms "horizontal," "vertical," and the like in the description of the present utility model, if any, do not denote a requirement that the component be absolutely horizontal or overhang, but rather may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present utility model, it should also be noted that, unless explicitly stated and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" should be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

Example 1:

the embodiment discloses a high suppression cavity band-pass filter of 2.5GHz frequency channel, including cavity rectangle's shell 1 and a plurality of cylinder cavitys 6 of setting in shell 1, shell 1 is the thin wall shell structure that the metallic material was made, and its inside cavity is independent airtight space.

The cylindrical cavities 6 are arranged side by side at equal intervals along the length direction of the housing 1, wherein the equal intervals are defined between adjacent cylindrical cavities 6, and the gaps between the cylindrical cavities 6 and the housing 1 are unequal, mainly the gaps between the two side ends and the parallel direction are unequal.

The two end surfaces of the shell 1 along the length direction are respectively provided with a feed port 2, and a feed line core 7 in the feed port 2 penetrates into the shell 1 and is connected with an adjacent cylindrical cavity 6; a tuning screw 3 which is in insulating and movable connection with the cylindrical cavity 6 is further arranged outside the shell 1, and the tuning screw 3 is provided with a rod part which is inserted into the cylindrical cavity 6.

Further, referring to fig. 1-2, a design of the cavity bandpass filter is shown. In the figure, it can be seen that the rectangular shell has a cuboid structure, and the lower positions of the end surfaces of two sides are provided with feed inlets 2. The so-called feed port 2, the SMA feed line joint standard common in the art, has an outer shielding layer and an inner wire core.

The cylindrical cavity 6 is an integral columnar structure formed by upward extension of the inner bottom of the shell 1, a gap is formed between the top of the cylindrical cavity 6 and the inner wall of the shell 1, and the shell 1 is provided with an opening corresponding to the cylindrical cavity 6. The feeder core 7 in the feeder port 2 penetrates into the shell 1 and is connected with the adjacent cylindrical cavity 6; a tuning screw 3 which is in insulating and movable connection with the cylindrical cavity 6 is further arranged outside the shell 1, and the tuning screw 3 is provided with a rod part which is inserted into the cylindrical cavity 6.

The housing 1 is used as a good conductor, and in order to further improve the conductivity, a silver plating layer is covered on the surface of the inner cavity, the thickness is 30-40um, and the shielding layer outside the feed port 2 is used as a strong conductive layer and connected with the silver plating layer.

Five open holes are formed in the top of the shell 1 at equal intervals along the length direction, the size of each open hole is the same, a cylindrical cavity 6 is correspondingly arranged on each open hole, the cylindrical cavity 6 is of a pure copper cylindrical structure produced independently, the pure copper cylindrical structure is provided with a blind hole, and the opening end face of the blind hole is fixedly connected with the open hole.

In one embodiment, the opening end face of the blind hole is lower than the opening end face of the opening, the opening end face can be outwards protruded to form a tubular structure, an inner thread is arranged on the inner wall of the opening end face, the tubular structure is in threaded fit with the tuning screw 3 through the inner thread, the protruded tubular structure is formed by adopting insulating materials different from the shell 1, and the tubular structure can be directly injection molded at the position or can be installed through viscose.

In another embodiment, the opening of the blind hole is provided with an insulating inner thread layer, and the blind hole is in threaded fit with the tuning screw 3 through the inner thread layer.

Referring to fig. 8, the size of the band pass filter is optimally defined.

Bx is the width dimension of the shell 1 in the x direction, namely 16mm;

by is the length dimension of the shell 1 in the y direction, namely 69mm;

bh is the height dimension of the housing 1 in the z direction, i.e. 18mm;

ga is the tangential distance between the inner side end surfaces of the two feed ports 2 serving as input and output ports and the two nearest cylindrical cavities 6, namely 4mm;

s12 is the distance value between the two outermost cylindrical cavities 6 and the adjacent cylindrical cavities 6, namely 6.7mm, s23 is the tangential distance between every two of the three inner cylindrical cavities 6, namely 8.8mm;

it should be noted that, in order to achieve better filtering effect and smaller insertion loss, the equidistant arrangement disclosed in the above embodiment optimizes the distance value between the cylindrical cavities 6, and adopts the arrangement mode that the internal distance is larger and the external distance is smaller.

gr is the cylinder radius value of the cylinder chamber 6, i.e. 3mm,

gri is the value of the radius of the internal blind hole of the cylindrical cavity 6, i.e. 2mm,

gh is the height of the cylindrical cavity 6, i.e. 15mm,

ch is the gap between the centre of the two feed openings 2 and the xOy plane, i.e. 5.5mm,

lr is the radius value of the tuning screw 3, i.e. 1.5mm;

ghi is the distance from the slotted bottom of the cylindrical cavity 6 to the top of the housing 1, i.e. 9mm,

lh1 is the length of the tuning screw 3 corresponding to the outermost two cylindrical cavities 6, i.e. 4.8mm,

lh2 and lh3 are the lengths of the tuning screws 3 corresponding to the inner three cylindrical cavities 6, i.e. 4mm,

rrf is the outer radius of the feed port 2 cylinder, i.e. 3mm,

cd is the length of the feed port 2 cylinder, i.e. 5mm.

Further, the feeding ports 2 arranged on the left and right sides in the Y-axis direction have inner cores made of pure copper silver plating materials and have characteristic impedance of 50 ohms.

Whereas the antenna has a normalized impedance of 0.5756-0.1090i at 2.4GHz and a termination impedance of 50 ohms at the input.

Referring to fig. 7, the simulation test structure shows that the filter has better performance, the in-band insertion loss is better than 1.8db, the in-band fluctuation is small, the out-of-band rejection is very high, -100M rejection is 25db, +100M rejection is 30db, the passband is 2.53-2.92GHz, and the bandwidth is 390MHz.

Referring to fig. 3-5, a fastening assembly of the tuning screw 3 is shown in detail. The opening of the cylindrical cavity 6 is provided with a limit sleeve 5, and the limit sleeve 5 is provided with internal threads and is in threaded fit connection with the tuning screw 3.

The stop collar 5 is fixed in the trompil department of shell 1, and cylinder cavity 6 sinks in the trompil, stop collar 5 and shell 1 fixed connection and with the opening alignment of cylinder cavity 6. The tuning screw 3 is provided with a rod part and an expansion end, and the expansion end and the limit sleeve 5 are rotated relatively by operating; the rod part is provided with an external thread matched with the internal thread of the limit sleeve 5, the rod part is also provided with a limit nut 4 in a threaded mode, the expansion end is operated to enable the tuning screw 3 to move to a corresponding position, and the tuning screw 3 is locked by rotating the limit nut 4 to abut against the end part of the limit sleeve 5.

The utility model is not limited to the alternative embodiments described above, but any person may derive other various forms of products in the light of the present utility model. The above detailed description should not be construed as limiting the scope of the utility model, which is defined in the claims and the description may be used to interpret the claims.

Claims (8)

1. A high suppression cavity band-pass filter of 2.5GHz frequency channel, its characterized in that: the device comprises a hollow rectangular shell (1) and a plurality of cylindrical cavities (6) arranged in the shell (1), wherein the cylindrical cavities (6) are arranged side by side along the length direction of the shell (1);

two end surfaces of the shell (1) along the length direction are respectively provided with a feed port (2), and a feed line core (7) in the feed port (2) penetrates into the shell (1) and is connected with an adjacent cylindrical cavity (6);

a tuning screw (3) which is in insulating and movable connection with the cylindrical cavity (6) is further arranged outside the shell (1), and the tuning screw (3) is provided with a rod part which is inserted into the cylindrical cavity (6).

2. The high rejection cavity band pass filter of the 2.5GHz band of claim 1, wherein: the inner layer of the shell (1) is provided with a silver plating layer, and the shielding layer outside the feed port (2) is connected with the silver plating layer.

3. The high rejection cavity band pass filter of the 2.5GHz band of claim 1, wherein: the novel cylindrical shell is characterized in that a row of five cylindrical cavities (6) are arranged in the shell (1) along the length direction, the cylindrical cavities (6) are of an integrated cylindrical structure formed by upward extension of the bottoms in the shell (1), a gap is reserved between the tops of the cylindrical cavities (6) and the inner wall of the shell (1), and openings corresponding to the cylindrical cavities (6) are formed in the shell (1).

4. A 2.5GHz band high rejection cavity bandpass filter according to claim 3, wherein: the length and width of the shell (1) are divided into 69mm, 16mm and 18mm, the radius of the cylindrical cavity (6) is 3mm, the height is 15mm, and the radius of the cavity is 2mm;

the length of the tuning screws (3) in the two cylindrical cavities (6) at the two ends of the length of the shell (1) is 4.8mm, and the length of the three tuning screws (3) in the middle is 4mm.

5. A 2.5GHz band high rejection cavity bandpass filter according to any one of claims 1-4, wherein: the cylindrical cavity (6) is of an independent copper pipe body structure, a plurality of openings are formed in the end face of one side of the shell (1), and the cylindrical cavity (6) is arranged in the openings and fixedly connected with the shell (1).

6. A 2.5GHz band high rejection cavity bandpass filter as in claim 5

Is characterized in that: the opening part of the cylindrical cavity (6) is provided with a limit sleeve (5), and the limit sleeve (5) is provided with internal threads and is in threaded fit connection with the tuning screw (3).

7. The high rejection cavity band pass filter of the 2.5GHz band of claim 6, wherein: the limiting sleeve (5) is fixed at the opening of the shell (1), the cylindrical cavity (6) is sunk into the opening, and the limiting sleeve (5) is fixedly connected with the shell (1) and aligned with the opening of the cylindrical cavity (6).

8. The high rejection cavity band pass filter of the 2.5GHz band of claim 7, wherein: the tuning screw (3) is provided with a rod part and an expansion end, and the expansion end and the limit sleeve (5) are operated to rotate relatively;

the rod part is provided with an external thread matched with the internal thread of the limit sleeve (5), the rod part is also provided with a limit nut (4) in a threaded mode, the expansion end is operated to enable the tuning screw (3) to move to a corresponding position, and the tuning screw (3) is locked by rotating the limit nut (4) to abut against the end part of the limit sleeve (5).