CN214227102U - Band-stop filter - Google Patents
Band-stop filter Download PDFInfo
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- CN214227102U CN214227102U CN202022679297.2U CN202022679297U CN214227102U CN 214227102 U CN214227102 U CN 214227102U CN 202022679297 U CN202022679297 U CN 202022679297U CN 214227102 U CN214227102 U CN 214227102U
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- 230000005540 biological transmission Effects 0.000 claims abstract description 63
- 230000008878 coupling Effects 0.000 claims abstract description 8
- 238000010168 coupling process Methods 0.000 claims abstract description 8
- 238000005859 coupling reaction Methods 0.000 claims abstract description 8
- 239000002184 metal Substances 0.000 claims description 8
- 230000008030 elimination Effects 0.000 abstract description 12
- 238000003379 elimination reaction Methods 0.000 abstract description 12
- 238000003780 insertion Methods 0.000 abstract description 4
- 230000037431 insertion Effects 0.000 abstract description 4
- 230000005764 inhibitory process Effects 0.000 abstract description 3
- 230000010354 integration Effects 0.000 abstract description 3
- 238000005452 bending Methods 0.000 description 8
- 230000004044 response Effects 0.000 description 5
- 238000004088 simulation Methods 0.000 description 4
- 230000001629 suppression Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
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Abstract
The utility model provides a band elimination filter, including cavity, low pass filter, first transmission line, second transmission line, first tap line and second tap line, be formed with two at least resonant cavities in the cavity, and with the notch/through-hole that the resonant cavity separates, every resonant cavity is equipped with the syntonizer, and is adjacent be equipped with the coupling windowing between the resonant cavity, first input/output connects is connected to first transmission line, second input/output connects is connected to the second transmission line. The band stop and the low-pass filter are combined, and certain inhibition characteristics are provided for far-end high-frequency signals on the premise of keeping the band stop characteristics of a near-end frequency band, so that the influence of high-frequency harmonics on a system is reduced, the requirements of relevant specifications are met, and the insertion loss of the whole module is reduced after integration. The filter built in the notch reduces the size and weight of the whole module and simplifies the connection structure.
Description
Technical Field
The utility model relates to a wave filter technical field especially relates to a band elimination filter.
Background
Filters, which are frequency selective devices indispensable for wireless communication, are generally classified into four broad categories, namely low-pass, high-pass, band-pass, and band-stop filters, according to their types of functions. The low-pass filter can pass signals with lower frequency and block or suppress signals with high frequency, and usually, in addition to a band-pass or band-stop filter and a duplexer which realize a frequency selection function, the radio frequency system needs an additional low-pass filter to eliminate or reduce the influence of high-frequency harmonics on the system. The band-stop filter can block or suppress signals of a specific frequency band, and simultaneously allows signals of other frequencies to pass through, and is usually used as a trap filter to suppress signals of a certain frequency band, or is matched with other filters to realize the frequency selection function of a system.
In the existing design, a low-pass filter is additionally cascaded after a filter or a duplexer for realizing frequency selection to realize the suppression of high-frequency harmonics, so that the whole system space is occupied, the size is increased, and the additional connection loss is increased to influence the system performance.
SUMMERY OF THE UTILITY MODEL
The utility model discloses the technical problem that will solve is: the existing filter has the problem of adding extra connection loss in order to realize high-frequency harmonic suppression.
In order to solve the technical problem, the utility model discloses a technical scheme be: the band elimination filter comprises a cavity, a low-pass filter, a first transmission line, a second transmission line, a first tap line and a second tap line, wherein at least two resonant cavities and a notch/through hole separated from the resonant cavities are formed in the cavity, each resonant cavity is provided with a resonator, a coupling window is arranged between every two adjacent resonant cavities, the low-pass filter, the first transmission line and the second transmission line are arranged in the notch/through hole, the two ends of the low-pass filter are respectively connected with the first transmission line and the second transmission line, the two ends of the first tap line are respectively connected with the resonators and the first transmission line, the two ends of the second tap line are respectively connected with the resonators and the second transmission line, the first transmission line is connected with a first input-output connector, and the second transmission line is connected with a second input-output connector.
Furthermore, a first connection point is arranged between the first tapped line and the first transmission line, a second connection point is arranged between the second tapped line and the second transmission line, and the electrical length between the first connection point and the second connection point is one-quarter wavelength of the resonant frequency of the resonator.
Furthermore, the first tapped line and the second tapped line both comprise a bending part and a connecting part, one end of the bending part is connected with the resonator, the other end of the bending part is connected with the connecting part, and the connecting part is connected with the first transmission line or the second transmission line.
Further, the diameter of the notch is matched with the diameters of the first transmission line and the second transmission line.
Furthermore, the number of the resonators is four.
Furthermore, the filter also comprises a sleeve, and the sleeve is sleeved outside the filter.
Furthermore, a metal cover plate is arranged above the cavity and the notch.
Further, the band elimination filter is a metal coaxial cavity filter.
The beneficial effects of the utility model reside in that: the band stop and the low-pass filter are combined, and certain inhibition characteristics are provided for far-end high-frequency signals on the premise of keeping the band stop characteristics of a near-end frequency band, so that the influence of high-frequency harmonics on a system is reduced, the requirements of relevant specifications are met, and the insertion loss of the whole module is reduced after integration. The filter built in the notch reduces the size and weight of the whole module and simplifies the connection structure.
Drawings
The following detailed description of the specific structure of the present invention with reference to the accompanying drawings
Fig. 1 is a schematic structural diagram of the band-stop filter of the present invention.
Fig. 2 is a narrow-band frequency response simulation curve of the band-stop filter of the present invention.
Fig. 3 is a simulation curve of the broadband frequency response of the band elimination filter of the present invention.
The reference numbers are as follows:
1-a cavity; 10-first tap line; 2-a second tap line; 21-bending part; 22-a connecting part; 3-a resonator; 41-a first transmission line; 42-a second transmission line; 5-a low-pass filter; 6-a sleeve; 7-a first input-output connector; 81-a first connection point; 82-a second connection point; 9-a second input-output connector; 11-coupled windowing; 12-notches.
Detailed Description
In order to explain technical contents, structural features, and objects and effects of the present invention in detail, the following description is given in conjunction with the embodiments and the accompanying drawings.
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a band-stop filter according to the present invention. The utility model provides a band elimination filter, including cavity 1, low pass filter 5, first transmission line 41, second transmission line 42, first tap line 10 and second tap line 2, be formed with two at least resonant cavities in the cavity 1, and with notch/through-hole 12 that the resonant cavity separates, every resonant cavity is equipped with syntonizer 3, and is adjacent be equipped with coupling window 11 between the resonant cavity, low pass filter 5, first transmission line 41 and second transmission line 42 are located in notch/through-hole 12, first transmission line 41 and second transmission line 42 are connected respectively at low pass filter 5 both ends, first tap line 10 both ends are connected respectively syntonizer 3 with first transmission line 41, second tap line 2 both ends are connected respectively syntonizer 3 with second transmission line 42, first transmission line 41 is connected first input output and is connected 7, the second transmission line 42 is connected to the second input/output connector 9.
Specifically, the cavity 1 is a metal cavity, and the resonator 3 is a coaxial resonator. The four coaxial resonators in the metal cavity are arranged in a shape of Chinese character 'tian'; the resonators 3 are exposed to each other through the coupling windows 11, and the coupling between the respective resonators 3 is achieved by controlling the size of the coupling windows 11. The band stop and the low-pass filter are combined, and certain inhibition characteristics are provided for far-end high-frequency signals on the premise of keeping the band stop characteristics of a near-end frequency band, so that the influence of high-frequency harmonics on a system is reduced, the requirements of relevant specifications are met, and the insertion loss of the whole module is reduced after integration. The low-pass filter 5 built in the notch 12 reduces the size and weight of the entire module and simplifies the connection structure.
Example 1
Further, the first tap line 10 and the first transmission line 41 are provided with a first connection point 81, the second tap line 2 and the second transmission line 42 are provided with a second connection point 82, and an electrical length between the first connection point 81 and the second connection point 82 is a quarter wavelength of a resonance frequency of the resonator 3.
Specifically, the first tapped line 10 and the second tapped line 2 are welded to the head-to-tail resonator respectively and connected with the first transmission line 41 and the second transmission line 42 which are located beside the resonator, and the head-to-tail resonator is coupled with the first input-output connector 7 and the second input-output connector 9 respectively by adjusting the welding height and shape of the first tapped line 10 and the second tapped line 2. The transmission line between the first tap line 10 and the second tap line 2 is replaced by a third order stepped impedance low pass filter and the equivalent electrical length of the low pass section is ensured to be maintained at a quarter wavelength by adjusting the first connection point 81 of the first tap line 10 and the first transmission line 41 and the second connection point 82 of the second tap line 2 and the second transmission line 42. For different performance requirements, a higher order low pass can be used to achieve higher high frequency rejection performance, and adjustment is also needed to meet the requirement of equivalent electrical length.
Example 2
The first tapped line 10 and the second tapped line 2 both include a bending portion 21 and a connecting portion 22, one end of the bending portion 21 is connected to the resonator, the other end of the bending portion 21 is connected to the connecting portion 22, and the connecting portion 22 is connected to the first transmission line 41 or the second transmission line 42.
Specifically, the bending shape of the first tap line 10 and the second tap line 2 can adjust the coupling size, the electrical length needs to be determined during design, and the opening position of the cavity 1 is also determined correspondingly.
Further, the diameter of the slot 12 is adapted to the diameter of the first transmission line 41 and the second transmission line 42.
Specifically, the first transmission line 41 and the second transmission line 42 are both located in the notch 12 beside the resonator 3, and the matching transmission of 50 ohms is realized by adjusting the diameters of the first transmission line 41 and the second transmission line 42 to match with the diameter of the notch 12. The number of the resonators 3 is four.
Example 3
Further, the filter further comprises a sleeve 6, and the sleeve 6 is sleeved outside the filter 5. And a metal cover plate is arranged above the cavity 1 and the notch 12 and used for electromagnetic shielding. The band elimination filter is a metal coaxial cavity filter. The sleeve 6 is an insulating low-pass sleeve.
Further, please refer to fig. 2 and fig. 3, fig. 2 is a simulation curve of the narrow band frequency response of the band elimination filter of the present invention. The center frequency of the stop band is about 2600MHz, the stop band bandwidth is about 80MHz, the stop band rejection is about 20dB, and the influence of the addition of the integrated low-pass on the narrow-band frequency response is small. Fig. 3 is the utility model discloses band elimination filter 'S broadband frequency response simulation curve benefits from the introduction of third-order low pass, and S21 has obvious attenuation effect on distal end frequency, has realized the suppression more than 10dB more than 7GHz, can effectively reduce the influence of high frequency harmonic to the system to satisfy relevant standard' S requirement.
To sum up, the utility model provides a pair of band elimination filter combines band elimination and low pass filter, also has certain rejection characteristic to the high frequency signal of distal end under the prerequisite that keeps near-end frequency channel band elimination characteristic to reduce the influence of high frequency harmonic to the system, satisfy relevant standard's requirement, and reduced the insertion loss of whole module after integrating. The filter built in the notch reduces the size and weight of the whole module and simplifies the connection structure.
The above only is the embodiment of the present invention, not limiting the patent scope of the present invention, all the equivalent structures or equivalent processes that are used in the specification and the attached drawings or directly or indirectly applied to other related technical fields are included in the patent protection scope of the present invention.
Claims (8)
1. A band stop filter, characterized by: the low-pass filter, the first transmission line, the second transmission line, the first tap line and the second tap line are formed in the cavity, at least two resonant cavities and notches/through holes separated from the resonant cavities are formed in the cavity, each resonant cavity is provided with a resonator, coupling windowing is arranged between the adjacent resonant cavities, the low-pass filter, the first transmission line and the second transmission line are arranged in the notches/through holes, the two ends of the low-pass filter are respectively connected with the first transmission line and the second transmission line, the two ends of the first tap line are respectively connected with the resonators and the first transmission line, the two ends of the second tap line are respectively connected with the resonators and the second transmission line, the first transmission line is connected with a first input-output connector, and the second transmission line is connected with a second input-output connector.
2. The band reject filter of claim 1, wherein the first tap line and the first transmission line are provided with a first connection point and the second tap line and the second transmission line are provided with a second connection point, an electrical length dimension between the first connection point and the second connection point being a quarter wavelength of a resonant frequency of the resonator.
3. The band reject filter of claim 2, wherein the first tap line and the second tap line each include a bend and a connection, the bend having one end connected to the resonator and the other end connected to the connection, the connection connected to the first transmission line or the second transmission line.
4. The band reject filter of claim 3, wherein the diameter of the notch is sized to fit the diameter of the first and second transmission lines.
5. The band reject filter of claim 4, wherein the number of resonators is four.
6. The band reject filter of claim 5, further comprising a sleeve disposed outside the filter.
7. The band stop filter of claim 6, wherein a metal cover plate is disposed over the cavity and the slot.
8. The band-stop filter of claim 1, wherein the band-stop filter is a metal coaxial cavity filter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022679297.2U CN214227102U (en) | 2020-11-18 | 2020-11-18 | Band-stop filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022679297.2U CN214227102U (en) | 2020-11-18 | 2020-11-18 | Band-stop filter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214227102U true CN214227102U (en) | 2021-09-17 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202022679297.2U Active CN214227102U (en) | 2020-11-18 | 2020-11-18 | Band-stop filter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN214227102U (en) |
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2020
- 2020-11-18 CN CN202022679297.2U patent/CN214227102U/en active Active
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