CN115458883A - High-order mode substrate integrated waveguide dual-passband circular cavity filter - Google Patents
High-order mode substrate integrated waveguide dual-passband circular cavity filter Download PDFInfo
- Publication number
- CN115458883A CN115458883A CN202211331585.6A CN202211331585A CN115458883A CN 115458883 A CN115458883 A CN 115458883A CN 202211331585 A CN202211331585 A CN 202211331585A CN 115458883 A CN115458883 A CN 115458883A
- Authority
- CN
- China
- Prior art keywords
- circular cavity
- substrate integrated
- integrated waveguide
- substrate
- waveguide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000758 substrate Substances 0.000 title claims abstract description 94
- 239000002184 metal Substances 0.000 claims abstract description 59
- 239000010410 layer Substances 0.000 claims abstract description 24
- 230000000149 penetrating effect Effects 0.000 claims abstract description 8
- 239000011229 interlayer Substances 0.000 claims abstract description 4
- 238000010295 mobile communication Methods 0.000 abstract description 2
- 238000012545 processing Methods 0.000 abstract description 2
- 238000005516 engineering process Methods 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 3
- 238000004891 communication Methods 0.000 description 3
- 238000011161 development Methods 0.000 description 3
- 238000003780 insertion Methods 0.000 description 3
- 230000037431 insertion Effects 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P1/00—Auxiliary devices
- H01P1/20—Frequency-selective devices, e.g. filters
- H01P1/207—Hollow waveguide filters
Landscapes
- Control Of Motors That Do Not Use Commutators (AREA)
Abstract
The invention discloses a high-order mode substrate integrated waveguide dual-passband circular cavity filter, which comprises a lower metal layer, a dielectric substrate and an upper metal layer which are sequentially arranged in an interlayer structure of the filter, wherein a substrate integrated waveguide circular cavity (3) is taken as a main body of a planar structure, and metal through holes (4) penetrating through the upper metal layer, the dielectric substrate and the lower metal layer are uniformly distributed along the circumferential direction; a second type of grooving line (11) is arranged in the middle of the substrate integrated waveguide circular cavity, a first type of grooving line (10) is arranged between the metal through hole and the second type of grooving line (11), a first coplanar waveguide (7) and a second coplanar waveguide are symmetrically arranged in the substrate integrated waveguide circular cavity, and a pair of metal perturbation through holes (9) penetrating through the upper metal layer, the dielectric substrate and the lower metal layer are further arranged between the first coplanar waveguide and the second coplanar waveguide (8). The invention has simple structure, convenient processing, can be suitable for higher frequency and can be applied to 5G millimeter wave and 6G mobile communication systems.
Description
Technical Field
The invention relates to the field of microwave passive devices, in particular to a high-order mode substrate integrated waveguide dual-passband circular cavity filter based on through hole disturbance and a slotted structure.
Background
With the rapid development and the increasing maturity of modern wireless communication systems, filters, which are important components thereof, have attracted extensive attention and research. However, multiband transmission is a development trend of future mobile communication systems, which makes single-frequency microwave/radio frequency devices unable to meet the demand, and therefore multiband filters are beginning to be widely researched. In the traditional multi-band design, a multi-band-pass filter with a micro-strip structure is widely designed, but in a millimeter wave frequency band, a passive device with the micro-strip structure has the problems of large insertion loss, difficulty in processing and the like; in addition, the filter with the non-planar structure has the advantages of low loss, large power capacity and the like similar to structures such as a rectangular waveguide, a coaxial line and the like, but is difficult to integrate with a planar circuit. Therefore, the substrate integrated waveguide technology solves these problems in the millimeter wave band, and thus has attracted much attention.
The substrate integrated waveguide technology is a novel waveguide device with low insertion loss, high quality factor and high power capacity which appears in the last decade, various substrate integrated waveguides realized based on the technologies of PCB, LTCC and the like have the advantages of the traditional metal waveguide and the planar circuit in a passive and active mode, and the production cost and the design complexity have incomparable advantages in the microwave and millimeter wave frequency band. In order to realize multi-level transmission response or a plurality of pass bands, a traditional substrate integrated waveguide filter or a multi-pass band filter usually needs to cascade a plurality of cavities, so that the size is overlarge, the structure of the high-order mode substrate integrated waveguide based on through hole disturbance and a slotted structure can utilize the inherent mode in a circular cavity to the maximum extent, thereby realizing multi-level and multi-pass band response by utilizing a single cavity, effectively reducing the area and enabling the circuit structure to be very compact.
With the rapid development of communication systems, especially 5G microwave millimeter wave communication systems and large-scale MIMO systems, the size of the radio frequency circuit has higher requirements, and the requirement of multiple pass bands is additionally provided as well as the requirement of small size. Therefore, miniaturization and multi-pass band are used as important research bases for designing the filter. However, in the prior art, the miniaturization of the filter and the multi-pass band are difficult to be compatible.
Disclosure of Invention
The technical problem is as follows: the invention aims to provide a high-order mode substrate integrated waveguide dual-passband circular cavity filter based on through hole disturbance and a slotted structure, which meets the requirements of miniaturization and multiple passbands. The closed structure has the characteristics of high quality factor and low loss, and can be applied to higher frequency.
The technical scheme is as follows: the interlayer structure sequence of the high-order mode substrate integrated waveguide dual-passband circular cavity filter is a lower metal layer, a dielectric substrate and an upper metal layer: the planar structure of the filter takes a substrate integrated waveguide circular cavity as a main body, and metal through holes penetrating through an upper metal layer, a medium substrate and a lower metal layer are uniformly distributed along the circumferential direction of the substrate integrated waveguide circular cavity; the middle of the substrate integrated waveguide circular cavity is provided with a second type of groove line, a first type of groove line is arranged between the metal through hole and the second type of groove line, a first coplanar waveguide and a second coplanar waveguide are symmetrically arranged in the substrate integrated waveguide circular cavity, and a pair of metal perturbation through holes penetrating through the upper metal layer, the dielectric substrate and the lower metal layer are further arranged between the first coplanar waveguide and the second coplanar waveguide.
Wherein,
the metal disturbance through holes comprise a first metal disturbance through hole positioned on the left side of the substrate integrated waveguide circular cavity and a second metal disturbance through hole positioned on the right side of the substrate integrated waveguide circular cavity, the two metal disturbance through holes are in mirror symmetry along the radius of the substrate integrated waveguide circular cavity, and the two metal disturbance through holes are positioned in an obtuse angle formed by the radius of the first coplanar waveguide on the left side of the substrate integrated waveguide circular cavity and the radius of the second coplanar waveguide on the right side of the substrate integrated waveguide circular cavity.
The first type of slotted structure comprises a left slotted structure positioned on the left side of the substrate integrated waveguide circular cavity and a right slotted structure positioned on the right side of the substrate integrated waveguide circular cavity, the two slotted structures are arc-shaped structures, the opening direction points to the circle center along the radius of the substrate integrated waveguide circular cavity, and meanwhile, the left slotted structure and the right slotted structure are in mirror symmetry along the radius of the substrate integrated waveguide circular cavity.
The second type of slotted structure is positioned at the center of the substrate integrated waveguide circular cavity, the slotted structure is of an arc structure, the circle center of the slotted structure is positioned at the circle center of the substrate integrated waveguide circular cavity, and the opening direction points to the metal perturbation through hole direction of the substrate integrated waveguide circular cavity.
The left lower side of the substrate integrated waveguide circular cavity is connected with an input port through a first coplanar waveguide and an output port through an output microstrip line through a second coplanar waveguide, and the input microstrip line and the output microstrip line are in mirror symmetry along the radius of the substrate integrated waveguide circular cavity and form an obtuse angle.
The input microstrip line and the output microstrip line are both 50 ohms.
Has the beneficial effects that: the invention discloses a high-order mode substrate integrated waveguide dual-passband circular cavity filter based on through hole disturbance and a slotted structure. Compared with the technologies of a multilayer structure, a half die, a quarter die, an eighth die and the like, the invention can be realized only by a common PCB process without the multilayer structure, and meanwhile, the closed structure has the characteristics of high quality factor and small loss and can be applied to higher frequency.
Drawings
FIG. 1 is a block diagram of a filter in accordance with an embodiment of the present invention;
fig. 2 is a frequency response graph of a filter in an embodiment of the invention.
The figure has the following components: the structure comprises an input port 1, an output port 2, a substrate integrated waveguide circular cavity 3, a metal through hole 4, an input microstrip line 5, an output microstrip line 6, a first coplanar waveguide 7, a second coplanar waveguide 8, a metal perturbation through hole 9, a first metal perturbation through hole 91, a second metal perturbation through hole 92, a first grooved line 10, a left grooved structure 101, a right grooved structure 102 and a second grooved line 11.
Detailed Description
The technical solution of the present invention will be further described with reference to the following detailed description and accompanying drawings.
The high-order mode substrate integrated waveguide dual-passband circular cavity filter is based on a through hole disturbance and slotting structure, and the interlayer structure of the filter comprises a lower metal layer, a dielectric substrate and an upper metal layer in sequence: the planar structure of the filter takes a substrate integrated waveguide circular cavity 3 as a main body, and metal through holes 4 penetrating through an upper metal layer, a medium substrate and a lower metal layer are uniformly distributed along the circumferential direction of the substrate integrated waveguide circular cavity 3; a second type of grooving line 11 is arranged in the middle of the substrate integrated waveguide circular cavity 3, a first type of grooving line 10 is arranged between the metal through hole 4 and the second type of grooving line 11, a first coplanar waveguide 7 and a second coplanar waveguide 8 are symmetrically arranged in the substrate integrated waveguide circular cavity 3, and a pair of metal perturbation through holes 9 penetrating through the upper metal layer, the dielectric substrate and the lower metal layer are further arranged between the first coplanar waveguide 7 and the second coplanar waveguide 8.
The metal disturbance through hole 9 comprises a first metal disturbance through hole 91 positioned on the left side of the substrate integrated waveguide circular cavity and a second metal disturbance through hole 92 positioned on the right side of the substrate integrated waveguide circular cavity, the two metal disturbance through holes are in mirror symmetry along the diameter of the substrate integrated waveguide circular cavity, and the two metal disturbance through holes are positioned on the inner side of an included angle formed by the radiuses of the first coplanar waveguide on the left side of the substrate integrated waveguide circular cavity and the second coplanar waveguide on the right side of the substrate integrated waveguide circular cavity, so that the frequencies of a pair of orthogonal degenerate modes TM110 and a pair of orthogonal degenerate modes TM210 can be respectively distinguished, and the frequency orders of two modes of the orthogonal degenerate modes TM210 are exchanged at the same time, so that the transmission zero point between the TM210 and the TM020 is transferred to a low frequency, and a second pass band is formed.
The first-class slotted structure 10 comprises a left slotted structure positioned on the left side of the substrate integrated waveguide circular cavity and a right slotted structure positioned on the right side of the substrate integrated waveguide circular cavity, the two slotted structures are arc-shaped structures, the opening direction of the two slotted structures points to the circle center of the substrate integrated waveguide circular cavity along the radius of the substrate integrated waveguide circular cavity, and the two slotted structures are in mirror symmetry along the radius of the substrate integrated waveguide circular cavity, so that the low-frequency modes of the mutually orthogonal degenerate mode TM110 and the mutually orthogonal degenerate mode TM210 can be respectively adjusted, and the bandwidths of the two pass bands can be adjusted.
The second type of slotted structure 11 is located at the center of the substrate integrated waveguide circular cavity, the slotted structure is an arc-shaped structure, the center of the arc-shaped structure is located at the center of the substrate integrated waveguide circular cavity, and the opening direction points to the lower side of the substrate integrated waveguide circular cavity, so that the high-frequency mode and the TM020 mode of the degenerate mode TM110 which are orthogonal to each other can be adjusted simultaneously, and the adjustment of the bandwidths of the two pass bands is more flexible.
The left lower side of the substrate integrated waveguide circular cavity is connected with an input microstrip line through a first coplanar waveguide, the right lower side of the substrate integrated waveguide circular cavity is connected with an output microstrip line through a second coplanar waveguide, and the two microstrip lines are in mirror symmetry along the diameter of the substrate integrated waveguide circular cavity and form an obtuse angle.
The input microstrip line and the output microstrip line are both 50 ohms, the end part of the input microstrip line is an input port, and the end part of the output microstrip line is an output port.
The relative dielectric constant of the dielectric substrate is 2.2, and the dielectric thickness is 0.254mm. The overall planar dimensions of the filter were 6.5mm.
In the specific embodiment, a signal is input through the input port 1, is input from the input microstrip line 5 to the substrate integrated waveguide circular cavity 3 loaded with the metal disturbance through hole 9, the first type of slotted structure 10 and the second type of slotted structure 11, and is transmitted to the output microstrip line 6 through the filtered signal, and is output through the output port 2.
FIG. 2 is a frequency response curve of the dual-passband filter in this embodiment, in which two solid lines are simulation result curves and two dashed line curves are test result curves, the center frequency of the dual-passband filter in this embodiment is 42/60GHz, the bandwidth is 3.3/5.2GHz, the insertion loss in the passband is better than 1.1/2.1dB, the return loss in the passband is better than 17/11.5dB, and the simulation and test results have good consistency.
Claims (6)
1. The utility model provides an integrated waveguide double passband circular cavity filter of higher mode substrate which characterized in that: the interlayer structure of the filter comprises a lower metal layer, a dielectric substrate and an upper metal layer in sequence: the planar structure of the filter takes a substrate integrated waveguide circular cavity (3) as a main body, and metal through holes (4) penetrating through an upper metal layer, a medium substrate and a lower metal layer are uniformly distributed along the circumferential direction of the substrate integrated waveguide circular cavity (3); the substrate integrated waveguide circular cavity is characterized in that a second type of grooving line (11) is arranged in the middle of the substrate integrated waveguide circular cavity (3), a first type of grooving line (10) is arranged between the metal through hole (4) and the second type of grooving line (11), a first coplanar waveguide (7) and a second coplanar waveguide (8) are symmetrically arranged in the substrate integrated waveguide circular cavity (3), and a pair of metal micro-interference through holes (9) penetrating through the upper metal layer, the dielectric substrate and the lower metal layer are further arranged between the first coplanar waveguide (7) and the second coplanar waveguide (8).
2. The high-order mode substrate integrated waveguide dual-passband circular cavity filter according to claim 1, wherein: the metal disturbance through hole (9) comprises a first metal disturbance through hole (91) positioned on the left side of the substrate integrated waveguide circular cavity (3) and a second metal disturbance through hole (92) positioned on the right side of the substrate integrated waveguide circular cavity (3), the two metal disturbance through holes are in mirror symmetry along the radius of the substrate integrated waveguide circular cavity (3), and the two metal disturbance through holes are positioned in an obtuse angle formed by the radius of a first coplanar waveguide (7) positioned on the left side of the substrate integrated waveguide circular cavity (3) and the radius of a second coplanar waveguide (8) positioned on the right side.
3. The high-order mode substrate integrated waveguide dual-passband circular cavity filter according to claim 1, wherein: the first slotted structure (10) comprises a left slotted structure (101) positioned on the left side of the substrate integrated waveguide circular cavity (3) and a right slotted structure (102) positioned on the right side of the substrate integrated waveguide circular cavity (3), the two slotted structures (10) are arc-shaped structures, the opening directions of the two slotted structures point to the circle center along the radius of the substrate integrated waveguide circular cavity (3), and meanwhile the left slotted structure (101) and the right slotted structure (102) are in mirror symmetry along the radius of the substrate integrated waveguide circular cavity (3).
4. The high-order mode substrate integrated waveguide dual-passband circular cavity filter according to claim 1, wherein: the second type of slotted structure (11) is positioned at the center of the substrate integrated waveguide circular cavity (3), the slotted structure is of an arc structure, the circle center of the slotted structure is positioned at the circle center of the substrate integrated waveguide circular cavity (3), and the opening direction points to the direction of the metal perturbation through hole (9) of the substrate integrated waveguide circular cavity (3).
5. The high-order mode substrate integrated waveguide dual-passband circular cavity filter according to claim 1, wherein: the left lower side of the substrate integrated waveguide circular cavity (3) is connected with the input port (1) through the first coplanar waveguide (7) through the input microstrip line (5), the right lower side of the substrate integrated waveguide circular cavity is connected with the output port (2) through the second coplanar waveguide (8) through the output microstrip line (6), and the input microstrip line (5) and the output microstrip line (6) are in mirror symmetry along the radius of the substrate integrated waveguide circular cavity (3) and form an obtuse angle.
6. The high-order mode substrate integrated waveguide double-passband circular cavity filter according to claim 5, wherein: the input microstrip line (5) and the output microstrip line (6) are both 50 ohms.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211331585.6A CN115458883B (en) | 2022-10-28 | 2022-10-28 | High-order mode substrate integrated waveguide dual-passband circular cavity filter |
| PCT/CN2023/085820 WO2024087509A1 (en) | 2022-10-28 | 2023-04-02 | High-order mode substrate integrated waveguide dual-passband circular cavity filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211331585.6A CN115458883B (en) | 2022-10-28 | 2022-10-28 | High-order mode substrate integrated waveguide dual-passband circular cavity filter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115458883A true CN115458883A (en) | 2022-12-09 |
| CN115458883B CN115458883B (en) | 2024-08-09 |
Family
ID=84311564
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211331585.6A Active CN115458883B (en) | 2022-10-28 | 2022-10-28 | High-order mode substrate integrated waveguide dual-passband circular cavity filter |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN115458883B (en) |
| WO (1) | WO2024087509A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116315553A (en) * | 2023-04-10 | 2023-06-23 | 电子科技大学 | Transition structure suitable for substrate integrated waveguide-microstrip |
| WO2024087509A1 (en) * | 2022-10-28 | 2024-05-02 | 东南大学 | High-order mode substrate integrated waveguide dual-passband circular cavity filter |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090243762A1 (en) * | 2008-03-27 | 2009-10-01 | Xiao-Ping Chen | Waveguide filter |
| CN108539338A (en) * | 2018-05-21 | 2018-09-14 | 东南大学 | A kind of a quarter mould substrate integral wave guide filter based on notching construction |
| CN109301414A (en) * | 2018-09-26 | 2019-02-01 | 曲阜师范大学 | A kind of circular substrate integrated waveguide bandpass filter |
| CN208622911U (en) * | 2018-08-21 | 2019-03-19 | 南京信息工程大学 | A kind of novel three moulds SIW resonant cavity filter |
| CN111276781A (en) * | 2020-03-11 | 2020-06-12 | 东南大学 | High-order mode substrate integrated waveguide circular cavity filter based on through hole disturbance |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT201600102172A1 (en) * | 2016-10-12 | 2018-04-12 | Rf Microtech S R L | Bandpass filter reconfigurable in e-plane type guide |
| CN110350273B (en) * | 2019-04-19 | 2020-11-17 | 江南大学 | Dual-passband millimeter wave substrate integrated waveguide filter |
| CN115458883B (en) * | 2022-10-28 | 2024-08-09 | 东南大学 | High-order mode substrate integrated waveguide dual-passband circular cavity filter |
-
2022
- 2022-10-28 CN CN202211331585.6A patent/CN115458883B/en active Active
-
2023
- 2023-04-02 WO PCT/CN2023/085820 patent/WO2024087509A1/en unknown
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090243762A1 (en) * | 2008-03-27 | 2009-10-01 | Xiao-Ping Chen | Waveguide filter |
| CN108539338A (en) * | 2018-05-21 | 2018-09-14 | 东南大学 | A kind of a quarter mould substrate integral wave guide filter based on notching construction |
| CN208622911U (en) * | 2018-08-21 | 2019-03-19 | 南京信息工程大学 | A kind of novel three moulds SIW resonant cavity filter |
| CN109301414A (en) * | 2018-09-26 | 2019-02-01 | 曲阜师范大学 | A kind of circular substrate integrated waveguide bandpass filter |
| CN111276781A (en) * | 2020-03-11 | 2020-06-12 | 东南大学 | High-order mode substrate integrated waveguide circular cavity filter based on through hole disturbance |
Non-Patent Citations (1)
| Title |
|---|
| 刘庆 等: "双/三模基片集成波导和共面波导混合结构滤波器设计", 电子学报, no. 04, 15 April 2018 (2018-04-15) * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024087509A1 (en) * | 2022-10-28 | 2024-05-02 | 东南大学 | High-order mode substrate integrated waveguide dual-passband circular cavity filter |
| CN116315553A (en) * | 2023-04-10 | 2023-06-23 | 电子科技大学 | Transition structure suitable for substrate integrated waveguide-microstrip |
| CN116315553B (en) * | 2023-04-10 | 2024-04-12 | 电子科技大学 | Transition structure suitable for substrate integrated waveguide-microstrip |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115458883B (en) | 2024-08-09 |
| WO2024087509A1 (en) | 2024-05-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115458883B (en) | High-order mode substrate integrated waveguide dual-passband circular cavity filter | |
| CN110444840B (en) | Double-frequency differential band-pass filter based on stub load resonator | |
| CN109462000B (en) | Multi-layer substrate integrated waveguide third-order filtering power divider | |
| CN109301416B (en) | Suspended substrate integrated waveguide transmission line | |
| CN103904391B (en) | Multilayer hybrid guided mode hexagon substrate integral wave guide filter | |
| CN114284673B (en) | Substrate integrated waveguide dual-band filtering balun | |
| CN112332051B (en) | Ultra-wideband filter | |
| CN108539338A (en) | A kind of a quarter mould substrate integral wave guide filter based on notching construction | |
| CN111276781B (en) | High-order mode substrate integrated waveguide circular cavity filter based on through hole disturbance | |
| CN110718732B (en) | Substrate integrated slow wave air waveguide for improving performance of microwave passive device | |
| CN110190371B (en) | Waveguide power divider | |
| CN116759779B (en) | 5G millimeter wave filtering power division module | |
| CN212257633U (en) | Half-mode substrate integrated waveguide dual-band filter | |
| CN111403861B (en) | UIR loaded three-order dual-passband substrate integrated waveguide filter | |
| CN109755711B (en) | Double-layer half-module substrate integrated waveguide broadband filter coupler | |
| CN111293390A (en) | UIR loaded three-order dual-passband substrate integrated waveguide filter | |
| CN115064851A (en) | Rectangular cavity and round cavity multimode coupled substrate integrated waveguide duplexer | |
| CN211238454U (en) | UIR loaded three-order dual-passband substrate integrated waveguide filter | |
| CN212033198U (en) | Substrate integrated waveguide filter combining one-eighth mode and one-fourth mode | |
| CN115275547A (en) | Frequency and amplitude independent adjustable substrate integrated waveguide filter | |
| CN114335966A (en) | Miniaturized substrate integrated waveguide magic T with filtering function | |
| CN210296585U (en) | Single-cavity dual-band microwave filter based on coplanar waveguide | |
| CN110416674B (en) | Single-cavity double-frequency-band microwave filter based on coplanar waveguide | |
| CN209747694U (en) | Low-pass filter with complementary split resonant ring and U-shaped groove defected ground | |
| CN114204241A (en) | Microstrip-open slot line coupled dual-band 90-degree directional coupler |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |