CN109659678A - A kind of periodicity microband leaky-wave antenna - Google Patents
A kind of periodicity microband leaky-wave antenna Download PDFInfo
- Publication number
- CN109659678A CN109659678A CN201811337892.9A CN201811337892A CN109659678A CN 109659678 A CN109659678 A CN 109659678A CN 201811337892 A CN201811337892 A CN 201811337892A CN 109659678 A CN109659678 A CN 109659678A
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- rectangular patch
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- wave antenna
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- slab
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- 230000005540 biological transmission Effects 0.000 claims abstract description 23
- 239000002184 metal Substances 0.000 claims abstract description 21
- 239000004020 conductor Substances 0.000 claims description 7
- 230000005855 radiation Effects 0.000 claims description 5
- 239000007787 solid Substances 0.000 claims description 4
- 230000000737 periodic effect Effects 0.000 claims description 3
- 238000004891 communication Methods 0.000 description 8
- 238000013461 design Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000011161 development Methods 0.000 description 2
- 238000010295 mobile communication Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
- H01Q1/38—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith formed by a conductive layer on an insulating support
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/48—Earthing means; Earth screens; Counterpoises
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/50—Structural association of antennas with earthing switches, lead-in devices or lightning protectors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
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- Waveguide Aerials (AREA)
Abstract
The invention discloses a kind of periodical microband leaky-wave antennas, including dielectric-slab, resonant element, transmission line, metal floor and feed connection, by the way that centrosymmetric harmonic period unit each other is arranged, periodical feed element is formed with transmission line, each harmonic period unit is arranged to multiple rectangular patch groups simultaneously, and the rectangular patch in different rectangular patch groups has different length-width ratios, it can be before and after realizing main beam to while scanning and obtain higher antenna gain, realize the flexible variation of harmonic period unit size, so that the structure of antenna is not limited by harmonic period unit, flexibility greatly increases.
Description
Technical field
The present invention relates to wireless communication field, especially a kind of periodical microband leaky-wave antenna.
Background technique
With the continuous development of wireless communication cause, people have the transmission rate and capacity of wireless communication system higher
Requirement, microband leaky-wave antenna is widely used as an important classification in microstrip antenna.Compared to biography
Uniting, smart antenna is bulky and feed system, the feature of control system complexity, microband leaky-wave antenna low section be easy to match
The characteristics of be suitable for integrated production, and the automatically controlled frequency of its main beam sweeps characteristic and microband leaky-wave antenna is made to can be applied to mobile communication
In the research of the novel intelligent antenna of system.Range is swept in order to increase frequency, expands the application range of antenna, periodical micro-strip leaky wave
Antenna is suggested, and the simple structure of Antenna Design is also maintained while realizing antenna main beam omnidirectional scan characteristic.So
And periodical microband leaky-wave antenna universal at present is made of the identical resonant element of physical structural characteristic, this period
Property microband leaky-wave antenna is since there are the identical resonant elements of multiple physical structural characteristics, so as to the integrally-built design of antenna
Limit to, is unfavorable for changing the shape of antenna, the flexibility used substantially reduces.
Summary of the invention
To solve the above problems, guaranteeing antenna the purpose of the present invention is to provide a kind of periodical microband leaky-wave antenna
While communication effect, neatly the structure of antenna can be designed.
Technical solution used by the present invention solves the problems, such as it is:
The invention proposes a kind of periodical microband leaky-wave antenna, including dielectric-slab, resonant element, transmission line, metal
Plate and feed connection, the resonant element and transmission line composition metal radiation body and the side for being set to dielectric-slab, it is described
Metal floor is set to the other side of dielectric-slab；The feed connection includes apex drive needle and outer conductor, the apex drive
Needle is connect with transmission line, and the outer conductor is connect with metal floor；The resonant element includes two harmonic period units, each
Harmonic period unit include at least three rectangular patch groups, single rectangular patch group by two pieces of centrosymmetric rectangular patches above and below
It is diagonally formed by connecting, the rectangular patch of different rectangular patch groups has different length-width ratios, and two rectangular patches of arbitrary neighborhood are not
In the same side of transmission line, two harmonic period units central symmetry each other.
Further, each harmonic period unit includes the first rectangular patch group, the second rectangular patch group and third rectangle patch
Piece group.
Further, the length of the first rectangular patch group, the second rectangular patch group and third rectangular patch group successively increases
Add, width is sequentially reduced.
Further, the dielectric-slab is solid dielectric plate or air dielectric plate.
Further, the metal floor is planar structure, and is mutually close to dielectric-slab.
Further, the entire length of antenna is greater than 3 times of working frequency range wavelength.
Further, the rectangular patch group periodical propagation constant having the same.
The one or more technical solutions provided in the embodiment of the present invention, at least have the following beneficial effects: and pass through setting
Centrosymmetric harmonic period unit each other forms periodical feed element with transmission line, while by each harmonic period unit
It is arranged to multiple rectangular patch groups, and the rectangular patch in different rectangular patch groups has different length-width ratios, it can be in reality
To while scanning and obtain higher antenna gain before and after existing main beam, the flexible variation of harmonic period unit size is realized,
So that the structure of antenna is not limited by harmonic period unit, flexibility is greatly increased.
Detailed description of the invention
The invention will be further described with example with reference to the accompanying drawing.
Fig. 1 is the front schematic view of antenna in one embodiment of the invention；
Fig. 2 is the schematic rear view of antenna in one embodiment of the invention；
Fig. 3 is the first rectangular patch group in one embodiment of the invention, the second rectangular patch group and third rectangular patch group
The electric field intensity map of six kinds of permutation and combination；
Fig. 4 is the first rectangular patch group in one embodiment of the invention, the second rectangular patch group and third rectangular patch group
The phase coefficient curve graph of six kinds of permutation and combination.
Specific embodiment
With the continuous development of wireless communication cause, people have the transmission rate and capacity of wireless communication system higher
Requirement, microband leaky-wave antenna is widely used as an important classification in microstrip antenna.Compared to biography
Uniting, smart antenna is bulky and feed system, the feature of control system complexity, microband leaky-wave antenna low section be easy to match
The characteristics of be suitable for integrated production, and the automatically controlled frequency of its main beam sweeps characteristic and microband leaky-wave antenna is made to can be applied to mobile communication
In the research of the novel intelligent antenna of system.Range is swept in order to increase frequency, expands the application range of antenna, periodical micro-strip leaky wave
Antenna is suggested, and the simple structure of Antenna Design is also maintained while realizing antenna main beam omnidirectional scan characteristic.So
And periodical microband leaky-wave antenna universal at present is made of the identical resonant element of physical structural characteristic, this period
Property microband leaky-wave antenna is since there are the identical resonant elements of multiple physical structural characteristics, so as to the integrally-built design of antenna
Limit to, is unfavorable for changing the shape of antenna, the flexibility used substantially reduces.
Based on this, the present invention provides a kind of periodical microband leaky-wave antennas, by the way that centrosymmetric resonance each other is arranged
Periodic unit forms periodical feed element with transmission line, while each harmonic period unit is arranged to multiple rectangular patches
Group, and the rectangular patch in different rectangular patch groups has different length-width ratios, it can be before and after realizing main beam to scanning
And while obtaining higher antenna gain, realize harmonic period unit size flexible variation so that the structure of antenna not by
The limitation of harmonic period unit, flexibility greatly increase.
With reference to the accompanying drawing, the embodiment of the present invention is further elaborated.
- Fig. 2 referring to Fig.1, An embodiment provides a kind of periodical microband leaky-wave antennas, including medium
Plate 100, resonant element, transmission line 300, metal floor 500 and feed connection 400, the resonant element and the transmission line 300
Composition metal radiation body and the side for being set to dielectric-slab 100, the metal floor 500 are set to the other side of dielectric-slab 100；
The feed connection 400 includes apex drive needle and outer conductor, and the apex drive needle is connect with transmission line 300, described to lead outside
Body is connect with metal floor 500；The resonant element includes two harmonic period units 200, and each harmonic period unit 200 wraps
At least three rectangular patch groups are included, single rectangular patch group is diagonally formed by connecting up and down by two pieces of centrosymmetric rectangular patches,
The rectangular patch of different rectangular patch groups has different length-width ratios, and two rectangular patches of arbitrary neighborhood are not in transmission line 300
The same side, two harmonic period units 200 central symmetry each other.
In the present embodiment, by the way that centrosymmetric harmonic period unit each other is arranged, periodical feedback is formed with transmission line
Electric unit, while each harmonic period unit is arranged to multiple rectangular patch groups, and the rectangle in different rectangular patch groups
Patch has different length-width ratios, can be before and after realizing main beam to while scanning and obtain higher antenna gain, reality
The flexible variation of existing harmonic period unit size, so that the structure of antenna is not limited by harmonic period unit, flexibility is significantly
Increase.
Further, another embodiment of the invention additionally provides a kind of periodical microband leaky-wave antenna, wherein each
Harmonic period unit 200 includes the first rectangular patch group 210, the second rectangular patch group 220 and third rectangular patch group 230.
In the present embodiment, three rectangular patch groups are contained in the harmonic period unit 200 of signal period, relative to setting
Two rectangular patch groups are set, there is better performance, meanwhile, relative to more than four rectangular patch groups are arranged, in guarantee property
It is more favorable for actual production while energy, reduces material cost.
Further, another embodiment of the invention additionally provides a kind of periodical microband leaky-wave antenna, wherein described
The length of first rectangular patch group 210, the second rectangular patch group 220 and third rectangular patch group 230 successively increases, and width is successively
Reduce.
In the present embodiment, the first rectangular patch group 210, the second rectangular patch group 220 and third rectangular patch group 230
Length successively increases, and width is sequentially reduced, and has preferable phase coefficient curve, and electromagnetic energy communication effect is good.
Further, another embodiment of the invention additionally provides a kind of periodical microband leaky-wave antenna, wherein described
Dielectric-slab 100 is solid dielectric plate 100 or air dielectric plate 100.
Further, another embodiment of the invention additionally provides a kind of periodical microband leaky-wave antenna, wherein described
Metal floor 500 is planar structure, and is mutually close to dielectric-slab 100.
In the present embodiment, by the way that metal floor 500 is arranged to planar structure, and mutually it is close to dielectric-slab 100,
Can make the structure of antenna entirety becomes more compact.
Further, another embodiment of the invention additionally provides a kind of periodical microband leaky-wave antenna, wherein antenna
Entire length be greater than 3 times of working frequency range wavelength.
In the present embodiment, by the way that the entire length of antenna is set greater than 3 times of working frequency range wavelength, so that antenna
Energy radiate more abundant, to reduce graing lobe, enhance the directionality of antenna entirety, enhance anti-interference ability, reduction signal
Decaying in transmission process.
Further, another embodiment of the invention additionally provides a kind of periodical microband leaky-wave antenna, wherein described
Rectangular patch group periodical propagation constant having the same.
In the present embodiment, the rectangular patch group periodical propagation constant having the same, is conducive to improve antenna
Gain enhances the performance of antenna.
In addition, another embodiment of the invention additionally provides a kind of periodical microband leaky-wave antenna, including dielectric-slab
100, resonant element, transmission line 300, metal floor 500 and feed connection 400, the dielectric-slab 100 are solid dielectric plate 100
Or air dielectric plate 100, the resonant element and the transmission line 300 form metal radiation body and are set to dielectric-slab 100
Side, the metal floor 500 is planar structure, and is mutually close to dielectric-slab 100；The feed connection 400 includes
Apex drive needle and outer conductor, the apex drive needle are connect with transmission line 300, and the outer conductor is connect with metal floor 500；
The resonant element includes two harmonic period units 200, and each harmonic period unit 200 includes periodically biography having the same
Broadcast the first rectangular patch group 210, the second rectangular patch group 220 and third rectangular patch group 230 of constant, the first rectangular patch group
210, the second rectangular patch group 220 and third rectangular patch group 230 are diagonal up and down by two pieces of centrosymmetric rectangular patches respectively
It is formed by connecting, and the rectangle of the first rectangular patch group 210, the second rectangular patch group 220 and third rectangular patch group 230
The length of patch successively increases, and width is sequentially reduced, and the length-width ratio of every group of rectangular patch is different；Two rectangle patches of arbitrary neighborhood
Piece is not in the same side of transmission line 300, two harmonic period units 200 central symmetry each other.
The present embodiment is described further below with reference to concrete case.
Shown in referring to Fig.1, the first rectangular patch group 210, the second rectangular patch group 220 and third rectangular patch group 230
Size are as follows:
1. W1=15mm, D1=20mm
2. W2=16mm, D2=19mm
3. W3=17.2mm, D3=17.5mm
As it can be seen that the length-width ratio D/ of the first rectangular patch group 210, the second rectangular patch group 220 and third rectangular patch group 230
W is different, has 6 kinds of arrangement modes altogether.6 kinds of arrangement modes are represented with serial number below, referring to Fig. 3,6 kinds of arrangement modes are equal
The propagation of electromagnetic wave energy may be implemented, wherein the effect of 1. arrangement mode 2. 3. 2. 1., energy radiation is best；Meanwhile
Referring to Fig. 4,1. arrangement mode 2. 3. 2. 1. has optimal phase coefficient curve graph, and front and back is also most wide to scanning range.
In conclusion the length of the first rectangular patch group 210, the second rectangular patch group 220 and third rectangular patch group 230 successively increases
Add, the arrangement mode that width is sequentially reduced has best electromagnetic wave energy communication effect.
The size of first rectangular patch group 210, the second rectangular patch group 220 and third rectangular patch group 230 can basis
Practical application is freely adjusted, as long as the length-width ratio for meeting rectangular patch in different groups is different and periodicity having the same
The arrangement mode of propagation constant, each rectangular patch group can also be with unrestricted choice, therefore can freely reduce some square
The size of shape patch group, to realize resonance to while scanning and obtain higher antenna gain before and after realizing main beam
The flexible variation of periodic unit size, so that the structure of antenna is not limited by harmonic period unit, flexibility is greatly increased.
In addition, the quantity of rectangular patch group is 3 groups in the present embodiment, it in other embodiments can also be according to requiring to increase
The quantity of rectangular patch group.
It is to be illustrated to preferable implementation of the invention, but the invention is not limited to above-mentioned embodiment party above
Formula, those skilled in the art can also make various equivalent variations on the premise of without prejudice to spirit of the invention or replace
It changes, these equivalent deformations or replacement are all included in the scope defined by the claims of the present application.
Claims (7)
1. it is a kind of periodicity microband leaky-wave antenna, it is characterised in that: including dielectric-slab, resonant element, transmission line, metal floor and
Feed connection, the resonant element and transmission line composition metal radiation body and the side for being set to dielectric-slab, the metal
Floor is set to the other side of dielectric-slab；The feed connection includes apex drive needle and outer conductor, the apex drive needle with
Transmission line connection, the outer conductor are connect with metal floor；The resonant element includes two harmonic period units, each resonance
Periodic unit includes at least three rectangular patch groups, and single rectangular patch group is diagonal up and down by two pieces of centrosymmetric rectangular patches
It is formed by connecting, the rectangular patch of different rectangular patch groups has different length-width ratios, and two rectangular patches of arbitrary neighborhood are not passing
The same side of defeated line, two harmonic period units central symmetry each other.
2. a kind of periodical microband leaky-wave antenna according to claim 1, it is characterised in that: each harmonic period unit packet
Include the first rectangular patch group, the second rectangular patch group and third rectangular patch group.
3. a kind of periodical microband leaky-wave antenna according to claim 2, it is characterised in that: first rectangular patch
The length of group, the second rectangular patch group and third rectangular patch group successively increases, and width is sequentially reduced.
4. a kind of periodical microband leaky-wave antenna according to claim 1, it is characterised in that: the dielectric-slab is solid Jie
Scutum or air dielectric plate.
5. a kind of periodical microband leaky-wave antenna according to claim 1, it is characterised in that: the metal floor is plane
Structure, and be mutually close to dielectric-slab.
6. a kind of periodical microband leaky-wave antenna according to claim 1, it is characterised in that: the entire length of antenna is greater than
3 times of working frequency range wavelength.
7. -6 any a kind of periodical microband leaky-wave antenna according to claim 1, it is characterised in that: the rectangle patch
Piece group periodical propagation constant having the same.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811337892.9A CN109659678A (en) | 2018-11-09 | 2018-11-09 | A kind of periodicity microband leaky-wave antenna |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201811337892.9A CN109659678A (en) | 2018-11-09 | 2018-11-09 | A kind of periodicity microband leaky-wave antenna |
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| CN109659678A true CN109659678A (en) | 2019-04-19 |
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| CN201811337892.9A Pending CN109659678A (en) | 2018-11-09 | 2018-11-09 | A kind of periodicity microband leaky-wave antenna |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111509393A (en) * | 2020-05-08 | 2020-08-07 | 杭州电子科技大学 | One-dimensional plane periodic leaky-wave antenna based on microstrip line structure |
| CN113745838A (en) * | 2021-08-26 | 2021-12-03 | 中山大学 | Leaky-wave antenna with dual-beam radiation |
| CN114002312A (en) * | 2021-09-13 | 2022-02-01 | 广东工业大学 | Metal crack detection sensor and metal crack feature extraction method |
| CN116130963A (en) * | 2023-04-14 | 2023-05-16 | 微网优联科技(成都)有限公司 | Leaky-wave antenna based on half-mode substrate integrated waveguide and dielectric resonator structure |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106785388A (en) * | 2016-12-09 | 2017-05-31 | 安徽四创电子股份有限公司 | A kind of series feed micro-strip array antenna |
| CN207116707U (en) * | 2017-09-13 | 2018-03-16 | 武汉雷可达科技有限公司 | Micro-strip phased array antenna and ground security radar equipment |
-
2018
- 2018-11-09 CN CN201811337892.9A patent/CN109659678A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106785388A (en) * | 2016-12-09 | 2017-05-31 | 安徽四创电子股份有限公司 | A kind of series feed micro-strip array antenna |
| CN207116707U (en) * | 2017-09-13 | 2018-03-16 | 武汉雷可达科技有限公司 | Micro-strip phased array antenna and ground security radar equipment |
Non-Patent Citations (1)
| Title |
|---|
| YUANXIN LI ET-AL: "《A Periodic Microstrip Leaky-wave Antenna》", 《2018 ASIA-PACIFIC MICROWAVE CONFERENCE》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111509393A (en) * | 2020-05-08 | 2020-08-07 | 杭州电子科技大学 | One-dimensional plane periodic leaky-wave antenna based on microstrip line structure |
| CN111509393B (en) * | 2020-05-08 | 2022-04-01 | 杭州电子科技大学 | One-dimensional plane periodic leaky-wave antenna based on microstrip line structure |
| CN113745838A (en) * | 2021-08-26 | 2021-12-03 | 中山大学 | Leaky-wave antenna with dual-beam radiation |
| CN114002312A (en) * | 2021-09-13 | 2022-02-01 | 广东工业大学 | Metal crack detection sensor and metal crack feature extraction method |
| CN114002312B (en) * | 2021-09-13 | 2023-10-24 | 广东工业大学 | Metal crack detection sensor and metal crack feature extraction method |
| CN116130963A (en) * | 2023-04-14 | 2023-05-16 | 微网优联科技(成都)有限公司 | Leaky-wave antenna based on half-mode substrate integrated waveguide and dielectric resonator structure |
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Application publication date: 20190419 |