CN107404005A - A kind of new high selectivity frequency-selective surfaces based on individual layer PCB technology - Google Patents
A kind of new high selectivity frequency-selective surfaces based on individual layer PCB technology Download PDFInfo
- Publication number
- CN107404005A CN107404005A CN201710791877.0A CN201710791877A CN107404005A CN 107404005 A CN107404005 A CN 107404005A CN 201710791877 A CN201710791877 A CN 201710791877A CN 107404005 A CN107404005 A CN 107404005A
- Authority
- CN
- China
- Prior art keywords
- frequency
- selective surfaces
- metal
- high selectivity
- new high
- 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
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
- H01Q15/0006—Devices acting selectively as reflecting surface, as diffracting or as refracting device, e.g. frequency filtering or angular spatial filtering devices
- H01Q15/0013—Devices acting selectively as reflecting surface, as diffracting or as refracting device, e.g. frequency filtering or angular spatial filtering devices said selective devices working as frequency-selective reflecting surfaces, e.g. FSS, dichroic plates, surfaces being partly transmissive and reflective
- H01Q15/0026—Devices acting selectively as reflecting surface, as diffracting or as refracting device, e.g. frequency filtering or angular spatial filtering devices said selective devices working as frequency-selective reflecting surfaces, e.g. FSS, dichroic plates, surfaces being partly transmissive and reflective said selective devices having a stacked geometry or having multiple layers
Landscapes
- Aerials With Secondary Devices (AREA)
Abstract
The invention discloses a kind of new high selectivity frequency-selective surfaces based on individual layer PCB technology, belong to the technical field of electromagnetic field and microwave.The metal level of the frequency-selective surfaces includes multiple metal units of periodic arrangement, antenna house, metal mirror etc. can be used as to be used for military and civilian field；The frequency-selective surfaces include upper and lower two layers mutually isostructural frequency-selective surfaces metal level and middle dielectric layer；The frequency-selective surfaces metal unit includes metal Fang Huan and four metal isosceles right triangles, and four angles of metal wire connection side ring with four bendings and triangle base.The present invention realizes frequency band-pass filtering property, respectively introduces a transmission zero in passband both sides using double layer of metal structure, reduces the intermediate zone between passband and stopband, realize the steep drop of band logical both sides, realize the high selectivity of frequency-selective surfaces.
Description
Technical field
The invention belongs to the technical field of electromagnetic field and microwave, more particularly to a kind of high selection based on individual layer PCB technology
Resistant frequency selects surface.
Background technology
Frequency-selective surfaces (Frequency selective surface, FSS) are according to periodically by identical unit
The single or multiple lift planar structure being arranged to make up, itself can not absorb energy, but have the function that filtering, substantially be a kind of
Spatial filter.Characteristic possessed by frequency-selective surfaces is widely used in antenna system, radome, wireless security screen
The field such as cover.
In recent years, frequency multiplexing technique is all received in commercial communication and military field and greatly paid attention to, and is quickly grown.But
The subsystem of multiple different frequencies is integrated in same system, and the coupling and interference between each subsystem may influence entirely
The performances of system, frequency-selective surfaces are applied in these systems and effectively can be come out the signal isolation of different frequency,
Influence between them is preferably minimized.The application of different frequency also result in the growing tension of frequency spectrum resource, therefore high-performance
Frequency-selective surfaces increasingly become a kind of focus, wherein the bilateral characteristic that drops suddenly is particularly critical.Pair of frequency-selective surfaces
The intermediate zone that can greatly reduce between passband and stopband drops in side suddenly, is allowed to close to preferable filtering performance.Realize frequency
The bilateral steep drop of rate selection surface transmission response, can utilize Multilayer Frequency-Selective Surfaces cascade structure, but this can cause entirety
Frequency-selective surfaces thickness it is very big, often do not agree with practical application；A transmission zero is respectively introduced in passband both sides also may be used
To realize the bilateral steep drop of frequency-selective surfaces transmission response.
For example, document《Design and experimental verification of compact frequency-
selective surface with quasi-elliptic bandpass response》(G.Q.Luo,W.Hong,
Q.H.Lai,K.Wu,and L.L.Sun,“IEEE Trans.Microw.Theory Techn.,vol.55,no.12,
Pp.2481-2487, Dec.2007 ") propose a kind of frequency-selective surfaces based on integrated waveguide, respectively introduced in passband both sides
One transmission zero, passband is realized to the steep drop between stopband.
It can be found that to realize that the bilateral frequency-selective surfaces dropped suddenly can utilize multilayer frequency to select from various documents
The technology such as surface superposition or integrated waveguide, but these technologies are often sufficiently complex so that frequency-selective surfaces processing and fabricating
It is very difficult, it is difficult in actual applications.
The content of the invention
The purpose to be realized of the present invention：In order to overcome in present technology, high selectivity frequency-selective surfaces are realized, are needed
The problem of wanting complex technology and being difficult to realize in actual applications, put forward a kind of new high selectivity frequency being easily achieved
Rate selects surface.
To achieve these goals, concrete scheme is as follows：
High selectivity frequency-selective surfaces of the present invention are made up of the unit of multiple periodic distributions, and each unit is from top to bottom
Include the first metal layer, dielectric layer, second metal layer successively；The first metal layer is identical with second metal layer structure size, and phase
It is symmetrical arranged for dielectric layer.
The first metal layer, second metal layer are mainly by square ring, and four metal structures being placed in Fang Huan are formed；Metal
Structure includes folding line, triangular structure, and four metal structures are centrosymmetric distribution；
One end of folding line and Fang Huan interior angle connect, and the length of side center of the other end and triangular structure connects.
Further, the Fang Huan of the frequency-selective surfaces unit, folding line, triangular structure are metal.
Further, material is F4B-2 used by the dielectric layer of the frequency-selective surfaces.
Further, when the frequency-selective surfaces working frequency is near 4.8-5.1GHz, thickness of dielectric layers 2mm.
Further, the unit size of the frequency-selective surfaces is 8.8mm × 8.8mm；
Further, metal side's ring size is 8.8mm × 8.8mm, hem width 0.8mm；
Further, a length of 9.3mm of metal folding line, a width of 0.2mm of metal folding line；
Further, triangles of metal is right angled isosceles triangle, a length of 2.4mm of its waist, and the spacing of adjacent triangle is
0.4mm.One end of folding line and Fang Huan interior angle connect, and the base center of the other end and right angled isosceles triangle connects.
Compared with prior art, beneficial effects of the present invention：
1. the frequency-selective surfaces of the present invention only need one layer of medium and double layer of metal, it is only necessary to which individual layer pcb board is processed, easily
Realized in processing.
2. the present invention realizes frequency band-pass filtering property, a transmission is respectively introduced in passband both sides using double layer of metal structure
Zero point, reduce the intermediate zone between passband and stopband, realize the bilateral steep drop of band logical both sides, reduce passband and stopband it
Between intermediate zone realize the high selectivities of frequency-selective surfaces.
3. transmission response band internal loss is less than 1dB in the frequency-selective surfaces of the present invention, there is good flat characteristic.
4. the frequency-selective surfaces of the present invention still there is good transmission to ring in the case of not same polarization and 45 ° of oblique incidences
Should.
5. the unit size of the frequency-selective surfaces of the present invention is 1/7th wavelength, there is the characteristic of miniaturization.
Brief description of the drawings
Fig. 1 is frequency-selective surfaces metal unit schematic diagram of the present invention；
Fig. 2 is frequency-selective surfaces structural representation of the present invention, wherein (2) are the first metal layer, (3) are medium
Layer, (4) are second metal layer；
Fig. 3 is frequency-selective surfaces artificial reflections coefficient of the present invention and transmission coefficient curve map；
Fig. 4 is transmission curve figure of the frequency-selective surfaces of the present invention under 45 ° of oblique incidences of electromagnetic wave：Wherein, Fig. 4 A
For the transmission curve of TE ripples；Fig. 4 B are the transmission curve of TM ripples.
Embodiment
The present invention is described in further detail with reference to the accompanying drawings and examples.
As shown in figure 1, the frequency-selective surfaces metal unit structure of the present invention includes metal Fang Huan (11) and four metals
Isosceles right triangle (13), and with four bending four angles of metal wire (12) connection side's ring and triangle base；Such as Fig. 2
For frequency-selective surfaces structural representation of the present invention, including frequency-selective surfaces the first metal layer (2), dielectric-slab (3), frequency
Rate selection surface second metal layer (4), wherein frequency-selective surfaces the first metal layer (2) and frequency-selective surfaces second metal layer
(4) it is identical and symmetrical on dielectric-slab (3).
The first metal layer (2) and second metal layer (4) of the high selectivity frequency-selective surfaces of the present invention are copper foil, medium
Layer (3) thickness is 2mm, and dielectric material F4B-2, dielectric constant 2.65, metal unit (1) size is 8.8mm × 8.8mm, gold
The hem width for belonging to Fang Huan (11) is 0.8mm, and isosceles right triangle of four right-angle sides at a distance of 0.4mm is placed among Fang Huan
(13) the metal folding line (12) for being, 9.3mm with length connects the corner of triangle (13) and square ring (11).
During electromagnetic wave vertical incidence, inductance is equivalent to when direction of an electric field is parallel to metal wire, direction of an electric field is perpendicular to metal
During line, the gap between adjacent wires can be equivalent to electric capacity.In the frequency-selective surfaces metal unit of the present invention, metal bending
Broken line (12) is equivalent to inductance, and the gap between adjacent metal triangle (13) is equivalent to electric capacity, and series capacitance inductance forms string
Join resonance and produce transmission zero；And gap and metal Fang Huan between metal folding line (12), adjacent metal triangle (13)
(11) form parallel resonance and produce transmission pole.Therefore single-layer metal unit can produce a transmission zero and a transmission pole
(fLimit＜ fZero point), double layer of metal unit can produce two transmission zero (f0. 1And f0. 2) and two transmission pole (fLimit 1With
fLimit 2), when dielectric thickness is very big, do not coupled between upper/lower layer metallic, caused transmission zero and limit are fLimit 1＜ fLimit 2
＜ f0. 1＜ f0. 2；When dielectric thickness is gradually reduced, upper/lower layer metallic produces coupling, and transmission pole position is almost unchanged, and one
Transmission zero moves to high frequency direction, and a transmission zero can be moved to the left side of transmission pole, f to low frequency direction0. 1＜ fLimit 1
＜ fLimit 2＜ f0. 2, obtain a band-pass transmissions response for respectively having a transmission zero in passband both sides.
Emulated, Fig. 3 is frequency-selective surfaces artificial reflections coefficient of the present invention and transmission coefficient curve map, horizontal seat
Frequency is designated as, ordinate is S parameter.It can be seen that the centre frequency of frequency-selective surfaces passband is 4.85GHz, three dB bandwidth is about
For 0.26GHz (4.78GHz-5.04GHz), relative bandwidth is 5.36%.Maximum insertion is less than 1dB in passband.In addition,
It can clearly observe that two transmission zeros can greatly increase in 4.7GHz and 6.1GHz, the introducing of transmission zero respectively in figure
Steep drop outside strong passband, the selectivity of frequency-selective surfaces can be realized well.And frequency-selective surfaces of the present invention
Unit size is 1/7th resonance wavelengths, has the characteristic of miniaturization, convenient application in practice.
As shown in figure 4, transmission curve of the high selectivity frequency-selective surfaces of the present invention in the case of 45 ° of oblique incidences of electromagnetic wave
Figure, wherein, Fig. 4 A are the transmission coefficient of TE ripples；Fig. 4 B are the transmission coefficient of TM ripples.Under TE ripple incidences, band logical is slightly reduced,
Insertion loss in passband has somewhat increased, and centre frequency is almost unchanged；Under TM ripple incidences, passband band logical becomes big, center
Frequency does not also shift.Therefore, frequency-selective surfaces of the present invention have good angle stability and polarizer stability.
The foregoing is only a specific embodiment of the invention, in addition with other embodiment, is not departing from the present invention
In the case of principle, modifications of the present invention and retouching, these modifications and retouching all should be in the guarantors of the claim of the present invention
In the range of shield.
Claims (9)
- A kind of 1. new high selectivity frequency-selective surfaces based on individual layer PCB technology, by the unit structure of multiple periodic distributions Into, it is characterised in that each unit includes the first metal layer, dielectric layer, second metal layer successively from top to bottom；The first metal layer It is identical with second metal layer structure size, and be symmetrical arranged relative to dielectric layer；The first metal layer, second metal layer are mainly by square ring, and four metal structures being placed in Fang Huan are formed；Metal structure Including folding line, triangular structure, and four metal structures are centrosymmetric distribution.
- 2. a kind of new high selectivity frequency-selective surfaces based on individual layer PCB technology as claimed in claim 1, its feature exist In the material that the dielectric layer uses for F4B-2.
- 3. a kind of new high selectivity frequency-selective surfaces based on individual layer PCB technology as claimed in claim 1, its feature exist When the frequency-selective surfaces working frequency is near 4.8-5.1GHz, thickness of dielectric layers 2mm.
- 4. a kind of new high selectivity frequency-selective surfaces based on individual layer PCB technology as claimed in claim 1, its feature exist In the unit size be 8.8mm × 8.8mm.
- 5. a kind of new high selectivity frequency-selective surfaces based on individual layer PCB technology as claimed in claim 1, its feature exist In gold side's ring hem width be 0.8mm.
- 6. a kind of new high selectivity frequency-selective surfaces based on individual layer PCB technology as claimed in claim 1, its feature exist In a length of 9.3mm of metal folding line, line width 0.2mm.
- 7. a kind of new high selectivity frequency-selective surfaces based on individual layer PCB technology as claimed in claim 1, its feature exist In triangles of metal be right angled isosceles triangle, a length of 2.4mm of its waist.
- 8. a kind of new high selectivity frequency-selective surfaces as claimed in claim 1, it is characterised in that between adjacent triangle Away from for 0.4mm.
- 9. a kind of high selectivity frequency-selective surfaces structure based on individual layer PCB technology as claimed in claim 1, its feature exist In unit size be 1/7th wavelength.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710791877.0A CN107404005B (en) | 2017-09-05 | 2017-09-05 | Novel high-selectivity frequency selective surface based on single-layer PCB process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710791877.0A CN107404005B (en) | 2017-09-05 | 2017-09-05 | Novel high-selectivity frequency selective surface based on single-layer PCB process |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107404005A true CN107404005A (en) | 2017-11-28 |
| CN107404005B CN107404005B (en) | 2023-09-29 |
Family
ID=60398046
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710791877.0A Active CN107404005B (en) | 2017-09-05 | 2017-09-05 | Novel high-selectivity frequency selective surface based on single-layer PCB process |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107404005B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110829018A (en) * | 2019-11-15 | 2020-02-21 | 中国科学院长春光学精密机械与物理研究所 | Broadband wide-angle frequency selective surface radome |
| CN111786120A (en) * | 2020-07-06 | 2020-10-16 | 电子科技大学 | Miniaturized frequency selective surface structure with rectangular coefficient close to 1 |
| CN111969325A (en) * | 2020-06-23 | 2020-11-20 | 广州智讯通信系统有限公司 | Frequency selection surface unit based on filter antenna and frequency selection surface |
| CN111987439A (en) * | 2020-07-27 | 2020-11-24 | 南京航空航天大学 | Miniaturized passive flexible band-pass frequency selection surface for antenna housing |
| CN113300112A (en) * | 2021-05-17 | 2021-08-24 | 广东福顺天际通信有限公司 | Reflecting plate and reflector with switchable working states |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB9913784D0 (en) * | 1997-04-29 | 1999-08-11 | Trw Inc | Frequency selective surface filter for any antenna |
| CN1248095A (en) * | 1998-07-15 | 2000-03-22 | 朗迅科技公司 | Filter with microstrip antenna and frequence-selective surface |
| CN101286584A (en) * | 2007-11-12 | 2008-10-15 | 杭州电子科技大学 | Novel bilateral frequency selecting surface having sudden drop characteristic |
| US20110210903A1 (en) * | 2010-02-26 | 2011-09-01 | The Regents Of The University Of Michigan | Frequency-selective surface (fss) structures |
| US20120098628A1 (en) * | 2009-02-13 | 2012-04-26 | University Of Kent | Tuneable Frequency Selective Surface |
| CN203774448U (en) * | 2014-03-26 | 2014-08-13 | 杭州电子科技大学 | 60GHz on-chip antenna based on artificial magnetic conductor structure |
| CN104538710A (en) * | 2015-01-23 | 2015-04-22 | 东南大学 | Frequency selection surface structure |
| CN104617361A (en) * | 2015-03-01 | 2015-05-13 | 中国人民解放军国防科学技术大学 | Three-way bandwidth frequency band frequency selecting surface structure and antenna cover |
| CN105870638A (en) * | 2016-03-31 | 2016-08-17 | 北京环境特性研究所 | Fractal-element-based frequency selective surface structure and window absorber |
| CN106602252A (en) * | 2017-01-20 | 2017-04-26 | 浙江大学 | 2.5-dimensional ultra-wide band mobile communication radome of grid square ring loading via hole structure |
| CN106654567A (en) * | 2017-01-20 | 2017-05-10 | 浙江大学 | Miniature high-performance and high-band communication antenna cover of capacitive and sensitive surface coupling mechanism |
| CN106887710A (en) * | 2017-03-07 | 2017-06-23 | 西安电子科技大学 | Improve the frequency-selective surfaces structure of angle stability |
-
2017
- 2017-09-05 CN CN201710791877.0A patent/CN107404005B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB9913784D0 (en) * | 1997-04-29 | 1999-08-11 | Trw Inc | Frequency selective surface filter for any antenna |
| CN1248095A (en) * | 1998-07-15 | 2000-03-22 | 朗迅科技公司 | Filter with microstrip antenna and frequence-selective surface |
| CN101286584A (en) * | 2007-11-12 | 2008-10-15 | 杭州电子科技大学 | Novel bilateral frequency selecting surface having sudden drop characteristic |
| US20120098628A1 (en) * | 2009-02-13 | 2012-04-26 | University Of Kent | Tuneable Frequency Selective Surface |
| US20110210903A1 (en) * | 2010-02-26 | 2011-09-01 | The Regents Of The University Of Michigan | Frequency-selective surface (fss) structures |
| CN203774448U (en) * | 2014-03-26 | 2014-08-13 | 杭州电子科技大学 | 60GHz on-chip antenna based on artificial magnetic conductor structure |
| CN104538710A (en) * | 2015-01-23 | 2015-04-22 | 东南大学 | Frequency selection surface structure |
| CN104617361A (en) * | 2015-03-01 | 2015-05-13 | 中国人民解放军国防科学技术大学 | Three-way bandwidth frequency band frequency selecting surface structure and antenna cover |
| CN105870638A (en) * | 2016-03-31 | 2016-08-17 | 北京环境特性研究所 | Fractal-element-based frequency selective surface structure and window absorber |
| CN106602252A (en) * | 2017-01-20 | 2017-04-26 | 浙江大学 | 2.5-dimensional ultra-wide band mobile communication radome of grid square ring loading via hole structure |
| CN106654567A (en) * | 2017-01-20 | 2017-05-10 | 浙江大学 | Miniature high-performance and high-band communication antenna cover of capacitive and sensitive surface coupling mechanism |
| CN106887710A (en) * | 2017-03-07 | 2017-06-23 | 西安电子科技大学 | Improve the frequency-selective surfaces structure of angle stability |
Non-Patent Citations (2)
| Title |
|---|
| WEI QIN ET.AL: "Complementary Compact Microstrip Resonant Cell and Its Applications to Microwave Single- and Dual-Band Bandpass Filters", pages 773 - 774 * |
| 郑书峰: "频率选择表面的小型化设计与优化技术研究" * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110829018A (en) * | 2019-11-15 | 2020-02-21 | 中国科学院长春光学精密机械与物理研究所 | Broadband wide-angle frequency selective surface radome |
| CN111969325A (en) * | 2020-06-23 | 2020-11-20 | 广州智讯通信系统有限公司 | Frequency selection surface unit based on filter antenna and frequency selection surface |
| CN111786120A (en) * | 2020-07-06 | 2020-10-16 | 电子科技大学 | Miniaturized frequency selective surface structure with rectangular coefficient close to 1 |
| CN111987439A (en) * | 2020-07-27 | 2020-11-24 | 南京航空航天大学 | Miniaturized passive flexible band-pass frequency selection surface for antenna housing |
| CN111987439B (en) * | 2020-07-27 | 2022-05-24 | 南京航空航天大学 | Miniaturized passive flexible band-pass frequency selection surface for antenna housing |
| CN113300112A (en) * | 2021-05-17 | 2021-08-24 | 广东福顺天际通信有限公司 | Reflecting plate and reflector with switchable working states |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107404005B (en) | 2023-09-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN207183542U (en) | High selectivity frequency-selective surfaces | |
| CN107404005A (en) | A kind of new high selectivity frequency-selective surfaces based on individual layer PCB technology | |
| Li et al. | Three-dimensional bandpass frequency-selective structures with multiple transmission zeros | |
| Bayatpur et al. | Multipole spatial filters using metamaterial-based miniaturized-element frequency-selective surfaces | |
| CN106602252B (en) | 2.5-dimensional ultra-wideband mobile communication radome with grid square ring loaded via hole structure | |
| CN102570020B (en) | Ultra-wideband trapped wave antenna with good rectangular degree and controllable stop band bandwidth | |
| CN107799903B (en) | Three-dimensional novel broadband frequency selection structure with suction | |
| CN106654567B (en) | Capacitive and inductive surface coupling mechanism miniaturized high-performance high-frequency band communication radome | |
| CN207183541U (en) | Bilateral steep drop bandwidth tunable FSS | |
| CN110265788B (en) | Novel two-three-dimensional combined dual-polarized band-pass radar wave absorber | |
| Li et al. | A novel FSS structure with high selectivity and excellent angular stability for 5G communication radome | |
| Liu et al. | Novel nested split-ring-resonator (SRR) for compact filter application | |
| CN110690577A (en) | Dual-polarization band-pass three-dimensional frequency selection surface with bilateral steep drop characteristic | |
| CN107425290A (en) | A kind of bilateral steep drop bandwidth tunable FSS | |
| US20110304413A1 (en) | High frequency filter | |
| CN103165986B (en) | A kind of super-medium wave-absorbing material and preparation method | |
| CN113972454A (en) | Terahertz band-pass filter based on artificial surface plasmon and interdigital structure | |
| CN107171042A (en) | A kind of frequency-selective surfaces structure | |
| Ebrahimi et al. | Narrowband bandpass frequency selective surface with miniaturized elements | |
| Li et al. | A high selectivity, miniaturized, low profile dual-band bandpass FSS with a controllable transmission zero | |
| Crnojevic-Bengin et al. | Complementary split ring resonators using square Sierpinski fractal curves | |
| KR101216433B1 (en) | High-pass filter using metameterial | |
| He et al. | A Tri-band Highly Selective Passband Frequency Selective Surface Based on Multi-layer Coupling | |
| KR101252687B1 (en) | Low-pass filter using metameterial | |
| CN113346250B (en) | Millimeter wave three-frequency selection surface based on multilayer coupling structure |
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 |