CA2218269A1 - Microstrip patch radiator with means for the suppression of cross-polarization - Google Patents
Microstrip patch radiator with means for the suppression of cross-polarization Download PDFInfo
- Publication number
- CA2218269A1 CA2218269A1 CA 2218269 CA2218269A CA2218269A1 CA 2218269 A1 CA2218269 A1 CA 2218269A1 CA 2218269 CA2218269 CA 2218269 CA 2218269 A CA2218269 A CA 2218269A CA 2218269 A1 CA2218269 A1 CA 2218269A1
- Authority
- CA
- Canada
- Prior art keywords
- apertures
- pair
- microstrip patch
- ground plane
- feed line
- 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.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
- H01Q9/04—Resonant antennas
- H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
- H01Q9/0478—Substantially flat resonant element parallel to ground plane, e.g. patch antenna with means for suppressing spurious modes, e.g. cross polarisation
-
- 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
- H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
- H01Q9/04—Resonant antennas
- H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
- H01Q9/0428—Substantially flat resonant element parallel to ground plane, e.g. patch antenna radiating a circular polarised wave
- H01Q9/0435—Substantially flat resonant element parallel to ground plane, e.g. patch antenna radiating a circular polarised wave using two feed points
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
- H01Q9/04—Resonant antennas
- H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
- H01Q9/045—Substantially flat resonant element parallel to ground plane, e.g. patch antenna with particular feeding means
- H01Q9/0457—Substantially flat resonant element parallel to ground plane, e.g. patch antenna with particular feeding means electromagnetically coupled to the feed line
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Waveguide Aerials (AREA)
Abstract
A dual polarized microstrip patch radiator comprising a ground plane, a thin layer of dielectric on each side thereof, a conductive microstrip patch on a first of the dielectric layers on a side remote from the ground plane, first and second feed lines on the side of the second dielectric layer remote from the ground plane, first and second pairs of apertures in the ground plane the second pair of apertures being orthogonal to the first pair of apertures, the first feed line being radiatively coupled to one of the first pair of apertures and not radiatively coupled to the other aperture of the first pair of apertures nor to the second pair of apertures, the second feed line being radiatively coupled to one of the apertures of the second pair of apertures and not radiatively coupled to the other of the second pair of apertures nor to the first pair of apertures, the other aperture of the first pair of apertures being positioned to provide a symmetrical boundary condition for power coupled from the second feed line, and the other aperture of the second pair of apertures being positioned to provide a symmetrical boundary condition for power coupled from the first feed line, whereby cross-polarization of the feeds is minimized.
Description
CA 02218269 1997-10-1~
MICROSTRIP PATCH RADIATOR WITH MEANS FOR THE
SUPPRESSION OF CROSS-POLARIZATION
FIELD OF THE INVENTION
The present invention relates to a dual polarized microstrip patch radiator including means for suppressing cross-polarization of the radiation.
BACKGROUND OF THE PRIOR ART
Microstrip patch radiators are well known in the art. These radiators are used at UHF through to millimetre wave lengths and are conventionally manufactured using photolithography techniques.
U.S. Patent 5,043,738 of August 27, 1991 illustrates a patch antenna which is fed by a pair of orthogonal apertures within the ground plane element of the antenna. These apertures either linearly or circularly polarize microwave power from the feed structures to the patch radiator.
U.S. Patent 5,005,019 of April 2, 1991 illustrates both the use of patches and slots as radiating elements of a printed circuit antenna. U.S.
Patent 4,489,328 illustrates the use of slot antennas in place of patch antennas. U.S. Patent 4,692,769 illustrates a patch antenna with a slotted microstrip.
U.S. Patent 4,771,291 shows the use of slots in the patch to provide an antenna intended for dual frequency operation.
U.S. Patent 4,929,959 is a compound antenna structure for transmitting and receiving dual polarized signals from different layers of the antenna. U.S.
Patent 4,926,189 is a similar antenna structure for receiving high gain single and dual polarized microwave signals. U.S. Patent 4,125,838 illustrates a square shaped patch radiator which may be notched for tuning purposes. U.S. Patent 4,903,033 illustrates a patch CA 02218269 1997-10-1~
antenna equipped with various frequency broadening components and a polarizer which can be used for converting linear to circular polarization. A cross-shaped slot is utilized for feeding the antenna.
None of the above microstrip antennas includes means for the suppression of cross-polarization in a dual polarized microstrip patch radiator.
SUMMARY OF THE PRESENT INVENTION
Conventional techniques for achieving dual independent linear polarization from a single slot coupled microstrip patch radiator result in either excessive cross-polarization levels, or require complex feeds having four feed lines exciting four active slots.
The present invention achieves very low cross-polarization while maintaining a simple two line feedstructure and only two active feed apertures. A single active feed aperture and a single feed line are combined with a passive aperture for each polarization.
Asymmetry in the field distributions under the patch is eliminated through the use of dummy apertures which do not have feed lines exciting them. This results in a simpler feed with very low cross-polarization.
The present invention provides for suppression of cross-polarization in a dual polarized microstrip patch radiator by providing two active slots and two dummy slots etched into the ground plane layer beneath a microstrip patch. The active slots are energized by feed lines produced on the bottom surface of a lower dielectric and the patch radiator is metallized on the top surface of an upper dielectric layer. The two active slots are coupled to the feed lines and the two dummy slots do not have coupling through the feed lines and are not energized by the feed lines. The dummy or passive slots provide the means for suppression of cross-polarization as discussed below.
BRIEF INTRODUCTION TO THE DRAWINGS
Figure 1 is a cross-sectional view of a patch antenna in accordance with the invention.
Figure 2 is a bottom view showing the feed lines for the active apertures and the dummy apertures in its second place, Figure 3 is a schematic view of an alternative embodiment of micropatch antenna having a dual polarized feed using active and passive circular apertures.
Figure 4 is a schematic diagram illustrating a series fed array of radiators using active and dummy apertures.
DETAILED DESCRIPTION OF THE INVENTION
Referring to Figure 1, there is shown in cross-section a dual polarized microstrip patch radiator in accordance with the invention. A ground plane 10 is surmounted by an upper dielectric layer 11 carrying a metallized photolithographically applied patch 13. A
lower dielectric layer 12 below the ground plane 10 carries photolithographically applied feed lines designated generally by 14.
Figure 2 is a bottom view of the microstrip patch radiator of Figure 1 for dual polarization. In this view, both the upper and lower dielectric layers 11 and 12 and the ground plane 10 have been removed for clarity. The apertures 17, 18, 19 and 20 in the ground plane 10 have been highlighted. The first feed line 15 and the second feed line 16 are arranged at right angles, feed line 15 extending across active aperture 17. Similarly, feed line 16 exténds across active aperture 19. In addition, dummy apertures 18 and 20 are provided on the ground plane 10. These dummy apertures 18 and 20 are not engaged by the feed lines 15 and 16.
The microstrip patch 13 is smaller than its ground plane 10, which is indicated in dotted outline.
CA 02218269 1997-10-1~
The feed line 15 is the input port for the power to be radiated in one sense of linear polarization, for example, vertical polarization. The feed line 15 crosses over the aperture 17 causing fields to be coupled through the slot into the space beneath the microstrip patch. These fields induce currents into the patch which then result in radiation into space.
Similarly, feed line 16 is the input port for the power to be radiated in the other sense of linear polarization, for example, horizontal polarization. The feed line 16 crosses over the active aperture 19 causing fields to be coupled through the aperture 19 into the space beneath the microstrip patch 13. These fields also induce currents into the patch which then result in radiation into space.
The fields excited into the space below the microstrip patch 13 by feed line 16 would find the boundary conditions of that space to be asymmetrical if dummy aperture 18 was not used. This asymmetry is what introduces high cross-polarization in existing implementations using only two feed lines and two slots.
The dummy aperture 18 thus provides a symmetrical boundary condition for power coupled from feed line 16 to the microstrip patch 13.
In the same way, the fields excited into the space below the microstrip patch 13 by feed line 15 would find the boundary conditions of that space to be asymmetrical if dummy aperture 20 was not present. As before, this asymmetry introduces high cross-polarization in existing implementations using only two feed lines and two slots. Aperture 20 thus provides a symmetrical boundary condition for the power coupled from feed line 15.
CA 02218269 1997-10-1~
As previously mentioned, apertures 17 and 19 provide a means for coupling power from the feed lines into the space below the microstrip patch.
As illustrated in Figure 1, the upper dielectric layer supports the microstrip patch 13 above the ground plane 10 at a constant height. The permittivity of the dielectric 11 affects the required dimensions of the microstrip patch 13 for resonance and the corresponding real input impedance. The lower dielectric layer 12 supports the feed lines below the ground plane 10. The ground plane 10 is a conductive layer which acts to separate the fields under the microstrip patch 13 from the fields under the feed lines 15 and 16. The apertures 17, 18, 19 and 20 are gaps in the ground plane 10 formed for example by etching.
Figure 3 is a bottom view of a dual polarized feed using active and passive circular apertures. As before, a first feed line 15 is positioned orthogonal to a second feed line 16, feed line 15 extending across active aperture 17. The second feed line 16 extends across active aperture 19. Dummy aperture 18 is positioned to provide a symmetrical boundary for the feed from second feed line 16, and dummy aperture 20 is positioned to provide a symmetrical boundary for second feed line 16.
Figure 4 illustrates a series fed array of microstrip patch radiators 30, 40 and 50 using dummy apertures illustrating how the separate feed lines 15 and 16 can be positioned so that they do not intersect the dummy apertures and that the first feed line only crosses the first active slot and the second feed line only crosses the second active slot of each microstrip patch radiator.
MICROSTRIP PATCH RADIATOR WITH MEANS FOR THE
SUPPRESSION OF CROSS-POLARIZATION
FIELD OF THE INVENTION
The present invention relates to a dual polarized microstrip patch radiator including means for suppressing cross-polarization of the radiation.
BACKGROUND OF THE PRIOR ART
Microstrip patch radiators are well known in the art. These radiators are used at UHF through to millimetre wave lengths and are conventionally manufactured using photolithography techniques.
U.S. Patent 5,043,738 of August 27, 1991 illustrates a patch antenna which is fed by a pair of orthogonal apertures within the ground plane element of the antenna. These apertures either linearly or circularly polarize microwave power from the feed structures to the patch radiator.
U.S. Patent 5,005,019 of April 2, 1991 illustrates both the use of patches and slots as radiating elements of a printed circuit antenna. U.S.
Patent 4,489,328 illustrates the use of slot antennas in place of patch antennas. U.S. Patent 4,692,769 illustrates a patch antenna with a slotted microstrip.
U.S. Patent 4,771,291 shows the use of slots in the patch to provide an antenna intended for dual frequency operation.
U.S. Patent 4,929,959 is a compound antenna structure for transmitting and receiving dual polarized signals from different layers of the antenna. U.S.
Patent 4,926,189 is a similar antenna structure for receiving high gain single and dual polarized microwave signals. U.S. Patent 4,125,838 illustrates a square shaped patch radiator which may be notched for tuning purposes. U.S. Patent 4,903,033 illustrates a patch CA 02218269 1997-10-1~
antenna equipped with various frequency broadening components and a polarizer which can be used for converting linear to circular polarization. A cross-shaped slot is utilized for feeding the antenna.
None of the above microstrip antennas includes means for the suppression of cross-polarization in a dual polarized microstrip patch radiator.
SUMMARY OF THE PRESENT INVENTION
Conventional techniques for achieving dual independent linear polarization from a single slot coupled microstrip patch radiator result in either excessive cross-polarization levels, or require complex feeds having four feed lines exciting four active slots.
The present invention achieves very low cross-polarization while maintaining a simple two line feedstructure and only two active feed apertures. A single active feed aperture and a single feed line are combined with a passive aperture for each polarization.
Asymmetry in the field distributions under the patch is eliminated through the use of dummy apertures which do not have feed lines exciting them. This results in a simpler feed with very low cross-polarization.
The present invention provides for suppression of cross-polarization in a dual polarized microstrip patch radiator by providing two active slots and two dummy slots etched into the ground plane layer beneath a microstrip patch. The active slots are energized by feed lines produced on the bottom surface of a lower dielectric and the patch radiator is metallized on the top surface of an upper dielectric layer. The two active slots are coupled to the feed lines and the two dummy slots do not have coupling through the feed lines and are not energized by the feed lines. The dummy or passive slots provide the means for suppression of cross-polarization as discussed below.
BRIEF INTRODUCTION TO THE DRAWINGS
Figure 1 is a cross-sectional view of a patch antenna in accordance with the invention.
Figure 2 is a bottom view showing the feed lines for the active apertures and the dummy apertures in its second place, Figure 3 is a schematic view of an alternative embodiment of micropatch antenna having a dual polarized feed using active and passive circular apertures.
Figure 4 is a schematic diagram illustrating a series fed array of radiators using active and dummy apertures.
DETAILED DESCRIPTION OF THE INVENTION
Referring to Figure 1, there is shown in cross-section a dual polarized microstrip patch radiator in accordance with the invention. A ground plane 10 is surmounted by an upper dielectric layer 11 carrying a metallized photolithographically applied patch 13. A
lower dielectric layer 12 below the ground plane 10 carries photolithographically applied feed lines designated generally by 14.
Figure 2 is a bottom view of the microstrip patch radiator of Figure 1 for dual polarization. In this view, both the upper and lower dielectric layers 11 and 12 and the ground plane 10 have been removed for clarity. The apertures 17, 18, 19 and 20 in the ground plane 10 have been highlighted. The first feed line 15 and the second feed line 16 are arranged at right angles, feed line 15 extending across active aperture 17. Similarly, feed line 16 exténds across active aperture 19. In addition, dummy apertures 18 and 20 are provided on the ground plane 10. These dummy apertures 18 and 20 are not engaged by the feed lines 15 and 16.
The microstrip patch 13 is smaller than its ground plane 10, which is indicated in dotted outline.
CA 02218269 1997-10-1~
The feed line 15 is the input port for the power to be radiated in one sense of linear polarization, for example, vertical polarization. The feed line 15 crosses over the aperture 17 causing fields to be coupled through the slot into the space beneath the microstrip patch. These fields induce currents into the patch which then result in radiation into space.
Similarly, feed line 16 is the input port for the power to be radiated in the other sense of linear polarization, for example, horizontal polarization. The feed line 16 crosses over the active aperture 19 causing fields to be coupled through the aperture 19 into the space beneath the microstrip patch 13. These fields also induce currents into the patch which then result in radiation into space.
The fields excited into the space below the microstrip patch 13 by feed line 16 would find the boundary conditions of that space to be asymmetrical if dummy aperture 18 was not used. This asymmetry is what introduces high cross-polarization in existing implementations using only two feed lines and two slots.
The dummy aperture 18 thus provides a symmetrical boundary condition for power coupled from feed line 16 to the microstrip patch 13.
In the same way, the fields excited into the space below the microstrip patch 13 by feed line 15 would find the boundary conditions of that space to be asymmetrical if dummy aperture 20 was not present. As before, this asymmetry introduces high cross-polarization in existing implementations using only two feed lines and two slots. Aperture 20 thus provides a symmetrical boundary condition for the power coupled from feed line 15.
CA 02218269 1997-10-1~
As previously mentioned, apertures 17 and 19 provide a means for coupling power from the feed lines into the space below the microstrip patch.
As illustrated in Figure 1, the upper dielectric layer supports the microstrip patch 13 above the ground plane 10 at a constant height. The permittivity of the dielectric 11 affects the required dimensions of the microstrip patch 13 for resonance and the corresponding real input impedance. The lower dielectric layer 12 supports the feed lines below the ground plane 10. The ground plane 10 is a conductive layer which acts to separate the fields under the microstrip patch 13 from the fields under the feed lines 15 and 16. The apertures 17, 18, 19 and 20 are gaps in the ground plane 10 formed for example by etching.
Figure 3 is a bottom view of a dual polarized feed using active and passive circular apertures. As before, a first feed line 15 is positioned orthogonal to a second feed line 16, feed line 15 extending across active aperture 17. The second feed line 16 extends across active aperture 19. Dummy aperture 18 is positioned to provide a symmetrical boundary for the feed from second feed line 16, and dummy aperture 20 is positioned to provide a symmetrical boundary for second feed line 16.
Figure 4 illustrates a series fed array of microstrip patch radiators 30, 40 and 50 using dummy apertures illustrating how the separate feed lines 15 and 16 can be positioned so that they do not intersect the dummy apertures and that the first feed line only crosses the first active slot and the second feed line only crosses the second active slot of each microstrip patch radiator.
Claims (7)
1. A dual polarized microstrip patch radiator comprising a ground plane, a thin layer of dielectric on each side thereof, a conductive microstrip patch on a first of said dielectric layers on a side remote from said ground plane, first and second feed lines on the side of said second dielectric layer remote from said ground plane, first and second pairs of apertures in said ground plane said second pair of apertures being orthogonal to said first pair of apertures, said first feed line being radiatively coupled to one of said first pair of apertures and not radiatively coupled to the other aperture of said first pair of apertures nor to said second pair of apertures, said second feed line being radiatively coupled to one of said apertures of said second pair of apertures and not radiatively coupled to the other of said second pair of apertures nor to said first pair of apertures, said other aperture of said first pair of apertures being positioned to provide a symmetrical boundary condition for power coupled from said second feed line, and said other aperture of said second pair of apertures being positioned to provide a symmetrical boundary condition for power coupled from said first feed line, whereby cross-polarization of said feeds is minimized.
2. A dual polarized microstrip patch radiator as defined in claim 1 wherein said pairs of apertures are etched into said ground plane, said patch is photolithographically deposited on said first dielectric layer, and said feed lines are photolithographically deposited on said second dielectric layer.
3. A dual polarized microstrip patch radiator as defined in claim 1 wherein said apertures are either rectangular or circular.
4. A dual polarized microstrip patch radiator as defined in claim 3 wherein all of said aperturess are of the same size and shape.
5. A dual polarized microstrip patch radiator as defined in claim 1 wherein said apertures are rectangular, said first pair of apertures being orthgonal to said second pair of apertures.
6. A dual polarized microstrip patch radiator as defined in claim 1, wherein apertures are circular.
7. A dual polarized microstrip patch radiator array comprising a plurality of microstrip patch radiators as defined in claim 1, wherein the first feed lines of each of said radiators are connected in series, and the second feed lines of each of said radiators are connected in series, each radiator being mounted in said array in the same orientation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2218269 CA2218269A1 (en) | 1997-10-15 | 1997-10-15 | Microstrip patch radiator with means for the suppression of cross-polarization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2218269 CA2218269A1 (en) | 1997-10-15 | 1997-10-15 | Microstrip patch radiator with means for the suppression of cross-polarization |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2218269A1 true CA2218269A1 (en) | 1999-04-15 |
Family
ID=4161627
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2218269 Abandoned CA2218269A1 (en) | 1997-10-15 | 1997-10-15 | Microstrip patch radiator with means for the suppression of cross-polarization |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2218269A1 (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001031738A1 (en) * | 1999-10-29 | 2001-05-03 | Telefonaktiebolaget Lm Ericsson (Publ) | Dual-polarised antenna |
| FR2940532A1 (en) * | 2008-12-23 | 2010-06-25 | Thales Sa | PLANAR RADIATION ELEMENT WITH DUAL POLARIZATION AND NETWORK ANTENNA COMPRISING SUCH A RADIANT ELEMENT |
| US8169312B2 (en) | 2009-01-09 | 2012-05-01 | Sirit Inc. | Determining speeds of radio frequency tags |
| US8226003B2 (en) | 2006-04-27 | 2012-07-24 | Sirit Inc. | Adjusting parameters associated with leakage signals |
| US8248212B2 (en) | 2007-05-24 | 2012-08-21 | Sirit Inc. | Pipelining processes in a RF reader |
| US8416079B2 (en) | 2009-06-02 | 2013-04-09 | 3M Innovative Properties Company | Switching radio frequency identification (RFID) tags |
| US8427316B2 (en) | 2008-03-20 | 2013-04-23 | 3M Innovative Properties Company | Detecting tampered with radio frequency identification tags |
| US8446256B2 (en) | 2008-05-19 | 2013-05-21 | Sirit Technologies Inc. | Multiplexing radio frequency signals |
| WO2014081543A1 (en) * | 2012-11-26 | 2014-05-30 | Raytheon Company | Dual linear and circularly polarized patch radiator |
| US20160190698A1 (en) * | 2014-12-31 | 2016-06-30 | Micron Devices Llc | Patch antenna assembly |
| US10062025B2 (en) | 2012-03-09 | 2018-08-28 | Neology, Inc. | Switchable RFID tag |
| WO2018167120A1 (en) * | 2017-03-15 | 2018-09-20 | Norbit Its | Patch antenna feed |
-
1997
- 1997-10-15 CA CA 2218269 patent/CA2218269A1/en not_active Abandoned
Cited By (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001031738A1 (en) * | 1999-10-29 | 2001-05-03 | Telefonaktiebolaget Lm Ericsson (Publ) | Dual-polarised antenna |
| US6531984B1 (en) | 1999-10-29 | 2003-03-11 | Telefonaktiebolaget Lm Ericsson (Publ) | Dual-polarized antenna |
| US8226003B2 (en) | 2006-04-27 | 2012-07-24 | Sirit Inc. | Adjusting parameters associated with leakage signals |
| US8248212B2 (en) | 2007-05-24 | 2012-08-21 | Sirit Inc. | Pipelining processes in a RF reader |
| US8427316B2 (en) | 2008-03-20 | 2013-04-23 | 3M Innovative Properties Company | Detecting tampered with radio frequency identification tags |
| US8446256B2 (en) | 2008-05-19 | 2013-05-21 | Sirit Technologies Inc. | Multiplexing radio frequency signals |
| FR2940532A1 (en) * | 2008-12-23 | 2010-06-25 | Thales Sa | PLANAR RADIATION ELEMENT WITH DUAL POLARIZATION AND NETWORK ANTENNA COMPRISING SUCH A RADIANT ELEMENT |
| EP2202846A1 (en) * | 2008-12-23 | 2010-06-30 | Thales | Planar radiating element with dual polarisation and network antenna comprising such a radiating element |
| US8248306B2 (en) | 2008-12-23 | 2012-08-21 | Thales | Dual polarization planar radiating element and array antenna comprising such a radiating element |
| US8169312B2 (en) | 2009-01-09 | 2012-05-01 | Sirit Inc. | Determining speeds of radio frequency tags |
| US8416079B2 (en) | 2009-06-02 | 2013-04-09 | 3M Innovative Properties Company | Switching radio frequency identification (RFID) tags |
| US10062025B2 (en) | 2012-03-09 | 2018-08-28 | Neology, Inc. | Switchable RFID tag |
| US10878303B2 (en) | 2012-03-09 | 2020-12-29 | Neology, Inc. | Switchable RFID tag |
| WO2014081543A1 (en) * | 2012-11-26 | 2014-05-30 | Raytheon Company | Dual linear and circularly polarized patch radiator |
| GB2523017B (en) * | 2012-11-26 | 2017-05-31 | Raytheon Co | Dual linear and circularly polarized patch radiator |
| GB2523017A (en) * | 2012-11-26 | 2015-08-12 | Raytheon Co | Dual linear and circularly polarized patch radiator |
| US9130278B2 (en) | 2012-11-26 | 2015-09-08 | Raytheon Company | Dual linear and circularly polarized patch radiator |
| US20160190698A1 (en) * | 2014-12-31 | 2016-06-30 | Micron Devices Llc | Patch antenna assembly |
| WO2016109833A1 (en) * | 2014-12-31 | 2016-07-07 | Chad David Andresen | Patch antenna assembly |
| US10056688B2 (en) | 2014-12-31 | 2018-08-21 | Micron Devices Llc | Patch antenna assembly |
| US11128049B2 (en) | 2014-12-31 | 2021-09-21 | Stimwave Technologies Incorporated | Patch antenna assembly |
| WO2018167120A1 (en) * | 2017-03-15 | 2018-09-20 | Norbit Its | Patch antenna feed |
| CN110431714A (en) * | 2017-03-15 | 2019-11-08 | 诺比特 Its 公司 | Paster antenna current feed department |
| US11018428B2 (en) | 2017-03-15 | 2021-05-25 | Norbit Its | Patch antenna feed |
| EA038606B1 (en) * | 2017-03-15 | 2021-09-22 | Норбит Итс | Patch antenna feed |
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| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |