Antennas based on metamaterial structures

• US 7,592,957 B2
• Filed: 08/24/2007
• Issued: 09/22/2009
• Est. Priority Date: 08/25/2006
• Status: Expired due to Fees

• Current Assignee: Tyco Electronics Services GmbH (TE Connectivity Ltd. (United Kingdom))
• Original Assignee: Rayspan Corporation
• Inventors: Achour, Maha, Gummalla, Ajay, Stoytchev, Marin
• Primary Examiner(s): MANCUSO, HUEDUNG XUAN CAO
• Application Number:
  US11/844,982
• Publication Number:
  US 20080048917A1
• Time in Patent Office: 760 Days
• Field of Search: 343/700.MS, 343/702, 343/767, 343/770, 343/729, 343/90
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 15/0086 said selective devices having materials with a synthesized negative refractive index, e.g. metamaterials or left-handed materials
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40

Abstract

Techniques, apparatus and systems that use one or more composite left and right handed (CRLH) metamaterial structures in processing and handling electromagnetic wave signals. Antennas and antenna arrays based on enhanced CRLH metamaterial structures are configured to provide broadband resonances for various multi-band wireless communications.

Claims

1. An antenna device, comprising:

a dielectric substrate having a first surface on a first side and a second surface on a second side opposing the first side;

a cell conductive patch formed on the first surface;

a cell ground conductive electrode formed on the second surface and in a footprint projected by the cell conductive patch onto the second surface;

a main ground electrode formed on the second surface and separated from the cell ground conductive electrode to leave part of the second surface exposed without being covered by a conductive electrode;

a cell conductive via connector formed in the substrate to connect the cell conductive patch to the cell ground conductive electrode;

a conductive feed line formed on the first surface and having a distal end located close to and electromagnetically coupled to the cell conductive patch to direct an antenna signal to or from the cell conductive patch; and

a conductive stripe line formed on the second surface and connecting cell ground conductive electrode to the main ground electrode,

wherein the cell conductive patch, the substrate, the cell conductive via connector and the cell ground conductive electrode, and the electromagnetically coupled conductive feed line are structured to form a composite left and right handed (CRLH) metamaterial structure that transmits or receives the antenna signal using the cell conductive patch.

2. The device as in claim 1, comprising:

a conductive launch pad formed near and separated from the distal end of the conductive feed line and the cell conductive patch to enhance capacitive coupling between the conductive feed line and the cell conductive patch under an impedance matching condition for supporting a resonant frequency in the antenna signal.

3. The device as in claim 1, wherein:

the cell ground electrode has an area greater than a cross section of the cell conductive via connector and less than an area of the cell conductive patch.

4. The device as in claim 1, wherein:

the cell ground electrode has an area greater than an area of the cell conductive patch.

5. The device as in claim 1, wherein:

the conductive stripe line has a width less than a dimension of the cell conductive patch.

6. The device as in claim 1, wherein:

the main ground conductive electrode formed on the second surface is located outside the footprint projected by the cell conductive patch onto the second surface.

7. The device as in claim 6, comprising:

a second main ground electrode formed on the first surface and patterned to form a co-planar waveguide, and

wherein;

the co-planar waveguide is connected to the conductive feed line to direct the antenna signal to or from conductive feed line.

8. The device as in claim 7, wherein:

the second main ground electrode formed on the first surface is patterned to form a second co-planar waveguide;

the device comprising a second composite left and right handed (CRLH) metamaterial structure formed on the substrate and electromagnetically coupled to the second co-planar waveguide on the first surface and to the main ground on the second surface, the second CRLH metamaterial structure comprising;

a second cell conductive patch formed on the first surface and electromagnetically coupled to the second co-planar waveguide which directs a second antenna signal to or from the second cell conductive patch;

a second cell ground conductive electrode formed on the second surface and in a footprint projected by the second cell conductive patch onto the second surface;

a second cell conductive via connector formed in the substrate to connect the second cell conductive patch to the second cell ground conductive electrode; and

a second conductive stripe line formed on the second surface and connecting the second cell ground conductive electrode to the main ground electrode.

9. The device as in claim 8, wherein:

the cell conductive patch and the second cell conductive patch have different dimensions to render the CRLH metamaterial structure formed by the cell conductive patch and the second CRLH metamaterial structure formed by the second cell conductive patch to have different resonant frequencies.

10. The device as in claim 9, wherein:

the CRLH metamaterial structure formed by the cell conductive patch forms a receiver antenna; and

the second CRLH metamaterial structure formed by the second cell conductive patch forms a transmitter antenna.

11. The device as in claim 10, wherein:

the second main ground electrode formed on the first surface is patterned to form a third co-planar waveguide;

the device comprising a third composite left and right handed (CRLH) metamaterial structure formed on the substrate and electromagnetically coupled to the third co-planar waveguide on the first surface and to the main ground on the second surface, the third CRLH metamaterial structure comprising;

a third cell conductive patch formed on the first surface and electromagnetically coupled to the third co-planar waveguide which directs a third antenna signal to or from the third cell conductive patch;

a third cell ground conductive electrode formed on the second surface and in a footprint projected by the third cell conductive patch onto the second surface;

a third cell conductive via connector formed in the substrate to connect the third cell conductive patch to the third cell ground conductive electrode; and

a third conductive stripe line formed on the second surface and connecting the third cell ground conductive electrode to the main ground electrode.

12. The device as in claim 11, wherein:

the third CRLH metamaterial structure formed by the third cell conductive patch forms a second receiver antenna.

13. The device as in claim 7, comprising:

a parasitic cell, which is electromagnetically coupled to the main ground electrode on the second surface and the second main ground electrode on the first surface, and which comprises;

a parasitic cell conductive patch formed on the first surface;

a parasitic cell ground conductive electrode formed on the second surface and in a footprint projected by the parasitic cell conductive patch onto the second surface;

a parasitic cell conductive via connector formed in the substrate to connect the parasitic cell conductive patch to the parasitic cell ground conductive electrode;

a first parasitic conductive line formed on the first surface to include a first end connected to electromagnetically couple to the parasitic cell conductive patch and a second end connected to the second main ground electrode; and

a second parasitic conductive line formed on the second surface and connecting the parasitic cell ground conductive electrode to the main ground electrode.

14. The device as in claim 13, comprising:

a second parasitic cell which is separate from the parasitic cell, and which is electromagnetically coupled to the main ground electrode on the second surface and the second main ground electrode on the first surface.

15. An antenna device, comprising:

a dielectric substrate having a first surface on a first side and a second surface on a second side opposing the first side;

a plurality of cell conductive patches formed over the first surface to be separated from and adjacent to one another to allow capacitive coupling between two adjacent cell conductive patches;

a main ground electrode formed on the second surface outside a footprint projected collectively by the cell conductive patches onto the second surface to leave part of the second surface exposed without being covered by a conductive electrode;

a plurality of cell ground electrodes formed on the second surface to spatially correspond to the cell conductive patches, one cell ground electrode to one cell conductive patch, respectively, wherein each cell ground electrode is within a footprint projected by a respective cell conductive patch onto the second surface, and wherein the cell ground electrodes are spatially separate from the main ground electrode;

a plurality of conductive via connectors formed in the substrate to connect the cell conductive patches to the cell ground electrodes, respectively, to form a plurality of unit cells that construct a composite left and right handed (CRLH) metamaterial structure;

at least one conductive stripe line formed on the second surface to connect the plurality of cell ground electrodes to the main ground electrode; and

a conductive feed line formed on the first surface and having a distal end located close to and electromagnetically coupled to one of the cell conductive patches to direct an antenna signal to or from the coupled cell conductive patch,

wherein the CRLH metamaterial structure transmits or receives the antenna signal using the cell conductive patches.

16. The device as in claim 15, wherein:

the main ground electrode formed on the second surface includes an electrode portion outside a footprint projected collectively by the cell conductive patches onto the second surface,

wherein the electrode portion is pattered to include an aperture that is larger than the footprint projected collectively by the cell conductive patches onto the second surface and that is located to overlap with the footprint projected collectively by the cell conductive patches.

17. The device as in claim 15, wherein:

each unit cell has a dimension not greater than one tenth of a wavelength of a signal in resonance with the CLRH metamaterial structure.

18. The device as in claim 17, wherein:

each unit cell has a dimension not greater than one fortieth of a wavelength of a signal in resonance with the CRLH metamaterial structure.

19. The device as in claim 15, wherein:

the plurality of cell conductive patches on the first surface are arranged to form a linear array with a first cell conductive patch on a first end of the linear array and a second cell conductive patch on a second end of the linear array,

the device comprising;

a feed line formed on the first surface and electromagnetically coupled to the first cell conductive patch to direct an antenna signal to or from the first cell conductive patch; and

a termination capacitor comprising a conductive electrode that is capacitively coupled to the second cell conductive patch.

20. The device as in claim 19, wherein:

the conductive electrode of the termination capacitor is located between the second cell conductive patch and the first surface.

21. An antenna device, comprising:

a first dielectric substrate having a first top surface on a first side and a first bottom surface on a second side opposing the first side;

a second dielectric substrate having a second top surface on a first side and a second bottom surface on a second side opposing the first side, the first and second dielectric substrates stacking over each other to engage the second top surface to the first bottom surface;

a plurality of cell conductive patches formed on the first top surface to be separated from and adjacent to one another to allow capacitive coupling between two adjacent cell conductive patches;

a first main ground electrode formed on the first top surface and spatially separate from the cell conductive patches, the first main ground electrode patterned to form a co-planar waveguide that is electromagnetically coupled to a selected cell conductive patch of the cell conductive patches to direct an antenna signal to or from the selected cell conductive patch;

a second main ground electrode formed between the first and second substrates and on the second top surface and the first bottom surface, wherein the second main around electrode is located outside a footprint projected collectively by the cell conductive patches onto the second top surface and the first bottom surface to leave part of the second top surface and the first bottom surface exposed without being covered by a conductive electrode;

a plurality of cell ground electrodes formed on the second bottom surface to spatially correspond to the cell conductive patches, one cell ground electrode to one cell conductive patch, respectively, wherein each cell ground electrode is within a footprint projected by a respective cell conductive patch onto the second bottom surface;

a plurality of bottom ground electrodes formed on the second bottom surface below the second main ground electrode;

a plurality of cell conductive via connectors formed in the first and second substrates to connect the cell around electrodes on the second bottom surface to the cell conductive patches on the first top surface, respectively;

a plurality of ground conductive via connectors formed in the second substrate to connect the bottom ground electrodes to the second main electrode, respectively;

a plurality of bottom surface conductive stripe lines formed on the second bottom surface to connect the plurality of cell ground electrodes to the bottom ground electrodes, respectively,

wherein the cell conductive patches, the cell around electrodes, and the cell conductive via connectors are structured and connected to form a composite left and right handed (CRLH) metamaterial structure which transmits and receives the antenna signal using the cell conductive patches.

22. The device as in claim 21, wherein:

the plurality of cell conductive patches on the first top surface are arranged to form a linear array that is parallel to an edge of the first main ground electrode facing the plurality of cell conductive patches.

23. The device as in claim 21, comprising:

a conductive launch pad formed adjacent to the selected cell conductive patch and spaced from the selected cell by a gap, wherein a dimension of the launch pad and the gap are configured to provide a matching network to excite a resonance at a target resonance frequency within the antenna signal; and

a conductive feed line connected between the co-planar waveguide and the conductive launch pad.

24. The device as in claim 21, comprising:

a conductive patch formed near a gap between two adjacent cell conductive patches to form a metal-insulator-metal (MIM) structure to enhance capacitive coupling between the two adjacent cell conductive patches.

25. An antenna device, comprising:

a first dielectric substrate having a first surface on a first side and a second surface on a second side opposing the first side;

a cell conductive patch formed over the first surface;

a perfect magnetic conductor (PMC) structure comprising a second dielectric substrate fabricated with a three-dimensional electrode structure to provide a perfect magnetic conductor (PMC) surface and engaged to the second surface of the substrate to press the PMC surface against the second surface;

a cell conductive via connector formed in the first dielectric substrate to connect the cell conductive patch to the PMC surface; and

a conductive feed line formed on the first surface and having a distal end located close to and electromagnetically coupled to the cell conductive patch to direct an antenna signal to or from the cell conductive patch,

wherein the cell conductive patch, the substrate, the cell conductive via connector, electromagnetically coupled conductive feed line, and the PMC surface are structured to form a composite left and right handed (CRLH) metamaterial structure which transmits and receives the antenna signal using the cell conductive patch.

26. The device as in claim 25, wherein the PMC structure comprises:

a periodic array of metal patches formed on a first surface of the second dielectric substrate;

a ground electrode layer formed on a second surface of the second dielectric substrate; and

a plurality of conductive vias formed in the second dielectric substrate to respectively connect the metal patches on the first surface to the ground electrode layer on the second surface wherein the metal patches, the ground electrode layer, the conductive vias and the second dielectric substrate are structured so that the first surface of the second dielectric substrate and the metal patches form the PMC surface which is engaged to the second surface of the first dielectric substrate.