Tunable Metamaterial Antenna Structures

• US 20100123635A1
• Filed: 11/16/2009
• Published: 05/20/2010
• Est. Priority Date: 11/19/2008
• Status: Active Grant

• Current Assignee: Tyco Electronics Services GmbH (TE Connectivity Limited)
• Original Assignee: Rayspan Corporation
• Inventors: Gummalla, Ajay, Lopez, Norberto
• Granted Patent: US 8,674,891 B2
• Time in Patent Office: Days
• US Class Current: 343/722
• 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 5/335 at the feed, e.g. for impedance matching
• CPC Class Codes: H01Q 5/364 Creating multiple current paths
• 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

Apparatus and techniques that provide tuning elements in antenna devices to tune frequencies of the antenna devices, including composite right and left handed (CRLH) metamaterial (MTM) antenna devices. Examples of the tuning elements for CRLH MTM antenna devices include feed line tuning elements, cell patch tuning elements, meandered stub tuning elements, via line tuning elements, and via pad tuning elements tuning elements that formed near corresponding antenna elements such as the feed line, cell patch, meander stub, via line and via pad, respectively.

Claims

1. A method for tuning a resonant frequency of a Composite Right/Left Handed (CRLH) Metamaterial (MTM) antenna device, comprising:

providing a CRLH MTM antenna on a substrate, the CRLH MTM antenna comprising antenna elements that are structured and electromagnetically coupled to one another to form a CRLH MTM structure;

providing a plurality of electrically conductive tuning elements on the substrate that are separated from one another and from the CRLH MTM antenna; and

selecting one or more electrically conductive tuning elements located next to respective antenna elements to connect the selected one or more electrically conductive tuning elements to at least one of the respective antenna elements to make the selected one or more electrically conductive tuning elements as part of the CRLH MTM antenna to tune a resonant frequency of the CRLH MTM antenna to be different from an initial value of the resonant frequency when the selected one or more electrically conductive tuning elements are not connected.

2. The method as in claim 1, comprising:

after the selected one or more electrically conductive tuning elements are connected to the at least one of the respective antenna elements, disconnecting one selected conductive tuning element from the CRLH MTM antenna to tune the resonant frequency of the CRLH MTM antenna to a different value.

3. The method as in claim 1, wherein two selected electrically conductive tuning elements are connected to the CRLH MTM antenna, and the two selected electrically conductive tuning elements are connected to two different antenna elements of the CRLH MTM antenna, respectively.

4. The method as in claim 1, wherein two selected electrically conductive tuning elements are connected to the CRLH MTM antenna, and wherein the two selected electrically conductive tuning elements are connected to each other and one of the two selected electrically conductive tuning elements is connected to an antenna element of the CRLH MTM antenna.

5. The method as in claim 1, wherein two selected electrically conductive tuning elements are connected to the CRLH MTM antenna by being connected to a common antenna element of the CRLH MTM antenna.

6. The method as in claim 1, wherein the electrically conductive tuning elements are electrically conductive patches.

7. The method as in claim 6, wherein at least two of the electrically conductive patches are different in size or shape.

8. The method as in claim 1, wherein the CRLH MTM antenna comprises:

an electrically conductive cell patch formed on a first surface of the substrate;

an electrically conductive feed line formed on the first surface to be separated from the cell patch and electromagnetically coupled to the cell patch;

an electrically conductive via pad formed on a second surface of the substrate underneath the cell patch;

an electrically conductive via penetrating the substrate to connect the cell patch on the first surface to the via pad on the second surface; and

a via line formed on the second surface to connect the via pad to a ground electrode on the second surface,

wherein one of the electrically conductive tuning elements is an electrically conductive element that is located next to one of a distal end of the feed line and the via pad, or is connected to the ground electrode.

9. The method as in claim 1, comprising using a zero-ohm resistor to connect a selected conductive tuning element to the CRLH MTM antenna.

23. The method as in claim 8, wherein the forming of the plurality of conductive parts on the substrate includes:

forming a ground electrode, a feed line and a cell patch;

forming a via line to connect the cell patch and the ground electrode;

electromagnetically coupling a distal end of the feed line to the cell patch through a gap to direct a signal to or from the cell patch; and

forming a meander stub with one end attached to the feed line;

forming the CRLH MTM antenna structure that generates a first left handed (LH) mode resonance and a first low right handed (RH) mode resonance in a low band and a first high RH mode resonance in a high band,

wherein the forming of the plurality of tuning elements on the substrate includes a step of forming cell patch tuning elements close to the cell patch and spatially separated from one another, and

wherein the connecting of one or more of the tuning elements to the conductive parts includes a step of electrically connecting or disconnecting one or more of the cell patch tuning elements to the cell patch, to change dimensions and shape of the cell patch to reconfigure the CRLH MTM antenna structure to generate a second LH mode resonance that has a different frequency from the first LH mode resonance.

24. The method as in claim 8, wherein the forming of the plurality of conductive parts on the substrate includes:

forming a ground electrode, a feed line and a cell patch;

forming a via line to connect the cell patch and the ground electrode;

electromagnetically coupling a distal end of the feed line to the cell patch through a gap to direct a signal to or from the cell patch; and

forming a meander stub with one end attached to the feed line;

forming the CRLH MTM antenna structure that generates a first left handed (LH) mode resonance and a first low right handed (RH) mode resonance in a low band and a first high RH mode resonance in a high band,

wherein the forming of the plurality of tuning elements on the substrate includes a step of forming meander stub tuning elements attached to the meander stub, and

wherein the connecting of one or more of the tuning elements to the conductive parts includes a step of electrically connecting or disconnecting two or more of the meander stub tuning elements, to change dimensions and shape of the meander stub to reconfigure the CRLH MTM antenna structure to generate a second low RH mode resonance that has a different frequency from the first low RH mode resonance.

10. A Composite Right and Left Handed (CRLH) Metamaterial (MTM) antenna device, comprising:

a CRLH MTM antenna on a substrate, the CRLH MTM antenna comprising antenna elements that are structured and electromagnetically coupled to one another to form a CRLH MTM structure; and

a plurality of electrically conductive tuning elements that are separated from one another and from the CRLH MTM antenna, and that are formed at selected locations close to the CRLH MTM antenna and are configured to allow tuning of a resonant frequency of the CRLH MTM antenna, when one or more of the electrically conductive tuning elements located next to respective antenna elements are connected to, or disconnected from, at least one of the respective antenna elements.

11. The device as in claim 10, wherein the CRLH MTM antenna comprises:

a conductive cell patch formed on a first surface of the substrate;

a conductive feed line formed on the first surface to be separated from the cell patch and electromagnetically coupled to the cell patch;

a conductive via pad formed on a second surface of the substrate underneath the cell patch;

a conductive via penetrating the substrate to connect the cell patch on the first surface to the via pad on the second surface; and

a via line formed on the second surface to connect the via pad to a ground electrode on the second surface,

wherein one of the electrically conductive tuning elements is a conductive element that is located next to one of a distal end of the feed line and the via pad, or is connected to the ground electrode.

12. The device as in claim 10, comprising a zero-ohm resistor to connect a selected conductive tuning element to the CRLH MTM antenna.

13. A metamaterial antenna device comprising:

a substrate;

a plurality of electrically conductive parts formed on the substrate; and

a plurality of tuning elements formed on the substrate,

wherein the electrically conductive parts are configured to form a composite right and left handed (CRLH) metamaterial antenna structure that generates a first plurality of frequency resonances when none of the tuning elements is connected to any of the electrically conductive parts, and

wherein one or more of the tuning elements, when electrically connected to the conductive parts, reconfigure the CRLH MTM antenna structure to generate a second plurality of frequency resonances different from the first plurality of frequency resonances.

14. The metamaterial antenna device as in claim 13, wherein the conductive parts comprise:

a ground electrode;

a cell patch;

a via line connecting the cell patch and the ground electrode;

a feed line, a distal end of which is electromagnetically coupled to the cell patch through a gap to direct a signal to or from the cell patch; and

a meander stub, one end of which is connected to the feed line,

wherein the first plurality of frequency resonances include a first left handed (LH) mode resonance and a first low right handed (RH) mode resonance in a low band and a first high RH mode resonance in a high band.

15. The metamaterial antenna device as in claim 14, wherein the cell patch and the via line are formed on different surfaces of the substrate, and wherein the via line includes:

a via pad; and

a via formed in the substrate and connecting the cell patch and the via pad.

16. The metamaterial antenna device as in claim 14, wherein the tuning elements include a plurality of feed line tuning elements formed close to the feed line, the feed line tuning elements being spatially separated from one another,

wherein one or more of the feed line tuning elements, when electrically connected to or disconnected from the feed line, change a dimension and a shape of the feed line to reconfigure the CRLH MTM antenna structure to generate a second high RH mode resonance that has a different frequency from the first high RH mode resonance.

17. The metamaterial antenna device as in claim 14, wherein the tuning elements include a plurality of cell patch tuning elements formed close to the cell patch, the cell patch tuning elements being spatially separated from one another,

wherein one or more of the cell patch tuning elements, when electrically connected to or disconnected from the cell patch, change a dimension and a shape of the cell patch to reconfigure the CRLH MTM antenna structure to generate a second LH mode resonance that has a different frequency from the first LH mode resonance.

18. The metamaterial antenna device as in claim 14, wherein the tuning elements include a plurality of meander stub tuning elements attached to the meander stub,

wherein two or more of the meander stub tuning elements, when electrically connected to or disconnected from one another, change a dimension and a shape of the meander stub to reconfigure the CRLH MTM antenna structure to generate a second low RH mode resonance that has a different frequency from the first low RH mode resonance.

19. The metamaterial antenna device as in claim 14, wherein the tuning elements include a plurality of via line tuning elements formed close to the via line, the via line tuning elements being spatially separated from one another,

wherein one or more of the via line tuning elements, when electrically connected to the via line, become part of the via line and thus change a dimension and a shape of the via line to reconfigure the CRLH MTM antenna structure to generate a second LH mode resonance that has a different frequency from the first LH mode resonance.

20. A method of tuning a metamaterial antenna device, comprising steps of:

providing a substrate for the metamaterial antenna device;

forming a plurality of conductive parts on the substrate to form a composite right and left handed (CRLH) metamaterial antenna structure that generates a first plurality of frequency resonances;

forming a plurality of tuning elements on the substrate; and

connecting one or more of the tuning elements to the conductive parts to reconfigure the CRLH MTM antenna structure in a way that generates a second plurality of frequency resonances.

21. The method as in claim 20, wherein the forming of the plurality of conductive parts on the substrate includes:

forming a ground electrode, a feed line and a cell patch;

forming a via line to connect the cell patch and the ground electrode;

electromagnetically coupling a distal end of the feed line to the cell patch through a gap to direct a signal to or from the cell patch; and

forming a meander stub with one end attached to the feed line; and

forming the CRLH MTM antenna structure that generates a first left handed (LH) mode resonance and a first low right handed (RH) mode resonance in a low band and a first high RH mode resonance in a high band,

wherein the forming of the plurality of tuning elements on the substrate includes a step of forming feed line tuning elements close to the feed line and spatially separated from one another, and

wherein the connecting of one or more of the tuning elements to the conductive parts includes a step of electrically connecting or disconnecting one or more of the feed line tuning elements to the feed line, to change dimensions and shape of the feed line to reconfigure the CRLH MTM antenna structure to generate a second high RH mode resonance that has a different frequency from the first high RH mode resonance.

22. The method as in claim 21, wherein the cell patch and the via line are formed on different surfaces of the substrate, and the second forming step comprises:

forming a via pad to be connected to the via line; and

forming a via in the substrate to connect the cell patch and the via pad.

25. The method as in claim 20, wherein the forming of the plurality of conductive parts on the substrate includes steps of:

forming a ground electrode, a feed line and a cell patch;

forming a via line to connect the cell patch and the ground electrode;

electromagnetically coupling a distal end of the feed line to the cell patch through a gap to direct a signal to or from the cell patch;

forming a meander stub with one end attached to the feed line; and

forming the CRLH MTM antenna structure that generates a first left handed (LH) mode resonance and a first low right handed (RH) mode resonance in a low band and a first high RH mode resonance in a high band,

wherein the forming of the plurality of tuning elements on the substrate includes a step of forming via line tuning elements close to the via line and spatially separated from each other, and

wherein the connecting of one or more of the tuning elements to the conductive parts includes a step of electrically connecting or disconnecting one or more of the via line tuning elements to the via line, to change dimensions and shape of the via line to reconfigure the CRLH MTM antenna structure to generate a second LH mode resonance that has a different frequency from the first LH mode resonance.

26. A method for tuning a resonant frequency of a Composite Right and Left Handed (CRLH) Metamaterial (MTM) antenna device by changing one or more connections of permanently-formed components of the device, comprising:

providing permanently-formed antenna components on a substrate that include permanently-formed conductive antenna elements on a substrate which are structured and electromagnetically coupled to one another to form a CRLH MTM structure, and permanently-formed electrically conductive tuning elements that are positioned at different locations from one another and from the permanently-formed antenna elements and are adjacent to respective permanently-formed conductive antenna elements;

selecting one or more permanently-formed electrically conductive tuning elements located next to respective permanently-formed antenna elements to connect to at least one of the respective permanently-formed antenna elements to make the selected one or more permanently-formed electrically conductive tuning elements as part of the CRLH MTM antenna to tune a resonant frequency of the CRLH MTM antenna to be different from a value of the resonant frequency when the selected one or more permanently-formed electrically conductive tuning elements are not connected.

27. The method as in claim 26, wherein:

two selected permanently-formed electrically conductive tuning elements are connected to each other, and

one of the two selected permanently-formed electrically conductive tuning elements that are connected to each other is connected to a permanently-formed antenna element.

28. The method as in claim 26, comprising:

disconnecting a selected permanently-formed electrically conductive tuning element that is connected to a permanently-formed antenna element to tune the CRLH MTM antenna.