Antennas based on metamaterial structures

• US 7,847,739 B2
• Filed: 09/17/2009
• Issued: 12/07/2010
• 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:
  US12/562,114
• Publication Number:
  US 20100238081A1
• Time in Patent Office: 446 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 substrate having a first surface on a first side and a second surface on a second side opposite to the first side;

a ground electrode formed on the first surface leaving part of the first surface exposed to have an exposed surface part;

a composite left and right handed (CRLH) metamaterial structure comprising;

(i) one or more unit cells including at least a portion of the exposed surface part, and

(ii) one or more conductive strips formed on the first surface and coupling the one or more unit cells to the ground electrode; and

a feed line formed on the second surface having a distal end capacitively coupled to the CRLH metamaterial structure and directing an antenna signal to or from the CRLH metamaterial structure;

wherein the CRLH metamaterial structure and the feed line are configured to exhibit one or more left handed (LH) resonant modes and one or more right handed (RH) resonant modes associated with the antenna signal.

2. The antenna device as in claim 1,

wherein a portion near the distal end of the feed line is modified to form a launch pad to enhance capacitive coupling between the CRLH metamaterial structure and the feed line.

3. The antenna device as in claim 1, further comprising:

an input port formed in the substrate and separated from the CRLH metamaterial structure,

wherein the feed line is configured to couple to the input port.

4. The antenna device as in claim 3, further comprising:

a second ground electrode formed on the second surface leaving part of the second surface exposed.

5. The antenna device as in claim 4, further comprising:

a coplanar waveguide (CPW) feed line formed in the second ground electrode,

wherein the feed line is configured to couple to the input port through the CPW feed line.

6. The antenna device as in claim 4, further comprising:

a parasitic element formed based on the substrate and separated from the feed line and the CRLH metamaterial structure, the parasitic element comprising;

a parasitic conductive line coupled to the second ground electrode; and

a parasitic cell block having one end coupled to the parasitic conductive line and another end coupled to the ground electrode.

7. The antenna device as in claim 6,

wherein the parasitic cell block is capacitively coupled to the parasitic conductive line and is configured to form a second CRLH metamaterial structure comprising:

(i) one or more parasitic unit cells including at least a second portion of the exposed surface part, and

(ii) one or more parasitic conductive strips formed on the first surface and coupling the one or more parasitic unit cells to the ground electrode.

8. The antenna device as in claim 1,

wherein the one or more unit cells comprise a first unit cell that is capacitively coupled to the feed line through a first gap formed on the second surface.

9. The antenna device as in claim 8,

wherein a middle metallization layer is formed in the substrate, the middle metallization layer being oriented substantially in parallel with the first and second surfaces and patterned to form one or more conductive patches, the one or more conductive patches comprising:

a first conductive patch formed to cover a footprint of the first gap projected onto the middle metallization layer,

wherein the feed line, the first conductive patch and at least a portion of the first unit cell form a metal-insulator-metal (MIM) structure to enhance capacitive coupling between the feed line and the first unit cell.

10. The antenna device as in claim 8,

wherein the one or more unit cells further comprise a second unit cell that is capacitively coupled to the first unit cell through a second gap formed on the second surface.

11. The antenna device as in claim 10,

wherein a middle metallization layer is formed in the substrate, the middle metallization layer being oriented substantially in parallel with the first and second surfaces and patterned to form one or more conductive patches, the one or more conductive patches comprising:

a first conductive patch formed to cover a second footprint of the first gap projected onto the middle metallization layer; and

a second conductive patch formed to cover a footprint of the second gap projected onto the middle metallization layer,

wherein the feed line, the first conductive patch, the second conductive patch, at least a portion of the first unit cell, and at least a portion of the second unit cell form a metal-insulator-metal (MIM) structure to enhance capacitive coupling between the feed line and the first unit cell and capacitive coupling between the first unit cell and the second unit cell.

12. The antennas device as in claim 1,

wherein the unit cell comprises:

a cell conductive patch formed on the second surface;

a dielectric gap formed on the second surface and coupled in series with the cell conductive patch; and

a cell conductive via formed in the substrate to couple the cell conductive patch on the second surface and one of the one or more conductive strips on the first surface;

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

13. The antenna device as in claim 1,

wherein the CRLH metamaterial structure and the feed line are configured to further generate one or more mixed resonant modes associated with the antenna signal.

14. The antenna device as in claim 1,

wherein the one or more unit cells comprise at least two unit cells placed in a one-dimensional series arrangement along one direction in the first and second surfaces,

and wherein each pair of adjacent unit cells are capacitively coupled through a gap.

15. The antenna device as in claim 1,

wherein the one or more unit cells comprise at least three unit cells placed in a two-dimensional series arrangement along two coplanar directions in the first and second surfaces,

and wherein each unit cell is capacitively coupled to adjacent unit cells through respective gaps.

16. The antenna device as in claim 1, further comprising:

a tuning element coupled to the CRLH metamaterial structure and structured to have a geometry and spacing from the CRLH metamaterial structure that tune antenna resonances.

17. The antenna device as in claim 16,

wherein a middle metallization layer is formed in the substrate, the middle metallization layer being oriented substantially in parallel with the first and second surfaces,

and wherein the tuning element comprises:

a tuning patch formed in the middle metallization layer to capacitively couple to at least a portion of the unit cell that is located at an end portion of the CRLH metamaterial structure.

18. The antenna device as in claim 3, further comprising:

a second composite left and right handed (CRLH) metamaterial structure comprising;

(i) one or more second unit cells including at least a second portion of the exposed surface part, and

(ii) one or more second conductive strips formed on the first surface and coupling the one or more second unit cells to the ground electrode; and

a second feed line formed on the second surface having a distal end capacitively coupled to the second CRLH metamaterial structure and directing a second antenna signal to or from the second CRLH metamaterial structure; and

a second input port formed in the substrate and separated from the CRLH metamaterial structure, the second CRLH metamaterial structure and the feed line, the second input port being coupled to the second feed line.

19. The antenna device as in claim 18,

wherein the second CRLH metamaterial structure and the second feed line are configured to generate one or more second LH resonant modes and one or more second RH resonant modes associated with the second antenna signal.

20. The antenna device as in claim 19,

wherein the one or more second LH resonant modes and the one or more second RH resonant modes associated with the second antenna signal are substantially the same in frequency as the one or more LH resonant modes and the one or more RH resonant modes associated with the antenna signal.

21. The antenna device as in claim 19,

wherein the one or more second LH resonant modes and the one or more second RH resonant modes associated with the second antenna signal are different in frequency from the one or more LH resonant modes and the one or more RH resonant modes associated with the antenna signal.

22. The antenna device as in claim 18,

wherein the feed line directs the antenna signal to the CRLH metamaterial structure to transmit out the antenna signal through the CRLH metamaterial structure;

and

the second feed line receives the second antenna signal through the second CRLH metamaterial structure to direct the second antenna signal from the second CRLH metamaterial structure.

23. The antenna device as in claim 18,

wherein the feed line directs the antenna signal to the CRLH metamaterial structure to transmit out the antenna signal through the CRLH metamaterial structure;

and

the second feed line directs the second antenna signal to the second CRLH metamaterial structure to transmit out the second antenna signal through the second CRLH metamaterial structure.

24. The antenna device as in claim 18,

wherein the feed line receives the antenna signal through the CRLH metamaterial structure to direct the antenna signal from the CRLH metamaterial structure;

and

the second feed line receives the second antenna signal through the second CRLH metamaterial structure to direct the second antenna signal from the second CRLH metamaterial structure.

25. An antenna device, comprising:

a first substrate having a first surface on a first side and a second surface on a second side opposite to the first side;

a second substrate having a third surface on a first side and a fourth surface on a second side opposite to the first side, the first and second substrates stacking over each other to engage the second surface to the third surface;

a middle metallization layer formed between the second and third surfaces and patterned to form one or more conductive patches;

a ground electrode formed on the first surface leaving part of the first surface exposed to have an exposed surface part;

a composite left and right handed (CRLH) metamaterial structure comprising;

(a) one or more unit cells including at least a portion of the exposed surface part, and

(b) one or more conductive strips formed on the first surface and coupling the one or more unit cells to the ground electrode; and

a feed line formed on the fourth surface having a distal end capacitively coupled to the CRLH metamaterial structure and directing an antenna signal to or from the CRLH metamaterial structure;

wherein the CRLH metamaterial structure and the feed line are configured to generate one or more left handed (LH) resonant modes and one or more right handed (RH) resonant modes associated with the antenna signal.

26. The antenna device as in claim 25,

wherein the one or more unit cells comprise a first unit cell that is capacitively coupled to the feed line through a first gap formed on the fourth surface,

wherein the one or more conductive patches in the middle metallization layer comprise a first conductive patch formed to cover a footprint of the first gap projected onto the middle metallization layer,

and wherein the feed line, the first conductive patch and at least a portion of the first unit cell form a metal-insulator-metal (MIM) structure to enhance capacitive coupling between the feed line and the first unit cell.

27. The antenna device as in claim 26,

wherein the one or more unit cells further comprise a second unit cell that is capacitively coupled to the first unit cell through a second gap formed on the fourth surface,

wherein the one or more conductive patches in the middle metallization layer further comprise a second conductive patch formed to cover a second footprint of the second gap projected onto the middle metallization layer,

and wherein the feed line, the first conductive patch, the second conductive patch, at least a portion of the first unit cell, and at least a portion of the second unit cell form a metal-insulator-metal (MIM) structure to enhance capacitive coupling between the feed line and the first unit cell and capacitive coupling between the first unit cell and the second unit cell.

28. The antenna device as in claim 25, further comprising:

a tuning element coupled to the CRLH metamaterial structure and structured to have a geometry and spacing from the CRLH metamaterial structure that tune antenna resonances.

29. The antenna device as in claim 28,

wherein the tuning element comprises:

a tuning patch formed in the middle metallization layer to capacitively couple to at least a portion of the unit cell that is located at an end portion of the CRLH metamaterial structure.