Multi-Metamaterial-Antenna Systems with Directional Couplers

• US 20090219213A1
• Filed: 12/20/2008
• Published: 09/03/2009
• Est. Priority Date: 12/21/2007
• Status: Abandoned Application

• Current Assignee: Ajay Gummalla, Cheng-Jung Lee, Maha Achour, Vaneet Pathak
• Original Assignee: Ajay Gummalla, Cheng-Jung Lee, Maha Achour, Vaneet Pathak
• Inventors: Achour, Maha, Gummalla, Ajay, Pathak, Vaneet, Lee, Cheng-Jung
• Application Number:
  US12/340,657
• Publication Number:
  US 20090219213A1
• Time in Patent Office: Days
• US Class Current: 343/700.MS
• CPC Class Codes: H01P 3/00 Waveguides; Transmission lines of the waveguide type
• CPC Class Codes: H01P 5/185 Edge coupled lines
• CPC Class Codes: H01Q 1/521 reducing the coupling between adjacent antennas
• 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 21/0006 Particular feeding systems
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037
• CPC Class Codes: H01Q 9/045 with particular feeding means for circular polarisation H01Q9/0428

Abstract

Examples of apparatus and techniques for providing metamaterial (MTM) multi-antenna array systems with directional couplers for various applications.

Claims

1. A metamaterial (MTM) multi-antenna array system for decoupling N number of signals between N number of antennas, where N is an integer greater than 1, comprising:

an N-element metamaterial (MTM) antenna array; and

an N-way directional coupler coupled to the N-element metamaterial (MTM) antenna array,

wherein the N-way directional coupler has 2N ports.

2. The metamaterial (MTM) multi-antenna system as in claim 1, wherein the N-way directional coupler comprises a coupled transmission line having N adjacent transmission lines.

3. The metamaterial (MTM) multi-antenna system as in claim 2, wherein the coupled transmission line coupling is controlled by the proximity of the coupled transmission line or LC components between the adjacent transmission lines, or a combination thereof.

4. The metamaterial (MTM) multi-antenna system as in claim 2, wherein the length, width, and spacing between each of the N adjacent transmission line are optimized for decoupling a plurality of coupling signals between adjacent antennas of the N-element MTM antenna array.

5. The metamaterial (MTM) multi-antenna system as in claim 2, wherein the transmission lines are metamaterial (MTM) transmission lines.

6. The metamaterial (MTM) multi-antenna system as in claim 5, wherein each metamaterial (MTM) transmission line comprises a series capacitor, a shunt inductor, and a transmission line section.

7. The metamaterial (MTM) multi-antenna system as in claim 6, wherein the series capacitors, shunt inductors, and coupling capacitors are optimized to decouple a plurality of coupling signals between adjacent antennas of the N-element MTM antenna array.

8. The metamaterial (MTM) multi-antenna system as in claim 1, wherein N=3, the metamaterial (MTM) antenna array comprises three antennas, and the direction coupler is a three-way directional coupler having 6 ports.

9. The metamaterial (MTM) multi-antenna system as in claim 8, wherein the three antennas comprises:

a first antenna having a first configuration;

a second antenna having a second configuration; and

a third antenna having a third configuration;

wherein the first, second, and third antennas operate at substantially the same frequency band.

10. The metamaterial (MTM) multi-antenna system as in claim 9, wherein each of the first, second, and third antennas comprises:

a cell patch formed on a first conductive layer, wherein the first conductive layer is formed on a first side of a substrate;

a launch pad formed on the first conductive layer and electromagnetically coupled to the cell patch, wherein the launch pad is separated from the cell patch by a coupling gap;

a metallic via formed in the first conductive layer and a second conductive layer for providing a conductive path between the first conductive layer and second conductive layer, wherein the via is positioned inside the cell patch and the second conductive layer is formed on an opposing side of the substrate;

an feed line formed on the first conductive layer and coupled to the launch pad;

a first ground formed on the first conductive layer which is coupled to the feed line;

a via pad formed on the second conductive layer, wherein the via pad is coupled to the via;

a via line formed on the second conductive layer, wherein the via line is coupled to the via pad; and

a second ground formed on the second conductive layer, wherein the second ground is coupled to the via line.

11. The metamaterial (MTM) multi-antenna system as in claim 10, wherein the length of the antenna CPW feed line is optimized to satisfy a phase requirement for decoupling a plurality of coupling signals between adjacent antennas of the three-element MTM antenna array.

12. The metamaterial (MTM) multi-antenna system as in claim 9, wherein the three-way directional coupler comprises:

three conductive lines formed on a first conductive layer, wherein the first conductive layer is formed on a first side of a substrate;

a first ground formed on the first conductive layer, wherein the first ground is adjacent and parallel to the conductive lines; and

a second ground formed on a second conductive layer, wherein the second ground is formed on an opposing side of the substrate,

wherein the three conductive lines form a coupled line.

13. The metamaterial (MTM) multi-antenna system as in claim 12, wherein the three conductive lines are arranged in parallel to each other.

14. The metamaterial (MTM) multi-antenna system as in claim 9, wherein the three-way directional coupler comprises:

a first, a second, and third metamaterial (MTM) transmission lines, wherein each of the first, second, and third metamaterial (MTM) transmission lines comprises a transmission line section, a shunt inductor, and a series capacitor;

a first LC Network adjoining the first metamaterial (MTM) transmission line to the second metamaterial (MTM) transmission line; and

a second LC Network adjoining the second metamaterial (MTM) transmission line to the third metamaterial (MTM) transmission line;

15. The metamaterial (MTM) multi-antenna system as in claim 14, wherein the series capacitors, shunt inductors, and coupling capacitors are optimized to decouple a plurality of coupling signals between adjacent antennas of the three-element MTM antenna array.

16. The metamaterial (MTM) multi-antenna system as in claim 14, wherein the width, length, and separation distance of the first, second, and third metamaterial (MTM) transmission lines are optimized to decouple a plurality of coupling signals between adjacent antennas of the three-element MTM antenna array.

17. The metamaterial (MTM) multi-antenna system as in claim 1, wherein N=2, the metamaterial (MTM) antenna array comprises two metamaterial (MTM) antennas, and the direction coupler is a two-way directional coupler having 4 ports.

18. The metamaterial (MTM) multi-antenna system as in claim 17, wherein the two antennas comprises:

a first antenna; and

a second antenna, wherein the first and second antennas operate at substantially the same frequency band.

19. The metamaterial (MTM) multi-antenna system as in claim 18, wherein each of the first and second antennas comprises:

a cell patch formed on a first conductive layer, wherein the first conductive layer is formed on a first side of a substrate;

a launch pad formed on the first conductive layer and electromagnetically coupled to the cell patch, wherein the launch pad is separated from the cell patch by a coupling gap;

a feed line formed on the first conductive layer, wherein one end portion of the feed line is coupled to the launch pad and the other end portion is coupled to the two-way directional coupler;

a metallic via formed in the first conductive layer and a second conductive layer for providing a conductive path between the first conductive layer and second conductive layer, wherein the via is positioned inside the cell patch and the second conductive layer is formed on an opposing side of the substrate;

a via pad formed on the second conductive layer and coupled to the via;

a via line formed on the second conductive layer and coupled to the via pad; and

a ground formed on the second conductive layer and coupled to the ground line.

20. The metamaterial (MTM) multi-antenna system as in claim 17, wherein the two-way directional coupler comprises:

two conductive lines formed on a first conductive layer, wherein the first conductive layer is formed on a first side of a substrate; and

a ground formed on the second conductive layer,

wherein the two conductive lines form a coupled line.

21. The metamaterial (MTM) multi-antenna system as in claim 20, wherein the first and second conductive lines each form a tapered line.

22. The metamaterial (MTM) multi-antenna system as in claim 20, wherein a bend is formed between each feed line and each conductive line.

23. The metamaterial (MTM) multi-antenna system as in claim 20, wherein a bend is formed between each conductive line and coupled line.

24. The metamaterial (MTM) multi-antenna system as in claim 19, wherein the two-way metamaterial (MTM) direction coupler comprises:

a first and second metamaterial (MTM) transmission lines, wherein each of the first and second metamaterial (MTM) transmission lines comprises a transmission line section, a shunt inductor, and a series capacitor; and

an LC Network adjoining the first metamaterial (MTM) transmission line to the second metamaterial (MTM) transmission line.

25. The metamaterial (MTM) multi-antenna system as in claim 18, wherein each of the first and second antennas comprises

a cell patch formed on a first conductive layer, wherein the first conductive layer is formed on a first side of a substrate;

a launch pad formed on the first conductive layer and electromagnetically coupled to the cell patch, wherein the launch pad is separated from the cell patch by a coupling gap;

a metamaterial (MTM) transmission line formed on the first conductive layer, wherein one end portion of the metamaterial (MTM) transmission line is coupled to the launch pad and the other end portion of the metamaterial (MTM) transmission line is coupled to the two-way directional coupler;

a metallic via formed in the first conductive layer and a second conductive layer for providing a conductive path between the first conductive layer and second conductive layer, wherein the via is positioned inside the cell patch and the second conductive layer is formed on an opposing side of the substrate;

a via pad formed on the second conductive layer, wherein the via pad is coupled to the via;

a via line formed on the second conductive layer, wherein the via line is coupled to the via pad; and

a ground formed on the second conductive layer, wherein the ground is coupled to the ground line.

26. The metamaterial (MTM) multi-antenna system as in claim 25, wherein the metamaterial (MTM) transmission line comprises a series capacitor, a shorted stub, and a transmission line section.

27. The metamaterial (MTM) multi-antenna system as in claim 18, wherein each of the first and second antennas comprises:

a cell patch formed on a first conductive layer, wherein the first conductive layer is formed on a first side of a substrate;

an L-shaped launch pad formed on the first conductive layer and electromagnetically coupled to the cell patch, wherein the launch pad is separated from the cell patch by a coupling gap;

a metallic via formed in the first conductive layer and a second conductive layer for providing a conductive path between the first conductive layer and second conductive layer, wherein the via is positioned inside the cell patch and the second conductive layer is formed on an opposing side of the substrate;

a via pad formed on the second conductive layer, wherein the via pad is coupled to the via;

an L-shaped via line formed on the second conductive layer, wherein the L-shaped via line is coupled to the via pad; and

a ground formed on the second conductive layer, wherein the ground is coupled to the L-shaped ground line.

28. The metamaterial (MTM) multi-antenna system as in claim 27, wherein the L-shaped launch pad comprises a rectangular line, two 90°

bends and a tapered line.

29. The metamaterial (MTM) multi-antenna system as in claim 27, wherein the two-way directional coupler comprises:

a first and second metamaterial (MTM) transmission lines, wherein each of the first and second metamaterial (MTM) transmission lines comprises a transmission line section, a shorted stub, and a series capacitor; and

an LC Network adjoining the first metamaterial (MTM) transmission line to the second metamaterial (MTM) transmission line.

30. The metamaterial (MTM) multi-antenna system as in claim 29, wherein the shorted stub comprises a stub where one side of the shorted stub is attached directly to a ground.

31. The metamaterial (MTM) multi-antenna system as in claim 1, wherein the metamaterial (MTM) antenna array comprises a plurality input antennas and a plurality of output antennas configured for transmitting and receiving signals at substantially the same time intervals;

and

the directional coupler comprises a plurality of input ports and a plurality of output ports in which the input ports communicate a plurality of input port signals and the output ports communicate a plurality of output port signals,

wherein the input port signals are transmitted to the input antennas and the output port signals are received from the output antennas wherein a receive port has an isolation better than 15 dB.

32. The metamaterial (MTM) multi-antenna system as in claim 17, wherein the two antennas are structured to operate at a first frequency and a second frequency, respectively.

33. The metamaterial (MTM) multi-antenna system as in claim 32, wherein the first antenna is configured to receive and transmit a first frequency, f1 and a second, different frequency, f2, each being a frequency different from a harmonic frequency of the other;

and

the second antenna is configured to receive and transmit the first frequency, f1 and the second frequency, f2,

wherein the MTM antenna array and the directional coupler are structured to effectuate a strong coupling between two adjacent antennas at both of the first frequency f1 and the second frequency f2.

34. The metamaterial (MTM) multi-antenna system as in claim 33, wherein each of the first and second antennas comprises:

a cell patch formed on a first conductive layer, wherein the first conductive layer is formed on a first side of a substrate;

a launch pad formed on the first conductive layer and electromagnetically coupled to the cell patch, wherein the launch pad is separated from the cell patch by a coupling gap;

a feed line formed on the first conductive layer, wherein one end portion of the feed line is coupled to the launch pad and the other end portion of the feed line is coupled to the two-way directional coupler;

a metallic via formed in the first conductive layer and a second conductive layer for providing a conductive path between the first conductive layer and second conductive layer, wherein the via is positioned inside the cell patch and the second conductive layer is formed on an opposing side of the substrate;

a via pad formed on the second conductive layer and coupled to the via;

a via line formed on the second conductive layer and coupled to the via pad; and

a ground formed on the second conductive layer and coupled to the ground line.

35. The metamaterial (MTM) multi-antenna system as in claim 34, wherein the two-way direction coupler comprises:

two conductive lines formed on a first conductive layer, wherein the first conductive layer is formed on a first side of a substrate; and

a ground formed on the second conductive layer,

wherein the two conductive lines form a coupled line.

36. The metamaterial (MTM) multi-antenna system as in claim 32, wherein the first antenna is configured to receive and transmit a first frequency, f1 and a second higher frequency, f2;

and

the second antenna is configured to receive and transmit the first frequency, f1 and the second frequency, f2,

wherein the MTM antenna array and the directional coupler are structured to effectuate a strong coupling between two adjacent antennas at the first frequency f1 and a weak coupling at the second frequency f2.

37. The metamaterial (MTM) multi-antenna system as in claim 36, wherein each of the first and second antennas comprises:

a cell patch formed on a first conductive layer, wherein the first conductive layer is formed on a first side of a substrate;

a launch pad formed on the first conductive layer and electromagnetically coupled to the cell patch, wherein the launch pad is separated from the cell patch by a coupling gap;

a feed line formed on the first conductive layer, wherein one end portion of the feed line is coupled to the launch pad and the other end portion of the CPW feed line is coupled to the two-way directional coupler;

a metallic via formed in the first conductive layer and a second conductive layer for providing a conductive path between the first conductive layer and second conductive layer, wherein the via is positioned inside the cell patch and the second conductive layer is formed on an opposing side of the substrate;

a via pad formed on the second conductive layer, wherein the via pad is coupled to the via;

a via line formed on the second conductive layer, wherein the via line is coupled to the via pad; and

a main ground formed on the second conductive layer, wherein the main ground is coupled to the ground line.

38. The metamaterial (MTM) multi-antenna system as in claim 37, wherein the two-way direction coupler comprises two conductive lines formed on a first conductive layer, wherein the first conductive layer is formed on a first side of a substrate;

and

a ground formed on the second conductive layer,

wherein the two conductive lines form a coupled line.

39. The metamaterial (MTM) multi-antenna system as in claim 32, wherein the first antenna is configured to receive and transmit a first frequency, f1 and second frequency, f2;

and

the second antenna is configured to receive and transmit the first frequency, f1 and the second frequency, f2,

wherein, f2 is not equal to 2 times f1, f2 is greater f1, and f1 has a strong coupling occurs at frequency, f1, and a weak coupling occurs at a frequency, f2.

40. The metamaterial (MTM) multi-antenna system as in claim 39, wherein each of the first and second antennas comprises:

a cell patch formed on a first conductive layer, wherein the first conductive layer is formed on a first side of a substrate;

a launch pad formed on the first conductive layer and electromagnetically coupled to the cell patch, wherein the launch pad is separated from the cell patch by a coupling gap;

a feed line formed on the first conductive layer, wherein one end portion of the feed line is coupled to the launch pad and the other end portion of the feed line is coupled to the two-way directional coupler;

a metallic via formed in the first conductive layer and a second conductive layer for providing a conductive path between the first conductive layer and second conductive layer, wherein the via is positioned inside the cell patch and the second conductive layer is formed on an opposing side of the substrate;

a via pad formed on the second conductive layer, wherein the via pad is coupled to the via;

a via line formed on the second conductive layer, wherein the via line is coupled to the via pad; and

a main ground formed on the second conductive layer, wherein the main ground is coupled to the ground line.

41. The metamaterial (MTM) multi-antenna system as in claim 40, wherein the two-way direction coupler comprises a first and second metamaterial (MTM) transmission lines, wherein each of the first and second metamaterial (MTM) transmission lines comprises a transmission line section, a shunt inductor, and a series capacitor;

and

an LC Network adjoining the first metamaterial (MTM) transmission line to the second metamaterial (MTM) transmission line.

42. The metamaterial (MTM) multi-antenna system as in claim 39, wherein the first antenna comprises

a first cell patch formed on a first conductive layer, wherein the first conductive layer is formed on a first side of a first substrate;

a first launch pad formed on the first conductive layer and electromagnetically coupled to the first cell patch, wherein the first launch pad is separated from the first cell patch by a coupling gap;

a first feed line formed on the first conductive layer, wherein one end portion of the first feed line is coupled to the first launch pad and the other end portion of the first feed line is coupled to the two-way directional coupler;

a first metallic via formed in the first conductive layer and a second conductive layer for providing a conductive path between the first conductive layer and second conductive layer, wherein the first via is positioned inside the first cell patch and the second conductive layer is formed on a first side of a second substrate;

a first via pad formed on the second conductive layer, wherein the first via pad is coupled to the first via;

a first via line formed on the second conductive layer, wherein the first via line is coupled to the first via pad; and

a first ground formed on the second conductive layer, wherein the first ground is coupled to the first ground line;

and, wherein the second antenna comprises;

a second cell patch formed on the second conductive layer;

a second launch pad formed on the second conductive layer and electromagnetically coupled to the second cell patch, wherein the second launch pad is separated from the second cell patch by a coupling gap;

a second feed line formed on the second conductive layer, wherein one end portion of the second feed line is coupled to the second launch pad and the other end portion of the second feed line is coupled to the two-way directional coupler;

a second metallic via formed in the second conductive layer and the first conductive layer for providing a conductive path between the first conductive layer and second conductive layer, wherein the second via is positioned inside the second cell patch;

a second via pad formed on the first conductive layer, wherein the second via pad is coupled to the second via;

a second via line formed on the first conductive layer, wherein the second via line is coupled to the second via pad; and

a second ground formed on the first conductive layer, wherein the second ground is coupled to the second ground line;

43. The metamaterial (MTM) multi-antenna system as in claim 42, wherein the two-way direction coupler comprises a vertical directional coupler.

44. The metamaterial (MTM) multi-antenna system as in claim 43, wherein the vertical directional coupler comprises four 50Ω

feed lines, four via pads and one coupled strip line.

45. The metamaterial (MTM) multi-antenna system as in claim 42, wherein the two-way direction coupler comprises a forward wave metamaterial (MTM) directional coupler.

46. The metamaterial (MTM) multi-antenna system as in claim 32, wherein the first antenna is configured to receive and transmit a first frequency;

the second antenna is configured to receive and transmit a second frequency; and

the directional coupler comprises a first port configured to communicate a first signal from the first antenna, a second port configured to communicate a second signal from the second antenna, a third port coupled to the first antenna which is resonant at the first frequency, and a fourth port coupled to the second antenna which is resonant at the second frequency.

47. The metamaterial (MTM) multi-antenna system as in claim 46, wherein

the directional coupler is a microwave directional coupler.

48. The metamaterial (MTM) multi-antenna system as in claim 46, wherein the directional coupler is a metamaterial (MTM) directional coupler.

49. The metamaterial (MTM) multi-antenna system as in claim 32 further comprises:

a first bandpass filter configured to receive and transmit a first signal; and

a second bandpass filter configured to receive and transmit a second signal,

wherein the directional coupler comprises

a first port coupled to the first bandpass filter in which the first port is configured to receive and transmit the first signal from the first bandpass filter;

a second port coupled to the second bandpass filter in which the second port is configured to receive and transmit the second signal from the second bandpass filter;

a third port coupled to the first antenna which is resonant at the first frequency; and

a fourth port coupled to the second antenna which is resonant at the second frequency,

wherein the first antenna is configured to receive and transmit a first frequency, and the second antenna is configured to receive and transmit a second frequency.

50. The metamaterial (MTM) multi-antenna system as in claim 49, wherein

the directional coupler is a microwave directional coupler.

51. The metamaterial (MTM) multi-antenna system as in claim 49, wherein

the directional coupler is a metamaterial (MTM) directional coupler.

52. A metamaterial (MTM) multi-antenna array system, comprising:

two or more MTM antennas spaced from one another, each MTM antenna comprising at least one unit cell comprising a series inductor, a shunt capacitor, a shunt inductor, and a series capacitor that are structured to form a composite right and left handed (CRLH) MTM structure; and

an MTM directional coupler comprising MTM transmission lines that are coupled to the MTM antennas, each MTM transmission line transmitting a signal to or receiving a signal from a respective MTM antenna,

wherein each MTM transmission line comprises a transmission line section, a shunt inductor, and a series capacitor that are structured to form a CRLH MTM structure and that are configured relative to an adjacent MTM transmission line coupled to an adjacent MTM antenna to reduce coupling between adjacent MTM antennas.

53. The system as in claim 52, wherein each MTM antenna is structured to exhibit two different resonance frequencies, each being a frequency different from a harmonic frequency of the other.

54. The system as in claim 53, wherein the MTM antennas and the MTM directional coupler are structured to produce strong coupling between two adjacent MTM antennas at both of the two different resonance frequencies.

55. The system as in claim 54, wherein the MTM antennas and the MTM directional coupler are structured to produce a strong coupling between two adjacent MTM antennas at one of the two different resonance frequencies and a weak coupling between the two adjacent MTM antennas at another one of the two different resonance frequencies.

56. The system as in claim 52, comprises a signal filter coupled to an MTM transmission line of the MTM directional coupler to transmit a selective frequency while blocking other frequencies.