MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) MULTI-BAND ANTENNAS WITH A CONDUCTIVE NEUTRALIZATION LINE FOR SIGNAL DECOUPLING

• US 20120013519A1
• Filed: 07/15/2010
• Published: 01/19/2012
• Est. Priority Date: 07/15/2010
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Ericsson Mobile Communications AB (Sony Group Corp.)
• Inventors: Ying, Zhinong, Håkansson, Mikael
• Granted Patent: US 8,780,002 B2
• Time in Patent Office: Days
• US Class Current: 343/835
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• 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 1/521 reducing the coupling between adjacent antennas
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00

Abstract

A MIMO antenna includes first and second radiating elements, a conductive neutralization line, and first and second parasitic radiating elements. Each of the first and second radiating elements includes a straight portion connected to a serpentine portion. The straight and serpentine portions are configured to resonate in at least two spaced apart RF frequency ranges in response to the straight portion being electrically excited through a RF feed. The conductive neutralization line conducts resonant currents between the first and second radiating elements and has a conductive length that is configured to phase shift the conducted resonant currents to cause at least partial cancellation of currents in the first and second radiating elements which are generated by wireless RF signals received by the first and second radiating element from each other. The first parasitic radiating element can be adjacent and parasitically coupled to the first radiating element to radiate responsive to the first radiating element resonating at a RF frequency. The second parasitic radiating element can be adjacent and parasitically coupled to the second radiating element to radiate responsive to the second radiating element resonating at a RF frequency.

Claims

1. A MIMO antenna comprising:

a first radiating element that includes a straight portion connected to a serpentine portion, wherein the straight and serpentine portions are configured to resonate in at least two spaced apart RF frequency ranges in response to the straight portion being electrically excited through a first RF feed;

a second radiating element that includes a straight portion connected to a serpentine portion, wherein the straight and serpentine portions are configured to resonate in at least two spaced apart RF frequency ranges in response to the straight portion being electrically excited through a second RF feed; and

a conductive neutralization line that connects the first and second radiating elements to conduct resonant currents therebetween that at least partially cancel RF transmission coupling between the first and second radiating elements.

2. The MIMO antenna of claim 1, wherein:

the straight portions of the first and second radiating elements have an equal conductive path length; and

the serpentine portions of the first and second radiating elements have an equal conductive path length.

3. The MIMO antenna of claim 2, wherein:

the straight and serpentine portions of the second radiating element are configured as a mirror image of the straight and serpentine portions of the first radiating element.

4. The MIMO antenna of claim 1, wherein:

a conductive path length of the conductive neutralization line is configured to phase shift the conducted resonant currents to cause at least partial cancellation of RF signals wirelessly received by the first and second radiating elements from each other.

5. The MIMO antenna of claim 4, wherein:

the location of connection of the conductive neutralization line to the first and second radiating elements and the conductive path length of the conductive neutralization line are configured to phase shift the resonant current conducted from the first radiating element to the second radiating element to cause its subtraction from a current induced by a wireless RF signal received by the second radiating element from the first radiating element, and configured to phase shift the resonant current conducted from the second radiating element to the first radiating element to cause its subtraction from a current induced by a wireless RF signal received by the first radiating element from the second radiating element.

6. The MIMO antenna of claim 1, wherein:

the first and second radiating elements are spaced apart by less than the combined conductive lengths of the straight and serpentine portions of the first radiating element.

7. The MIMO antenna of claim 6, wherein:

the first and second radiating elements are spaced apart by less than the conductive length of the straight portion of the first radiating element.

8. The MIMO antenna of claim 1, wherein:

the first radiating element is configured to resonant within a higher RF frequency range defined by a combined conductive length of its straight and serpentine portions, and to resonant within a lower RF frequency range defined by a conductive length of its straight portion.

9. The MIMO antenna of claim 1, wherein:

the first and second radiating elements are configured to resonate within higher and lower RF frequency ranges, the higher frequency range including a frequency at least twice as great as frequencies within the lower RF frequency range.

10. The MIMO antenna of claim 9, wherein the higher frequency range includes 5.2 GHz and the lower frequency range includes 2.4 GHz.

11. The MIMO antenna of claim 1, wherein:

the conductive neutralization line includes at least two abrupt opposite direction changes along its conductive path to decrease distance between the first and second radiating elements.

12. The MIMO antenna of claim 1, wherein:

a conductive length of the serpentine portion of each of the first and second radiating elements is at least four time greater than a respective conductive length of the straight portion of the first and second radiating elements.

13. The MIMO antenna of claim 1, wherein:

the first and second radiating elements each include an inductive load element that is connected to a distal end of the serpentine portion from an end connected to the straight portion.

14. The MIMO antenna of claim 1, further comprising:

a first parasitic radiating element that is adjacent and parasitically coupled to the first radiating element to radiate responsive to the first radiating element resonating at a RF frequency;

a second parasitic radiating element that is adjacent and parasitically coupled to the second radiating element to radiate responsive to the second radiating element resonating at a RF frequency.

15. The MIMO antenna of claim 1, wherein:

the linear portions of the first and second radiating elements lie on a planar substrate surface is perpendicular to another planar substrate surface on which the serpentine portions of the first and second radiating elements lie.

16. The MIMO antenna of claim 1, wherein:

the linear and serpentine portions of the first and second radiating elements are on a planar substrate.

17. The MIMO antenna of claim 1, further comprising:

a third radiating element that includes a straight portion connected to a serpentine portion, wherein the straight and serpentine portions are configured to resonate within at least two spaced apart RF frequency ranges in response to the straight portion being electrically excited through a third RF feed;

a fourth radiating element that includes a straight portion connected to a serpentine portion, wherein the straight and serpentine portions are configured to resonate within at least two spaced apart RF frequency ranges in response to the straight portion being electrically excited through a fourth RF feed; and

another conductive neutralization line that connects the third and fourth radiating elements and connects to the other conductive neutralization line to at least partially cancel RF transmission coupling between the first, second, third, and fourth radiating elements.

18. The MIMO antenna of claim 17, wherein:

the linear portions of the first, second, third, and fourth radiating elements lie in a plane that is perpendicular to another plane in which the serpentine portions of the first, second, third, and fourth radiating elements lie.

19. A MIMO antenna comprising:

a first radiating element that includes a straight portion connected to a serpentine portion, wherein the straight and serpentine portions are configured to resonate in at least two spaced apart RF frequency ranges in response to the straight portion being electrically excited through a first RF feed;

a second radiating element that includes a straight portion connected to a serpentine portion, wherein the straight and serpentine portions are configured to resonate in at least two spaced apart RF frequency ranges in response to the straight portion being electrically excited through a second RF feed;

a conductive neutralization line that conducts resonant currents between the first and second radiating elements and has a conductive length that is configured to phase shift the conducted resonant currents to cause at least partial cancellation of currents in the first and second radiating elements which are generated by wireless RF signals received by the first and second radiating element from each other;

a first parasitic radiating element that is adjacent and parasitically coupled to the first radiating element to radiate responsive to the first radiating element resonating at a RF frequency; and

a second parasitic radiating element that is adjacent and parasitically coupled to the second radiating element to radiate responsive to the second radiating element resonating at a RF frequency.