Multi-loop antenna system and electronic apparatus having the same

1. A multi-loop antenna system comprising:

an antenna module including

a substrate, and

a plurality of loop antennas disposed on said substrate, and arranged such that each of extending lines extending respectively from geometric centers of said loop antennas to a center point that is bounded by said loop antennas has a predetermined length, and that each of said loop antennas is spaced apart from an adjacent one of said loop antennas by a predetermined minimum distance, each of said loop antennas including

a first radiator portion operable in a first frequency band, and having opposite ends that respectively serve as a signal-feed section and a grounding section, and that are adjacent to and spaced apart from each other such that said first radiator portion substantially forms a loop, and

a second radiator portion operable in a second frequency band, and having opposite ends that are connected electrically and respectively to said signal-feed section and said grounding section of said first radiator portion, such that said second radiator portion substantially forms a loop; and

a system module having a grounding plane that faces toward and that is spaced apart from and parallel to said substrate such that said grounding plane is able to reflect radiation from said antenna module.

2. The multi-loop antenna system as claimed in claim 1 , wherein:

said substrate has opposite first and second surfaces, said loop antennas being disposed on said first and second surfaces; and

said grounding plane of said system module faces toward and is spaced from and parallel to said second surface.

3. The multi-loop antenna system as claimed in claim 1 , wherein:

said substrate has opposite first and second surfaces, said loop antennas being disposed on said first surface; and

said grounding plane of said system module faces toward and is spaced from and parallel to said second surface.

4. The multi-loop antenna system as claimed in claim 1 , wherein, for each of said loop antennas, said first radiator portion substantially encloses said second radiator portion.

5. The multi-loop antenna system as claimed in claim 1 , wherein said loop antennas are further arranged such that each of said extending lines forms a predetermined angle with an adjacent one of said extending lines.

6. The multi-loop antenna system as claimed in claim 1 , wherein said second radiator portion includes a substantially loop-shaped radiator section having opposite ends, and a pair of extending sections extending from said opposite ends of said radiator section and serving as said opposite ends of said second radiator portion, respectively.

7. The multi-loop antenna system as claimed in claim 6 , wherein said pair of extending sections and said radiator section cooperate to define a slot that opens in a direction that forms a predetermined included angle with the respective one of said extending lines.

8. The multi-loop antenna system as claimed in claim 6 , wherein said pair of extending sections and said radiator section cooperate to define a slot that opens toward said center point.

9. The multi-loop antenna system as claimed in claim 1 , wherein said second radiator portion includes a substantially loop-shaped radiator section having opposite ends serving as said opposite ends of said second radiator portion, respectively.

10. The multi-loop antenna system as claimed in claim 9 , wherein said radiator section defines a slot that opens in a direction that forms a predetermined included angle with the respective one of said extending lines.

11. The multi-loop antenna system as claimed in claim 9 , wherein said radiator section defines a slot that opens toward said center point.

12. The multi-loop antenna system as claimed in claim 1 , wherein each of said first and second radiator portions has a shape independently selected from a rectangular loop and a circular loop.

13. The multi-loop antenna system as claimed in claim 1 , wherein said substrate is formed with a through-hole corresponding in position to said center point so as to permit extension of cables therethrough.

14. The multi-loop antenna system as claimed in claim 1 , wherein said substrate occupies an area not larger than that occupied by said system module.

15. An electronic apparatus comprising a housing, and an antenna module and a system module disposed in said housing;

said antenna module including

a substrate, and

a plurality of loop antennas disposed on said substrate, and arranged such that each of extending lines extending respectively from geometric centers of said loop antennas to a center point that is bounded by said loop antennas has a predetermined length, and that each of said loop antennas is spaced apart from an adjacent one of said loop antennas by a predetermined minimum distance, each of said loop antennas including

a first radiator portion operable in a first frequency band, and having opposite ends that respectively serve as a signal-feed section and a grounding section, and that are adjacent to and spaced apart from each other such that said first radiator portion substantially forms a loop, and

a second radiator portion operable in a second frequency band, and having opposite ends that are connected electrically and respectively to said signal-feed section and said grounding section of said first radiator portion, such that said second radiator portion substantially forms a loop;

said system module having a grounding plane that faces toward and that is spaced apart from and parallel to said substrate such that said grounding plane is able to reflect radiation from said antenna module.