Communication device and method for designing multi-antenna system thereof

• US 9,559,422 B2
• Filed: 08/15/2014
• Issued: 01/31/2017
• Est. Priority Date: 04/23/2014
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute, National Sun Yat-sen University
• Original Assignee: Industrial Technology Research Institute, National Sun Yat-sen University
• Inventors: Wong, Kin-Lu, Kao, Yeh-Chun, Lin, Po-Wei, Li, Wei-Yu
• Primary Examiner(s): GREGORY, BERNARR E
• Application Number:
  US14/460,377
• Publication Number:
  US 20150311588A1
• Time in Patent Office: 900 Days
• US Class Current: 1/1
• CPC Class Codes: H01Q 13/10 Resonant slot antennas
• CPC Class Codes: H01Q 21/20 the units being spaced along or adjacent to a curvilinear path slotted waveguide arrays H01Q21/005; circularly or helically slotted waveguides H01Q21/0062
• CPC Class Codes: H01Q 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 9/14 Length of element or elements adjustable telescopic elements H01Q1/10

Abstract

The disclosure provides a communication device. The communication device includes a ground conductor portion and a multi-antenna system. The multi-antenna system includes at least a first and a second resonant portion, each of which is disposed on the corresponding radiating edge of the ground conductor portion. Each of the resonant portions may have a loop resonant structure or may have an open-slot resonant structure, and has a resonant path. The electrically coupling portion makes the length of the resonant path less than or equal to 0.18 times the wavelength of the lowest operating frequency of the multi-antenna system, and thereby excites the corresponding radiating edge and forms a strong surface current distribution, and generates an effective radiating energy and at least one resonant mode, in which the effective radiating energy has a corresponding strongest radiation direction.

Claims

1. A communication device, comprising:

a ground conductor portion comprising at least a first radiating edge and a second radiating edge; and

a multi-antenna system, comprising at least;

a first resonant portion disposed on the first radiating edge of the ground conductor portion, the first resonant portion comprising a first electrically coupling portion and a first switch, wherein the first resonant portion has a loop resonant structure or an open-slot resonant structure, and the first resonant portion has a first resonant path, the first switch is disposed on the first resonant path, the first electrically coupling portion makes the length of the first resonant path less than or equal to 0.18 times the wavelength of the lowest operating frequency of the multi-antenna system, thereby exciting the first radiating edge to form a strong surface current distribution, and generating a first effective radiating energy and at least one first resonant mode covering at least one first operating band, the first effective radiating energy generated having a first strongest radiation direction;

a second resonant portion disposed on the second radiating edge of the ground conductor portion, the second resonant portion comprising a second electrically coupling portion and a second switch, wherein the second resonant portion has a loop resonant structure or an open-slot resonant structure, and the second resonant portion has a second resonant path, the second switch is disposed on the second resonant path, the second electrically coupling portion makes the length of the second resonant path less than or equal to 0.18 times the wavelength of the lowest operating frequency of the multi-antenna system, thereby exciting the second radiating edge to form a strong surface current distribution, and generating a second effective radiating energy and at least one second resonant mode covering at least the first operating band, the second effective radiating energy generated having a second strongest radiation direction;

a first control circuit respectively and electrically coupled to the first resonant portion and the second resonant portion through a plurality of signal lines, the first control circuit switching a signal source to electrically couple to one of the first resonant portion or the second resonant portion, and generating the first strongest radiation direction or the second strongest radiation direction, or controlling the signal source to concurrently electrically couple to the first resonant portion and the second resonant portion, and generating a third effective radiating energy having a third strongest radiation direction; and

a second control circuit respectively and electrically coupled to the first switch and the second switch through a plurality of signal lines, the second control circuit switching the first switch to a conducting state when the signal source is electrically coupled to the first resonant portion, and switching the second switch to the conducting state when the signal source is electrically coupled to the second resonant portion.

2. The communication device of claim 1, wherein each of the first resonant portion and the second resonant portion has a loop resonant structure and a shorting point.

3. The communication device of claim 1, wherein each of the first resonant portion and the second resonant portion has an open-slot resonant structure and a feeding metal strip.

4. The communication device of claim 3, wherein the ground conductor portion is implemented on a surface of a dielectric substrate, and the open-slot resonant structure and the corresponding feeding metal strip are respectively disposed on different surfaces above and below the dielectric substrate.

5. The communication device of claim 1, wherein the first electrically coupling portion or the second electrically coupling portion comprises at least one lumped capacitive element, variable capacitive element, or distributive capacitive conductor structure.

6. The communication device of claim 1, wherein the first switch or the second switch is a diode element, a capacitive switch element, an integrated circuit switch element, or a micro-electro-mechanical system (MEMS) switch element.

7. The communication device of claim 1, wherein the at least one first radiating edge and the second radiating edge serve as two adjacent sides of the ground conductor portion.

8. The communication device of claim 1, wherein when the signal source is not electrically coupled to the first resonant portion, the first switch is in an open state to prevent resonance of the first resonant portion.

9. The communication device of claim 1, wherein when the signal source is not electrically coupled to the second resonant portion, the second switch is in an open state to prevent resonance of the second resonant portion.

10. The communication device of claim 1, wherein an included angle between the first and second strongest radiation directions is at least 30 degrees.

11. A method for designing a multi-antenna system suitable for a communication device, the method comprising:

disposing a multi-antenna system in a communication device comprising a ground conductor portion, wherein the ground conductor portion comprises at least a first radiating edge and a second radiating edge, and the multi-antenna system comprises at least a first resonant portion and a second resonant portion;

disposing the first resonant portion on the first radiating edge, wherein the first resonant portion has a loop resonant structure or an open-slot resonant structure, and the first resonant portion has a first resonant path, the first resonant portion comprising a first electrically coupling portion and a first switch, the first switch is disposed on the first resonant path, the first electrically coupling portion makes the length of the first resonant path less than or equal to 0.18 times the wavelength of the lowest operating frequency of the multi-antenna system, thereby exciting the first radiating edge to form a strong surface current distribution, and generating a first effective radiating energy and at least one first resonant mode covering at least one first operating band, and the first effective radiating energy generated has a first strongest radiation direction;

disposing the second resonant portion on the second radiating edge of the ground conductor portion, wherein the second resonant portion has a loop resonant structure or an open-slot resonant structure, and the second resonant portion has a second resonant path, the second resonant portion comprising a second electrically coupling portion and a second switch, the second switch is disposed on the second resonant path, the second electrically coupling portion makes the length of the second resonant path less than or equal to 0.18 times the wavelength of the lowest operating frequency of the multi-antenna system, thereby exciting the second radiating edge to form a strong surface current distribution, and generating a second effective radiating energy and at least one second resonant mode covering at least the first operating band, the second effective radiating energy generated having a second strongest radiation direction;

disposing a first control circuit respectively electrically coupled to the first resonant portion and the second resonant portion through a plurality of signal lines, the first control circuit switching a signal source to electrically couple to one of the first resonant portion or the second resonant portion, and generating the first strongest radiation direction or the second strongest radiation direction, or controlling the signal source to concurrently and electrically couple to the first resonant portion and the second resonant portion, and generating a third effective radiating energy having a third strongest radiation direction; and

disposing a second control circuit respectively and electrically coupled to the first switch and the second switch through a plurality of signal lines, the second control circuit switching the first switch to a conducting state when the signal source is electrically coupled to the first resonant portion, and switching the second switch to the conducting state when the signal source is electrically coupled to the second resonant portion.

12. The method of claim 11, wherein each of the first resonant portion and the second resonant portion has a loop resonant structure and a shorting point.

13. The method of claim 11, wherein each of the first resonant portion and the second resonant portion has an open-slot resonant structure and a feeding metal strip.

14. The method of claim 13, wherein the ground conductor portion is implemented on a surface of a dielectric substrate, and the open-slot resonant structure and the corresponding feeding metal strip are respectively disposed on different surfaces above and below the dielectric substrate.

15. The method of claim 11, wherein the first electrically coupling portion or the second electrically coupling portion comprises at least one lumped capacitive element, variable capacitive element, or distributive capacitive conductor structure.

16. The method of claim 11, wherein the first switch or the second switch is a diode element, a capacitive switch element, an integrated circuit switch element, or a MEMS switch element.

17. The method of claim 11, wherein the at least one first radiating edge and the second radiating edge serve as two adjacent sides of the ground conductor portion.

18. The method of claim 11, wherein when the signal source is not electrically coupled to the first resonant portion, the first switch is in an open state to prevent resonance of the first resonant portion.

19. The method of claim 11, wherein when the signal source is not electrically coupled to the second resonant portion, the second switch is in an open state to prevent resonance of the second resonant portion.

20. The method of claim 11, wherein an included angle between the first and second strongest radiation directions is at least 30 degrees.