ANTENNA, ANTENNA DEVICE, AND WIRELESS DEVICE

• US 20160087334A1
• Filed: 12/07/2015
• Published: 03/24/2016
• Est. Priority Date: 06/21/2013
• Status: Active Grant

• Current Assignee: AGC, Inc.
• Original Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Inventors: SAYAMA, Toshiki, SONODA, Ryuta, IKAWA, Koji
• Granted Patent: US 9,905,919 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01Q 1/50 Structural association of antennas with earthing switches, lead-in devices or lightning protectors
• CPC Class Codes: H01Q 9/065 Microstrip dipole antennas patch antenna H01Q9/0407
• CPC Class Codes: H01Q 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

An antenna includes a feeding element connected to a feeding point, a first radiating element that is spaced apart from the feeding element and is coupled to the feeding element through electromagnetic field coupling, a second radiating element that is spaced apart from the feeding element and is coupled to the feeding element through electromagnetic field coupling, a first control element that is connected to the feeding element via a first impedance variable unit, and a second control element that is connected to the feeding element via a second impedance variable unit, and a control unit that controls the first impedance variable unit to adjust the connection between the feeding element and the first control element and controls the second impedance variable unit to adjust the connection between the feeding element and the second control element.

Claims

1. An antenna, comprising:

a feeding element that is connected to a feeding point;

a first radiating element that is spaced apart from the feeding element and is fed by being coupled to the feeding element through electromagnetic field coupling to function as a radiating conductor;

a second radiating element that is spaced apart from the feeding element and is fed by being coupled to the feeding element through electromagnetic field coupling to function as a radiating conductor;

a first control element that is connected to the feeding element via a first impedance variable unit and is arranged such that when an impedance of the first impedance variable unit at a resonant frequency of the first radiating element is decreased, the electromagnetic field coupling between the feeding element and the first radiating element is weakened and the function of the first radiating element as the radiating conductor is degraded;

a second control element that is connected to the feeding element via a second impedance variable unit and is arranged such that when an impedance of the second impedance variable unit at a resonant frequency of the second radiating element is decreased, the electromagnetic field coupling between the feeding element and the second radiating element is weakened and the function of the second radiating element as the radiating conductor is degraded; and

a control unit that controls the first impedance variable unit to adjust the connection between the feeding element and the first control element, and controls the second impedance variable unit to adjust the connection between the feeding element and the second control element.

2. The antenna according to claim 1, wherein

the first control element is arranged such that when the impedance of the first impedance variable unit between the first control element and the feeding element at the resonant frequency of the first radiating element is reduced to a low impedance, the electromagnetic field coupling between the feeding element and the first radiating element is weakened and the first radiating element ceases to function as the radiating conductor;

and

the second control element is arranged such that when the impedance of the second impedance variable unit between the second control element and the feeding element at the resonant frequency of the second radiating element is reduced to a low impedance, the electromagnetic field coupling between the feeding element and the second radiating element is weakened and the second radiating element ceases to function as the radiating conductor.

4. The antenna according to claim 1, wherein

the control unit is configured to degrade the function of the first radiating element as the radiating conductor by lowering an impedance between the feeding element and the first control element, and degrade the function of the second radiating element as the radiating conductor by lowering an impedance between the feeding element and the second control element.

5. The antenna according to claim 1, wherein

the feeding element extends from the feeding point toward a gap formed between the first radiating element and the second radiating element.

6. The antenna according to claim 1, wherein

provided Le20 denotes an electrical length that imparts a fundamental mode of resonance to the feeding element, Le30 denotes an electrical length that imparts a fundamental mode of resonance to the first radiating element, Le40 denotes an electrical length that imparts a fundamental mode of resonance to the second radiating element, and λ

denotes a wavelength on the feeding element or the first radiating element and the second radiating element at a resonant frequency of a fundamental mode of the first radiating element and the second radiating element,

Le20 is less than or equal to (3/8)λ

; and

if the fundamental mode of resonance of the first radiating element or the second radiating element corresponds to a dipole mode, Le30 and Le40 are greater than or equal to (3/8)λ and

less than or equal to (5/8)λ

;

if the fundamental mode of resonance of the first radiating element or the second radiating element corresponds to a loop mode, Le30 and Le40 is greater than or equal to (7/8)λ and

less than or equal to (9/8)λ

; and

if the fundamental mode of resonance of the first radiating element or the second radiating element corresponds to a monopole mode, Le30 and Le40 are greater than or equal to (1/8)λ and

less than or equal to (3/8)λ

.

7. The antenna according to claim 1, wherein

provided λ

₀ denotes a wavelength in vacuum at a resonant frequency of a fundamental mode of the first radiating element and the second radiating element, a shortest distance between the feeding element and the first radiating element and a shortest distance between the feeding element and the second radiating element are less than or equal to 0.2λ

₀.

8. The antenna according to claim 1, further comprising:

a matching circuit that adjusts a resonant frequency of a fundamental mode of the first radiating element and the second radiating element in cooperation with the control unit.

9. The antenna according to claim 1, wherein

in a dipole mode, a feeding portion of each of the first radiating element and the second radiating element at which the feeding element feeds the first radiating element or the second radiating element is located at a region spaced apart from a lowest impedance portion of the first radiating element or the second radiating element by a distance greater than or equal to 1/8 of a total length of the first radiating element or the second radiating element;

in a monopole mode, the feeding portion is located at a region spaced apart from the lowest impedance portion of the first radiating element or the second radiating element by a distance greater than or equal to 1/4 of the total length of the first radiating element or the second radiating element; and

in a loop mode, the feeding portion is located at a region spaced apart from a highest impedance portion of the first radiating element or the second radiating element by a distance less than or equal to 3/16 of an inner circumference of a loop formed by the first radiating element or the second radiating element.

10. The antenna according to claim 1, wherein

in a dipole mode, a distance over which the feeding element and the first radiating element or the second radiating element run parallel to each other spaced a shortest distance apart is less than or equal to 3/8 of a length of the first radiating element or the second radiating element;

in a loop mode, the distance is less than or equal to 3/16 of an inner circumference of a loop formed by the first radiating element or the second radiating element; and

in monopole mode, the distance is less than or equal to 3/4 of the length of the first radiating element or the second radiating element.

11. The antenna according to claim 1, further comprising:

a ground plane;

wherein the feeding element extends in a direction away from the ground plane; and

wherein the first radiating element and the second radiating element include a portion arranged along an edge of the ground plane.

12. The antenna according to claim 11, further comprising:

a plate conductor including a portion spaced apart from the ground plane and facing the ground plane;

wherein the first radiating element and the second radiating element are connected to the plate conductor.

13. The antenna according to claim 12, wherein

the ground plane and the plate conductor are DC coupled.

14. The antenna according to claim 12, wherein

the plate conductor includes a heat dissipating function.

15. An antenna device, comprising:

a plurality of the antennas according to claim 1;

wherein the plurality of the antennas share a ground plane corresponding to a ground reference of the feeding point.

17. A wireless device, comprising:

the antenna according to claim 1.

18. A wireless device, comprising:

a plurality of the antennas according to claim 1;

wherein the plurality of the antennas share a ground plane corresponding to a ground reference of the feeding point.

3. An antenna, comprising:

a feeding element that is connected to a feeding point;

a first radiating element that is spaced apart from the feeding element and is fed by being coupled to the feeding element through electromagnetic field coupling to function as a radiating element;

a second radiating element that is spaced apart from the feeding element and is fed by being coupled to the feeding element through electromagnetic field coupling to function as a radiating element;

a first control element that is connected to the feeding element via a first impedance variable unit;

a second control element that is connected to the feeding element via a second impedance variable unit; and

a control unit that controls the first impedance variable unit to adjust the connection between the feeding element and the first control element, and controls the second impedance variable unit to adjust the connection between the feeding element and the second control element;

wherein the first control element is arranged such that a high impedance portion of the first control element having a high impedance at a resonant frequency of the first radiating element and a low impedance portion of the first radiating element having a low impedance at the resonant frequency of the first radiating element are positioned close to each other; and

wherein the second control element is arranged such that a high impedance portion of the second control element having a high impedance at a resonant frequency of the second radiating element and a low impedance portion of the second radiating element having a low impedance at the resonant frequency of the second radiating element are positioned close to each other.

16. An antenna device, comprising:

a plurality of the antennas according to claim 3;

wherein the plurality of the antennas share a ground plane corresponding to a ground reference of the feeding point.

19. A wireless device, comprising:

the antenna according to claim 3.

20. A wireless device, comprising:

a plurality of the antennas according to claim 3;

wherein the plurality of the antennas share a ground plane corresponding to a ground reference of the feeding point.