Antenna device and wireless communication device using same

• US 20050024286A1
• Filed: 07/30/2004
• Published: 02/03/2005
• Est. Priority Date: 07/30/2003
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Fukuda, Junichi
• Granted Patent: US 7,068,237 B2
• Time in Patent Office: Days
• US Class Current: 343/816
• CPC Class Codes: H01Q 21/061 Two dimensional planar arrays
• CPC Class Codes: H01Q 21/22 Antenna units of the array energised non-uniformly in amplitude or phase, e.g. tapered array or binomial array
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching

Abstract

An antenna device is provided which is capable of dealing with two or more frequencies or of carrying out communications using two or more communication methods by a single antenna and of controlling its directivity and, therefore, of achieving improvements in communication performance of the antenna device. The antenna device is so constructed that its shape is freely changed and its directivity can be changed to deal with a signal in any frequency band. The antenna device is made up of two or more antenna elements and switches which put each of the antenna elements into a connected or disconnected state. By controlling the switches, a shape of the antenna is changed so as to have a 90-degree bent dipole configuration to provide directivity, and a length of the antenna is changed so as to allow a changeover of a frequency band. The antenna device has a reflector being similar to the dipole-type antenna, which enables improvements in its directivity.

Claims

1. An antenna device comprising:

two or more antenna elements; and

switches to control so as to put said antenna elements being adjacent to each other into an electrically connected or disconnected state;

wherein antenna directivity is controlled by controlling said switches.

2. The antenna device according to claim 1, wherein each of said switches has a variable reactance component.

3. The antenna device according to claim 1, wherein a signal line for inputting and outputting of signals is connected to at least one antenna element selected from a group of said antenna elements being electrically connected to one another by said switches.

4. The antenna device according to claim 3, further comprising an other group of said antenna elements being connected to one another by said switches and being located at a specified distance apart from said group of said antenna elements,

wherein said group of said antenna elements to be connected to said signal line from which power is fed act as a radiation element, whereas said other group of antenna elements acts as a reflector or as a wave director.

5. The antenna device according to claim 4, wherein said other group of antenna elements also have a 90-degree bent shape.

6. The antenna device according to claim 1, wherein each of said switches comprises a high-frequency transistor, pin diode, or MEMS (Micro Electro Mechanical System) switch.

7. The antenna device according to claim 1, wherein said antenna elements and said switches are formed on a dielectric.

8. The antenna device according to claim 1, further comprising a storing unit to store, in advance, two or more sets of combinations of electrically connected or disconnected states of said switches and a controlling unit to read a specified set of said combinations from said storing unit according to a control signal so that said switches are controlled.

15. The antenna device according to claim 1, wherein said antenna elements and said switches are formed on a dielectric.

9. An antenna device comprising:

two or more antenna elements; and

switches to control so as to put said antenna elements being adjacent to each other into an electrically connected or disconnected state,

wherein a cross-dipole antenna having a 90-degree bent shape is formed by a group of said antenna elements being electrically connected to one another by said switches.

10. The antenna device according to claim 9, wherein each of said switches has a variable reactance component.

11. The antenna device according to claim 9, wherein a signal line for inputting and outputting of signals is connected to at least one antenna element selected from a group of said antenna elements being electrically connected to one another by said switches.

12. The antenna device according to claim 11, further comprising an other group of said antenna elements being connected to one another by said switches and being located at a specified distance apart from said group of said antenna elements,

wherein said group of said antenna elements to be connected to said signal line from which power is fed act as a radiation element, whereas said other group of antenna elements acts as a reflector or as a wave director.

13. The antenna device according to claim 12, wherein said other group of antenna elements also have a 90-degree bent shape.

14. The antenna device according to claim 9, wherein each of said switches comprises a high-frequency transistor, pin diode, or MEMS (Micro Electro Mechanical System) switch.

16. The antenna device according to claim 9, further comprising a storing unit to store, in advance, two or more sets of combinations of electrically connected or disconnected states of said switches and a controlling unit to read a specified set of said combinations from said storing unit according to a control signal so that said switches are controlled.

17. A wireless communication device being equipped with an antenna device comprising two or more antenna elements;

and switches to control so as to put said antenna elements being adjacent to each other into an electrically connected or disconnected state,

wherein antenna directivity is controlled by controlling said switches.

18. A wireless communication device according to claim 17, wherein a signal line for inputting and outputting of signals is connected to at least one antenna element selected from a group of said antenna elements being electrically connected to one another by said switches, wherein said antenna device further has an other group of said antenna elements being connected to one another by said switches and being located at a specified distance apart from said group of said antenna elements, and

wherein said group of said antenna elements to be connected to said signal line from which power is fed act as a radiation element, whereas said other group of antenna elements acts as a reflector or as a wave director.

19. A wireless communication device being equipped with an antenna device comprising two or more antenna elements, and switches to control so as to put said antenna elements being adjacent to each other into an electrically connected or disconnected state, wherein a cross-dipole antenna having a 90-degree bent shape is formed by a group of said antenna elements being electrically connected to one another by said switches.

20. A wireless communication device according to claim 19, wherein a signal line for inputting and outputting of signals is connected to at least one antenna element selected from a group of said antenna elements being electrically connected to one another by said switches, wherein said antenna device further has an other group of said antenna elements being connected to one another by said switches and being located at a specified distance apart from said group of said antenna elements, and p1 wherein said group of said antenna elements to be connected to said signal line from which power is fed act as a radiation element, whereas said other group of antenna elements acts as a reflector or as a wave director.