Signal incoming direction estimation apparatus

• US 20060261968A1
• Filed: 08/26/2005
• Published: 11/23/2006
• Est. Priority Date: 05/23/2005
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Shirakawa, Kazuo
• Granted Patent: US 7,501,959 B2
• Time in Patent Office: Days
• US Class Current: 340/671
• CPC Class Codes: G01S 3/38 using adjustment of real or effective orientation of directivity characteristic of an antenna or an antenna system to give a desired condition of signal derived from that antenna or antenna system, e.g. to give a maximum or minimum signal G01S3/16, G01S3/28 take precedence
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence

Abstract

A signal incoming direction estimation apparatus is constructed so as to comprise a sensor array having plural sensors and the impedance of each of the sensors being set to a predetermined value, respectively, and a variable impedance adjustment means having a variable impedance, being selectively connected to any one of the sensors of the sensor array, and controlling the current distribution of each of the above-mentioned sensors. Due to this, it becomes possible for the signal incoming direction estimation apparatus to carry out a beam scan only by manipulating at least one impedance without simultaneously manipulating all of the sensor impedances and thereby a high-speed beam scan (directional control) becomes possible.

Claims

1. A signal incoming direction estimation apparatus comprising:

a sensor array having plural sensors and the impedance of each of said sensors being set to a predetermined value, respectively; and

a variable impedance adjustment means having a variable impedance, being selectively connected to any one of the sensors of said sensor array, and controlling the current distribution of each of said sensors.

2. The signal incoming direction estimation apparatus according to claim 1, further comprising a time division switch section for connecting each of said sensors to said variable impedance adjustment means in a time division manner.

3. The signal incoming direction estimation apparatus according to claim 1, wherein said sensor and said variable impedance adjustment means are coupled electromagnetically.

4. The signal incoming direction estimation apparatus according to claim 1, wherein the impedance of each of said sensors is also variable.

5. The signal incoming direction estimation apparatus according to claim 1, wherein said sensor array is constructed as an ESPAR (Electronically Steerable Passive Array Radiator) type sensor array for electromagnetically coupling each of said sensors.

6. The signal incoming direction estimation apparatus according to claim 1, further comprising:

a monitor means for monitoring the output power of either or both of the output of each of said sensors and the output of said variable impedance adjustment means; and

a control means for adjusting the impedance of said variable impedance adjustment means based on the output power monitored by said monitor means.

7. The signal incoming direction estimation apparatus according to claim 2, wherein the impedance of each of said sensors is also variable.

8. The signal incoming direction estimation apparatus according to claim 2, wherein said sensor array is constructed as an ESPAR (Electronically Steerable Passive Array Radiator) type sensor array for electromagnetically coupling each of said sensors.

9. The signal incoming direction estimation apparatus according to claim 2, wherein said time division switch section is constructed by using a MEMS (Micro Electro Mechanical System) technique.

10. The signal incoming direction estimation apparatus according to claim 7, wherein said sensor array is constructed as an ESPAR (Electronically Steerable Passive Array Radiator) type sensor array for electromagnetically coupling each of said sensors.

11. The signal incoming direction estimation apparatus according to claim 3, wherein the impedance of each of said sensors is also variable.

12. The signal incoming direction estimation apparatus according to claim 3, wherein said sensor array is constructed as an ESPAR (Electronically Steerable Passive Array Radiator) type sensor array for electromagnetically coupling each of said sensors.

13. The signal incoming direction estimation apparatus according to claim 11, wherein said sensor array is constructed as an ESPAR (Electronically Steerable Passive Array Radiator) type sensor array for electromagnetically coupling each of said sensors.

14. The signal incoming direction estimation apparatus according to claim 4, wherein said sensor array is constructed as an ESPAR (Electronically Steerable Passive Array Radiator) type sensor array for electromagnetically coupling each of said sensors.

15. The signal incoming direction estimation apparatus according to claim 6, wherein said monitor means is constructed so as to comprise a wave detector for detecting the output of each of said sensors.

16. The signal incoming direction estimation apparatus according to claim 6, wherein said monitor means is constructed so as to comprise a branch circuit for branching part of the output of said variable impedance adjustment means and inputting it into said control means.

17. The signal incoming direction estimation apparatus according to claim 15, wherein said monitor means is constructed so as to comprise a branch circuit for branching part of the output of said variable impedance adjustment means and inputting it into said control means.