Radio direction and position finding apparatus

• US 20030218569A1
• Filed: 06/03/2003
• Published: 11/27/2003
• Est. Priority Date: 09/28/2001
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Kobayashi, Eiji, Iwase, Kazutaka, Kimura, Kazuaki, Akazawa, Hayato, Kurihara, Tsugihiro
• Granted Patent: US 6,759,982 B2
• Time in Patent Office: Days
• US Class Current: 342/430
• CPC Class Codes: G01S 3/36 the separate antennas having differently-oriented directivity characteristics
• CPC Class Codes: G01S 5/04 Position of source determined by a plurality of spaced direction-finders
• CPC Class Codes: H01Q 25/02 providing sum and difference patterns H01Q25/04 takes precedence

Abstract

A detection apparatus is provided to detect the direction of arrival and the position of an emission source of radio wave with high accuracy. The apparatus comprises; a first and a second directional antenna 1 and 10 which rotates with a desired angle of elevation; a first and a second phase integral means 2 and 11 for outputting an integration of the output from an antenna; a first and second phase differential means 3 and 12 for outputting an difference of the outputs from an antenna; a first and a second frequency dividing means 4 and 13 for dividing frequency of the integral component of the output from an antenna; a first and a second differential gain control means 5 and 14 for controlling a gain of the differential component of the output from an antenna; a first and a third receiving means 6 and 15 for receiving an output of the frequency dividing means; a second and a fourth receiving means 8 and 17 for receiving an output of the differential gain control means; a first and a second subtraction means 7 and 16 for subtracting one detection signal output from the other detection signal output of each of receiving means 6 and 8 and receiving mans 15 and 17; a first and a second calculation means 9 and 18 for determining a direction of arrival of radio wave based on an output from the subtraction means; and a position determining calculation means 19 for determining the position of the emission source of the radio wave based on an output from the calculation means.

Claims

1. A radio direction and position finding apparatus comprising;

a first directional antenna which rotates with a desired angle elevation;

a first phase integral means for producing an output through an integration of output from said directional antenna;

a first phase difference means for producing an output as a difference of the outputs from said first directional antenna;

a first frequency dividing means for dividing frequency of integral component of the output from said directional antenna;

a first differential gain control means for controlling gain of differential component of the output from said directional antenna;

a first receiving means for receiving output from said first frequency dividing means and producing a detection signal output;

a second receiving means for receiving output from said first differential gain control means and producing a detection signal output;

a first subtraction means for subtracting one detection signal output from the other detection signal output of said first and second receiving means;

a first calculation means for determining a direction of arrival of radio wave based on output from said first subtraction means;

a second directional antenna which rotates with a desired angle of elevation;

a second phase integral means for producing an output through an integration of output from said second directional antenna;

a second phase difference means for producing an output as a difference of the outputs from said second directional antenna;

a second frequency dividing means for dividing frequency of integral component of the output from said second directional antenna;

a second differential gain control means for controlling gain of differential component of the output from said second directional antenna;

a third receiving means for receiving output from said second frequency dividing means and producing a detection signal output;

a fourth receiving means for receiving output from said second differential gain control means and producing a detection signal output;

a second subtraction means for subtracting one detection signal output from the other detection signal output of said third and fourth receiving means;

a second calculation means for determining a direction of arrival of radio wave based on output from said second subtraction means; and

a position determining calculation means for determining the position of the emission source of the radio wave based on outputs from said first and second calculation means;

wherein said directional antenna and said second directional antenna rotate interlockingly.

2. A radio direction and position finding apparatus in accordance with claim 1, in which each of said first and second directional antennas uses at least two vertical polarized waves.

3. A radio direction and position finding apparatus in accordance with claim 1 or 2, in which one of said first and second directional antennas is adapted to use a vertical polarized wave with an acute horizontal directivity, and the other of said first and second directional antennas is adapted to use a vertical polarized wave with an acute vertical directivity.

4. A radio direction and position finding apparatus in accordance with anyone of claims 1 to 3 in which said phase integral means is adapted to integrate strength of electrical field component of said first and second directional antennas.

5. A radio direction and position finding apparatus in accordance with anyone of claims 1 to 4 in which said phase difference means is capable of setting a phase difference based on outputs from said first and the second directional antennas in providing the differences.

6. A radio direction and position finding apparatus in accordance with anyone of claims 1 to 5 in which the position of the emission source of the radio wave can be specified by adjusting gain of the differential component of the output from said first and second directional antennas.