Array antenna

• US 8,427,372 B2
• Filed: 12/07/2009
• Issued: 04/23/2013
• Est. Priority Date: 12/05/2008
• Status: Active Grant

• Current Assignee: Sakura Tech Corporation
• Original Assignee: Sakura Tech Corporation
• Inventors: Sakai, Fuminori, Ohta, Kazuo
• Primary Examiner(s): Keith, Jack W.
• Assistant Examiner(s): Mull, Fred H
• Application Number:
  US12/995,477
• Publication Number:
  US 20110084880A1
• Time in Patent Office: 1,233 Days
• Field of Search: 342373-375
• US Class Current: 342/375
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• CPC Class Codes: G01S 2013/0254 Active array antenna
• CPC Class Codes: G01S 7/282 Transmitters
• CPC Class Codes: G01S 7/285 Receivers
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037
• CPC Class Codes: H01Q 3/2682 Time delay steered arrays
• CPC Class Codes: H01Q 3/30 varying the relative phase between the radiating elements of an array H01Q3/2605, H01Q3/2658, H01Q3/2682, H01Q3/44 take precedence

Abstract

Disclosed is an electronic scanning array antenna which can be used as a UWB radar having an occupied band of not less than 500 MHz. An impulse generator is connected to each of a plurality of antenna elements constituting the electronic scanning array antenna, and a transmission trigger time to each of the impulse generators connected to the antenna elements is changed, whereby the phase of radio waves emitted from an antenna is equivalently changed. Moreover, a transmission trigger repletion interval is changed to thereby control a direction of a beam emitted from the array antenna. As means of changing a transmission trigger timing to each of the impulse generators connected to the antenna elements, a method of changing a frequency of a transmission trigger pulse and a method of changing a pulse position are adopted.

Claims

1. An electronic scanning array antenna comprising:

a plurality of antenna elements constituting the electronic scanning array antenna are respectively connected to a single trigger generator through impulse generators;

a different number of delay lines are provided between the trigger generator and each of the impulse generators to cause a time difference to occur between inputs to each of the antenna elements; and

wherein a direction of a beam emitted from the electronic scanning array antenna is controlled by changing a transmission interval of the trigger generator.

2. The electronic scanning array antenna according to claim 1, wherein the trigger generator is a variable frequency trigger generator.

3. The electronic scanning array antenna according to claim 1, wherein a switch which performs on/off switching control of an input to each of the impulse generators based on an instruction of an on/off switching control signal is provided on the input side of each of the impulse generators.

4. The electronic scanning array antenna according to claim 1, wherein a narrowband filter is inserted into an output of the impulse generator.

5. An electronic scanning array antenna comprising:

a plurality of antenna elements constituting the electronic scanning array antenna are respectively connected to a single trigger generator through a correlation detecting circuit or a sampling circuit;

a different number of delay lines are provided between the trigger generator and each of the correlation detecting circuits or each of the sampling circuits to cause a time difference to occur between inputs to each of the antenna elements; and

wherein a direction of a beam received by the electronic scanning array antenna is controlled by changing a reception interval of the trigger generator.

6. The electronic scanning array antenna according to claim 5, wherein a narrowband filter is inserted into an impulse generation output in the correlation detecting circuit or an impulse generation output in the sampling circuit.

7. An electronic scanning array antenna comprising:

a plurality of antenna elements constituting the electronic scanning array antenna are respectively connected to a single trigger generator through impulse generators;

the plurality of antenna elements are respectively connected to the trigger generator through a correlation detecting circuit or a sampling circuit;

a different number of delay lines are provided between the trigger generator and each of the impulse generators to cause a time difference to occur between inputs to each of the antenna elements, and, at the same time, a different number of delay lines are provided between the trigger generator and each of the correlation detecting circuits or each of the sampling circuits to cause a time difference to occur between inputs to each of the antenna elements;

wherein a direction of a transmission beam emitted from the electronic scanning array antenna is controlled by changing a transmission interval of the trigger generator; and

wherein a direction of a reception beam received by the electronic scanning array antenna is controlled by changing a reception interval of the trigger generator.

8. An electronic scanning array antenna, wherein:

an impulse generator is connected to each of a plurality of antenna elements constituting the electronic scanning array antenna;

each of the impulse generators is connected to a single pulse position modulator receiving an input of a clock pulse from a clock generator;

a different number of delay lines are provided between the pulse position modulator and each of the impulse generators to cause a time difference to occur between inputs to each of the antenna elements; and

wherein a direction of a beam emitted from the electronic scanning array antenna is controlled by changing a transmission interval of the pulse position modulator.

9. An electronic scanning array antenna wherein:

a correlation detecting circuit or a sampling circuit is connected to each of a plurality of antenna elements constituting the electronic scanning array antenna;

each of the correlation detecting circuits or each of the sampling circuits is connected to a single pulse position modulator receiving an input of a clock pulse from a clock generator;

a different number of delay lines are provided between the pulse position modulator and each of the correlation detecting circuits or each of the sampling circuits to cause a time difference to occur between inputs to each of the antenna elements; and

wherein a direction of a beam received by the electronic scanning array antenna is controlled by changing a reception interval of the pulse position modulator.

10. The electronic scanning array antenna according to claim 9, wherein a plurality of delay lines are connected in series to the pulse position modulator;

a phase comparator is connected to a tail end or the middle of a wiring through which the plurality of delay lines are connected in series to the pulse position modulator;

a phase of a trigger signal at a position where the phase comparator is connected and a phase of a signal output from the clock generator are compared with each other by the phase comparator;

the comparison result of the phase comparator is input to the clock generator or input to a pulse position controller which inputs a pulse position control signal to the pulse position modulator.