Navigation, identification, and collision avoidance antenna systems

• US 8,269,684 B2
• Filed: 06/08/2010
• Issued: 09/18/2012
• Est. Priority Date: 06/08/2010
• Status: Expired due to Fees

• Current Assignee: Sensor Systems
• Original Assignee: Sensor Systems
• Inventors: Robin, Seymour, Weber, Robert C., Castillo, Rajah
• Primary Examiner(s): Nguyen, Hoang V
• Application Number:
  US12/796,096
• Publication Number:
  US 20110298649A1
• Time in Patent Office: 833 Days
• Field of Search: 343/749, 343/752, 343/830, 343/705, 343/708
• US Class Current: 343/749
• CPC Class Codes: G01S 13/785 Distance Measuring Equipment [DME] systems
• CPC Class Codes: H01Q 1/28 Adaptation for use in or on aircraft, missiles, satellites, or balloons
• CPC Class Codes: H01Q 1/3233 particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems
• CPC Class Codes: H01Q 1/3275 mounted on a horizontal surface of the vehicle, e.g. on roof, hood, trunk
• CPC Class Codes: H01Q 3/267 Phased-array testing or checking devices
• CPC Class Codes: H01Q 9/36 with top loading

Abstract

Antenna embodiments are illustrated that are particularly suited for use in aircraft navigation, identification and collision avoidance systems. An exemplary antenna embodiment operates about a center wavelength and in association with a ground plane and comprises first and second grounded, shortened, and top loaded monopoles. These monopoles are spaced apart above a ground plane and each of them includes a feed post, a shorted post, and a top load wherein the shorted post is spaced from the feed post, is coupled to the ground plane, and has a length less than one fourth of the center wavelength. In addition, the top load is coupled to the feed post and the shorted post and is configured along orthogonal minor and major axes of the top load to have a width along the minor axis and a length along the major axis that exceeds the width.

Claims

1. An antenna to operate about a center wavelength and in association with a ground plane, comprising first and second grounded, shortened, and top loaded monopoles that are spaced apart above said ground plane wherein each of said first and second monopoles includes:

a feed post;

a shorted post spaced from said feed post, coupled to said ground plane, and having a length less than one fourth of said center wavelength; and

a top load coupled to said feed post and said shorted post and configured along orthogonal minor and major axes of said top load to have a width along said minor axis and a length along said major axis that exceeds said width.

2. The antenna of claim 1, wherein said top load has a substantially elliptical shape.

3. The antenna of claim 2, wherein:

said first and second monopoles are spaced apart along a monopole axis of said antenna; and

said major axis is rotated from said monopole axis by a rotation angle.

4. The antenna of claim 3, wherein said rotation angle is between 40 and 50 degrees.

5. The antenna of claim 2, wherein:

said first and second monopoles are spaced apart along a monopole axis of said antenna; and

said feed post and said shorted post are positioned on a post axis of said antenna that is substantially orthogonal to said monopole axis.

6. The antenna of claim 5, wherein the feed posts of said first and second monopoles are positioned on opposite sides of said monopole axis and the shorted posts of said first and second monopoles are positioned on opposite sides of said monopole axis.

7. The antenna of claim 5, wherein said major axis is rotated from said monopole axis by a rotation angle between 40 and 50 degrees.

8. The antenna of claim 2, further including:

a first signal compensation path arranged to communicate with feed posts of said first and second monopoles and having a first length; and

a second signal compensation path arranged to communicate with feed posts of said first and second monopoles and having a second length that differs from said first length to thereby enhance performance of said antenna.

9. The antenna of claim 2, further including a probe positioned above said ground plane and between said first and second monopoles to thereby provide a calibration signal for said antenna.

10. The antenna of claim 9, wherein said probe is configured as a coil.

11. The antenna of claim 2, further including:

first and second electrical connectors;

first and second transmission lines each connecting a feed post of a respective one of said first and second monopoles to a respective one of said first and second connectors; and

a synthesizer arranged to provide a calibration signal to a respective one of said first and second electrical connectors.

12. The antenna of claim 1, wherein said top load has a substantially oblong shape.

13. An antenna to operate about a center wavelength and in association with a ground plane, comprising:

first and second monopoles that are spaced apart above said ground plane wherein each of said first and second monopoles includes;

a feed post;

a shorted post spaced from said feed post, coupled to said ground plane, and having a length less than one fourth of said center wavelength; and

a top load coupled to said feed post and said shorted post and configured along orthogonal minor and major axes of said top load to have a width along said minor axis and a length along said major axis that exceeds said width;

and wherein;

said first and second monopoles are spaced apart along a monopole axis of said antenna; and

said major axis is rotated from said monopole axis by a rotation angle between 40 and 50 degrees.

14. The antenna of claim 13, wherein:

said feed post and said shorted post are positioned on a post axis of said antenna that is substantially orthogonal to said monopole axis; and

the feed posts of said first and second monopoles are positioned on opposite sides of said monopole axis and the shorted posts of said first and second monopoles are positioned on opposite sides of said monopole axis.

15. The antenna of claim 13, further including:

a first signal compensation path arranged to communicate with feed posts of said first and second monopoles and having a first length; and

a second signal compensation path arranged to communicate with feed posts of said first and second monopoles and having a second length that differs from said first length to thereby facilitate enhancement of an antenna pattern of said antenna.

16. An antenna system to operate about a center wavelength, comprising:

first and second antennas each formed with a ground plane and first and second monopoles that each includes;

a feed post;

a shorted post spaced from said feed post, coupled to said ground plane, and having a length less than one fourth of said center wavelength; and

a top load coupled to said feed post and said shorted post and configured along orthogonal minor and major axes of said top load to have a width along said minor axis and a length along said major axis that exceeds said width;

wherein said first and second monopoles are spaced apart along a monopole axis of their respective antenna and the major axis of each of said first and second top loads is rotated from said monopole axis by a rotation angle between 40 and 50 degrees;

and wherein said first and second antennas are arranged with the ground plane of one facing the ground plane of the other and the monopole axis of one substantially orthogonal to the monopole axis of the other.

17. The system of claim 16, wherein said feed post and said shorted post are positioned on a post axis of their respective monopole that is substantially orthogonal to said monopole axis.

18. The system of claim 17, wherein the feed posts of said first and second monopoles are positioned on opposite sides of said monopole axis and the shorted posts of said first and second monopoles are positioned on opposite sides of said monopole axis.

19. The system of claim 16, further including in each of said antennas:

a first signal compensation path arranged to communicate with feed posts of said first and second monopoles and having a first length; and

a second signal compensation path arranged to communicate with feed posts of said first and second monopoles and having a second length that differs from said first length to thereby facilitate enhancement of an antenna patterns of said antenna.

20. The system of claim 16, further including, in each of said antennas,

first and second electrical connectors;

first and second transmission lines each connecting a feed post of a respective one of said first and second monopoles to a respective one of said first and second connectors; and

a synthesizer arranged to provide a calibration signal to a respective one of said first and second electrical connectors.