Pole antenna with multiple array segments

• US 6,388,622 B1
• Filed: 01/11/2001
• Issued: 05/14/2002
• Est. Priority Date: 01/11/2001
• Status: Expired due to Term

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: TRW Inc. (Northrop Grumman Corporation)
• Inventors: Jennetti, Anthony G., Budack, James D., Manassero, Greg A., Belingheri, Ralph A.
• Primary Examiner(s): LE, HOANGANH T
• Application Number:
  US09/759,761
• Time in Patent Office: 488 Days
• Field of Search: H01/Q.138, 343/700.MS, 343/872, 343/890, 343/892, 343/891, 343/893, 343/853
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 1/42 Housings not intimately mechanically associated with radiating elements, e.g. radome
• CPC Class Codes: H01Q 1/44 using equipment having another main function to serve additionally as an antenna , e.g. means for giving an antenna an aesthetic aspectH01Q1/27 - H01Q1/34 take precedence
• CPC Class Codes: H01Q 21/065 Patch antenna array
• CPC Class Codes: H01Q 21/205 providing an omnidirectional coverage turnstile aerials H01Q21/26

Abstract

A three-array pole antenna highly suited for use in a communication system, and mounted in a cylindrical cover that may be supported atop a conventional pole of similar diameter. The antenna includes a ground plane structure (26) with three outwardly facing facets (28) that are joined together to form a rigid structure. Three antenna feed printed circuit boards (14) each provide two antenna feeds to an array of antenna patches (16) that are electromagnetically coupled to the circuit boards. Metal-to-metal connections are limited to radio-frequency (RF) feed connectors to the circuit boards (24), to minimize intermodulation effects. The entire antenna structure is of low cost and is easy to assemble and install.

Claims

1. A radio-frequency (RF) pole antenna with multiple arrays, the antenna comprising:

a ground plane structure having a plurality (n) of structurally and electrically connected facets directed in uniformly spaced angular directions;

a plurality (n) of antenna feed printed circuit boards, each of which is attached to but spaced apart from one of the ground plane facets, wherein each antenna feed printed circuit board has two feed points and two symmetrical circuit paths for feeding RF signals of different polarizations, and wherein each of the circuit paths has divergent branches leading to a plurality (m) of antenna patch drive segments;

a plurality (n) of arrays of antenna patches, each array having a plurality (m) of antenna patches distributed along one of the antenna feed printed circuit boards and mounted to provide electromagnetic coupling between each antenna patch and a pair of antenna patch drive segments, one from each circuit path in the antenna feed printed circuit board, wherein each antenna patch is coupled simultaneously to an associated pair of antenna feed patch drive segments, and wherein each antenna patch includes a drive element electromagnetically coupled to its associated pair of antenna feed patch drive segments, and at least one parasitic element mounted in a spaced relationship with the drive element;

a plurality (n) of pairs of RF feed connectors, each pair providing electromagnetic coupling with respective feed points on one of the antenna feed printed circuit boards, and providing connection to RF transmitting and receiving circuitry that employ the pole antenna; and

a cylindrical cover positioned to conceal the ground plane structure, the antenna feed printed circuit boards, the antenna patches and the RF feed antennas, wherein the entire antenna is enclosed in the cylindrical cover, and whereby the enclosed antenna is highly suited for mounting on a support pole of similar diameter to that of the cover.

2. An RF pole antenna as defined in claim 1, wherein:

each antenna array formed by the ground plane structure, one of the antenna feed printed circuit boards, one of the arrays of antenna patches, and one of the pairs of RF feed connectors, has metal-to-metal connection only in the pair of RF feed connectors, whereby intermodulation effects on antenna performance are minimized.

3. An RF pole antenna as defined in claim 2, wherein:

the ground plane structure is assembled using a dimple welding process that further reduces the likelihood of adverse intermodulation effects.

4. An RF pole antenna as defined in claim 1, wherein:

the number (n) of antenna arrays and ground plane facets is three.

5. An RF pole antenna as defined in claim 1, wherein:

each antenna patch includes two parasitic elements, including a first parasitic element mounted in a parallel spaced relationship with the drive element, and a second parasitic element mounted in a parallel spaced relationship with the first parasitic element.

6. An RF pole antenna as defined in claim 5, wherein:

the drive element in each antenna patch is a flat plate of generally octagonal shape;

the first parasitic element in each antenna patch is a flat plate of irregular shape having four extending arms and diagonally slanting edges between the arms; and

the second parasitic element in each antenna patch is a flat plate having an approximately square shape with diagonally cutoff corners.

7. An RF pole antenna as defined in claim 1, wherein each array of antenna patches is driven simultaneously in two different polarization modes to provide polarization diversity gain.

8. An RF pole antenna as defined in claim 7, wherein each array of antenna patches is driven simultaneously in linear polarization modes at +45°

and −

45°

with respect to a vertical axis of the pole antenna.

9. A radio-frequency (RF) pole antenna with multiple arrays, the antenna comprising:

a ground plane structure having a plurality (n) of structurally and electrically connected facets directed in uniformly spaced angular directions;

a plurality (n) of antenna feed printed circuit boards, each of which is attached to but spaced apart from one of the ground plane facets, wherein each antenna feed printed circuit board has two feed points and two symmetrical circuit paths for feeding RF signals of different polarizations, and wherein each of the circuit paths has divergent branches leading to a plurality (m) of antenna patch drive segments;

a plurality (n) of arrays of antenna patches, each array having a plurality (m) of antenna patches distributed along one of the antenna feed printed circuit boards and mounted to provide electromagnetic coupling between each antenna patch and a pair of antenna patch drive segments, one from each circuit path in the antenna feed printed circuit board, wherein each antenna patch is coupled simultaneously to an associated pair of antenna feed patch drive segments, and wherein each antenna patch includes a drive element electromagnetically coupled to its associated pair of antenna feed patch drive segments, and two additional parasitic elements mounted one over the other in an overlapping, spaced relationship with the drive element;

a plurality (n) of pairs of RF feed connectors, each pair providing electromagnetic coupling with respective feed points on one of the antenna feed printed circuit boards, and providing connection to RF transmitting and receiving circuitry that employ the pole antenna; and

a cylindrical cover positioned to conceal the ground plane structure, the antenna feed printed circuit boards, the antenna patches and the RF feed antennas, wherein the entire antenna is enclosed in the cylindrical cover, and whereby the enclosed antenna is highly suited for mounting on a support pole of similar diameter to that of the cover;

wherein each antenna array formed by the ground plane structure, one of the antenna feed printed circuit boards, one of the arrays of antenna patches, and one of the pairs of RF feed connectors, has metal-to-metal connection only in the pair of RF feed connectors, whereby intermodulation effects on antenna performance are minimized, and wherein the ground plane structure is assembled using a dimple welding process that further reduces the likelihood of adverse intermodulation effects;

and wherein each array of antenna patches is driven simultaneously in linear polarization modes at +45° and

−

45°

with respect to a vertical axis of the pole antenna, for polarization diversity gain and improved reliability in transmitting digital data.

10. A radio-frequency (RF) pole antenna with three arrays, the antenna comprising:

a ground plane structure having three structurally and electrically connected facets directed in uniformly spaced angular directions;

three antenna feed printed circuit boards, each of which is attached to but spaced apart from one of the ground plane facets, wherein each antenna feed printed circuit board has two feed points and two symmetrical circuit paths for feeding RF signals of different polarizations, and wherein each of the circuit paths has divergent branches leading to a plurality (m) of antenna patch drive segments;

three arrays of antenna patches, each array having a plurality (m) of antenna patches distributed along one of the antenna feed printed circuit boards and mounted to provide electromagnetic coupling between each antenna patch and a pair of antenna patch drive segments, one from each circuit path in the antenna feed printed circuit board, wherein each antenna patch is coupled simultaneously to an associated pair of antenna feed patch drive segments, and wherein each antenna patch includes a drive element electromagnetically coupled to its associated pair of antenna feed patch drive segments, and two additional parasitic elements mounted one over the other in an overlapping, spaced relationship with the drive element;

three pairs of RF feed connectors, each pair providing electromagnetic coupling with respective feed points on one of the antenna feed printed circuit boards, and providing connection to RF transmitting and receiving circuitry that employ the pole antenna; and

a cylindrical cover positioned to conceal the ground plane structure, the antenna feed printed circuit boards, the antenna patches and the RF feed antennas, wherein the entire antenna is enclosed in the cylindrical cover, and whereby the enclosed antenna is highly suited for mounting on a support pole of similar diameter to that of the cover;

wherein each antenna array formed by the ground plane structure, one of the antenna feed printed circuit boards, one of the arrays of antenna patches, and one of the pairs of RF feed connectors, has metal-to-metal connection only in the pair of RF feed connectors, whereby intermodulation effects on antenna performance are minimized, and wherein the ground plane structure is assembled using a dimple welding process that further reduces the likelihood of adverse intermodulation effects;

and wherein each array of antenna patches is driven simultaneously in linear polarization modes at +45° and

45°

with respect to a vertical axis of the pole antenna, for polarization diversity gain and improved reliability in transmitting digital data.