Antenna array assembly and method of construction thereof

Patent metadata

Field	Value
Publication number	US-10431904-B2
Application number	US-201715675309-A
Country	US
Kind code	B2
Filing date	Aug 11, 2017
Priority date	Feb 13, 2015
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

An antenna array assembly comprises a dielectric film ( 2 ) carrying an array of conductive patch radiator elements ( 7 ) and a plurality of conductive feed tracks and a ground plate ( 1 ), a face of the ground plate ( 1 ) having a contoured shape comprising a first part configured to be in contact with the dielectric film ( 2 ), and a second part comprising sunken sections with respect to the first part arranged to underlie the conductive feed tracks and conductive patch radiator elements ( 7 ), and the ground plate having locating protrusions ( 6 g, 6 f ) protruding from the first part. The dielectric film is attached to the ground plate by location of holes in the dielectric film with the locating protrusions ( 6 g, 6 f ) such that the dielectric film is held under tension to maintain spacing of the dielectric film ( 2 ) from the sunken sections of the ground plate ( 1 ) without the use of a dielectric spacer layer between the dielectric film ( 2 ) and the ground plate ( 1 ).

First claim

The invention claimed is:

1. An antenna array assembly, comprising:
a dielectric film carrying an array of conductive patch radiator elements and a plurality of conductive feed tracks; and
a ground plate, a face of the ground plate having a contoured shape, the contoured shape comprising a first part configured to be in contact with the dielectric film, and a second part comprising sunken sections with respect to the first part arranged to underlie the conductive feed tracks and conductive patch radiator elements, and the ground plate having locating protrusions protruding from the first part,
wherein the dielectric film is attached to the ground plate by location of holes in the dielectric film with the locating protrusions, such that the dielectric film is held under tension, whereby to maintain spacing of the dielectric film from the sunken sections of the ground plate without the use of a dielectric spacer layer between the dielectric film and the ground plate.

2. The antenna array assembly of claim 1 , wherein each said hole in the dielectric film has a respective diameter, before assembly, that is less than the diameter of the corresponding locating protrusion, and the dielectric film is attached such that the dielectric film in the region of each hole is raised away from the first part of the ground plate and parts of the dielectric film more distant from each hole are in contact with the first part of the ground plate and held in tension.

3. The antenna array assembly of claim 1 , wherein the second part is arranged to provide an air gap under the dielectric film, the air gap having a depth of at least 10 times the thickness of the dielectric film.

4. The antenna array assembly of claim 1 , wherein the dielectric film has a thickness less than 0.05 mm.

5. The antenna array assembly of claim 1 , wherein the dielectric film is composed of polyester.

6. The antenna array assembly of claim 1 , wherein the first part of the ground plate is substantially planar and is shaped so as not to underlie the conductive feed network or the conductive patch radiator elements and to provide at least a margin around the feed network and patch radiator elements.

7. The antenna array assembly of claim 1 , wherein the margin has a width of greater than twice the distance between a feed track and the ground plate underlying the feed track.

8. The antenna array assembly of claim 1 , wherein the distance between a patch radiator element and the ground plate underlying the patch radiator element is at least 5 times the distance between a feed track and the ground plate underlying the feed track.

9. The antenna array assembly of claim 1 , wherein the distance between a patch radiator element and the ground plate underlying the patch radiator element is at least 2 mm.

10. The antenna array assembly of claim 1 , wherein the thickness of the planar dielectric substrate is less than a tenth of the width of at least one of the plurality of feed tracks.

11. The antenna array assembly of claim 1 , wherein the ground plate comprises a non-conductive material having a conductive coating.

12. The antenna array assembly of claim 1 , comprising a radome attached the ground plate and arranged to cover the top face of the ground plate, the radome having pillars configured to bear against the dielectric film,
whereby further to locate the dielectric film to the ground plate.

13. A radio terminal comprising an antenna array assembly according to claim 1 .

14. The radio terminal according of claim 13 , wherein the radio terminal comprises a radio transceiver having a printed circuit board mounted on the opposite face of the ground plate to said face, the radio transceiver being connected to the conductive patch radiator elements by respective feed tracks.

15. A method of construction of an antenna array assembly having an array of patch antenna elements, the method comprising:
providing a dielectric film carrying an array of conductive patch radiator elements and a plurality of conductive feed tracks;
providing a ground plate, a face of the ground plate having a contoured shape, the contoured shape comprising a first part configured to be in contact with the dielectric film, and a second part comprising sunken sections with respect to the first part arranged to underlie the conductive feed tracks and the conductive patch radiator elements, and the ground plate having locating protrusions protruding from the first part wherein the shape of the first part is configured to provide support to the dielectric film by extending up to a margin around the conductive feed network and the conductive patch radiator elements, whereby to support the flexible film; and
attaching the dielectric film to the ground plate by location of holes in the dielectric film with the locating protrusions, such that the dielectric film is held under tension, whereby to maintain spacing of the dielectric film from the sunken sections of the ground plate without the use of a dielectric spacer layer between the dielectric film and the ground plate.

16. The method of claim 15 , wherein each said hole in the dielectric film has a respective diameter, before assembly, that is less than the diameter of the corresponding locating protrusion, and attaching the dielectric film comprises applying pressure to the dielectric film in the region of each said hole, so as to dilate the hole and force the dielectric film, in the region of the hole, to slide along the locating protrusion to a position such that the dielectric film in the region of the hole is raised away from the first part of the ground plate and parts of the dielectric film more distant from each hole are in contact with the first part of the ground plate and held in tension.

17. The method of claim 15 , wherein the dielectric film has a thickness less than 0.05 mm.

18. The method of claim 15 , comprising:
attaching a radome to the ground plate, the radome being arranged to cover the top face of the ground plate; and
providing pillars attached to the radome configured to bear against the dielectric film,
whereby further to locate the dielectric film to the ground plate.

Assignees

• Cambium Networks Ltd

Inventors

• Wilkins Adam
• King Nigel Jonathan Richard
• Morrell Carl
• Clark Paul
• Strong Peter

Classifications

• H01Q1/48

  Earthing means; Earth screens; Counterpoises · CPC title

• H01Q1/38

  formed by a conductive layer on an insulating support {(patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface  H01Q15/142)} · CPC title

• H01Q1/42

  Housings not intimately mechanically associated with radiating elements, e.g. radome · CPC title

• H01Q1/50

  Structural association of antennas with earthing switches, lead-in devices or lightning protectors · CPC title

• H01Q21/0006

  Particular feeding systems · CPC title