Antenna assembly with shielding structure

Patent metadata

Field	Value
Publication number	US-9368865-B2
Application number	US-201114357494-A
Country	US
Kind code	B2
Filing date	Nov 15, 2011
Priority date	Nov 15, 2011
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

The present invention relates to an antenna assembly ( 2, 102, 202, 302 ) comprising: a plurality of transmit antennas, at least one receive antenna ( 4 ), at least one shielding structure ( 6 ), and at least one frame ( 8 ), wherein the at least one frame is configured for: setting a pointing direction of a first transmit antenna ( 10 ) such that a first transmit minimum ( 16 ) of the first receive antenna ( 10 ) points towards a first zone ( 24 ), and setting a pointing direction of a second transmit antenna ( 12 ) such that a second transmit minimum ( 18 ) of the second antenna ( 12 ) points towards a second zone ( 26 ), whereby coupling of radiation from the plurality of transmit antennas to the receive antenna ( 4 ) is reduced.

First claim

The invention claimed is:

1. Antenna assembly comprising:
a plurality of transmit antennas comprising a first transmit antenna and a second transmit antenna, the first transmit antenna having a first transmit pattern with a first transmit minimum when transmitting, the second transmit antenna having a second transmit pattern with a second transmit minimum when transmitting;
at least one receive antenna including a first receive antenna;
at least one shielding structure configured for obstructing direct electromagnetic radiation generated by the plurality of transmit antennas; and
at least one frame configured for setting mutual positions of:
the plurality of transmit antennas;
the at least one shielding structure; and
the at least one receive antenna, such that the at least one shielding structure shields the at least one receive antenna from direct electromagnetic radiation generated by the plurality of transmit antennas,

wherein:
the setting of mutual positions defines a plurality of zones at the at least one shielding structure, the plurality of zones including a first zone and a second zone;
radiation, which emanates from the first transmit antenna and which is diffracted by the at least one shielding structure towards the at least one receive antenna, is subject to a lower power loss if diffracted by the at least one shielding structure at the first zone than if diffracted by the at least one shielding structure outside the first zone;
radiation, which emanates from the second transmit antenna and which is diffracted by the at least one shielding structure towards the at least one receive antenna, is subject to a lower power loss if diffracted by the at least one shielding structure at the second zone than if diffracted by the at least one shielding structure outside the second zone; and
the at least one frame is configured for:
setting a pointing direction of the first transmit antenna such that the first transmit minimum points towards the first zone; and
setting a pointing direction of the second transmit antenna such that the second transmit minimum points towards the second zone.

2. Antenna assembly according to claim 1 , wherein:
the first zone is at an outline of a first contour of the at least one shielding structure as defined from the position of the first transmit antenna; and
the second zone is at an outline of a second contour of the at least one shielding structure as defined from the position of the second transmit antenna.

3. Antenna assembly according to claim 1 , wherein:
the antenna assembly is configured for setting the pointing direction of the first transmit antenna such that the first transmit minimum points along a first diffraction path, the first diffraction path being about the at least one shielding structure towards the at least one receive antenna;
the antenna assembly is configured for setting the pointing direction of the second transmit antenna such that the second transmit minimum points along a second diffraction path, the second diffraction path being about the at least one shielding structure towards the at least one receive antenna;
the first diffraction path is shorter than any immediately adjacent path from the first transmit antenna about the at least one shielding structure and towards the at least one receive antenna; and
the second diffraction path is shorter than any immediately adjacent path from the second transmit antenna about the at least one shielding structure and towards the at least one receive antenna.

4. Antenna assembly according to claim 3 , wherein:
radiation along the first diffraction path is subject to a plurality of diffractions by the at least one shielding structure; and
radiation along the second diffraction path is subject to a plurality of diffractions by the at least one shielding structure.

5. Antenna assembly according to claim 1 , wherein the at least one shielding structure comprises a planar surface part at the first zone.

6. Antenna assembly according to claim 1 , wherein the at least one shielding structure comprises a first edge at the first zone.

7. Antenna assembly according to claim 1 , wherein the at least one shielding structure comprises a radiation absorbing material such as a radiation absorbing coating.

8. Antenna assembly according to claim 7 , wherein the at least one shielding structure comprises the radiation absorbing material at the plurality of zones.

9. Antenna assembly according to claim 1 , wherein:
the plurality of transmit antennas comprises a third transmit antenna having a third transmit pattern with a third transmit minimum when transmitting and wherein the plurality of zones includes a third zone defined by the setting of position of the third transmit antenna;
radiation, which emanates from the third transmit antenna and being diffracted by the at least one shielding structure towards the at least one receive antenna, is subject to a lower power loss if diffracted by the at least one shielding structure at the third zone than if diffracted by the at least one shielding structure outside the third zone;
the antenna assembly is further configured for setting the pointing direction of the third transmit antenna such that the third transmit minimum points towards the third zone.

10. Antenna assembly according to claim 1 , wherein each of the plurality of transmit antennas are configured for transmitting independent signals.

11. Antenna assembly according to claim 1 , wherein the plurality of transmit antennas are dipole antennas, such as folded dipole antennas.

12. Antenna assembly according to claim 1 , wherein the first transmit antenna is collinear with the second transmit antenna.

13. Antenna assembly according to claim 1 , wherein the at least one receive antenna comprises a second receive antenna.

14. Antenna assembly according to claim 1 , wherein each of the plurality of transmit antennas have an longitudinal extension of at least 5 cm.

15. Antenna assembly according to claim 1 , wherein the plurality of transmit antennas are configured for transmitting at a frequency within 30 MHz and 3 GHz.

16. Antenna assembly according to claim 1 , wherein the at least one frame is configured for adjusting the setting of individual pointing directions of the plurality of transmit antennas.

17. Antenna assembly according to claim 1 , wherein the at least one frame forms an integral part with the at least one shielding structure.

18. Antenna assembly according to claim 1 , wherein the antenna assembly comprises a stabilized platform onto which the at least one frame is mounted.

19. Use of an antenna assembly according to claim 1 , wherein the antenna assembly is mounted at least one of in or on a vehicle, such as a ship or an aircraft.

20. Use of an antenna assembly according to claim 1 , wherein the antenna assembly is mounted at least one of in or on a building or mounted as a ground installation.

21. Method for shielding at least one receiver antenna of an antenna assembly from radiation emanating from a plurality of transmit antennas of the antenna assembly by means of at least one shielding structure of the antenna assembly, the plurality of transmit antennas comprising a first transmit antenna and a second transmit antenna, the first transmit antenna having a first transmit pattern with a first transmit minimum when transmitting, the second transmit antenna having a second transmit pattern with a second transmit minimum when transmitting, the at least one receive ant

Assignees

• Bäckman Anders
• Höök Anders
• Saab Ab

Inventors

• Bäckman Anders
• Höök Anders

Classifications

• H01Q3/14

  for varying the relative position of primary active element and a refracting or diffracting device · CPC title

• H01Q1/1235

  Collapsible supports; Means for erecting a rigid antenna · CPC title

• H01Q1/525 Primary

  between emitting and receiving antennas · CPC title

• H01Q1/18

  Means for stabilising antennas on an unstable platform · CPC title

• H01Q1/1242

  Rigid masts specially adapted for supporting an aerial · CPC title