IP Library Granted Patent US 7,474,272
Granted Patent B2
US 7,474,272 · App. 11/819,337 · Granted Jan 6, 2009

Parasitic element for helical antenna

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Quick Facts
Patent No.
US 7,474,272
App. No.
11/819,337
Granted
Jan 6, 2009
Kind
B2
Abstract

A parasitic element for a helical antenna having at least one helix conductor extending from a secured first longitudinal end of the antenna to an opposite free second longitudinal end thereof around an antenna major-axis. The parasitic element includes an electrically conductive ring located adjacent and spaced apart from the second end in a direction leading away from the first end with the ring axis being parallel to and substantially collinear with the antenna major-axis. The ring has an outer diameter substantially equal to the diameter of the helix conductor at the second end.

Claims (10)

1. A parasitic element for a helical antenna, the antenna including at least one helix conductor extending from a secured first longitudinal end of the antenna to an opposite free second longitudinal end thereof around an antenna major-axis, the parasitic element comprising an electrically conductive ring defining a ring axis and an inner and an outer wall thereof, the ring being adjacent and spaced apart from the second end in a direction leading away from the first end with the ring axis being substantially parallel to and collinear with the antenna major-axis, the ring outer wall having a diameter substantially equal to a diameter of the helix conductor at the second end.

2. The parasitic element of claim 1 , further including a plurality of electrically conductive arms extending radially inwardly from the ring inner wall, the arms being generally angularly equidistantly spaced from each other.

3. The parasitic element of claim 2 , wherein the arms connect to each other adjacent the ring axis.

4. The parasitic element of claim 3 , wherein said ring and said arms are of irregular cross-section so as to be weight relieved.

5. The parasitic element of claim 1 , wherein said ring inner wall has a diameter being substantially smaller than the ring outer diameter, whereby said ring has an annular disc shape.

6. The parasitic element of claim 5 , further including a plurality of electrically conductive arms extending radially inwardly from the ring inner wall, the arms being generally angularly equidistantly spaced from each other.

7. The parasitic element of claim 6 , wherein the arms connect to each other adjacent the ring axis.

8. The parasitic element of claim 5 , wherein said ring inner diameter is generally equal to zero, whereby said ring has a full disc shape.

9. The parasitic element of claim 5 , wherein said ring is of irregular cross-section so as to be weight relieved.

10. The parasitic element of claim 1 , wherein said ring is of irregular cross-section so as to be weight relieved.

Assignments (6)
SECURITY INTEREST Recorded Apr 24, 2020
From: MAXAR TECHNOLOGIES ULC; MACDONALD, DETTWILER AND ASSOCIATES CORPORATION; MACDONALD, DETTWILER AND ASSOCIATES INC.
To: COMPUTERSHARE TRUST COMPANY OF CANADA
Reel/Frame 052486/0564 →
SECURITY INTEREST Recorded Apr 9, 2020
From: MAXAR TECHNOLOGIES ULC; MACDONALD,DETTWILER AND ASSOCIATES CORPORATION; MACDONALD, DETTWILER AND ASSOCIATES INC.
To: THE BANK OF NOVA SCOTIA
Reel/Frame 052353/0317 →
RELEASE OF SECURITY INTEREST Recorded Apr 8, 2020
From: ROYAL BANK OF CANADA
To: MAXAR TECHNOLOGIES ULC; MACDONALD, DETTWILER AND ASSOCIATES INC.; MACDONALD, DETTWILER AND ASSOCIATES CORPORATION; MDA GEOSPATIAL SERVICES INC.
Reel/Frame 052351/0001 →
AMENDED AND RESTATED U.S. PATENT AND TRADEMARK SECURITY AGREEMENT Recorded Dec 13, 2019
From: MACDONALD, DETTWILER AND ASSOCIATES CORPORATION
To: ROYAL BANK OF CANADA, AS COLLATERAL AGENT
Reel/Frame 051287/0330 →
SECURITY INTEREST Recorded Oct 5, 2017
From: DIGITALGLOBE, INC.; MACDONALD, DETTWILER AND ASSOCIATES LTD.; MACDONALD, DETTWILER AND ASSOCIATES CORPORATION; MACDONALD, DETTWILER AND ASSOCIATES INC.; MDA GEOSPATIAL SERVICES INC.; SPACE SYSTEMS/LORAL, LLC; MDA INFORMATION SYSTEMS LLC
To: ROYAL BANK OF CANADA, AS THE COLLATERAL AGENT
Reel/Frame 044167/0396 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 21, 2007
From: LAMOUREUX, STEPHANE; MCLAREN, DAVID; LAROUCHE, STEVE; GAUDETTE, YVES; DALLAIRE, JEAN
To: MACDONALD, DETTWILER AND ASSOCIATES CORPORATION
Reel/Frame 019728/0846 →