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US5327148A Expired / Lapsed US ⏱️ 0.0 years remaining

Ferrite microstrip antenna

Assignee: Northeastern University
•
Filing: 1993-02-17
•
Granted: 1994-07-05
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Expires: 2013-02-17
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Abstract

Abstract A microstrip antenna includes a ferrite loaded substrate having a ground plane conductor disposed over a first surface thereof and having a strip conductor disposed over a second surface thereof. A DC magnetic field biasing circuit provides a directed DC magnetic field to the ferrite substrate such that the strip conductor radiates electromagnetic energy having circular polarization. In one embodiment, a ferrite material is disposed over the strip conductor to reduce the radar cross section of the antenna.

Inventors

  • 👤 Hoton How
  • 👤 Carmine Vittoria

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 09:15
CPC Classifications
H; H01; H01Q; H01Q3/00; H01Q3/44; H01Q1/00; H01Q1/36; H01Q1/38

Claims Analysis

Total Claims: 23
Claim 1
Independent Claim 120 words
A microstrip antenna comprising: a ferrite loaded substrate having first and second opposing surfaces; a ground plane conductor disposed over the first surface of said substrate; a strip conductor having a rectangular shape disposed over the second surface of said substrate; an RF feed circuit disposed on a first one of the first and second surfaces of said substrate and coupled to said first strip conductor; and a DC magnetic field biasing circuit for providing a DC magnetic field to said ferrite substrate wherein the DC magnetic field is provided in a plane parallel to a plane in which the ferrite substrate is disposed and wherein the direction of the DC magnetic field is perpendicular to said RF feed circuit.
Claim 2
Dependent Claim 120 words
A microstrip antenna comprising: a ferrite loaded substrate having first and second opposing surfaces; a ground plane conductor disposed over the first surface of said substrate; a strip conductor having a rectangular shape disposed over the second surface of said substrate; an RF feed circuit disposed on a first one of the first and second surfaces of said substrate and coupled to said first strip conductor; and a DC magnetic field biasing circuit for providing a DC magnetic field to said ferrite substrate wherein the DC magnetic field is provided in a plane parallel to a plane in which the ferrite substrate is disposed and wherein the direction of the DC magnetic field is perpendicular to said RF feed circuit.
Claim 3
Dependent Claim 13 words
The microstrip antenna of claim 1 wherein said ferrite substrate includes spinel ferrites.
Claim 4
Dependent Claim 13 words
The microstrip antenna of claim 1 wherein said ferrite substrate includes hexagonal ferrites.
Claim 5
Dependent Claim 25 words
The microstrip antenna of claim 1 wherein said RF feed circuit is provided as a strip conductor disposed on the second surface of said substrate.
Claim 6
Dependent Claim 42 words
The microstrip antenna of claim 1 wherein said ground plane conductor has portions thereof removed to expose said substrate and said RF feed circuit is provided as a strip conductor disposed in the exposed portions of the first surface of said substrate.
Claim 7
Dependent Claim 17 words
The microstrip antenna of claim 1 wherein said rectangular shaped strip conductor corresponds to a square shape.
Claim 8
Dependent Claim 69 words
The microstrip antenna of claim 1 wherein: said strip conductor is a first one of a plurality of strip conductors each of said plurality of strip conductors disposed over the second surface of the substrate; and said RF feed circuit is a first one of a plurality of feed circuits each one of said plurality of feed circuits coupled to a corresponding one of said plurality of strip conductors.
Claim 9
Dependent Claim 14 words
The microstrip antenna of claim 7 wherein said ferrite substrate includes a spinel ferrite.
Claim 10
Dependent Claim 14 words
The microstrip antenna of claim 7 wherein said ferrite substrate includes a hexagonal ferrite.
Claim 11
Dependent Claim 45 words
The microstrip antenna array of claim 7 wherein said ground plane conductor has portions thereof removed to expose said substrate and at least one of said plurality of RF feed circuits is provided as a strip conductor disposed on the first surface of said substrate.
Claim 12
Dependent Claim 34 words
The microstrip antenna array of claim 7 wherein at least one of said plurality of said RF feed circuits is provided as a strip conductor disposed on the second surface of said ferrites substrate.
Claim 13
Dependent Claim 153 words
A microstrip antenna comprising: a ferrite loaded substrate having first and second opposing surfaces and having a first permeability; a ground plane conductor disposed over the first surface of said substrate; a first antenna element disposed over the second surface of said substrate wherein said first antenna element is provided having a shape selected such that said first antenna element is responsive to electromagnetic energy at a first frequency; an RF feed circuit disposed on a first one of the first and second surfaces of said substrate and coupled to said first antenna element; a ferrite material disposed over said first antenna element wherein said ferrite material is selected having a second permeability wherein the second permeability is different than the first permeability of said ferrite substrate; and a DC magnetic field biasing circuit for providing a DC magnetic field in a direction normal to said ferrite substrate and said first antenna element.
Claim 14
Dependent Claim 153 words
A microstrip antenna comprising: a ferrite loaded substrate having first and second opposing surfaces and having a first permeability; a ground plane conductor disposed over the first surface of said substrate; a first antenna element disposed over the second surface of said substrate wherein said first antenna element is provided having a shape selected such that said first antenna element is responsive to electromagnetic energy at a first frequency; an RF feed circuit disposed on a first one of the first and second surfaces of said substrate and coupled to said first antenna element; a ferrite material disposed over said first antenna element wherein said ferrite material is selected having a second permeability wherein the second permeability is different than the first permeability of said ferrite substrate; and a DC magnetic field biasing circuit for providing a DC magnetic field in a direction normal to said ferrite substrate and said first antenna element.
Claim 15
Dependent Claim 13 words
The microstrip antenna of claim 12 wherein said ferrite substrate includes spinel ferrites.
Claim 16
Dependent Claim 13 words
The microstrip antenna of claim 12 wherein said ferrite substrate includes hexagonal ferrites.
Claim 17
Dependent Claim 25 words
The microstrip antenna of claim 12 wherein said RF feed circuit is provided as a strip conductor disposed on the second surface of said substrate.
Claim 18
Dependent Claim 25 words
The microstrip antenna of claim 12 wherein said RF feed circuit is provided as a strip conductor disposed on the first surface of said substrate.
Claim 19
Dependent Claim 83 words
The RF antenna of claim 12 wherein: said first antenna element is a first one of a plurality of antenna elements each of said plurality of antenna elements disposed over the second surface of the substrate, wherein each of said antenna elements radiate electromagnetic energy in response to RF energy fed thereto; said RF feed circuit is a first one of a plurality of RF feed circuits, each one of said RF feed circuits coupled to one of said plurality of antenna elements.
Claim 20
Dependent Claim 15 words
The microstrip antenna array of claim 17 wherein said ferrite substrate includes a spinel ferrite.
Claim 21
Dependent Claim 15 words
The microstrip antenna array of claim 17 wherein said ferrite substrate includes a hexagonal ferrite.
Claim 22
Dependent Claim 32 words
The microstrip antenna array of claim 17 wherein at least one of said plurality of RF feed circuits is provided as a strip conductor disposed on the second surface of said substrate.
Claim 23
Dependent Claim 33 words
The microstrip antenna array of claim 17 wherein at least one of said plurality of RF feed circuits is provided as a strip conductor disposed on the first surface of said ferrite substrate.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-07-04 1998-01-03 1998-07-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-07-04 2002-01-03 2002-07-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-07-04 2006-01-03 2006-07-05 $7700.00 Window Closed / Lapsed

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