Planar lower cost multilayer dual-band microstrip antenna

• US 5,561,435 A
• Filed: 02/09/1995
• Issued: 10/01/1996
• Est. Priority Date: 02/09/1995
• Status: Expired due to Fees

• Current Assignee: United States of America, The, As Represented By The Secretary of Army of Department of Army
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Nalbandian, Vahakn, Sae Lee, Choon, Schwering, Felix
• Primary Examiner(s): Hajec, Donald T.
• Assistant Examiner(s): PHAN, THO GIA
• Application Number:
  US08/385,615
• Time in Patent Office: 600 Days
• Field of Search: 343/700 MS, 343/849, 343/829, 343/830, 343/853, 343/818
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 5/385 Two or more parasitic elements

Abstract

A planar dual band antenna comprising three superimposed dielectric layers, ground plane on one external surface, a conductive patch on the other and parallel conductive strips at the interface of dielectric layers that is closer to the patch. The dielectric constant of the middle layer is different from that of the two other layers.

Claims

1. A dual frequency antenna comprising:

a metallic sheet;

a first layer of dielectric material;

a first bonding film on said first layer;

a second layer of dielectric material on said first bonding film;

a second bonding film on said second layer of dielectric material;

first and second conductive strips on said second bonding film, said first and second conductive strips being spaced so as to not contact each other and being disposed in a same plane;

a third layer of dielectric material on said second bonding film and said first and second conductive strips;

a patch of conductive material on said third layer of dielectric material; and

a probe having a central conductor and a shield, said probe mounted with its shield in contact with said metallic sheet and its central conductor extending through said sheet, through said first, second, and third dielectric layers and through said first and second bonding films to said patch of conductive material, via a space between said first and second conductive parallel strips;

wherein said probe is disposed perpendicular to the plane of the first and second conductive strips such when radiating energy is exposed to the antenna a first resonance above the first and second conductive strips and a second resonance below the first and second conductive strips result.

2. An antenna as set forth in claim 1, wherein the dielectric constant of said second dielectric layer is different from the dielectric constants of said first and third dielectric layers.

3. A dual band antenna as set forth in claim 1, wherein:

said first and second conductive strips have edges which are remote from one another and said patch is wider than a distance between the remote edges of said parallel strips.

4. A dual band antenna as set forth in claim 1, wherein said first dielectric layer is thicker then said third dielectric layer and said second dielectric layer is the thinnest.

5. An antenna comprising:

first, second and third successive layers of dielectric material forming a striated structure having first and second outside surfaces, the first and third successive layers of dielectric material having a dielectric constant which is different from a dielectric constant of the second layer;

a sheet of conductive material on said first outside surface;

a patch of conductive material on said second outside surface;

first and second conductive strips mounted between two of said dielectric layers, said first and second conductive strips being spaced apart and being disposed in a same plane; and

a probe having a central conductor and a shield, said probe mounted with its shield in contact with said metallic sheet and its central conductor extending through said sheet, through said first, second, and third dielectric layers to said patch of conductive material, via a space between said first and second conductive parallel strips;

wherein said probe is disposed perpendicular to the plane of the first and second conductive strips such when radiating energy is exposed to the antenna a first resonance above the first and second conductive strips and a second resonance below the first and second conductive strips result.

6. A dual frequency microstrip antenna comprising:

a conductive sheet;

a first layer of dielectric material having a first dielectric constant, the first layer of dielectric material disposed over the conductive sheet;

a second layer of dielectric material having a second dielectric constant which is different than the first dielectric constant, the second layer of dielectric material being disposed over the first layer of dielectric material;

first and second conductive strips disposed on the second layer of dielectric material, the first and second conductive strips being spaced so as to not contact each other and being disposed in a same plane;

a third layer of dielectric material disposed over the first and second conductive strips and on the second layer of dielectric material, the third layer of dielectric material having a third dielectric constant which is different from the second dielectric constant;

a patch of conductive material disposed on the third layer of dielectric material; and

a probe having a central conductor and a shield, said probe mounted with its shield in contact with the conductive sheet and its central conductor extending through the conductive sheet, the first, second, and third dielectric layers to the patch of conductive material, via a space between the first and second conductive parallel strips;

wherein the space between the first and second conductive parallel strips is selected to cause an impedance match to a predetermined low frequency; and

wherein said probe is disposed perpendicular to the plane of the first and second conductive strips such when radiating energy is exposed to the antenna a first resonance above the first and second conductive strips and a second resonance below the first and second conductive strips result.