Ultra-wide-band (UWB) antenna assembly with at least one director and electromagnetic reflective subassembly and method

Patent metadata

Field	Value
Publication number	US-9444147-B2
Application number	US-201314018661-A
Country	US
Kind code	B2
Filing date	Sep 5, 2013
Priority date	Jul 18, 2011
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

An ultra-wideband antenna assembly comprising:
an electromagnetic reflective structure for reflecting electromagnetic waves; the electromagnetic reflective structure operating to reflect electromagnetic waves in a first direction; an antenna operatively associated with the electromagnetic reflective structure such that electromagnetic waves emitted from the antenna towards the electromagnetic wave reflective structure are reflected back by the electromagnetic reflective structure in the first direction; the antenna being substantially planar and extending in a first plane; the first direction being substantially perpendicular to the first plane; and at least one director operatively associated with the antenna for focusing the electromagnetic waves transmitted by the antenna in the first direction; the at least one director being substantially planar and extending in a second plane wherein the second plane is substantially parallel to the first plane.

First claim

What is claimed is:

1. An ultra-wideband antenna assembly comprising:
an electromagnetic reflective structure for reflecting electromagnetic waves over an ultrawide bandwidth: the electromagnetic reflective structure configured to to reflect electromagnetic waves in a first direction and comprising first, second and third groups of differently sized patches configured to resonate at different closely spaced frequency bands, thereby providing an ultra-wide band operation:
a printed circular monopole antenna supported by a dielectric substrate and further comprising an electrically conductive coplanar waveguide designed for the 700-3000 MHz band in electrical communication with the antenna, the electrically conductive coplanar waveguide comprising two ground planes supported by the dielectric substrate;
the printed circular monopole antenna being operatively associated with the electromagnetic reflective structure such that electromagnetic waves emitted from the printed circular monopole antenna towards the electromagnetic wave reflective structure are reflected back by the electromagnetic reflective structure in the first direction: the antenna being substantially planar and extending in a first plane: the first direction being substantially perpendicular to the first plane: and
at least one director operatively associated with the antenna for focusing the electromagnetic waves transmitted by the antenna in the first direction: the at least one director being substantially planar and extending in a second plane wherein the second plane is substantially parallel to the first plane.

2. The assembly of claim 1 the dielectric substrate comprising one of fiberglass reinforced epoxy laminate (FR-4), polytetrafluoroethylene (PTFE) composites reinforced with glass microfibers, and ceramic, and wherein the dielectric substrate is rectilinear in shape.

3. An ultra-wideband antenna assembly comprising:
an electromagnetic reflective structure for reflecting electromagnetic waves over an ultrawide bandwidth; the electromagnetic reflective structure configured to to reflect electromagnetic waves in a first direction and comprising first, second and third groups of differently sized patches configured to resonate at different closely spaced frequency bands, thereby providing an ultra-wide band operation:
a dielectric:
a circular monopole antenna mounted to a first surface of the dielectric and operatively associated with the electromagnetic reflective structure such that electromagnetic waves emitted from the antenna towards the electromagnetic wave reflective structure are reflected back by the electromagnetic reflective structure in the first direction: the antenna being substantially planar and extending in a first plane: the first direction being substantially perpendicular to the first plane: and
an electrically conductive coplanar waveguide configured to feed the antenna mounted to the first surface of the dielectric substrate, the electrically conductive coplanar waveguide being designed for the 700-3000 MHz band;
a plurality of planar directors operatively associated with the antenna for focusing the electromagnetic waves transmitted by the antenna in the first direction: each of the plurality of directors being substantially planar and extending in a second plane wherein the second plane is substantially parallel to the first plane: each of the planes being spaced form one another.

4. The assembly of claim 3 wherein the first, second and third groups are stacked layers, each layer configured to resonate at a different frequency leading to a plurality of resonances at different frequencies resulting in the ultra-wide band operation and wherein the plurality of resonances are a function of the spacing between the patches and the size of the patches.

5. The assembly of claim 3 wherein resonance is created within cavities defined between the first, second and third groups.

6. The structure of claim 3 wherein the first, second and third groups are substantially planar and are substantially parallel to one another and wherein the electromagnetic waves are reflected in the first direction, away from the first group.

7. The structure of claim 3 wherein the first, second and third groups are separated by at least one dielectric material comprising one of ceramic, foam and plastic, and wherein the spacing between the first, second and third groups forms resonant cavities.

8. An ultra-wideband antenna assembly comprising:
an electromagnetic reflective subassembly for reflecting electromagnetic waves; the electromagnetic reflective subassembly comprising a first layer, a second layer, and a third layer; each layer being in the stacked arrangement configured to reflect electromagnetic waves in a first direction;
a dielectric substrate;
a circular monopole antenna mounted to a first surface of the dielectric and operatively associated with the electromagnetic reflective subassembly such that electromagnetic waves emitted from the antenna towards the electromagnetic reflective subassembly are reflected back by each layer of the electromagnetic reflective subassembly in the first direction; the antenna being substantially planar and extending in a first plane; the first direction being substantially perpendicular to the first plane;
an electrically conductive coplanar waveguide mounted to the first surface of the dielectric substrate; the electrically conductive coplanar waveguide configured to feed the antenna and being designed for the 700-3000 MHz band;
at least one director operatively associated with the antenna for focusing the electromagnetic waves transmitted by the antenna in the first direction; the at least one director being substantially planar and extending in a second plane wherein the second plane is substantially parallel to the first plane;
the first layer comprising a first plurality of spaced apart patches of conductive material extending in a third plane substantially parallel to the first and second planes; the first plurality of spaced apart patches configured to reflect the electromagnetic waves in a first frequency range: a second layer substantially parallel to and separated from the first layer, the second layer being substantially planar and comprising a second plurality of spaced apart patches of conductive material configured to reflect the electromagnetic waves in a second frequency range: a third layer substantially parallel to and separated from the first and second layers the third layer being substantially planar and comprising a third plurality of spaced apart patches of conductive material configured to reflect the electromagnetic waves in a third frequency range: wherein the first, second and third plurality of spaced apart patches have different sizes so as to produce a resonate condition at the first, second and third frequency ranges; the first, second and third frequency ranges being additive and being substantially close to one another such that the reflective subassembly reflects electromagnetic waves in an ultra wide frequency band; and
the electromagnetic reflective subassembly configured to reflect electromagnetic waves originating from the antenna, the electromagnetic waves being reflected by the electromagnetic reflective subassembly being such that the phase of the electromagnetic waves reflected from the electromagnetic reflective subassembly results in the constructive addition of the originating and reflected waves, thus enhancing the radiation of electromagnetic waves by the antenna.

9. A method of making an ultra-wideband antenna comprising:
providing an electromagnetic reflective structure having three layers for reflecting electromagnetic radiation; the electromagnetic reflective structure configure

Assignees

• U S Army Res Laboratory Attn: Rdrl-Loc-I
• Us Army

Inventors

• Zaghloul Amir Ibrahim
• Lee Youn Moo

Classifications

• Y10T29/49016

  Antenna or wave energy "plumbing" making · CPC title

• H01Q19/10 Primary

  using reflecting surfaces · CPC title

• H01Q9/30

  with feed to end of elongated active element, e.g. unipole (H01Q9/44 takes precedence) · CPC title

• H01Q19/005

  Patch antenna using one or more coplanar parasitic elements · CPC title

• H01Q15/008

  said selective devices having Sievenpipers' mushroom elements · CPC title