Multiple input loop antenna

Patent metadata

Field	Value
Publication number	US-9397400-B2
Application number	US-201514865131-A
Country	US
Kind code	B2
Filing date	Sep 25, 2015
Priority date	Dec 20, 2012
Publication date	Jul 19, 2016
Grant date	Jul 19, 2016

Abstract

A multiple input loop antenna comprising one or more half-loop antennas disposed above a ground plane wherein the plane of each half loop is perpendicular to the ground plane such that the multiple input loop antenna is a three-dimensional structure and electromagnetic waves are radiated from points within the volume occupied by the antenna rather than from a two-dimensional surface. For this reason, the multiple input loop antenna can radiate levels of peak power without inducing excessive air breakdown which are relatively high compared with peak power levels of conventional antennas having comparable transverse dimensions. Also described is an array antenna comprised of an array of multiple input loop antennas.

First claim

What is claimed is:

1. A high power array element having plurality of inputs, the high power array element comprising:
a ground plane;
a plurality of coaxial transmission line feeds disposed through said ground plane;
a center conductor of each of said plurality of coaxial transmission line feeds arranged on a circle having a predetermined radius wherein the heights of said center conductors above the ground plane and the horizontal separation between said center conductors are selected to match an impedance characteristic at each of the plurality of inputs of the high power array element;
a plurality of pill-shaped caps, each of said plurality of pill-shaped caps disposed over a center conductors of a respective one of said coaxial transmission line feeds, each of said caps having a size and shape selected to reduce a peak electric field on a surface of the high power array element.

2. The high power array element of claim 1 , wherein a junction at which an outer conductor of each feeding transmission line meets said ground plane is rounded with a predetermined radius selected to prevent edge enhancement.

3. The high power array element of claim 1 , wherein each cap is provided from a cylindrical section having a selected length and diameter capped on each end by hemispheres having a diameter.

4. The high power array element of claim 1 , wherein each pill-shaped cap is offset from said ground plane such that a midpoint of each pill-shaped cap lies a selected distance above said ground plane.

5. The high power array element of claim 1 , further comprising a plurality of joining sections disposed to couple diagonally opposite pill-shaped caps.

6. The high power array element of claim 5 , wherein said joining sections corresponds to rods.

7. The high power array element of claim 5 , further comprising a grounding rod disposed to couple to a midpoint of said joining sections to said ground plane in order to provide a return path to ground for any direct current components that might be present in input signals provided to the high power array element.

Assignees

• Raytheon Co

Inventors

• Crouch David D
• Kato Keith G

Classifications

• H01Q21/28

  Combinations of substantially independent non-interacting antenna units or systems {(multiple beam H01Q25/00)} · CPC title

• H01Q7/00 Primary

  Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop · CPC title

• H01Q1/40

  Radiating elements coated with or embedded in protective material · CPC title

• H01Q21/24

  Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction {(circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001)} · CPC title

• H01Q21/0006

  Particular feeding systems · CPC title