Base mounted re-entry vehicle antenna

Claim 2

A space projectile having an antenna flush mounted in its base, said antenna comprising a plurality of concentric ring radiating elements, each ring radiating element comprising a metallic dielectric loaded cavity having a rectangular crosssection and a circumferential radiating slot which faces rearwardly of said projectile.

Claim 3

The projectile of claim 1 wherein said concentric ring radiating elements lie in the same plane and wherein adjacent elements contact each other about their peripheral surfaces.

Claim 4

The projectile of claim 2 wherein each of said plurality of ring radiating elements has a different diameter but wherein all of said elements have the same volume and thickness.

Claim 5

The projectile of claim 3 wherein each of said ring radiating elements is a copper-plated dielectric loaded cavity and wherein said dielectric is comprised of epoxy and fiberglass materials.

Claim 6

The projectile of claim 3 wherein said ring radiating elements are excited in different relative phases.

Claim 7

The projectile of claim 1 wherein said projectile further comprises a re-entry vehicle.

Claim 8

A space projectile having an antenna mounted at its base, said antenna comprising a plurality of concentric ring radiating elements, each ring radiating element comprising a metallic dielectric cavity having a circumferential radiating slot and being L-shaped in cross-section, said projectile comprising a re-entry vehicle having a bottom portion which terminates at the rear of the vehicle in a base, each of said L-shaped ring radiating elements having a first portion which is perpendicular to said base and a second portion which is parallel to said base, said circumferential radiating slot being located in said first portion and facing in the direction of the side of said re-entry vehicle, said ring radiating elements being stacked on each other so that said first portion of each radiating element above the bottommost element is mounted at the interior end of said second portion or the element immediately below it and said first portion of said bottommost ring radiating element being mounted on said base of said re-entry vehicle.

Claim 9

A space projectile having an antenna mounted at its base, said antenna comprising a plurality of concentric ring radiating elements, each ring radiating element comprising a metallic dielectric cavity having a circumferential radiating slot and being L-shaped in cross-section, said projectile comprising a re-entry vehicle having a bottom portion which terminates at the rear of the vehicle in a base, each of said L-shaped ring radiating elements having a first portion which is perpendicular to said base and a second portion which is parallel to said base, said circumferential radiating slot being located in said first portion and facing in the direction of the side of said re-entry vehicle, said ring radiating elements being stacked on each other so that said first portion of each radiating element above the bottommost element is mounted at the interior end of said second portion or the element immediately below it and said first portion of said bottommost ring radiating element being mounted on said base of said re-entry vehicle.

Claim 10

The projectile of claim 7 wherein the diameter and width of said second portion of each radiating element above the bottommost element are respectively smaller and greater than the diameter and width of the second portion of the element immediately below, and wherein the volumes of all of said ring radiating elements are substantially equal.

Claim 11

The projectile of claim 8 wherein said circumferential radiating slots extend around the greater part of the circumference of said first portions of said ring radiating elements but do not extend around the entire circumference.

Claim 12

The antenna of claim 8 wherein said re-entry vehicle comprises a body portion which terminates at the rear of the vehicle in the base and said ring radiators are L-shaped in cross-section, each of said radiators having a first portion which is perpendicular to said base when said antenna is mounted and a second portion which is parallel to said base when said antenna is mounted, said circumferential radiating slots being located in said first portion and facing in the direction of the side of said re-entry vehicle when said antenna is mounted.