Thin broadband microstrip antenna

Claim 2

An elementary antenna comprising: a constant thickness dielectric substrate having a first side and a second side; an electrically conductive microstrip feed line physically connected to said second side of said dielectric substrate; a conductive metal layer forming a ground plane located on said first side of said dielectric substrate; a radiating patch electrically connected to said feed line, said radiating patch being formed by only a single conductive loop of constant width (l); an inner parasitic patch which is not energized, said radiating patch surrounding and separated from said inner parasitic patch and defining therebetween a closed continuous slot of constant width (e) adapted to bring about coupling between said conductive loop and said inner parasitic patch.

Claim 3

An elementary antenna according to claim 1 wherein a ratio of said width (l) of said conductive loop to said width (e) of said slot is between 1/5 and 5/1, said width l or said width e being at least approximately between 0.001 and 0.1 times a ratio λ o /√ε e wherein λ o is the wavelength of said elementary antenna at an operating frequency and ε e is an effective dielectric constant of a propagation medium embodying said dielectric substrate.

Claim 4

An elementary antenna according to claim 2 wherein said width l of said connective loop and/or said width e of said slot is at least approximately between 0.003 and 0.05 times said ratio λ o /√ε e .

Claim 5

An elementary antenna according to claim 2 wherein a diameter of said inner parasitic patch is at least approximately 0.5 times said ratio λ o /√ε e .

Claim 6

An elementary antenna according to claim 1 wherein said inner parasitic patch is circular and said conductive loop and said slot are concentric with said inner parasitic patch.

Claim 7

An elementary antenna according to claim 1 wherein said inner parasitic patch is polygonal in shape.

Claim 8

An elementary antenna according to claim 1 wherein said inner parasitic patch is square in shape.

Claim 9

An elementary antenna according to claim 7 wherein the said length of said inner parasitic patch is at least approximately 0.5 times a ratio λ o /√ε e where λ o is the wavelength of said elementary antenna at an operating frequency and ε e is an effective dielectric constant of a propagation medium comprising said dielectric substrate and said inner parasitic patch.

Claim 10

An elementary antenna according to claim 1 wherein said feed line is coplanar with said radiating patch.

Claim 11

An antenna array comprising a plurality of elementary antennas fed in series and in parallel, each elementary antenna of said plurality of elementary antennas embodying: a constant thickness dielectric substrate having a first side and a second side; an electrically conductive microstrip feed line physically connected to said second side of said dielectric substrate; a conductive metal layer forming a ground plane located on said first side of said dielectric substrate; a radiating patch electrically connected to said feed line, said radiating patch being formed by only a single conductive loop of constant width (1); an inner parasitic patch which is not energized, said radiating patch surrounding and separated from said inner parasitic patch and defining therebetween a closed continuous slot of constant width (e) adapted to bring about coupling between said conductive loop and said inner parasitic patch.

Claim 12

An antenna array comprising a plurality of elementary antennas fed in series and in parallel, each elementary antenna of said plurality of elementary antennas embodying: a constant thickness dielectric substrate having a first side and a second side; an electrically conductive microstrip feed line physically connected to said second side of said dielectric substrate; a conductive metal layer forming a ground plane located on said first side of said dielectric substrate; a radiating patch electrically connected to said feed line, said radiating patch being formed by only a single conductive loop of constant width (1); an inner parasitic patch which is not energized, said radiating patch surrounding and separated from said inner parasitic patch and defining therebetween a closed continuous slot of constant width (e) adapted to bring about coupling between said conductive loop and said inner parasitic patch.

Claim 13

An antenna array according to claim 10 further comprising a feed array which is at least in part coplanar with each conductive loop of each of said elementary antenna of said plurality of elementary antennas.

Claim 14

An antenna array according to claim 10 wherein each said elementary antenna is fed at the same phase and the same amplitude.

Claim 15

An antenna comprising: a cylinder; and an annular series of equidistant elementary antennas disposed in a plane transverse to a longitudinal axis of said cylinder, each elementary antenna of said series of elementary antennas comprising: a constant thickness dielectric substrate having a first side and a second side; an electrically conductive microstrip feed line physically connected to said second side of said dielectric substrate; a conductive metal layer forming a ground plane located on said first side of said dielectric substrate; a radiating patch electrically connected to said feed line, said radiating patch being formed by only a single conductive loop of constant width l; and an inner parasitic patch which is not energized, said radiating patch surrounding and separated from said inner parasitic patch and defining therebetween a closed continuous slot of constant width e adapted to bring about coupling between said conductive loop and said inner parasitic patch.

Claim 16

An antenna comprising: a cylinder; and an annular series of equidistant elementary antennas disposed in a plane transverse to a longitudinal axis of said cylinder, each elementary antenna of said series of elementary antennas comprising: a constant thickness dielectric substrate having a first side and a second side; an electrically conductive microstrip feed line physically connected to said second side of said dielectric substrate; a conductive metal layer forming a ground plane located on said first side of said dielectric substrate; a radiating patch electrically connected to said feed line, said radiating patch being formed by only a single conductive loop of constant width l; and an inner parasitic patch which is not energized, said radiating patch surrounding and separated from said inner parasitic patch and defining therebetween a closed continuous slot of constant width e adapted to bring about coupling between said conductive loop and said inner parasitic patch.