Thin broadband microstrip array antenna having active and parasitic patches

Claim 2

An array antenna comprising: a dielectric support; and a plurality of rectangular microstrip patches successively arranged on said dielectric support parallel to an alignment direction, wherein said plurality of rectangular microstrip patches establishes a periodic succession including more than a single period, each said period including more than one rectangular microstrip patch of said plurality of rectangular microstrip patches, and comprises: a plurality of parasitic patches and a plurality of active patches disposed on said dielectric support in a parasitic patch/active patch alternating arrangement where each of said plurality of active patches is separated by one of said plurality of parasitic patches and each of said plurality of parasitic patches is separated by one of said active patches, each of said plurality of active patches are identically dimensioned to have substantially the same resonant frequency, each of said plurality of active patches further being disposed on said dielectric support so that respective phase centers of consecutive ones of said active patches in each said period are separated by a distance less than a wavelength in air λ o associated with the resonant frequency, each of said plurality of active patches further being fed with electromagnetic energy to produce radiating sides parallel to said alignment direction, each of said plurality of parasitic patches having respective resonant frequencies near the resonant frequency of said plurality of active patches, each of said plurality of parasitic patches further being disposed on said dielectric support to be separated from adjacent active patches by a slot of constant non-null width extending transversely to said alignment direction, and each parasitic patch of said plurality of parasitic patches is necessarily electromagnetically coupled to two active patches of said plurality of active patches.

Claim 3

The array antenna according to claim 1 wherein said plurality of parasitic patches comprises a first type having a first resonant frequency and a second type having a second resonant frequency, wherein each said period consists of four microstrip patches.

Claim 4

The array antenna according to claim 2 wherein said first type of said plurality of parasitic patches are disposed on said dielectric support offset a first distance relative to said plurality of active patches in a direction transverse to said alignment direction and said second type of said plurality of parasitic patches are disposed on said dielectric support offset a second distance relative to said plurality of active patches in a direction transverse to said alignment direction.

Claim 5

The array antenna according to claim 3 wherein said first type and said second type of said plurality of parasitic patches are offset in the same direction transverse to said alignment direction.

Claim 6

The array antenna according to claim 1 wherein said plurality of parasitic patches are of a single type having a common resonant frequency near the resonant frequency of said plurality of active patches.

Claim 7

The array antenna according to claim 1 wherein at least one parasitic patch of said plurality of parasitic patches is disposed of said dielectric support and offset relative to said plurality of active patches in a direction transverse to said alignment direction.

Claim 8

The array antenna according to claim 6 wherein said plurality of parasitic patches are offset in the same transverse direction.

Claim 9

The array antenna according to claim 1 wherein the distance between said phase centers of said active patches is less than approximately λ o /2.

Claim 10

The array antenna according to claim 1 wherein said plurality of active patches are connected in parallel to a feed circuit.

Claim 11

The array antenna according to claim 1 wherein said plurality of active patches are connected in series to a feed circuit.

Claim 12

The array antenna according to claim 1 wherein the non-null width slots is no greater than approximately ##EQU7## where ε r is the dielectric constant of each dielectric support.

Claim 13

The array antenna according to claim 11 wherein said non-null width of each of said slots is equal.

Claim 14

The array antenna according to claim 11 wherein said non-null width of each of said slots is different to define a desired bandwidth of said array antenna.

Claim 15

The array antenna according to claim 1 wherein said constant non-null width slots extend over at least 80% of a transverse dimension of each of said plurality of active patches, said transverse dimension extending transversely to said alignment direction.

Claim 16

The array antenna according to claim 1 wherein said plurality of parasitic patches are disposed on said dielectric support offset relative to said plurality of active patches in a direction transverse to the alignment direction.

Claim 17

An array antenna comprising: a dielectric support; and a plurality of rectangular microstrip patches successively arranged on said dielectric support parallel to an alignment direction, wherein said plurality of rectangular microstrip patches establishes a periodic succession including more than a single period, each said period including more than one rectangular microstrip patch of said plurality of rectangular microstrip patches, and comprises: a plurality of parasitic patches and a plurality of active patches disposed on said dielectric support in a parasitic patch/active patch alternating arrangement where each of said plurality active patches is separated by one of said plurality of parasitic patches and each of said plurality of parasitic patches is separated by one of said active patches, each parasitic patch of said plurality of parasitic patches is necessarily electromagnetically coupled to two active patches of said plurality of active patches, said two active patches being the nearest of said plurality of active patches to each said parasitic patch, each of said plurality of active patches are identically dimensioned and have substantially the same resonant frequency, each of said plurality of active patches further being disposed on said dielectric support so that respective phase centers of consecutive ones of said active patches in each said period are separated by a distance less than a wavelength in air λ o associated with the resonant frequency, each of said plurality of active patches further being fed with electromagnetic energy to produce radiating sides parallel to said alignment direction, said plurality of parasitic patches comprising a first type having a first resonant frequency near the resonant frequency of said plurality of active patches and a second type having a second resonant frequency, wherein each said period includes four microstrip patches, each of said plurality of parasitic patches further being disposed on said dielectric support to be separated from adjacent active patches by a slot of constant non-null width extending transversely to said alignment direction; whereby said first type of said plurality of parasitic patches are disposed on said dielectric support offset relative to said plurality of active patches in a direction transverse to said alignment direction by a first distance and said second type of said plurality of parasitic patches are disposed on said dielectric support offset relative to said plurality of active patches in a direction transverse to said alignment direction by a second distance.

Claim 18

An array antenna comprising: a dielectric support; and a plurality of rectangular microstrip patches successively arranged on said dielectric support parallel to an alignment direction, wherein said plurality of rectangular microstrip patches establishes a periodic succession including more than a single period, each said period including more than one rectangular microstrip patch of said plurality of rectangular microstrip patches, and comprises: a plurality of parasitic patches and a plurality of active patches disposed on said dielectric support in a parasitic patch/active patch alternating arrangement where each of said plurality active patches is separated by one of said plurality of parasitic patches and each of said plurality of parasitic patches is separated by one of said active patches, each parasitic patch of said plurality of parasitic patches is necessarily electromagnetically coupled to two active patches of said plurality of active patches, said two active patches being the nearest of said plurality of active patches to each said parasitic patch, each of said plurality of active patches are identically dimensioned and have substantially the same resonant frequency, each of said plurality of active patches further being disposed on said dielectric support so that respective phase centers of consecutive ones of said active patches in each said period are separated by a distance less than a wavelength in air λ o associated with the resonant frequency, each of said plurality of active patches further being fed with electromagnetic energy to produce radiating sides parallel to said alignment direction, said plurality of parasitic patches comprising a first type having a first resonant frequency near the resonant frequency of said plurality of active patches and a second type having a second resonant frequency, wherein each said period includes four microstrip patches, each of said plurality of parasitic patches further being disposed on said dielectric support to be separated from adjacent active patches by a slot of constant non-null width extending transversely to said alignment direction; whereby said first type of said plurality of parasitic patches are disposed on said dielectric support offset relative to said plurality of active patches in a direction transverse to said alignment direction by a first distance and said second type of said plurality of parasitic patches are disposed on said dielectric support offset relative to said plurality of active patches in a direction transverse to said alignment direction by a second distance.

Claim 19

An array antenna comprising: a dielectric support; and a plurality of rectangular microstrip patches successively arranged on said dielectric support parallel to an alignment direction, wherein said plurality of rectangular microstrip patches establishes a periodic succession including more than a single period, each said period including more than one rectangular microstrip patch of said plurality of rectangular microstrip patches, and comprises: a plurality of parasitic patches and a plurality of active patches disposed on said dielectric support in a parasitic patch/active patch alternating arrangement where each of said plurality of active patches is separated by one of said plurality of parasitic patches and each of said plurality of parasitic patches is separated by one of said active patches, each parasitic patch of said plurality of parasitic patches is necessarily electromagnetically coupled to two active patches of said plurality of active patches, said two active patches being the nearest of said plurality of active patches to each said parasitic patch, each of said plurality of active patches are identically dimensioned and have substantially the same resonant frequency, each of said plurality of active patches further being disposed on said dielectric support so that respective phase centers of consecutive ones of said active patches in each said period are separated by a distance less than a wavelength in air λ o associated with the resonant frequency, each of said plurality of active patches further being fed with electromagnetic energy to produce radiating sides parallel to said alignment direction, said plurality of parasitic patches comprising a first type having a first resonant frequency near the resonant frequency of said plurality of active patches and a second type having a second resonant frequency, wherein each said period has four microstrip patches, each of said plurality of parasitic patches further being disposed on said dielectric support to be separated from adjacent active patches by a set of slots of constant non-null width extending transversely to said alignment direction; said non-null width of each of said set of slots being different depending on a desired bandwidth of said array antenna; whereby said first type of said plurality of parasitic patches are disposed on said dielectric support offset relative to said plurality of active patches in a direction transverse to said alignment direction by a first distance and said second type of said plurality of parasitic patches are disposed on said dielectric support offset relative to said plurality of active patches in a direction transverse to said alignment direction by a second distance.

Claim 20

An array antenna comprising: a dielectric support; and a plurality of rectangular microstrip patches successively arranged on said dielectric support parallel to an alignment direction, wherein said plurality of rectangular microstrip patches establishes a periodic succession including more than a single period, each said period including more than one rectangular microstrip patch of said plurality of rectangular microstrip patches, and comprises: a plurality of parasitic patches and a plurality of active patches disposed on said dielectric support in a parasitic patch/active patch alternating arrangement where each of said plurality of active patches is separated by one of said plurality of parasitic patches and each of said plurality of parasitic patches is separated by one of said active patches, each parasitic patch of said plurality of parasitic patches is necessarily electromagnetically coupled to two active patches of said plurality of active patches, said two active patches being the nearest of said plurality of active patches to each said parasitic patch, each of said plurality of active patches are identically dimensioned and have substantially the same resonant frequency, each of said plurality of active patches further being disposed on said dielectric support so that respective phase centers of consecutive ones of said active patches in each said period are separated by a distance less than a wavelength in air λ o associated with the resonant frequency, each of said plurality of active patches further being fed with electromagnetic energy to produce radiating sides parallel to said alignment direction, said plurality of parasitic patches comprising a first type having a first resonant frequency near the resonant frequency of said plurality of active patches and a second type having a second resonant frequency, wherein each said period has four microstrip patches, each of said plurality of parasitic patches further being disposed on said dielectric support to be separated from adjacent active patches by a set of slots of constant non-null width extending transversely to said alignment direction; said non-null width of each of said set of slots being different depending on a desired bandwidth of said array antenna; whereby said first type of said plurality of parasitic patches are disposed on said dielectric support offset relative to said plurality of active patches in a direction transverse to said alignment direction by a first distance and said second type of said plurality of parasitic patches are disposed on said dielectric support offset relative to said plurality of active patches in a direction transverse to said alignment direction by a second distance.

Claim 21

The array antenna according to claim 16 wherein the distance between said phase centers of said active patches is less than approximately λ o 2.

Claim 22

The array antenna according to claim 17 wherein the distance between said phase centers of said active patches is less than approximately λ o 2.

Claim 23

The array antenna according to claim 16 wherein said plurality of active patches are connected in series to a feed circuit.

Claim 24

The array antenna according to claim 17 wherein said plurality of active patches are connected in series to a feed circuit.