Man-made composite material and man-made composite material antenna
View Patent ↗The present invention relates to a man-made composite material and a man-made composite material antenna. The man-made composite material is divided into a plurality of regions. An electromagnetic wave is incident on a first surface exits from a second surface of the man-made composite material opposite to the first surface. A line connecting a radiation source to a point on the bottom surface of the i th region and a line perpendicular to the man-made composite material form an angle θ therebetween, which uniquely corresponds to a curved surface in the i th region. A set formed by points on the bottom surface of the i th region that have the same angle θ forms a boundary of the curved surface to which the angle θ uniquely corresponds. The refraction, diffraction and reflection of the present invention at the abrupt transition points can be reduced.
1. A man-made composite material, wherein the man-made composite material has a thickness and is divided into a plurality of regions; an electromagnetic wave is incident on a first surface of the man-made composite material and exits from a second surface of the man-made composite material opposite to the first surface; an i th region is one of the plurality of regions, and i is a positive integer and selected from a group consisted of 1, 2, 3, . . . , etc.;
an intersection between the i th region and the first surface is a bottom surface of the i th region, an intersection between the i th region and the second surface is a top surface of the i th region; a line connecting a radiation source to a point on the bottom surface of the i th region and a line perpendicular to the man-made composite material form an angle θ therebetween, which uniquely corresponds to a curved surface in the i th region, the curved surface to which the angle θ uniquely corresponds is sandwiched between the bottom surface and the top surface of the i th region, a set of points on the bottom surface of the i th region that have the same angle θ forms a boundary of the curved surface to which the angle θ uniquely corresponds;
each point on the curved surface to which the angle θ uniquely corresponds has a same refractive index; the curved surface to which the angle θ uniquely corresponds has a generatrix which extends along a direction of the thickness of the man-made composite material and between the bottom surface and the top surface of the i th region, the curved surface to which the angle θ uniquely corresponds is formed by rotating the generatrix about the line perpendicular to the man-made composite material; and refractive indices of each of the regions decrease gradually as the angle θ increases.
2. The man-made composite material of claim 1 , wherein a line connecting the radiation source to a point on an outer circumference of the bottom surface of the i th region and the line perpendicular to the man-made composite material form an angle θi therebetween, and the closer the region is to a center of the man-made composite material, the smaller the value of i will be; wherein a generatrix of a curved surface to which the angle θi corresponds has an arc length c(θ i ), and the arc length c(θ i )and the angle θi satisfy the following equations:
c
(
θ
i
)
=
λ
n
max
(
i
+
1
)
-
n
min
(
i
)
;
s
×
(
1
cos
θ
i
-
1
cos
θ
i
-
1
)
=
c
(
θ
i
-
1
)
n
max
(
i
)
-
c
(
θ
i
)
n
min
(
i
)
)
,
where, θ 0 =0, c(θ 0 )=d ; s is a distance from the radiation source to the man-made composite material; d is the thickness of the man-made composite material; λ is a wavelength of the electromagnetic waves, n max(i) and n min(i) are the maximum refractive index and the minimum refractive index of the i th region respectively, and n max(i+1) is the maximum refractive index of the (i+1)th region.
3. The man-made composite material of claim 2 , wherein the maximum refractive indices and the minimum refractive indices of any two adjacent ones of the regions satisfy: n max(i) −n min(i) =n max(i+1) −n max(i+1) −n min(i+1) .
4. The man-made composite material of claim 3 , wherein the maximum refractive indices and the minimum refractive indices of any three adjacent ones of the regions satisfy: n max(i+1) −n min(i) =n max(i+2) −n min(i+1) .
5. The man-made composite material of claim 2 , wherein a refractive index of the i th region satisfies:
n
i
(
θ
)
=
1
c
(
θ
)
(
n
max
(
i
)
×
d
+
s
-
s
cos
θ
)
,
where d is the thickness of the man-made composite material, θ is an angle formed between a line connecting the radiation source to a point on the bottom surface of the i th region and a line perpendicular to the man-made composite material, and c(θ) is an arc length of a generatrix of the curved surface to which the angle θ corresponds.
6. The man-made composite material of claim 5 , wherein when the generatrix of the curved surface is a parabolic arc, the arc length c(θ) satisfies the following equation:
c
(
θ
)
=
d
2
[
log
(
tan
θ
+
1
+
tan
2
θ
)
+
δ
tan
θ
+
δ
+
1
+
tan
2
θ
]
,
where δ is a preset decimal.
7. The man-made composite material of claim 6 , wherein when a line passing through a center of the first surface of the man-made composite material and perpendicular to the man-made composite material is taken as an abscissa axis and a line passing through the center of the first surface of the man-made composite material and parallel to the first surface is taken as an ordinate axis, an equation of a parabola where the parabolic arc is located is represented as:
y
(
x
)
=
tan
θ
(
-
1
2
d
x
2
+
x
+
s
)
.
8. The man-made composite material of claim 5 , wherein when the generatrix of the curved surface is an elliptical arc,
if the line passing through the center of the first surface of the man-made composite material and perpendicular to the man-made composite material is taken as an abscissa axis and the line passing through the center of the first surface of the man-made composite material and parallel to the first surface is taken as an ordinate axis, then an equation of an ellipse where the elliptical arc is located is represented as:
(
x
-
d
)
2
a
2
+
(
y
-
c
)
2
b
2
=
1
,
where a, b and c satisfy the following relationships:
d
2
a
2
+
(
s
tan
θ
-
c
)
2
b
2
=
1
;
and
sin
θ
n
2
(
θ
)
-
sin
2
(
θ
)
=
b
2
a
2
d
s
tan
θ
-
c
.
9. The man-made composite material of claim 8 , wherein a refraction angle at a point on the first surface that corresponds to the angle θ is represented by θ′, and the refractive index n(θ) at the point satisfies:
n
(
θ
)
=
sin
θ
sin
θ
′
.
10. The man-made composite material of claim 1 , wherein a line connecting the radiation source to a point on the outer circumference of the bottom surface of the i th region and the line perpendicular to the man-made composite material form an angle θi therebetween, i is a positive integer, and the closer the region is to a center of the man-made composite material, the smaller the value of i will be; wherein the angle θi satisfies the following equations:
sin
c
(
θ
i
)
=
d
λ
(
n
max
(
i
+
1
)
-
n
min
(
i
)
)
;
s
×
(
1
cos
θ
i
-
1
cos
θ
i
-
1
)
=
d
sin
c
(
θ
i
-
1
)
n
max
(
i
)
-
d
sin
c
(
θ
i
)
n
min
(
i
)
)
,
where
,
sin
c
(
θ
i
)
=
sin
(
θ
i
)
θ
i
,
sin
c
(
θ
i
-
1
)
=
sin
(
θ
i
-
1
)
θ
i
-
1
,
θ
0
=
0
;
S is a distance from the radiation source to the man-made composite material; d is the thickness of the man-made composite material; λ is the wavelength of the electromagnetic waves, n max(i) and n min(i) are the maximum refractive index and the minimum refractive index of the i th region respectively, and n max(i+1) and n min(i+1) are the maximum refractive index and the minimum refractive index of the (i+1)th region respectively.
11. The man-made composite material of claim 10 , wherein the maximum refractive indices and the minimum refractive indices of any two adjacent ones of the regions satisfy: n max(i) −n min(i) =n max(i+1) −n min(i+1) .
12. The man-made composite material of claim 11 , wherein the maximum refractive indices and the minimum refractive indices of any three adjacent ones of the regions satisfy: n max(i+1) −n min(i) >n max(i+2) −n min(i+1) .
13. The man-made composite material of claim 10 , wherein a refractive index of the i th region satisfies:
n
i
(
θ
)
=
sin
θ
d
×
θ
(
n
max
(
i
)
×
d
+
s
-
s
cos
θ
)
,
where θ is an angle formed between a line connecting the radiation source to a point on the bottom surface of the i th region and a line perpendicular to the man-made composite material.
14. The man-made composite material of any of claim 1 , wherein the man-made composite material is provided with an impedance matching layer at two sides thereof respectively.
15. A man-made composite material antenna, comprising a man-made composite material and a radiation source disposed at a focus of the man-made composite material, wherein the man-made composite material has a thickness and is divided into a plurality of regions; an electromagnetic wave is incident on a first surface of the man-made composite material and exits from a second surface of the man-made composite material opposite to the first surface; an i th region is one of the plurality of regions, and i is a positive integer and selected from a group consisted of 1, 2, 3, . . . , etc.;
an intersection between the i th region and the first surface is a bottom surface of the i th region, an intersection between the i th region and the second surface is a top surface of the i th region; a line connecting the radiation source to a point on the bottom surface of the i th region and a line perpendicular to the man-made composite material form an angle θ therebetween, which uniquely corresponds to a curved surface in the i th region, the curved surface to which the angle θ uniquely corresponds is sandwiched between the bottom surface and the top surface of the i th region, a set of points on the bottom surface of the i th region that have the same angle θ forms a boundary of the curved surface to which the angle θ uniquely corresponds; each point on the curved surface to which the angle θ uniquely corresponds has a same refractive index; the curved surface to which the angle θ uniquely corresponds has a generatrix which extends along a direction of the thickness of the man-made composite material and between the bottom surface and the top surface of the i th region, the curved surface to which the angle θ uniquely corresponds is formed by rotating the generatrix about the line perpendicular to the man-made composite material; and refractive indices of each of the regions decrease gradually as the angle θ increases.
16. The man-made composite material antenna of claim 15 , wherein a line connecting the radiation source to a point on an outer circumference of the bottom surface of the i th region and the line perpendicular to the man-made composite material form an angle θi therebetween, and the closer the region is to a center of the man-made composite material, the smaller the value of i will be; wherein a generatrix of a curved surface to which the angle θi corresponds has an arc length c(θ i ), and the arc length c(θ i ) and the angle θi satisfy the following equations:
c
(
θ
i
)
=
λ
n
max
(
i
+
1
)
-
n
min
(
i
)
;
s
×
(
1
cos
θ
i
-
1
cos
θ
i
-
1
)
=
c
(
θ
i
-
1
)
n
max
(
i
)
-
c
(
θ
i
)
n
min
(
i
)
)
,
where, θ 0 =0, c(θ 0 )=d; s is a distance from the radiation source to the man-made composite material; d is the thickness of the man-made composite material; λ is a wavelength of the electromagnetic wave, n max(i) and n min(i) are the maximum refractive index and the minimum refractive index of the i th region respectively, and n max(i+1) is the maximum refractive index of the (i+1)th region.
17. The man-made composite material antenna of claim 16 , wherein the maximum refractive indices and the minimum refractive indices of any two adjacent ones of the regions satisfy: n max(i)−n min(i) =n max(i+1) −n min(i+1) .
18. The man-made composite material antenna of claim 17 , wherein the maximum refractive indices and the minimum refractive indices of any three adjacent ones of the regions satisfy: n max(i+1) −n min(i) >n max(i+2) −n min(i+1) .
19. The man-made composite material antenna of claim 17 , wherein a refractive index of the i th region satisfies:
n
i
(
θ
)
=
1
c
(
θ
)
(
n
max
(
i
)
×
d
+
s
-
s
cos
θ
)
,
where d is the thickness of the man-made composite material, θ is an angle formed between a line connecting the radiation source to a point on the bottom surface of the i th region and a line perpendicular to the man-made composite material, and c(θ) is an arc length of a generatrix of the curved surface to which the angle θ corresponds.
20. The man-made composite material antenna of claim 15 , wherein the generatrix of the curved surface is a parabolic arc, an elliptical arc or a circular arc.