Vehicle
A vehicle includes laminated glass located between a vehicle interior and an outside, and an on-vehicle radar device fixed to an inner surface of the laminated glass, a rear-view mirror, or a ceiling. The laminated glass includes an innermost glass layer, an outermost glass layer, and an intermediate resin layer. The on-vehicle radar device includes an antenna part that includes a transmitting antenna for transmitting a transmission wave. Reflection of the transmission wave on the laminated glass will be suppressed by selecting optimum values for the incident angle of the transmission wave on the innermost glass layer and the refractive index and thickness of each layer.
1. A vehicle comprising:
a vehicle body;
a drive mechanism that moves the vehicle body;
laminated glass fixed to the vehicle body and located between a vehicle interior and an outside; and
an on-vehicle radar device fixed directly or indirectly to an inner surface of the laminated glass, a rear-view mirror arranged inward of the inner surface, or a ceiling; wherein
the laminated glass includes an innermost glass layer, an outermost glass layer, and an intermediate resin layer sandwiched between the innermost glass layer and the outermost glass layer, a first air layer being positioned inward from the innermost glass layer and a second air layer is provided outward from the outermost air layer;
the on-vehicle radar device includes an antenna part that transmits a transmission wave from inside the innermost glass layer to outside the outermost glass layer, the transmission wave being a radio wave in a millimeter waveband, and receiving a received wave that enters inside the innermost glass layer from outside the outermost glass layer;
the antenna part includes a transmitting antenna that transmits the transmission wave, the transmitting antenna including a main lobe;
the transmission wave has a vertical polarization component greater than a horizontal polarization component thereof with respect to the laminated glass;
If
n
1
<
n
2
<
n
3
or
n
1
>
n
2
>
n
3
and
θ
a
is
smaller
than
or
greater
than
both
of
sin
-
1
(
n
1
sin
(
tan
-
1
n
2
n
1
)
)
and
sin
-
1
(
n
2
sin
(
tan
-
1
n
3
n
2
)
)
,
(
2
N
+
3
4
)
n
2
λcos
(
sin
-
1
(
1
n
2
sin
θ
a
)
)
4
(
n
2
2
-
sin
2
θ
a
)
≤
d
2
≤
(
2
N
+
5
4
)
n
2
λcos
(
sin
-
1
(
1
n
2
sin
θ
a
)
)
4
(
n
2
2
-
sin
2
θ
a
)
,
and
if
n
1
<
n
2
<
n
3
or
n
1
>
n
2
>
n
3
and
θ
a
is
value
between
or
equal
to
one
of
sin
-
1
(
n
1
sin
(
tan
-
1
n
2
n
1
)
)
and
sin
-
1
(
n
2
sin
(
tan
-
1
n
3
n
2
)
)
,
(
2
N
+
7
4
)
n
2
λcos
(
sin
-
1
(
1
n
2
sin
θ
a
)
)
4
(
n
2
2
-
sin
2
θ
a
)
≤
d
2
≤
(
2
N
+
9
4
)
n
2
λcos
(
sin
-
1
(
1
n
2
sin
θ
a
)
)
4
(
n
2
2
-
sin
2
θ
a
)
;
and
If
n
1
>
n
2
<
n
3
or
n
1
<
n
2
>
n
3
and
θ
a
is
smaller
than
or
greater
than
both
of
sin
-
1
(
n
1
sin
(
tan
-
1
n
2
n
1
)
)
and
sin
-
1
(
n
2
sin
(
tan
-
1
n
3
n
2
)
)
,
(
2
N
+
7
4
)
n
2
λcos
(
sin
-
1
(
1
n
2
sin
θ
a
)
)
4
(
n
2
2
-
sin
2
θ
a
)
≤
d
2
≤
(
2
N
+
9
4
)
n
2
λcos
(
sin
-
1
(
1
n
2
sin
θ
a
)
)
4
(
n
2
2
-
sin
2
θ
a
)
,
and
if
n
1
>
n
2
<
n
3
or
n
1
<
n
2
>
n
3
and
θ
a
is
a
value
between
or
equal
to
one
of
sin
-
1
(
n
1
sin
(
tan
-
1
n
2
n
1
)
)
and
sin
-
1
(
n
2
sin
(
tan
-
1
n
3
n
2
)
)
,
(
2
N
+
3
4
)
n
2
λcos
(
sin
-
1
(
1
n
2
sin
θ
a
)
)
4
(
n
2
2
-
sin
2
θ
a
)
≤
d
2
≤
(
2
N
+
5
4
)
n
2
λcos
(
sin
-
1
(
1
n
2
sin
θ
a
)
)
4
(
n
2
2
-
sin
2
θ
a
)
.
,
where (i) θ a is an angle defined by a normal to the laminated glass and a direction of propagation of the transmission wave at a center of the main lobe of the transmitting antenna, (ii) n 1 , and n 2 , and n 3 are refractive indices of an inner layer, a middle layer, and an outer layer that are in contact with one another and selected from the first air layer, the innermost glass layer, the intermediate resin layer, the outermost glass layer, and the second air layer, (iii) d 2 is a thickness of the middle layer, and (iv) N is an integer of 0 or more.
2. The vehicle according to claim 1 , wherein
the innermost glass layer and the outermost glass layer have a same thickness and a same refractive index.
3. The vehicle according to claim 1 , wherein
the middle layer is the outermost glass layer; and
(θ b −10°)≤θ a ≤(θ b +5°)
where θ b is a Brewster angle of the radio wave on an inner surface of the innermost glass layer.
4. The vehicle according to claim 2 , wherein
the middle layer is the outermost glass layer; and
(θ b −10°)≤θ a ≤(θ b +5°)
θ b is a Brewster angle of the radio wave on an inner surface of the innermost glass layer.
5. A vehicle comprising:
a vehicle body;
a drive mechanism that moves the vehicle body;
laminated glass fixed to the vehicle body and located between a vehicle interior and an outside; and
an on-vehicle radar device fixed directly or indirectly to an inner surface of the laminated glass, a rear-view mirror arranged inward of the inner surface, or a ceiling; wherein
the laminated glass includes an innermost glass layer, an outermost glass layer, and an intermediate resin layer sandwiched between the innermost glass layer and the outermost glass layer, a first air layer being positioned inward from the innermost glass layer and a second air layer is provided outward from the outermost air layer;
the on-vehicle radar device includes an antenna part that transmits a transmission wave from inside the innermost glass layer to outside the outermost glass layer, the transmission wave being a radio wave in a millimeter waveband, and receiving a received wave that enters inside the innermost glass layer from outside the outermost glass layer;
the antenna part includes a transmitting antenna that transmits the transmission wave, the transmitting antenna including a main lobe;
the transmission wave has a horizontal polarization component greater than a vertical polarization component thereof with respect to the laminated glass; and
If
n
1
<
n
2
<
n
3
or
n
1
>
n
2
>
n
3
,
(
2
N
+
3
4
)
n
2
λcos
(
sin
-
1
(
1
n
2
sin
θ
a
)
)
4
(
n
2
2
-
sin
2
θ
a
)
≤
d
2
≤
(
2
N
+
5
4
)
n
2
λcos
(
sin
-
1
(
1
n
2
sin
θ
a
)
)
4
(
n
2
2
-
sin
2
θ
a
)
and
If
n
1
>
n
2
<
n
3
or
n
1
<
n
2
>
n
3
,
(
2
N
+
7
4
)
n
2
λcos
(
sin
-
1
(
1
n
2
sin
θ
a
)
)
4
(
n
2
2
-
sin
2
θ
a
)
≤
d
2
≤
(
2
N
+
9
4
)
n
2
λcos
(
sin
-
1
(
1
n
2
sin
θ
a
)
)
4
(
n
2
2
-
sin
2
θ
a
)
.
,
where (i) θ a is an angle formed by a normal to the laminated glass and a direction of propagation of the transmission wave at a center of the main lobe of the transmitting antenna, (ii) n 1 , n 2 , and n 3 are refractive indices of an inner layer, a middle layer, and on outer layer that are in connect with one another and selected from the first, and the second air layer the innermost glass layer, the intermediate resin layer, the outermost glass layer, and the second air layer, (iii) d 2 is a thickness of the middle layer, and (iv) N is an integer of 0 or more.
6. The vehicle according to claim 1 , wherein
the antenna part includes another transmitting antenna that transmits another transmission wave having a radiation pattern different from a radiation pattern of the transmission wave.
7. The vehicle according to claim 5 , wherein
the antenna part includes another transmitting antenna that transmits another transmission wave having a radiation pattern different from a radiation pattern of the transmission wave.
8. The vehicle according to claim 1 , wherein
the intermediate resin layer is made of polyvinyl butyrate.
9. The vehicle according to claim 5 , wherein
the intermediate resin layer is made of polyvinyl butyrate.
10. The vehicle according to claim 1 , wherein
each of at least one antenna included in the antenna part is a horn antenna, a lens antenna, a printed antenna, a microstrip antenna, or a slit antenna.
11. The vehicle according to claim 5 , wherein
each of at least one antenna included in the antenna part is a horn antenna, a lens antenna, a printed antenna, a microstrip antenna, or a slit antenna.
12. The vehicle according to claim 1 , wherein
every antenna included in the antenna part is a horn antenna.
13. The vehicle according to claim 5 , wherein
every antenna included in the antenna part is a horn antenna.
14. The vehicle according to claim 1 , further comprising:
a reflection suppression layer including a dielectric layer that closely adheres to a surface on the antenna part side of the laminated glass;
wherein the dielectric layer has a refractive index that is lower than a refractive index of the innermost glass layer and higher than a refractive index of air; and
the dielectric layer has a thickness that allows reflection of the transmission wave to be suppressed by interference between a reflected wave generated by reflection of the transmission wave on an interface at which the dielectric layer closely adheres to the surface of the laminated glass, and a reflected wave generated by reflection of the transmission wave on a surface on the antenna part side of the dielectric layer.
15. The vehicle according to claim 5 , further comprising:
a reflection suppression layer including a dielectric layer that closely adheres to a surface on the antenna part side of the laminated glass;
wherein the dielectric layer has a refractive index that is lower than a refractive index of the innermost glass layer and higher than a refractive index of air; and
the dielectric layer has a thickness that allows reflection of the transmission wave to be suppressed by interference between a reflected wave generated by reflection of the transmission wave on an interface at which the dielectric layer closely adheres to the surface of the laminated glass, and a reflected wave generated by reflection of the transmission wave on a surface on the antenna part side of the dielectric layer.
16. The vehicle according to claim 14 , wherein
the reflection suppression layer includes another dielectric layer that closely adheres to the surface on the antenna part side of the dielectric layer; and
the another dielectric layer has a thickness that allows reflection of the transmission wave to be suppressed by interference between a reflected wave generated by reflection of the transmission wave on an interface at which the another dielectric layer closely adheres to the dielectric layer, and a reflected wave generated by reflection of the transmission wave on a surface on the antenna part side of the another dielectric layer.
17. The vehicle according to claim 15 , wherein
the reflection suppression layer includes another dielectric layer that closely adheres to the surface on the antenna part side of the dielectric layer; and
the another dielectric layer has a thickness that allows reflection of the transmission wave to be suppressed by interference between a reflected wave generated by reflection of the transmission wave on an interface at which the another dielectric layer closely adheres to the dielectric layer, and a reflected wave generated by reflection of the transmission wave on a surface on the antenna part side of the another dielectric layer.
18. The vehicle according to claim 16 , wherein
the another dielectric layer has a refractive index that is lower than the refractive index of the dielectric layer and higher than the refractive index of air.
19. The vehicle according to claim 17 , wherein
the another dielectric layer has a refractive index that is lower than the refractive index of the dielectric layer and higher than the refractive index of air.
20. The vehicle according to claim 14 , wherein
an incident angle of the transmission wave on the reflection suppression layer at a center of a main lobe of the transmitting antenna is greater than 10 degrees.
21. The vehicle according to claim 15 , wherein
an incident angle of the transmission wave on the reflection suppression layer at a center of a main lobe of the transmitting antenna is greater than 10 degrees.
22. The vehicle according to claim 14 , further comprising:
an antenna cover located between the antenna part and the laminated glass and covering a front of the antenna part;
wherein the antenna cover also serves as the reflection suppression layer.
23. The vehicle according to claim 15 , further comprising:
an antenna cover located between the antenna part and the laminated glass and covering a front of the antenna part;
wherein the antenna cover also serves as the reflection suppression layer.