Intelligent reflecting surface
According to one embodiment, an intelligent reflecting surface includes a first substrate, a second substrate, a sealing material, a liquid crystal layer, and a radar absorbent material. The first substrate includes a first basement located in a first area and a second area, and a plurality of patch electrodes. The second substrate includes a second basement and a common electrode. The radar absorbent material is located in the second area.
1 . An intelligent reflecting surface comprising:
a first substrate having a first surface and a second surface opposite to the first surface;
a second substrate having a third surface and a fourth surface opposite to the third surface;
a sealing material bonding the first substrate with the second substrate;
a liquid crystal layer held between the first substrate and the second substrate and surrounded by the sealing material;
a plurality of patch electrodes on the first surface, the plurality of patch electrodes arrayed in a matrix;
a common electrode on the third surface, the common electrode overlapping with the plurality of patch electrodes, and
a radio wave absorber,
wherein
the sealing material is located so as to surround the plurality of patch electrodes in a plan view, and
the radio wave absorber overlaps with the sealing material, and does not overlap with the plurality of patch electrodes.
2 . The intelligent reflecting surface according to claim 1 , wherein
an intensity of a reflected wave for a radio wave made incident on a surface of the radio wave absorber serving as a reflected surface is smaller than an intensity of a reflected wave for a radio wave made incident on the plurality of patch electrodes serving as a reflected surface.
3 . The intelligent reflecting surface according to claim 1 , wherein
the radio wave absorber includes:
a first conductive layer;
a second conductive layer; and
a dielectric layer between the first conductive layer and the second conductive layer.
4 . The intelligent reflecting surface according to claim 3 , wherein
the first conductive layer is located on the first surface,
the second conductive layer is located on the second surface, and
the dielectric layer comprises a part of the first substrate.
5 . The intelligent reflecting surface according to claim 3 , wherein
the first conductive layer is located on the first surface,
the second conductive layer is located on the third surface, and
the dielectric layer comprises a part of the sealing material.
6 . The intelligent reflecting surface according to claim 3 , further comprising:
a third substrate having a fifth surface and a sixth surface opposite to the fifth surface,
wherein
the third substrate is located so that the fifth surface and the second surface are faced each other at the second surface side of the first substrate,
the first conductive layer is located on the second surface,
the second conductive layer is located on the sixth surface, and
the dielectric layer comprises a part of the third substrate.
7 . The intelligent reflecting surface according to claim 3 , wherein
the first conductive layer is electrically connected to the ground or is in an electrically floating state, and
the second conductive layer is in an electrically floating state.
8 . The intelligent reflecting surface according to claim 3 , wherein
at least one of the first conductive layer and the second conductive layer comprises a plurality of frequency selective surfaces,
each of the plurality of patch electrodes has a same shape and a same size each other, and
each of the plurality of frequency selective surfaces has a different shape or a different size from the one of the plurality of patch electrodes.
9 . The intelligent reflecting surface according to claim 1 , wherein
the radio wave absorber includes:
a first dielectric layer; and
a second dielectric layer,
the second dielectric layer is located on the second surface,
the first dielectric layer comprises a part of the first substrate, and
the second dielectric layer overlaps with the seal material, and does not overlap with the plurality of patch electrodes.
10 . The intelligent reflecting surface according to claim 9 , wherein
a total thickness of the first dielectric layer and the second dielectric layer is greater than a thickness of the first substrate.