Antenna device
View Patent ↗An antenna device according to an aspect of the present invention includes a plurality of radiation elements, an array antenna, a skin material, a core material and an antenna casing. The plurality of radiation elements transmit radio waves of a predetermined frequency. The array antenna has a radiation surface and a back surface opposite to the radiation surface. The plurality of radiation elements are disposed on the radiation surface. The skin material is disposed in a direction in which the skin material faces the radiation surface. The core material is disposed between the array antenna and the skin material, and has a plurality of through-holes. The antenna casing is disposed in a direction in which the antenna casing faces the back surface. A distance between centers of adjacent through-holes of the through-hole is equal to or less than one-half of a wavelength corresponding to the predetermined frequency.
1. An antenna device, comprising:
a plurality of radiation elements configured to transmit radio waves of a predetermined frequency;
an array antenna having a radiation surface on which the plurality of radiation elements are disposed and a back surface opposite to the radiation surface;
a skin material disposed in a direction in which the skin material faces the radiation surface;
a core material disposed between the array antenna and the skin material, the core material having a plurality of through-holes; and
an antenna casing disposed in a direction in which the antenna casing faces the back surface,
wherein a distance between centers of adjacent through-holes of the plurality of through-holes is equal to or less than one-half of a wavelength corresponding to the predetermined frequency; and
a distance between adjacent radiation elements of the plurality of radiation elements is longer than the distance between the centers of the adjacent through-holes of the plurality of through-holes.
2. The antenna device according to claim 1 , wherein the distance between the centers of the adjacent through-holes is equal to or less than one-half of the wavelength to suppress amplitude variation occurring in antenna aperture distribution in a surface of the skin material.
3. The antenna device according to claim 1 , wherein:
the core material has a honeycomb structure; and
cells of the honeycomb structure correspond to the through-holes.
4. The antenna device according to claim 1 , wherein a thickness of a part or an entirety of the skin material is equal to or less than one-twentieth of the wavelength.
5. The antenna device according to claim 1 , further comprising a bonding layer configured to bond the skin material and the core material to each other.
6. The antenna device according to claim 1 , further comprising a heat source disposed in a space surrounded by the antenna casing and the skin material.
7. The antenna device according to claim 6 , wherein:
the heat source is a film heater; and
the heat source is in contact with the back surface.
8. The antenna device according to claim 1 , wherein the distance between the adjacent radiation elements is longer than one-half of the wavelength corresponding to the predetermined frequency.
9. The antenna device according to claim 1 , wherein the core material has an insulating property.