Antenna, array antenna, and radio communication apparatus
An antenna according to one exemplary aspect of the present invention includes an antenna element and a reflector conductor that is arranged to be spaced apart from the antenna element. The antenna element includes a first split-ring conductor having such a shape that a part of a ring is cut by a split part, a first connection conductor having one end that is electrically connected to the first split-ring conductor and another end that is electrically connected to the reflector conductor, and a feed line conductor having one end that is electrically connected to the first split-ring conductor. The feed line conductor spans an opening that is formed inside the first split-ring conductor and overlaps an area surrounded by an outer edge of the first connection conductor.
1. An antenna comprising:
at least one antenna element; and
a reflecting conductive plane, wherein:
the antenna element comprises:
a first Split Ring Resonator;
a first conductor; and
a feed line, wherein
the first Split Ring Resonator is practically perpendicular to the reflecting conductive plane,
the first conductor is:
elongated-plate-shaped or tube-shaped, and
practically perpendicular to the reflecting conductive plane,
a first end of the first conductor is:
electrically connected to the first Split Ring Resonator,
a second end of the first conductor is:
electrically connected to the reflecting conductive plane, or
disposed on a side opposite to the first end of the first conductor with the reflecting conductive plane in between as the first conductor passes through the reflecting conductive plane,
a first end of the feed line is:
electrically connected to the first Split Ring Resonator, and
the feed line is:
across an opening of the first Split Ring Resonator.
2. The antenna according to claim 1 , wherein
the first Split Ring Resonator comprises:
a long side in a direction practically parallel to the reflecting conductive plane, and
a connection part between the first Split Ring Resonator and the first end of the first conductor is:
disposed within a range of ¼ length of the long side from a center of the long side to both end of the long side.
3. The antenna according to claim 1 , wherein
the feed line passes through the reflecting conductive plane.
4. The antenna according to claim 1 , wherein
the first Split Ring Resonator, the first conductor, and the feed line are:
disposed in the same layer,
the feed line is:
disposed inside a clearance of the first Split Ring Resonator and the first conductor, and
portions of the first Split Ring Resonator on either side of a split of the first Split Ring Resonator are:
electrically connected via a conductive bridge.
5. The antenna according to claim 1 , wherein
the first Split Ring Resonator and the first conductor are:
disposed in a first layer,
the feed line and a supplementary conductor are:
electrically connected, and
disposed in a second layer.
6. The antenna according to claim 1 , wherein
the first Split Ring Resonator and the first conductor are:
disposed in a first layer,
a second Split Ring Resonator electrically connected to the first Split Ring Resonator is:
disposed in a third layer, and
the feed line and a supplementary conductor are:
disposed between the first layer and the third layer.
7. The antenna according to claim 1 , wherein
the first Split Ring Resonator and the first conductor are:
disposed in a first layer,
at least one of a second Split Ring Resonator electrically connected to the first Split Ring Resonator or a second conductor electrically connected to the first conductor is:
disposed in a third layer, and
the feed line is:
disposed between the first layer and the third layer.
8. The antenna according to claim 1 , wherein
the first conductor is a tube-shaped part of a coaxial cable, and
the feed line is a core part of the coaxial cable.
9. The antenna according to claim 1 , comprising:
a plurality of the antenna elements arranged in array.
10. A communication device comprising:
the antenna according to claim 1 .