Slot antenna
A slot antenna includes: a first electrically conductive member having a first electrically conductive surface; a second electrically conductive member having a second electrically conductive surface opposing the first electrically conductive surface; a waveguide member between the first electrically conductive member and the second electrically conductive member, the waveguide member having an electrically conductive waveguide face of a stripe shape opposing the first electrically conductive surface, the waveguide member extending in a first direction along the first electrically conductive surface; and an artificial magnetic conductor extending on both sides of the waveguide member, between the first electrically conductive member and the second electrically conductive member. The first electrically conductive member has one or more slots. At least one of the slot or slots is a complex slot having a pair of vertical portions and a lateral portion that interconnects the pair of vertical portions. The lateral portion of the complex slot opposes the waveguide face, and intersects the first direction.
1. A slot antenna comprising:
a first electrically conductive member including a first electrically conductive surface;
a second electrically conductive member including a second electrically conductive surface opposing the first electrically conductive surface;
a plurality of waveguide members between the first electrically conductive member and the second electrically conductive member, the plurality of waveguide members including a first waveguide member and a second waveguide member which extend in a first direction along the first electrically conductive surface; and
an artificial magnetic conductor extending on both sides of the plurality of waveguide members, between the first electrically conductive member and the second electrically conductive member, wherein
the first electrically conductive member includes a plurality of slots including a first slot and a second slot;
the first slot and the second slot are arranged in a second direction which intersects the first direction;
each of the first waveguide member and the second waveguide member includes an electrically conductive waveguide face with a stripe shape opposing the first electrically conductive surface;
the waveguide face of the first waveguide member opposes the first slot, and the waveguide face of the second waveguide member opposes the second slot;
at least one of the first slot and the second slot is a complex slot including a pair of vertical portions and a lateral portion that interconnects the pair of vertical portions; and
the lateral portion of the complex slot opposes one of the waveguide faces, and intersects the first direction.
2. The slot antenna of claim 1 , wherein
a total width of a portion of the one of the waveguide faces that opposes the lateral portion of the complex slot is narrower than a total width of the complex slot inclusive of the pair of vertical portions; and
the one of the waveguide faces intersects the lateral portion.
3. The slot antenna of claim 1 , wherein,
the slot antenna is used for at least one of transmission and reception of an electromagnetic wave of a band having a central wavelength λo in free space; and
a sum of a distance between centers of the pair of vertical portions of the complex slot and lengths of both of the pair of vertical portions is greater than λo/2.
4. The slot antenna of claim 1 , wherein,
the first slot and the second slot are complex slots each including a pair of vertical portions and a lateral portion that interconnects the pair of vertical portions; and
the lateral portion of each complex slot opposes the one of the waveguide faces of the one of the plurality of waveguide members, and intersects the first direction.
5. The slot antenna of claim 4 , wherein,
each of the plurality of slots is a complex slot including a pair of vertical portions and a lateral portion that interconnects the pair of vertical portions; and
the lateral portion of each complex slot opposes the one of the waveguide faces of one of the plurality of waveguide members, and intersects the first direction.
6. The slot antenna of claim 4 , wherein,
the slot antenna is used for at least one of transmission and reception of an electromagnetic wave of a band having a central wavelength Ao in free space; and
a sum of a distance between centers of the pair of vertical portions of each complex slot among the plurality of slots and lengths of both of the pair of vertical portions is greater than λo/2.
7. The slot antenna of claim 1 , wherein,
the artificial magnetic conductor includes a plurality of electrically conductive rods, each of the plurality of electrically conductive rods including a leading end opposing the first electrically conductive surface;
the slot antenna is used for at least one of transmission and reception of an electromagnetic wave of a predetermined band; and,
given a wavelength Am in free space of an electromagnetic wave of a highest frequency among electromagnetic waves of the predetermined band,
a width of the plurality of waveguide members, a width of each electrically conductive rod, a width of a space existing between two adjacent electrically conductive rods, a distance between the first electrically conductive surface and the second electrically conductive surface, and a width of a space existing between respective ones of the plurality of the waveguide members and respective ones of the electrically conductive rods that are adjacent to the respective ones of the waveguide members are each less than λm/2.
8. A radar device comprising:
the slot antenna of claim 1 ; and
a microwave integrated circuit that is connected to the slot antenna.
9. A radar system comprising:
the radar device of claim 8 ; and
a signal processing circuit connected to the microwave integrated circuit of the radar device.
10. A wireless communication system comprising:
the slot antenna of claim 1 ; and
a communication circuit connected to the slot antenna.
11. The slot antenna of claim 1 , wherein a total length of the vertical portions in a direction that the vertical portions extend is shorter than a total length of the lateral portion in a direction that the lateral portion extends.
12. The slot antenna of claim 1 , wherein a total length of the vertical portions in a direction that the vertical portions extend is longer than a total length of the lateral portion in a direction that the lateral portion extends.
13. The slot antenna of claim 1 , wherein a total width of a portion of the one of the waveguide faces that opposes the lateral portion of the complex slot is identical to a total length of the lateral portion.
14. The slot antenna of claim 1 , wherein a total width of a portion of the one of the waveguide faces that opposes the lateral portion of the complex slot is smaller than a total length of the lateral portion.
15. The slot antenna of claim 1 , wherein a width of a portion of the one of the waveguide faces that opposes the lateral portion of the complex slot is greater than a total length of the lateral portion.
16. The slot antenna of claim 1 , wherein the plurality of slots further includes a third slot which is adjacent to the first slot in the first direction.
17. The slot antenna of claim 1 , wherein the first electrically conductive member further includes a plurality of horns each including four sidewalls including surfaces that are electrically conductive, the four sidewalls respectively surrounding ones of the plurality of slots.