RADAR APPARATUS
A radar apparatus of the present invention includes an antenna member capable of emitting or receiving microwaves; a feed unit including a plurality of waveguides each having one end connected to a base portion of the antenna member; a radio frequency circuit in contact with the feed unit; an information-processing circuit; a signal line connecting the radio frequency circuit and the information-processing circuit; and a common board equipped with the radio frequency circuit and the information-processing circuit. Since planar positions of the information-processing circuit and the radio frequency circuit on the common board do not overlap with each other, it is possible to downsize the radar apparatus. The common board includes a closed foil made of conductive material and surrounding the radio frequency circuit, and the closed foil made of conductive material is grounded.
1 . A radar apparatus comprising:
an antenna member capable of emitting or receiving microwaves;
a feed unit including a plurality of waveguides each having one end connected to a base portion of the antenna member;
a radio frequency circuit in contact with the feed unit;
an information-processing circuit;
a signal line connecting the radio frequency circuit and the information-processing circuit; and
a common board equipped with the radio frequency circuit and the information-processing circuit; wherein
planar positions of the information-processing circuit and the radio frequency circuit on the common board do not overlap with each other;
the common board includes a closed foil made of conductive material and surrounding the radio frequency circuit; and
the closed foil made of conductive material is grounded.
2 . The radar apparatus of claim 1 , wherein
the radar apparatus includes a feed member that is a block-shaped or plate-like member including holes or grooves;
the feed member is in contact with the antenna member on a feed member-side contact surface thereof;
the antenna member is in contact with the feed member on an antenna member-side contact surface thereof;
the feed member includes holes or grooves provided in the feed member-side contact surface;
the antenna member includes holes or grooves provided in the antenna member-side contact surface;
the feed unit includes the feed member and the antenna member including the antenna member-side contact surface; and
the holes and grooves provided in the feed member-side contact surface and the holes and grooves provided in the antenna member-side contact surface constitute the waveguides of the feed unit.
3 . The radar apparatus of claim 1 , wherein
the common board is a glass epoxy board.
4 . The radar apparatus of claim 2 , wherein
the common board is a glass epoxy board.
5 . The radar apparatus of claim 1 , wherein
the antenna member includes a first-type horn and at least one second-type horn that are pyramidal horns each having an aperture and a base portion, the apertures of the first-type horns having a height greater than a width thereof, a length from a base portion to an aperture of the first-type horn being a first-type length, a length from a base portion to an aperture of the at least one second-type horn being a second length and greater than the first-type length;
at least three first-type horns are present in the antenna member;
the waveguides connected to the respective base portions of the first-type horns are open on different receiving ends on the radio frequency circuit at another end of each waveguide;
the first-type horns and the at least one second-type horn are directed generally a same direction which is defined to be a forward direction;
the at least three first-type horns line up side by side in a width direction thereof to form a row in the width direction;
at least one of the at least one second-type horn is positioned at a leftmost or rightmost end of the row of the first-type horns;
the waveguide connected to the base portion of the at least one second-type horn is open on a transmitting end on the radio frequency circuit at another end of the waveguide;
a positional difference between the apertures of the first-type horns and the at least one second-type horn in an longitudinal direction of the antenna member is smaller than a free space wavelength of a radio frequency electromagnetic wave output by the radio frequency circuit;
the base portion of the at least one second-type horn is positioned more backward than the base portions of the first-type horns by as much as a distance greater than the free space wavelength of the radio frequency wave output by the radio frequency circuit; and
at least part of the feed unit is positioned more forward than the base portion of the at least one second-type horn.
6 . The radar apparatus of claim 2 , wherein
the antenna member includes a first-type horn and at least one second-type horn that are pyramidal horns each having an aperture and a base portion, the apertures of the first-type horns having a height greater than a width thereof, a length from a base portion to an aperture of the first-type horn being a first-type length, a length from a base portion to an aperture of the at least one second-type horn being a second length and greater than the first-type length;
at least three first-type horns are present in the antenna member;
the waveguides connected to the respective base portions of the first-type horns are open on different receiving ends on the radio frequency circuit at another end of each waveguide;
the first-type horns and the at least one second-type horn are directed generally a same direction which is defined to be a forward direction;
the at least three first-type horns line up side by side in a width direction thereof to form a row in the width direction;
at least one of the at least one second-type horn is positioned at a leftmost or rightmost end of the row of the first-type horns;
the waveguide connected to the base portion of the at least one second-type horn is open on a transmitting end on the radio frequency circuit at another end of the waveguide;
a positional difference between the apertures of the first-type horns and the at least one second-type horn in an longitudinal direction of the antenna member is smaller than a free space wavelength of a radio frequency electromagnetic wave output by the radio frequency circuit;
the base portion of the at least one second-type horn is positioned more backward than the base portions of the first-type horns by as much as a distance greater than the free space wavelength of the radio frequency wave output by the radio frequency circuit; and
at least part of the feed unit is positioned more forward than the base portion of the at least one second-type horn.
7 . The radar apparatus of claim 4 , wherein
the antenna member includes a first-type horn and at least one second-type horn that are pyramidal horns each having an aperture and a base portion, the apertures of the first-type horns having a height greater than a width thereof, a length from a base portion to an aperture of the first-type horn being a first-type length, a length from a base portion to an aperture of the at least one second-type horn being a second length and greater than the first-type length;
at least three first-type horns are present in the antenna member;
the waveguides connected to the respective base portions of the first-type horns are open on different receiving ends on the radio frequency circuit at another end of each waveguide;
the first-type horns and the at least one second-type horn are directed generally a same direction which is defined to be a forward direction;
the at least three first-type horns line up side by side in a width direction thereof to form a row in the width direction;
at least one of the at least one second-type horn is positioned at a leftmost or rightmost end of the row of the first-type horns;
the waveguide connected to the base portion of the at least one second-type horn is open on a transmitting end on the radio frequency circuit at another end of the waveguide;
a positional difference between the apertures of the first-type horns and the at least one second-type horn in an longitudinal direction of the antenna member is smaller than a free space wavelength of a radio frequency electromagnetic wave output by the radio frequency circuit;
the base portion of the at least one second-type horn is positioned more backward than the base portions of the first-type horns by as much as a distance greater than the free space wavelength of the radio frequency wave output by the radio frequency circuit; and
at least part of the feed unit is positioned more forward than the base portion of the at least one second-type horn.
8 . The radar apparatus of claim 7 , wherein
the common board is positioned on an upper or lower side of the antenna member.
9 . The radar apparatus of claim 5 , wherein
a number of the first-type horns is five; and
the five first-type horns line up side by side in a width direction thereof to form a row in the width direction.
10 . The radar apparatus of claim 6 , wherein
a number of the first-type horns is five; and
the five first-type horns line up side by side in a width direction thereof to form a row in the width direction.
11 . The radar apparatus of claim 7 , wherein
a number of the first-type horns is five; and
the five first-type horns line up side by side in a width direction thereof to form a row in the width direction.
12 . The radar apparatus of claim 8 , wherein
a number of the first-type horns is five; and
the five first-type horns line up side by side in a width direction thereof to form a row in the width direction.
13 . The radar apparatus of claim 5 , wherein
a number of the at least one second-type horn is two;
all of the apertures of the first-type horns have an identical first height, and
all of the apertures of the second-type horns have a height greater than the first height.
14 . The radar apparatus of claim 6 , wherein
a number of the at least one second-type horn is two;
all of the apertures of the first-type horns have an identical first height, and
all of the apertures of the second-type horns have a height greater than the first height.
15 . The radar apparatus of claim 7 , wherein
a number of the at least one second-type horn is two;
all of the apertures of the first-type horns have an identical first height, and
all of the apertures of the second-type horns have a height greater than the first height.
16 . The radar apparatus of claim 8 , wherein
a number of the at least one second-type horn is two;
all of the apertures of the first-type horns have an identical first height, and
all of the apertures of the second-type horns have a height greater than the first height.
17 . The radar apparatus of claim 9 , wherein
a number of the at least one second-type horn is two;
all of the apertures of the first-type horns have an identical first height, and
all of the apertures of the second-type horns have a height greater than the first height.
18 . The radar apparatus of claim 10 , wherein
a number of the at least one second-type horn is two;
all of the apertures of the first-type horns have an identical first height, and
all of the apertures of the second-type horns have a height greater than the first height.
19 . The radar apparatus of claim 11 , wherein
a number of the at least one second-type horn is two;
all of the apertures of the first-type horns have an identical first height, and
all of the apertures of the second-type horns have a height greater than the first height.
20 . The radar apparatus of claim 12 , wherein
a number of the at least one second-type horn is two;
all of the apertures of the first-type horns have an identical first height, and
all of the apertures of the second-type horns have a height greater than the first height.