Antenna installed on radar
Disclosed is an antenna for a radar device which is available for angle measuring in a wide angle for both of the right and the left directions from a travelling direction of a vehicle. SOLUTION: An antenna for radar device 100 comprises an antenna unit 110 as a combination of one of antenna elements 102 and one of second bottom boards 103 , wherein a plurality thereof are arrayed on a first bottom board 101 . The antenna element 102 is bent as L-shaped, one end thereof is opened, another end thereof penetrates the first bottom board 101 as noncontact therewith, and is connected to a transmission line 104 with further penetrating a line substrate 105.
1. An antenna for radar device comprising:
a first bottom board having a planar shape;
a second bottom board to be electrically conducted on a surface of one side of the first bottom board and to be provided with standing in a direction approximately vertical thereto; and
an antenna element having a linear shape arranged in a direction parallel to the first bottom board with spacing a predetermined distance of d 1 therefrom, and arranged at a predetermined position to be approximately vertical to the second bottom board,
wherein it is formed with a length between the second bottom board and a tip of the antenna element to be approximately a λ/4 in a case where a wavelength of a transmitting and receiving electric wave is assumed as λ.
2. The antenna for radar device according to claim 1 ,
wherein the antenna element and the second bottom board form one unit, two of the antennas individually comprised of the one unite are arrayed on a similar plane or a similar curved surface of the first bottom board, and a D/λ<0.5 in a case where a distance between the two antennas is assumed as D.
3. The antenna for radar device according to claim 2 ,
wherein a plurality of the one units are arranged to be an array form.
4. The antenna for radar device according to claim 2 ,
wherein a transmission line is provided at another surface of the first bottom board, and the antenna element is connected to the transmission line with being bent toward the first bottom board side to be in a direction parallel thereto in a vicinity of the second bottom board.
5. The antenna for radar device according to claim 2 ,
wherein a transmission line is provided at the second bottom board side, and the antenna element is connected to the transmission line.
6. The antenna for radar device according to claim 2 ,
wherein the distance d 1 is approximately equal to the λ/4.
7. The antenna for radar device according to claim 2 ,
wherein the second bottom board has a planar shape or a curved surface to be provided with standing in a direction approximately vertical onto the first bottom board.
8. The antenna for radar device according to claim 1 ,
wherein a transmission line is provided at another surface of the first bottom board, and the antenna element is connected to the transmission line with being bent toward the first bottom board side to be in a direction parallel thereto in a vicinity of the second bottom board.
9. The antenna for radar device according to claim 1 ,
wherein a transmission line is provided at the second bottom board side, and the antenna element is connected to the transmission line.
10. The antenna for radar device according to claim 1 ,
wherein the distance d 1 is approximately equal to the λ/4.
11. The antenna for radar device according to claim 10 ,
wherein the antenna element is formed by being printed on a top surface of a dielectric substance mounted and set on the first bottom board.
12. The antenna for radar device according to claim 1 ,
wherein the second bottom board has a planar shape or a curved surface to be provided with standing in a direction approximately vertical onto the first bottom board.
13. The antenna for radar device according to claim 1 ,
wherein a height of the second bottom board in the direction approximately vertical to the first bottom board is determined to be available to measure an elevation angle till a predetermined degree for the first bottom board as a horizontal plane on a plane vertical to the first bottom board and including the antenna element.
14. The antenna for radar device according to claim 13 ,
wherein the antenna element is formed by being printed on a top surface of a dielectric substance mounted and set on the first bottom board.
15. The antenna for radar device according to claim 1 ,
wherein the antenna element is formed by being printed on a top surface of a dielectric substance mounted and set on the first bottom board.
16. The antenna for radar device according to claim 15 ,
wherein the antenna element is formed by being printed on the top surface of the dielectric substance mounted and set on the first bottom board, and connected to the transmission line via a through hole formed at the dielectric substance.
17. The antenna for radar device according to claim 16 ,
wherein the second bottom board is formed by arraying a plurality of the through holes in an annular manner with a predetermined space respectively, that penetrate the dielectric substance individually, and are provided with standing in a direction approximately vertical to the first bottom board.
18. The antenna for radar device according to claim 16 ,
wherein the second bottom board is formed by metal plating an inner surface of a hole having an open part at a face side contacting with the first bottom board of the dielectric substance and formed for a side surface thereof to be approximately vertical to the first bottom board.
19. The antenna for radar device according to claim 15 ,
wherein the second bottom board is formed by arraying a plurality of the through holes in an annular manner with a predetermined space respectively, that penetrate the dielectric substance individually, and are provided with standing in a direction approximately vertical to the first bottom board.
20. The antenna for radar device according to claim 15 ,
wherein the second bottom board is formed by metal plating an inner surface of a hole having an open part at a face side contacting with the first bottom board of the dielectric substance and formed for a side surface thereof to be approximately vertical to the first bottom board.