Vehicular radar sensor
A vehicular radar sensor includes an emission part for emitting an electromagnetic wave and a reception part for receiving an electromagnetic wave, and a waveguide including a restriction portion, which is open at front and rear surfaces thereof so as to allow an electromagnetic wave to be transmitted therethrough and which is fixed at the open rear surface thereof to the antenna and extends outwards from a front end of the antenna, and a flaring portion, which extends outwards with an increasing cross-sectional area from a front end of the restriction portion.
1. A vehicular radar sensor comprising:
an antenna including an emission part for emitting an electromagnetic wave and a reception part for receiving an electromagnetic wave;
a waveguide including a restriction portion, which is open at front and rear surfaces thereof so as to allow an electromagnetic wave to be transmitted therethrough and which is fixed at the open rear surface thereof to the antenna and extends outwards from a front end of the antenna, and a flaring portion, which extends outwards with an increasing cross-sectional area from a front end of the restriction portion; and
a shield case, which is open at a front surface thereof and which covers a circuit board and the waveguide mounted therein,
wherein the shield case has a form of a cuboid and a shield space which is concave toward the antenna.
2. The vehicular radar sensor according to claim 1 , further comprising a housing, which includes a connector pin electrically connected to the antenna and accommodates therein the shield case having the antenna and the waveguide mounted therein.
3. The vehicular radar sensor according to claim 2 , wherein the housing is open at a front surface thereof, and
wherein the vehicular radar sensor further comprises a radome, which covers the front open surface of the housing and prevents interference with an electromagnetic wave emitted from or received by the antenna.
4. The vehicular radar sensor according to claim 1 , wherein the waveguide has a rectangular cross-section, and
wherein the flaring portion is inclined upwards and downwards at a first predetermined angle and is inclined rightwards and leftwards at a second predetermined angle, the first predetermined angle being greater than the second predetermined angle.
5. The vehicular radar sensor according to claim 1 , wherein the restriction portion has a depth equal to one wavelength of the electromagnetic wave emitted from the antenna.
6. The vehicular radar sensor according to claim 1 , wherein the flaring portion has a depth that is two times a wavelength of the electromagnetic wave emitted from the antenna.
7. The vehicular radar sensor according to claim 1 , wherein the antenna includes a circuit board, on which a circuit is formed, and a semiconductor mounted on the circuit board so as to project in a forward direction of the circuit board, the semiconductor being adapted to emit and receive the electromagnetic wave.
8. The vehicular radar sensor according to claim 7 , wherein the waveguide has a groove formed in a rear end thereof, the groove being formed through one wall of the restriction portion and having a depth greater than a thickness of the semiconductor.
9. The vehicular radar sensor according to claim 8 , wherein the groove is formed in a lower wall of the waveguide so as to create a side lobe, which is positioned under a main lobe of the electromagnetic wave emitted from and received by the antenna.
10. The vehicular radar sensor according to claim 1 , wherein the waveguide includes a connector, which extends rearwards from the restriction portion and which is fitted onto the circuit board so as to integrally couple the waveguide to the antenna.
11. The vehicular radar sensor according to claim 1 , wherein the waveguide includes a partition wall, which partitions an internal space of the waveguide into two spaces.
12. The vehicular radar sensor according to claim 11 , wherein the partition wall extends vertically from an inner surface of the waveguide to divide the antenna into an emission part and a reception part.
13. The vehicular radar sensor according to claim 11 , wherein
the antenna includes a circuit board, on which a circuit is formed, and a semiconductor mounted on the circuit board so as to project in a forward direction of the circuit board, the semiconductor being adapted to emit and receive the electromagnetic wave,
wherein the waveguide has a groove formed in a rear end thereof, the groove being formed through a side wall of the restriction portion and having a depth greater than a thickness of the semiconductor, and
wherein the partition wall is formed on an inner surface of the waveguide in front of the semiconductor or the groove.
14. The vehicular radar sensor according to claim 1 , wherein the antenna comprises a directional antenna.
15. The vehicular radar sensor according to claim 1 , wherein the shield case is formed from at least one of copper, a copper and nickel alloy, and aluminum.
16. A vehicular radar sensor comprising:
an antenna including an emission part for emitting an electromagnetic wave and a reception part for receiving an electromagnetic wave;
a waveguide including a first portion which allows an electromagnetic wave to be transmitted therethrough and which is fixed at one surface thereof to the antenna and extends outwards from a front end of the antenna, and a second portion which extends outwards with an increasing cross-sectional area from the first portion; and
a shield case, which is open at a front surface thereof and covers a circuit board and the waveguide mounted therein,
wherein the shield case has a form of a cuboid and a shield space which is concave toward the antenna.
17. The vehicular radar sensor according to claim 16 , wherein the first portion of the waveguide extends outwards from the antenna with a constant cross-sectional area, and wherein the second portion of the waveguide extends outwards from the first portion of the waveguide with an increasing cross-sectional area.