JP2649191B2 - Antenna with reflector for automotive radar - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automotive radar for converting a spherical wave beam emitted from a primary radiator into a plane wave beam by a reflector comprising a parabolic mirror, a spherical mirror or the like, and radiating the beam into space . The present invention relates to an antenna with a reflector.

[0002]

2. Description of the Related Art Conventionally, in the case of an antenna with a reflector for radar such as a parabolic antenna, when the radiation direction of a radio wave beam is changed, the entire antenna, that is, the reflector and the primary radiator, the high-frequency oscillator, and the primary radiation The parts of the feed system consisting of the waveguides connecting the devices are integrally moved.

[0003]

In order to move the entire antenna in this way, since the entire antenna is heavy and large, a large amount of power is required to move the antenna. There is a problem that an occupied space for moving the entire antenna is increased.

[0004]

SUMMARY OF THE INVENTION The present invention is directed , in particular, to a horizontal orientation.
Are radiated from the primary radiators that are
Beam by spherical wave is reflected by plane wave by reflector
By the multi-beam system that radiates into space by converting the beam
In the case of an antenna with reflector for automotive ruder,
And the primary radiator group are mechanically separated from each other.
By driving the actuator under roller control
A drive that moves the primary radiators parallel to the reflector
A moving mechanism is provided.

[0005]

According to the present invention, a multi-beam system is employed.
In this case, the radiation direction of the beam can be made variable without deteriorating the radiation characteristics of the beam, and the movable part becomes lighter. It can be changed, and the movable part can be reduced, so that the space occupied by the movable part can be reduced.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a reflector-equipped antenna is provided by mechanically separating a reflector 1 from a primary radiator 2 and appropriately driving an actuator 7 under the control of a controller 6, as shown in FIG. It is configured such that the reflector 1 can be moved in parallel with the primary radiator 2 along the guide 9 via the power transmission mechanism 8. In the drawing, reference numeral 5 denotes a power supply system portion composed of a high-frequency oscillator 3 and a waveguide 4 connecting the high-frequency oscillator 3 and the primary radiator 2.

Incidentally, by manually operating the controller 6, the moving direction and the moving amount of the reflector 1 can be appropriately adjusted. Alternatively, the controller 6 comprises a microcomputer,
Under the control of the program, the moving direction and the moving amount of the reflector 1 are appropriately adjusted.

A step motor or the like that can be driven forward and reverse is used as the actuator 7, and the reflector 1 linearly reciprocates via a power transmission mechanism 8 that converts a rotational force composed of a rack and pinion into a linear drive force. It is configured to be. Alternatively, the actuator 7
May be used to drive the reflector directly.

FIG. 2 shows the basic principle of beam radiation of a parabolic antenna using a parabolic mirror as the reflector 1. The beam is composed of a spherical wave radiated from the primary radiator 2 at the focal point f of the reflector 1. Is reflected by the reflector 1 as a plane wave, and a predetermined beam BM is radiated straight into a space in front of the reflector 1. In the drawing, W indicates a phase plane of the reflected wave by the reflector 1, and the plane is parallel to the reflector 1.

In such an antenna with a reflector, as shown in FIG. 3, when the reflector 1 is translated and the primary radiator 2 is defocused by being shifted from the focal point f of the reflector 1 by a distance d, The phase plane W of the reflected wave at the reflector 1 is inclined with respect to the reflector 1 by θ
And the radiation direction of the beam BM reflected by the reflector 1 can be changed according to the inclination θ. The radiation direction of the corresponding beam BM is determined according to the direction in which the primary radiator 2 is shifted from the focal point f of the reflector 1 and the moving distance d thereof. Then, the radiation characteristics of the beam BM at that time hardly deteriorate.

FIG. 4 shows the case of an antenna with a reflector according to the multi-beam system. In this case, four primary radiators are arranged near the focal point f of the reflector 1 and symmetrically about the focal point f. 21 to 24, and the beam B is shifted in the direction corresponding to the direction of the shift from the focal point f of each primary radiator 21 to 24 and the amount of the shift.
M1 to BM4 are radiated.

However, even in the case of such a multi-beam antenna with a reflector, as shown in FIG. 5, the reflector 1 is moved in parallel with respect to the primary radiator groups 21 to 24. The radiation direction of the entire beam BM1 to BM4 can be appropriately changed according to the moving direction and the moving distance.

As an embodiment of the present invention, as shown in FIG. 6, the reflector 1 and the primary radiators 21 to 24 are mechanically separated from each other, and the actuator 7 is appropriately driven under the control of the controller 6. Thus, the primary radiators 21 to 24 can be moved in parallel with the reflector 1 along the guide 9 'via the power transmission mechanism 8.

Here, the high-frequency oscillating portion 3 'and the feeder system portion 5' comprising the waveguide groups 41 to 44 connecting the high-frequency oscillating portions 3 'and the primary radiator groups 21 to 24 are also integrated with the primary radiator 2. However, if flexible waveguides 4 (41 to 44) are used, only the primary radiator groups 21 to 24 can be moved.

The above description is based on one primary radiator 2
The same applies to the case where is provided.

Even when such a primary radiator 2 is moved in parallel with respect to the reflector 1, the radiation direction of the beam can be changed in exactly the same manner as in the case where the reflector 1 is moved in parallel. . In this case, since the primary radiator 2 is moved with the largest reflector fixed, the space occupied by the movement is reduced.

FIG. 7 shows another embodiment of the present invention. In this case, the reflector 1 and the primary radiator 2 are mechanically separated from each other, and the reversible rotation under the control of the controller 6 is performed. The primary radiator 2 and its power supply system portion 5 can be rotated at predetermined positions by appropriately driving an actuator 7 such as a drivable pulse motor.

In such a configuration, the rotation causes the primary radiator 2 to rotate substantially along the surface of the reflector 1, and as a result, the primary radiator 2
Is shifted from the focal point f of the reflector 1 and defocused, and the radiation direction of the beam can be made variable.

Although not particularly shown, the primary radiator 2 is not rotated, and instead, the reflector 1 is rotated around the center of its surface, or the reflector 1 is rotated around its focal point f. In this case, the beam emission direction can be similarly varied. When the reflector 1 is to be rotated with respect to the focal point f, a guide for that purpose is provided, and the reflector 1 is rotated according to the guide.

[0020]

As described above, the antenna with a reflector for a vehicle-mounted radar according to the present invention employs a multi-beam system.
The primary radiator group is integrated with the reflector
By moving the antenna in parallel , it is possible to easily change the radiation direction of the beam without damaging the radiation characteristics of the beam by the reflector. The advantage is that the system can be made smaller and the radiation direction of the beam can be changed quickly.

According to the present invention, since the primary radiator group is moved with the largest reflector fixed, the occupied space for movement can be reduced. It is particularly advantageous as an antenna for a vehicle-mounted radar.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration example of a movable antenna with a reflector .

FIG. 2 is a diagram showing a basic beam radiation state of an antenna with a reflector.

FIG. 3 is a diagram showing a beam emission state when a primary radiator is shifted from a focal position of a reflector.

FIG. 4 is a diagram showing a basic beam radiation state of an antenna with a reflector employing a multi-beam system.

FIG. 5 is a diagram showing a beam radiation state when a primary radiator group is shifted from a focal position of a reflector in an antenna with a reflector using a multi-beam method.

FIG. 6 is a perspective view showing an embodiment of an antenna with a reflector for a vehicle-mounted radar according to the present invention.

FIG. 7 is a perspective view showing another configuration example of a movable reflector-equipped antenna.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Reflector 2 (21-24) ... Primary radiator 3,3 '... High frequency oscillating part 4 (41-44) ... Waveguide 5,5' ... Power supply system part 6 ... Controller 7 ... Actuator 8 ... Power transmission mechanism 9,9 '… Guide

Claims (1)

(57) [Claims] 1. A group of primary radiators arranged in a plurality in the horizontal direction
Beam reflected by spherical waves emitted from
Radiated into space by converting the beam into a plane wave beam
Antenna with reflector for in-vehicle radar using multi-beam method
Mechanically disconnects the reflector and primary radiator group
Remote from the actuator under the control of the controller.
Drives the primary radiators to the reflector
Characterized in that a drive mechanism for moving the object in parallel is provided.
Antenna with reflector for automotive radar .