JPH04299604A - Antenna with reflector - Google Patents

Abstract

PURPOSE:To easily vary the radiation direction without losing the radiation characteristic of a beam by a reflector moving the reflector relatively with respect to the primary radiator. CONSTITUTION:A reflector 1 and a primary radiator 2 are disconnected mechanically. An actuator 7 is driven in the control of a controller 6 and the reflector 1 is moved in parallel with the primary radiator 2 along a guide 9. A waveguiding path 4 is used to interconnect the high frequency oscillation section 3 of a feeding system 5 and the primary radiator 2. The controller 6 is manually controlled or made up of a microcomputer and the moving direction and quantity of the reflector 1 are adjusted in the control of the program.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is an antenna with a reflector that converts a spherical wave beam emitted from a primary radiator into a plane wave beam using a reflector consisting of a parabolic mirror, a spherical mirror, etc. and radiates it into space. Regarding.

0002

[Prior Art] Conventionally, in a radar antenna with a reflector such as a parabolic antenna, when changing the radiation direction of a radio wave beam, the entire antenna, that is, the reflector, the primary radiator, the high frequency oscillating part, and the primary radiation The part of the power supply system consisting of the waveguide that connects the device to the device is moved in unison.

0003

[Problems to be Solved by the Invention] 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 it, and the moving speed is slow. There is a problem in that the space required to move the entire antenna becomes large.

0004

[Means for Solving the Problems] The present invention provides an antenna with a reflector in which the reflector and the primary radiator can be moved relative to each other so that the radiation direction of the beam can be varied easily and quickly. As a possible structure, the radiation direction of the beam can be changed by moving either one of them.

[0005]

[Operation] According to the present invention, the radiation direction of the beam can be varied without impairing the radiation characteristics of the beam, and since the movable parts are lighter, the driving force of the actuator can be reduced, and the beam The direction of radiation can be quickly changed, and since the movable parts are small, the space occupied for movement can be reduced.

[0006]

[Embodiment] In the antenna with a reflector according to the present invention, as shown in FIG. By driving, the reflector 1 is guided through the power transmission mechanism 8.
It is configured such that it can be moved parallel to the primary radiator 2 along. In the figure, reference numeral 5 indicates a portion of a power feeding system consisting of a high frequency oscillation section 3 and a waveguide 4 connecting it to the primary radiator 2.

[0007] By manually operating the controller 6, the direction and amount of movement of the reflector 1 can be adjusted as appropriate. Alternatively, the controller 6 is composed of a microcomputer,
Under the control of the program, the direction and amount of movement of the reflector 1 are adjusted as appropriate.

In addition, a step motor or the like capable of forward and reverse driving is used as the actuator 7, and the reflector 1 is linearly reciprocated via a power transmission mechanism 8 that converts rotational force from a rack and pinion or the like into linear driving force. is configured to do so. Or actuator 7
Alternatively, a linear motor 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. A beam due to a spherical wave radiated from the primary radiator 2 at the focal point f of the reflector 1 is shown in FIG. is reflected by the reflector 1 as a plane wave, and a predetermined beam BM is radiated straight into the space in front of the reflector 1. In the figure, W indicates the phase plane of the reflected wave by the reflector 1, and that plane is parallel to the reflector 1.

In such an antenna with a reflector, as shown in FIG. 3, the reflector 1 is moved in parallel,
When the primary radiator 2 is defocused by shifting the distance d from the focal point f of the reflector 1, the phase plane W of the reflected wave at the reflector 1 has an inclination θ with respect to the reflector 1, and according to the inclination θ, It becomes possible to change the radiation direction of the beam BM reflected by the reflector 1. The radiation direction of the beam BM at that time is
It 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 distance d of its movement. and,
At that time, the radiation characteristics of the beam BM hardly deteriorate.

FIG. 4 shows the case of a multi-beam type reflector-equipped antenna, in which four primary radiator groups are arranged near the focal point f of the reflector 1, symmetrically about the focal point f. 21 to 24 are installed, and the beam B is directed in a direction corresponding to the direction and amount of deviation from the focal point f position of each primary radiator 21 to 24.
M1 to BM4 are radiated.

Even in the case of an antenna with a reflector that uses such a multi-beam system, as shown in FIG. , the radiation direction of the entire beams BM1 to BM4 can be changed as appropriate depending on the moving direction and moving distance.

As described above, according to the present invention, only the relatively light reflector 1 is moved, so that the radiation direction of the beam can be quickly changed with a small driving force.

Further, as another embodiment of the present invention, FIG.
As shown, the reflector 1 and the primary radiator groups 21 to 24
By mechanically separating the two and driving the actuator 7 as appropriate under the control of the controller 6,
The configuration is such that the primary radiator groups 21 to 24 can be moved parallel to the reflector 1 along a guide 9' via a power transmission mechanism 8.

[0015] Here, the portion 5' of the feed system consisting of the respective high-frequency oscillation sections 3' and the waveguide groups 41 to 44 connecting them to the primary radiator groups 21 to 24 is also integrated with the primary radiator 2. However, by using flexible waveguides 4 (41 to 44), it is possible to move only the primary radiator groups 21 to 24.

[0016] The above is based on one primary radiator 2.
The same is true even if .

Even when such a primary radiator 2 is moved in parallel to the reflector 1, the radiation direction of the beam can be varied in exactly the same way as when the reflector 1 is moved in parallel as described above. . In this case, in particular, the largest reflector in terms of shape is fixed and the primary radiator 2 side is moved, so the space occupied by the movement is reduced.

Furthermore, FIG. 7 shows another embodiment of the present invention, in which the reflector 1 and the primary radiator 2 are mechanically separated and reversible under the control of the controller 6. The primary radiator 2 and its power supply system portion 5 can be rotated at a predetermined position by appropriately driving an actuator 7 consisting of a drivable pulse motor or the like.

With this configuration, the rotation causes the primary radiator 2 to rotate substantially along the surface of the reflector 1, and as a result, the above-mentioned primary radiator 2
This is the same as defocusing the reflector 1 by shifting it from the focus f position of the reflector 1, and the radiation direction of the beam can be varied.

Although not particularly shown, it is possible to rotate the reflector 1 at the center of its surface without rotating the primary radiator 2, or to rotate the reflector 1 around its focal point f. Even if a configuration is adopted in which the radiation direction is changed, the radiation direction of the beam can be made variable in the same way. When the reflector 1 is to be rotated with respect to its focal point f position, a guide for this purpose is provided, and the reflector 1 is rotated according to the guide.

[0021]

As described above, in the antenna with a reflector according to the present invention, by moving the reflector relative to the primary radiator, the radiation direction of the beam can be changed without impairing the radiation characteristics of the beam by the reflector. It can be easily made variable, and the movable parts are lighter compared to the conventional method of moving the entire antenna, so the power system can be made smaller and the beam radiation direction can be quickly changed. There is an advantage.

Furthermore, in the antenna with a reflector according to the present invention, by moving the primary radiator relative to the reflector, in addition to being able to exhibit the same effects as in the case described above, Since the reflector, which has the largest shape in terms of shape, is fixed and the primary radiator 2 side is movable, it has the advantage of reducing the space occupied by movement, which is particularly advantageous as an antenna for automotive radar. It is.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of an antenna with a reflector according to the present invention.

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 radiation state when the primary radiator is shifted from the focus position of the reflector.

FIG. 4 is a diagram showing the basic beam radiation state of a reflector-equipped antenna that uses a multi-beam system.

FIG. 5 is a diagram showing a beam radiation state when the primary radiator group is shifted from the focus position of the reflector in an antenna with a reflector that uses a multi-beam system.

FIG. 6 is a perspective view showing another embodiment of the antenna with a reflector according to the present invention.

FIG. 7 is a perspective view showing still another embodiment of the antenna with a reflector according to the present invention.

[Explanation of symbols] 1...Reflector 2 (21-24)...Primary radiator 3, 3'...High frequency oscillation section 4 (41-44)...Waveguide 5, 5'...Power supply system part 6...Controller 7...Actuator 8...Power transmission mechanism 9,9´...Guide

Claims (6)

[Claims] Claim 1. An antenna with a reflector that converts a spherical wave beam emitted from a primary radiator into a plane wave beam using a reflector and radiates it into space, in which the beam is radiated by moving the reflector relative to the primary radiator. An antenna with a reflector, characterized in that it takes a means to make the direction variable. 2. The antenna with a reflector according to claim 1, wherein the reflector is moved in parallel. 3. The antenna with a reflector according to claim 1, wherein the reflector is rotated at the center of its surface or around its focal point. 4. An antenna with a reflector that converts a spherical wave beam emitted from a primary radiator into a plane wave beam by a reflector and radiates it into space, in which the beam is radiated by moving the primary radiator relative to the reflector. An antenna with a reflector, characterized in that it takes a means to make the direction variable. 5. The reflector-equipped antenna according to claim 1, wherein the primary radiator is moved in parallel. 6. The antenna with a reflector according to claim 1, wherein the primary radiator is rotated substantially along the surface of the reflector.