JP2001127524A - Beam scan antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive beam scan antenna that is made small in size and low in profile. SOLUTION: A primary radiator 3 that sends/receives an electromagnetic wave and a wave collection device 4 of a flat plate shape collecting an electromagnetic wave are placed between two metallic plates 1, 2 placed in parallel in a way of varying their relative positions, input output sections 5 are provided to the beam scan antenna to couple the electromagnetic with the wave collection device 4 and the beam scan antenna can vary a beam direction of the electromagnetic wave to be emitted to or absorbed from the input/output section 5. Moving the wave collection device 4 and/or the primary radiator 3 in parallel with the faces of the metallic plates 1, 2 changes the phase of the electromagnetic wave to each input/output section 5 to scan the beam direction from each input/output section 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly uses a phase shifter for high frequency waves such as microwaves and millimeter waves to change the phase of electromagnetic waves, thereby making the beam direction of electromagnetic waves radiated or absorbed variable. The present invention relates to a beam scan antenna.

[0002]

2. Description of the Related Art Conventionally, various beam scanning antennas have been proposed.
There is a so-called eagle scanner having a structure as shown in FIG.

FIG. 5A is a top view of an Eagle scanner which is a conventional beam scan antenna, and FIG. 5B is a cross-sectional view taken along a line AB in FIG. In FIG. 5, reference numeral 8 denotes a rectangular waveguide. A group of slots 5 as antenna elements is formed on one E surface of the rectangular waveguide 8, and the other E surface is movably inserted. It is composed of a movable part 9. By moving the movable portion 9, the tube width of the rectangular waveguide 8 changes.

Now, assuming that the reference waveguide width is a, the guide wavelength at this time is λg, and the group of slots 5 is formed on the E surface of the rectangular waveguide 8 at an interval of λg. The electromagnetic waves input from the input port 30 of the slot 8
The electromagnetic waves radiated from the group of the slots 5 are all in the same phase. On the other hand, when the movable section 9 is moved to make the tube width larger than the reference waveguide width a, the guide wavelength becomes shorter than λg.
The phase of the electromagnetic wave radiated from the group of the slots 5 is gradually delayed in the traveling direction of the electromagnetic wave. Conversely, when the movable section 9 is moved to make the tube width smaller than the reference waveguide width a, the guide wavelength becomes longer than λg, and as a result, the phase of the electromagnetic wave radiated from the group of slots 5 is shifted in the traveling direction of the electromagnetic wave. It will proceed gradually. As described above, the phase of the electromagnetic wave radiated from the group of slots 5 can be changed by moving the movable portion 9 to adjust the width of the rectangular waveguide 8.

According to this principle, the phase of the electromagnetic wave beam radiated from these groups of slots 5, that is, the entire antenna, can be changed in the traveling direction (elevation direction) of the electromagnetic wave in the rectangular waveguide 8, and the beam direction is changed. It functions as a beam scan antenna capable of performing the above.

FIG. 6 is a perspective view showing the structure of a conventional beam scan antenna called a lens antenna. In FIG. 6, 1 is a conductor substrate, 3 is a primary radiator, and 41 is a lens. In the case of this antenna, the spherical wave of the electromagnetic wave radiated from the primary radiator 3 is converted into a plane wave by the lens 41 and radiated. At this time, by moving the position of the lens 41 with respect to the primary radiator 3, the beam direction of the plane wave can be moved in the same manner as in the optical principle, and as a result, it functions as a beam scanner antenna.

A parabolic antenna is a beam scan antenna that operates on the same principle as the lens antenna. This is to convert a spherical wave radiated from the primary radiator 3 into a plane wave by a metal curved surface (parabola) instead of converting the spherical wave into a plane wave by the lens 41. This parabolic antenna also has a primary radiator 3
By moving the position of the parabola with respect to the above, the beam direction of the plane wave can be moved similarly to the optical principle, and as a result, it functions as a beam scanner antenna.

Further, as another beam scan antenna, there is an antenna that performs beam scan by electronically adjusting the phase of the antenna element using a semiconductor element.

The above-described beam scan antenna has been described with respect to the case where an electromagnetic wave is radiated from the antenna and transmitted. Needless to say, it is also used for

[0010]

However, the conventional beam scan antenna has the following problems.

For example, in the case of an eagle scanner as shown in FIG. 5, first, there is a problem of coupling between an electromagnetic wave and an output slot. It is desirable that the electromagnetic waves radiated from each output slot by the beam scan antenna have basically the same intensity even if the phase is adjusted. However, each output slot 5 in the Eagle scanner is fed in series by the rectangular waveguide 8, and the length of each slot 5 is changed to make the electromagnetic waves radiated from each output slot 5 the same intensity. Therefore, the amount of binding must be adjusted. When the electromagnetic wave that has propagated through the waveguide 8 is coupled to the slot 5, the phase of the electromagnetic wave that subsequently propagates is shifted. This phase shift can be corrected by adjusting the position of the slot 5 if the guide wavelength is constant. . However, since the Eagle scanner is characterized by changing the guide wavelength by moving the movable part 9, there is a problem that it is difficult in principle to completely correct it.

Second, there is the problem of reflection. This is not a problem when the scan angle of the beam is small by slightly changing the phase. However, in order to increase the scan angle, the width of the waveguide 8 must be used close to the cutoff length of the electromagnetic wave. At this time, the impedance of the waveguide 8 becomes very large. As a result, while a high-frequency line having a constant impedance is connected to the input port 30 of the waveguide 8, there is a problem that large reflection occurs due to impedance mismatch at this connection. Further, in the case of a millimeter wave, for example, at a high frequency of about 77 GHz, the size of the waveguide 8 used is 2.5 m in cross section.
Since it is as small as about mx 1.2 mm, there is also a problem that manufacturing is very difficult.

On the other hand, in the case of the lens antenna shown in FIG. 6, the above-mentioned problem does not occur because of its simplicity in principle, but its size is large due to its structure. There is a problem that it is difficult to reduce the size of the high-frequency antenna. For example, when the aperture surface of the antenna is about 10 cm, the thickness required for this antenna is, in principle, at least the sum of the lens thickness and the focal length of the lens. . Since a considerable thickness is required in this way, the aperture area is determined by the characteristics required for the antenna, so it is not possible to reduce the size.However, the large thickness of the entire antenna is inconvenient for the entire system. At the time of practical use such as the application of, there is a strong demand for reducing the thickness at present.

The problem of the thickness is the same in the case of a parabolic antenna.

Further, in the case of a beam scan antenna using a semiconductor element, the antenna can be formed in a plane, and an electronic component with a very small phase adjustment section is used, so that a thin antenna can be manufactured. However, a semiconductor element for such an application has a problem that insertion loss is large in the case of, for example, a PIN diode phase shifter, and is expensive and requires a large number of semiconductor elements. There is also a problem that the antenna system becomes complicated.

The present invention has been devised in view of the above-mentioned problems of the prior art, and has as its object the purpose of making it possible to reduce the thickness and size with a simple structure, and to manufacture it easily and at low cost. It is an object of the present invention to provide a beam scanning antenna that can perform the beam scanning.

[0017]

Means for Solving the Problems The inventors of the present invention have repeatedly studied the above problems, and as a result, have set a flat collector and a primary radiator in two metal conductor plates. It has been found that a beam scan antenna can be thinly and easily manufactured by variably disposing the phase shifter, and the present invention has been completed.

That is, in the beam scan antenna of the present invention, a primary radiator for transmitting and receiving electromagnetic waves between two metal plates arranged in parallel and a flat collector for the electromagnetic waves are variably arranged relative to each other. A plurality of input / output units for coupling the electromagnetic wave between the collector and the collector are provided on one of the metal plates, and a beam direction of the electromagnetic wave radiated or absorbed from the input / output unit is variable. It is assumed that.

Further, in the beam scanning antenna according to the present invention, in the above configuration, the flat collector is a lens.

Further, in the beam scanning antenna according to the present invention, in the above-mentioned configuration, the flat plate-shaped collector is a metal curved plate.

Still further, a beam scan antenna according to the present invention is characterized in that, in the above configuration, a plurality of the primary radiators are provided, and these are used by switching.

That is, in the beam scan antenna of the present invention, in the above configuration, in the case of transmission, the electromagnetic wave radiated from the primary radiator passes through the collector and then at least two or more input / output units, for example, slots Antenna element, or an antenna array, or a feed line, etc., which adjusts the phase of the electromagnetic wave by changing the relative position between the primary radiator and the collector, thereby reducing the overall antenna. The direction of the main beam of the output electromagnetic wave can be changed.

According to such a configuration, the phase of the electromagnetic wave beam radiated or absorbed from each input / output unit is changed by moving the collector or the primary radiator in parallel with the surface of the metal plate to change the relative position. The direction of the electromagnetic wave can be changed. Here, the flat collector may be a lens or a metal curved plate.

Also, by providing a plurality of primary radiators and switching between the plurality of primary radiators, it is possible to change the phase of the electromagnetic wave beam radiated or absorbed from each input / output unit, thereby changing the electromagnetic wave beam. The direction can be changed to a desired direction.

In the beam scan antenna of the present invention, a flat collector and a primary radiator are arranged between two metal conductor plates, and one of the metal conductor plates has a slot or the like as an antenna element. Since it is constituted by providing the input / output unit, it can be made thinner and smaller, and can be manufactured easily and at low cost.

In particular, since the current collector has a flat plate shape, the movable portion, the lens, and the lens in the conventional beam scan antenna are used.
A three-dimensional processing such as a parabola is not required. In the case of a lens, a dielectric substrate such as a resin or a ceramic can be easily punched out with a mold, and a metal curved plate may be used. Since it can be easily manufactured by similar processing, a small and thin beam scan antenna can be manufactured very easily and inexpensively.

Further, in order to scan the beam of the electromagnetic wave radiated from the antenna, the relative position between the collector and the primary radiator may be shifted, and such adjustment of the position is performed by the collector and / or the primary radiator. Alternatively, by connecting the primary radiator to a movable part such as a linear actuator, the radiator can be easily and accurately realized, and the beam scan can be performed with sufficient accuracy while reducing the size.

The scan of the beam scan antenna of the present invention is limited to two-dimensional scan as compared with the conventional lens antenna and parabolic antenna. Are two-dimensional, and therefore have sufficient antenna characteristics.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a top view illustrating an example of an embodiment of a beam scan antenna according to the present invention, and FIG. 1B is a cross-sectional view taken along a line AB in FIG. In FIG. 1, 1 is a lower metal plate, 2 is an upper metal plate,
The metal plates 1 and 2 are arranged in parallel with each other. Reference numeral 3 denotes a primary radiator for transmitting and receiving electromagnetic waves, and reference numeral 4 denotes a flat collector for electromagnetic waves from or to the primary radiator 3, and here, a flat lens is used.
These primary radiator 3 and lens 4 are composed of two metal plates 1.
The two are arranged in a state where their relative positions are variable. 5
Is an input / output unit provided on one metal plate, here the upper metal plate 2, in which a plurality of slots (antenna elements) are formed in a line at equal intervals. This slot 5
Couples an electromagnetic wave with the lens 4 and radiates the electromagnetic wave radiated and transmitted from the primary radiator 3 to the outside through the lens 4 or absorbs the electromagnetic wave arriving from the outside and passes through the lens 4 To the primary radiator 3 for reception.

The primary radiator 3 may be a monopole antenna, a waveguide antenna, a slot antenna, or the like, but when a monopole antenna is used,
Since electromagnetic waves are also emitted to the side opposite to the side where the lens 4 is located, it is desirable to use a metal curved plate as described later.

The lens 4 serving as a wave collector functions as a converter between a spherical wave of an electromagnetic wave transmitted and received from the primary radiator 3 by transmitting an electromagnetic wave and a plane wave of the electromagnetic wave radiated or absorbed from the slot 5. In addition, it functions as a phase shifter that changes the phase of the electromagnetic wave together with the primary radiator 3 by changing the relative position with respect to the primary radiator 3. Then, by changing the phase of the electromagnetic wave, the beam direction of the electromagnetic wave radiated or absorbed from the slot 5 which is an input / output unit where the electromagnetic wave is coupled to the lens 4 is changed. Such a lens 4 is formed, for example, by punching a green sheet of a resin such as tetrafluoroethylene resin or various plastics, or a ceramic such as alumina ceramics or glass ceramics with a mold, or by press molding or slip casting. Then, it is produced by firing.
It is desirable that these materials have a small dielectric loss. The shape is biconvex or plano-convex in the case of a refraction lens, and it is biplanar in the case of a diffraction lens.

The lens 4 only needs to be disposed between the metal plates 1 and 2, and does not necessarily have to be in contact with the metal plates 1 and 2. Further, a plurality of lenses may be combined to improve the characteristics.

An electromagnetic wave in the parallel plate mode propagates between the two metal plates 1 and 2 arranged in parallel. Therefore, the distance between the metal plates 1 and 2 may be any value, but may be appropriately determined in consideration of the impedance of the slot 5 as the input / output unit, the size of the primary radiator 3, the size of the entire beam scan antenna, and the like. .

The slot 5 serving as an input / output unit functions as an antenna element for radiating or absorbing an electromagnetic wave from the beam scan antenna in a predetermined beam direction, and its shape, size, forming position, number, etc. are desired. What is necessary is just to set suitably so that a radiation pattern can be realized. Further, as the input / output unit, an antenna array may be formed by forming a large number of these slots 5 in an array shape, or may be joined to another planar array antenna or the like.

In the beam scan antenna of the present invention shown in FIG. 1, the axis of the flat lens 4 is indicated by y shown in FIG.
In the axial direction, the plurality of slots 5 are arranged in the x-axis direction. Further, the primary radiator 3 is arranged near the focal length of the lens 4.

Considering the case of transmission, the electromagnetic wave transmitted from the primary radiator 3 is radiated as a two-dimensional spherical wave, and the primary radiator 3 is disposed near the focal length of the lens 4. Therefore, the electromagnetic wave passing through the lens 4 is converted into a two-dimensional plane wave.

At this time, the primary radiator 3 is placed on the axis of the lens 4.
In this case, the wavefront of the electromagnetic wave becomes parallel to the x-axis, and the phase of the electromagnetic wave coupled to all the slots 5 provided at equal intervals becomes the same. As a result, the electromagnetic waves radiated from the group of slots 5 are radiated in a direction (z-axis direction) perpendicular to the xy plane.

On the other hand, for example, when the axis of the lens 4 and the primary radiator 3 are relatively displaced in the x-axis direction, the two-dimensional spherical wave radiated from the primary radiator 3 Is converted to a two-dimensional plane wave in the same manner as
Since the phases of the electromagnetic waves coupled to the equally spaced slots 5 are shifted by the same amount with respect to the respective slots 5, the electromagnetic waves radiated from the group of slots 5 are shifted in phase with respect to the axis. The beam is shifted in the x-axis direction in accordance with.

On the other hand, in the case of reception, the electromagnetic wave in the beam direction corresponding to the phase shift amount changed by the primary radiator 3 and the lens 4 can be absorbed and received by the operation opposite to the above. It will be.

Next, another embodiment of the beam scan antenna of the present invention is shown in FIG.

FIG. 2A is a top view similar to FIG.
FIG. 2B is a cross-sectional view taken along a line AB in FIG. FIG.
In FIG. 7, the same parts as those in FIG.
1 is a lower metal plate, 2 is an upper metal plate, 3 is a primary radiator, 5
Is a slot (antenna element) as an input / output unit.
In this example, a metal curved plate 6 is used as a flat collector in place of the lens 4 in the example of FIG. 1, and an electromagnetic wave is reflected by the curved surface of the metal curved plate 6. Numeral 7 is a reflector, which reflects the electromagnetic wave transmitted from the primary radiator 3 to the side opposite to the metal curved plate 6 side and the electromagnetic wave from the side opposite to the metal curved plate 6 side to the primary radiator 3. It is installed to prevent reception. In particular, when a monopole antenna is used as the primary radiator 3, since the electromagnetic wave is directly radiated also in the direction in which the slot 5 exists, it is desirable to provide such a reflection plate 7.

The metal curved plate 6, which is a collector, reflects an electromagnetic wave on the curved surface portion and causes a gap between the spherical wave of the electromagnetic wave transmitted and received from the primary radiator 3 and the plane wave of the electromagnetic wave radiated or absorbed from the slot 5. And also functions as a phase shifter that changes the phase of the electromagnetic wave together with the primary radiator 3 by changing the relative position with respect to the primary radiator 3. By changing the phase of the electromagnetic wave, the beam direction of the electromagnetic wave radiated or absorbed from the slot 5 which is an input / output unit to which the electromagnetic wave is coupled with the metal curved plate 6 is changed. . Such a metal curved plate 6 is produced, for example, by punching a metal plate such as copper or aluminum with a mold, or by molding it with plastic or the like and then plating the surface. When the spherical wave is transmitted and received from the primary radiator 3, the curved surface portion is a paraboloid, and when the spherical wave deviates from the spherical wave, the wave is converted into a plane wave.

The metal curved plate 6 is composed of upper and lower metal plates 1 and 2
It is desirable to be in contact with each. This is because an electromagnetic wave in the parallel plate mode is propagated between the metal plates 1 and 2, and if there is a gap between the metal plates 1 and 2 and the metal curved plate 6, the electromagnetic waves leak therefrom. In order to prevent this leakage, the metal curved plate 6 may be brought into complete contact with the metal plates 1 and 2 or a chalk may be formed between the metal curved plate 6 and the metal plates 1 and 2.

In the example shown in FIG. 2, the axis of the metal curved plate 6 is in the y-axis direction shown in FIG.
Are arranged in the x-axis direction. Further, the primary radiator 3 is arranged near the focal length of the metal curved plate 6.

The operation as a beam scan antenna according to this example is based on the same principle as that of the example in which the lens 4 is used in the collector shown in FIG.

Next, still another example of the embodiment of the beam scan antenna of the present invention is shown in FIG. FIG. 3A is a top view similar to FIG. 1A and FIG.
FIG. 3B is a cross-sectional view taken along a line AB in FIG. In FIG. 3, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, 1 is a lower metal plate, 2 is an upper metal plate, 3 is a primary radiator, 5 is a slot as an input / output unit (antenna). Element). In this example, in contrast to the example shown in FIG. 1, an example in which a plurality of primary radiators 3-1-3-2-3-3 are provided instead of one primary radiator 3. Is shown.

In the example shown in FIG. 3, the axis of the lens 4 is in the y-axis direction, and the plurality of slots 5 are arranged in the x-axis direction. The primary radiators 3-1, 3-2, 3-3 are formed near the focal length of the lens 4.

The primary radiators 3-1, 3-2, 3-3 may be of any type such as a monopole antenna, a waveguide antenna, a slot antenna, etc. In the example, instead of shifting the primary radiators 3 in the x-axis direction, three primary radiators 3-1-3-2-3-3 are arranged side by side in the x-axis direction. Thus, by switching between the three primary radiators 3-1, 3-2-, and 3-3 for transmitting and receiving electromagnetic waves by using a switch or the like,
The beam direction of the electromagnetic wave radiated or absorbed from the group of slots 5 can be switched and changed without shifting the lens 4 which is a collector.

When a plurality of primary radiators are installed as described above, since the beam directions are discrete, the arrangement may be such that a desired beam direction can be obtained.

Although the number of primary radiators is three in the example shown in FIG. 3, it is needless to say that more primary radiators may be arranged and switched according to the use of the beam scan antenna.

[0051]

Next, a specific example of the beam scan antenna of the present invention will be described.

The dimensions are 100 mm × 60 m as two metal plates
Those having a size of mx 1 mm in thickness were used, and they were arranged in parallel at an interval of 1.25 mm. As a flat lens as a flat collector, an alumina ceramic biconvex lens having a refractive index of about 3 having a radius of curvature of 100 mm, a focal length of 25 mm, and a thickness of 1.2 mm was used. A glass film having a refractive index of 2 and a thickness of 0.5 mm was provided on the curved surface of the lens. This is to suppress reflection of electromagnetic waves on the lens surface. On the metal plate on the upper surface side, 32 slots each having an opening size of 1.96 mm × 0.3 mm as an input / output section were formed in an array shape with a distance between slots being 3 mm, and a distance between a lens center and a slot group was set to 25 mm. . As a primary radiator
A 2.5 mm × 1.25 mm waveguide was used, and the radiating section was set at a position 25 mm from the center of the lens. Thus, the beam scan antenna of the present invention having the configuration shown in FIG. 1 was manufactured. The frequency used was 76.5 GHz.

Then, for this beam scan antenna, the lens was shifted in the x-axis direction, and the direction of the beam emitted from the slot array was evaluated accordingly. The results are shown diagrammatically in FIG. In FIG. 4, the horizontal axis represents the lens movement distance d (unit: mm), the vertical axis represents the beam tilt angle θ (unit: deg), and the black points and characteristic curves in the figure represent measurement results. Accordingly, the tilt angle θ of the beam is approximately ± 10 corresponding to the lens movement distance d of ± 5 mm.
It changes linearly in the range of deg, and it can be seen that the beam scan antenna of the present invention can perform beam scan with high accuracy while being small and thin.

Further, as a flat collector, the thickness is 1.24 m.
m is processed into a copper plate, and the reflective surface is y = xx / 10 (unit is c
m) with a parabolic aperture of 100 mm and a focal point of 20 m
m was prepared. This was placed between the metal plates in place of the lens of the previous embodiment, and a 0.98 mm length was set at this focal position.
Monopole antenna was placed. On the back side of the monopole antenna, a reflector made of a metal plate having a length of 3 mm was arranged so as to be movable in an arc around the focal point.
Further, the distance between the focal point and the slot array was set to 25 mm, and the beam scanning antenna of the present invention having the configuration shown in FIG.

When the direction of the beam emitted from the slot array was evaluated by moving the metal curved plate, it was confirmed that the radiation beam from the slot array was inclined at the same angle as the rotation angle of the metal curved plate. did it.

Further, in the same configuration as that of the embodiment of FIG. 1, five primary radiators formed of 2.5 mm × 1.25 mm waveguides are arranged at intervals of 3 mm, and these are switched and used by switches. Thus, the beam scan antenna of the present invention having the configuration shown in FIG. 3 was manufactured.

When the primary radiator to be used is switched by switching the switch and the beam direction radiated from the slot array is evaluated correspondingly, the radiation beam is 0 deg, ± 6.5 corresponding to the switching of the primary radiator. d
eg, ± 13 deg. In addition,
Although the beam switching angle in this case is large, it is possible to reduce the beam switching angle by, for example, increasing the focal length of the collector.

From the above results, it was confirmed that the beam scan antenna of the present invention can perform beam scan with high accuracy while being small and thin.

It should be noted that the present invention is not limited to the above-described embodiments, and various changes and improvements can be made without departing from the scope of the present invention. For example, a two-dimensional antenna array may be formed by arranging slots 5 as input / output units in a plurality of rows.

[0060]

As described above in detail, according to the beam scan antenna of the present invention, a primary radiator for transmitting and receiving electromagnetic waves between two metal plates arranged in parallel and a flat collector for electromagnetic waves are relatively positioned. Along with arranging the position variably, it is provided with a plurality of input / output units for coupling the electromagnetic wave between the collector and one of the metal plates, and the beam direction of the electromagnetic wave radiated or absorbed from the input / output unit is variable. From doing
By adjusting the phase of the electromagnetic wave by changing the relative position between the primary radiator and the collector, the beam direction of the electromagnetic wave output from the entire antenna can be changed with sufficient accuracy, making it thinner and smaller. And it can be easily and inexpensively manufactured.

As described above, according to the present invention, it is possible to provide a beam scan antenna which can be reduced in thickness and size with a technically simple structure and can be manufactured easily and at low cost. Was completed.

[Brief description of the drawings]

FIG. 1A is a top view showing an example of an embodiment of a beam scan antenna according to the present invention, and FIG. 1B is a view showing AB in FIG.
It is a line sectional view.

FIG. 2A is a top view showing another example of the embodiment of the beam scanning antenna of the present invention, and FIG.
It is a B sectional view.

FIG. 3A is a top view showing still another example of the embodiment of the beam scan antenna according to the present invention, and FIG.
FIG. 3 is a sectional view taken along line AB of FIG.

FIG. 4 is a diagram showing a relationship between a lens movement distance and a beam tilt angle by the beam scan antenna of the present invention.

FIG. 5A is a top view showing an example of an Eagle scanner which is a conventional beam scan antenna, and FIG. 5B is a cross-sectional view taken along a line AB in FIG.

FIG. 6 is a perspective view showing an example of a lens antenna which is a conventional beam scan antenna.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Lower metal plate 2 ... Upper metal plate 3 ... Primary radiator 3-1; 3-1; 3-3 ... Primary radiator 4 ... Lens (collector) 5. ..Slot (input / output unit) 6 ... Metal curved plate (wave collector)

Claims (4)

[Claims] 1. A primary radiator for transmitting and receiving an electromagnetic wave between two metal plates arranged in parallel and a flat collector for the electromagnetic wave are variably positioned relative to each other, and the collector is provided on one of the metal plates. A beam scanning antenna, comprising: a plurality of input / output units for coupling the electromagnetic wave with a wave device; wherein a beam direction of the electromagnetic wave radiated or absorbed from the input / output unit is variable. 2. The beam scanning antenna according to claim 1, wherein said flat plate-like collector is a lens. 3. The beam scan antenna according to claim 1, wherein the flat collector is a metal curved plate. 4. The beam scan antenna according to claim 1, wherein a plurality of said primary radiators are provided, and these are switched and used.