JP3216649B2 - Radar antenna device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar antenna device.

[0002]

2. Description of the Related Art As a radar antenna, a radar microstrip array antenna in which a conductive pattern having a microstrip line structure is formed on an insulating plate made of a dielectric material and this conductive pattern is used as a radio wave emitting surface has been put to practical use. FIG. 12 shows a structure of a main part of a conventional microstrip array antenna for radar. In the figure, 100 is a microstrip array antenna plate, 200 is a rotating shaft supporting the microstrip array antenna plate 100, and 300 is a waveguide. Support 35 on waveguide 300
0 is formed, and the rotating shaft 200 is rotatably supported by the support base 350. That is, 351 and 352
Denotes a bearing, and the rotating shaft 200 is rotatably supported by the bearings 351 and 352. A large gear 250 is attached to the rotating shaft 200, and a motor 251 is connected to the large gear 250.
The rotary shaft 200 is rotated at a rotation speed of about four rotations, and the microstrip array antenna plate 1
Rotate 00.

An end of the waveguide 300 is connected to a circulator 40.
Connected to 0. The circulator 400 has a waveguide connection hole 401 on three surfaces, and a magnetron (not particularly shown) as a transmitter is provided in the waveguide connection hole 401 formed on one of two parallel surfaces. ), And the receiver is connected to the waveguide connection hole 401 formed on the other parallel surface.

[0004] A waveguide 300 shown in the figure is connected to a waveguide connection hole formed in a central surface sandwiched between a surface where a magnetron and a receiver are connected, and a microwave transmitted from the magnetron is guided. The waveguide 3 is introduced into the waveguide 300.
00 to the feed point F of the microstrip array antenna plate 100 through the inside of the rotary shaft 200, and the patches arranged in a matrix from the feed point F to the feed line of the microstrip structure formed on the insulating plate. Electric power is supplied to the array, and radio waves are emitted from the array surface of the patch array.

[0005] When the radio wave reflected by the target returns, the radio wave is received by the microstrip array antenna plate 100, and the received wave is transmitted from the feeding point F to the rotating shaft 2.
00 to the waveguide 300 and the waveguide 30
0 to the circulator 400. The circulator 400 has a property of transmitting microwaves applied to one waveguide connection hole 401 in one direction. Therefore, when a received wave is provided from the waveguide 300 to the circulator 400, the received wave propagates to the waveguide connection hole opposite to the waveguide connection hole to which the magnetron is connected, and is input to the receiver.

[0006]

SUMMARY OF THE INVENTION A radar antenna is:
Since the radio wave radiating surface must be rotated, the microwave must be propagated from the fixed portion to the rotating portion and vice versa. For this purpose, conventionally, the coupling between the waveguide 300 and the rotating shaft 200 is insulated from the center conductor 201 disposed on the axis of the rotating shaft 200, the cylindrical rotating shaft 200, and one end of the center conductor 201. A coaxial transmission structure is formed by the supporting insulator 202, and one end of the center conductor 201 is connected to the inner wall of the rotation shaft 200 in the rotating shaft 200, and is converted into a waveguide transmission structure again. The waveguide transmission structure is converted into a coaxial transmission structure by conductive pins 203 arranged so as to cross the hollow portion of the waveguide transmission structure, and the microwave is led out of the rotating shaft 200 by the coaxial transmission structure, and the microwave is converted to a microstrip array. Antenna plate 100
Is supplied to the power supply point F of.

As described above, conventionally, the conversion from the waveguide 300 to the coaxial transmission structure, the waveguide transmission structure, and the coaxial transmission structure is performed three times. The conversion from the waveguide transmission structure to the coaxial transmission structure or from the coaxial transmission structure to the waveguide transmission structure has a disadvantage that a loss is generated with respect to the propagation of the microwave. Therefore, the conversion of the transmission structure should be as small as possible. Further, in the conventional structure, the center conductor 201 is bent inside the rotating shaft 200 and is electrically connected to the inner wall surface of the rotating shaft 200. It is difficult to assemble this part, it takes time to assemble, and it is troublesome to perform adjustment to obtain desired characteristics.

FIG. 13 shows the structure of a conductive pattern of a conventional microstrip array antenna plate 100 .
Square patches 102 are arranged in a matrix form on one surface of the insulating plate made of a dielectric material having Jo Tokoro dielectric constant. The patch 102 is supplied with power from a power supply line, and emits and receives radio waves. The power supply line between
A common power supply line 103 formed along the lower side of the microstrip array antenna plate 100 , a branch power supply line 104 branched from the common power supply line 103, and a lead portion 105 branched from the branch power supply line 104;
A λ / 4 (λ is the wavelength of the radiated radio wave) matching circuit 106 connected between the branch feed line 104 and the patch 102 by the lead portion 105.

The λ / 4 matching circuit 106 has a length of at least λ / 4, and the lead 1 connected to both ends thereof.
If the length of 05 is adjusted, it will be longer than λ / 4. For this reason, conventionally, the λ / 4 matching circuit 106 is arranged in parallel with the branch feed line 104 as shown in FIG.
The branch feed lines 104 and by extending in the direction of the patch 102 is connected, to reduce the distance L between the branch feed line 104 and patch 102, thereby microstrip
The total length LL of the array antenna plate 100 is prevented from increasing.

However, to reduce the dimension L, λ /
4 matching circuit 106 includes the branch feed line 104 and the patch 10
2 must be placed close to λ /
4 matching circuit 106 and branch feed line 104 are coupled,
Further, there is a disadvantage that the λ / 4 matching circuit 106 and the patch 102 are coupled to each other, thereby causing impedance mismatch.

In order to solve this drawback, the λ / 4 matching circuit 1
06 and interval may be Re adopt significantly between the spacing and lambda / 4 matching circuit 106 and patch 102 between the branch feed line 104. However if these dimensions Ru adopted large distance between the branch feed line 104 and patch 102 is increased, the disadvantage that the length LL of the microstrip array antenna plate 100 becomes longer occurs. For this reason, conventionally, the λ / 4 matching circuit 106 is slightly coupled to the branch feed line 104 and the patch 102, and even if impedance mismatch occurs, priority is given to shortening the length LL of the microstrip array antenna plate 100. I have. As a result, the directivity characteristics of the antenna are somewhat deteriorated. That is, the occurrence of the side lobe is relatively large with respect to the main beam. Further, since the λ / 4 matching circuit 106 is extended in the vertical direction, it is necessary to increase the interval between the patches 102 in the vertical direction. Therefore, the microstrip array antenna plate 100
There is a disadvantage that the dimension in the short side direction becomes large.

An object of the present invention is to reduce the number of conversions of a high-frequency transmission structure from a circulator to a feed point of an antenna as much as possible, and to provide a unidirectional characteristic having a good characteristic without increasing the size of an insulating plate. It is an object of the present invention to provide a radar microstrip array antenna.

[0013]

In the first invention of this application, a radio wave outlet is provided on the upper surface of an antenna connecting waveguide, and a cylindrical rotary shaft is mounted on the same axis as the high frequency outlet. . That is, the hollow portion of the rotary shaft is arranged on the same axis as the high-frequency outlet, and the shaft for the central conductor constituting the coaxial transmission structure is arranged in this hollow portion.

The center conductor shaft extends to the upper end of the rotating shaft, and is electrically connected to the rotating shaft at the upper end of the rotating shaft to terminate the coaxial transmission structure. A microstrip array antenna plate is mounted on the upper end side of the rotating shaft, and a conductive pin is provided through the feeding point of the microstrip array antenna plate and the side wall of the rotating shaft to reach the central conductor shaft. A coaxial transmission structure is formed by covering an insulator with a coaxial transmission structure, and the coaxial transmission structure is used to connect the center conductor shaft and the feeding point of the microstrip array antenna plate at a high frequency.

Therefore, according to the first invention of this application, the inside of the rotary shaft is constituted only by the coaxial transmission structure, and the transmission structure is not changed. Therefore, transmission loss can be reduced. In addition, the shaft for the center conductor, which is placed inside the rotating shaft, is placed over the entire length from the lower end to the upper end of the rotating shaft, and is bent inside the rotating shaft.
Therefore, the terminal of the coaxial transmission line is not configured. Therefore, the structure is simple and the assembling can be easily performed.

Further, in the second invention of this application, a linear re-branch having a length of λ / 4 parallel to the long side direction of the insulating plate is provided between the branch feed line and the patch of the microstrip array antenna plate. The structure is connected by a power supply line. According to the second invention of this application, the re-branch feed line is extended in a direction orthogonal to the branch feed line, and further connected in a direction orthogonal to the sides of the patch. Therefore, the coupling between the re-branching feed line and the branch feeding line and the coupling between the re-branching feeding line and the patch can be reduced, and the length of the re-branching feeding line is limited to λ / 4. Therefore, a microstrip array antenna for radar having excellent directivity characteristics can be configured without increasing the overall length of the microstrip array antenna plate 100.

Further, according to the fourth invention of this application, a branch line formed by branching from the center of the common feed line constituting the microstrip array antenna in a direction opposite to the extension direction of the branch feed line, A stub which is electrically connected to the tip and is constituted by a strip conductive pattern extended in a long side direction of the insulating plate, and a structure in which a feed point is provided on the stub at a center point of the insulating plate.

According to the fourth aspect of the present invention, the impedance is matched by the stub, so that the microstrip array antenna plate 100 is not located at the center of the common feed line.
The power feeding point can be arranged at the center of. Accordingly, it is not necessary to provide an extension for impedance matching at the end of the microstrip array antenna plate 100, and the length of the microstrip array antenna plate 100 can be shortened in this respect as well.

[0019]

1 to 11 show an embodiment of the present invention.
In the figure, parts corresponding to FIGS. 12 and 13 are denoted by the same reference numerals. Microstrip array antenna plate 100
Is attached to a reinforcing plate 110 made of a metal plate, and is attached to the rotary shaft 200 via the reinforcing plate 110.

Microstrip array antenna plate 10
0 has a patch 102 on the front side, a common power supply line 103,
The branch feed line 104 and the re-branch feed line 107 are formed by a microstrip line structure. I mean
Microstrip array antenna plate 100 is constituted by a dielectric having a desired dielectric constant, the microstrip
A conductive foil is formed on the entire back surface of the array antenna plate 100 , and the conductive foil is electrically connected to a common potential point to form a ground conductor.

At the same time, a common power supply line 103 having a predetermined width dimension, a branch power supply line 104, a re-power supply line 107, and a patch 102 are formed on the front side to form a microstrip line. That is, each part is set to a predetermined impedance by the microstrip line structure. A shield plate 111 is attached along the lower side of the microstrip array antenna plate 100, and the shield plate 111 shields radio waves radiated from the common feed line 103.

The reinforcing plate 110 is attached to the flat portion 210 of the rotating shaft 200. A flat portion is also formed on the rear side of the flat portion 210, and a protective cover 112 is attached to the flat portion on the rear side, and the upper end of the rotating shaft 200 is covered and protected by the protective cover 112. The upper half of the rotary shaft 200 has a prismatic shape to form the above-described flat portion 210, but the lower half has a cylindrical shape. The inner ring of the bearings 351 and 352 is fitted to the cylindrical portion 211. The outer rings of the bearings 351 and 352 are fitted to the support 350 formed on the waveguide 300 for antenna connection.

The bearings 351 and 352 are provided with a holding plate 353.
And 354 are held down inside the support base 350.
Along with this, the flange 21 formed on the rotating shaft 200
2, a large gear 250 is attached. A pinion 253 attached to a shaft 252 that reduces the rotation of the motor 251 meshes with the large gear 250, and the rotary shaft 200 is rotated at a rotation speed of, for example, about 24 rotations per minute.

A circular hole 213 is formed in the axis of the rotary shaft 200.
Are formed penetrating vertically. An insulating spacer 214 formed of an insulator such as Teflon is fitted into the lower end of the circular hole 213. The insulating spacer 214 has a hole in the axis thereof, and the shaft 215 for the central conductor is inserted into the hole.
It is insulated and supported at the 0 axis position. A conductive spacer 216 is inserted into the upper end of the circular hole 213, and a shaft 215 for a central conductor is inserted into a central hole of the conductive spacer 216. Therefore, the upper end side of the center conductor shaft 215 is electrically connected to the rotating shaft 200 by the conductive spacer 216, and the end of the coaxial transmission structure is formed. The central conductor shaft 215 has a screw hole 219 in a direction orthogonal to the axis.
Is formed, and the conductive pin 220 is screwed into the screw hole 219.

That is, the plane portion 210 of the rotating shaft 200
Is formed with a circular hole 221, and a cylindrical insulating spacer 222 is fitted into the circular hole 221.
Through the central hole screwed to the conductive pin 220 to the center conductor shaft 215. The conductive pins 220 protrude from the flat portion 210, and the protruding conductive pins 220 pass through holes formed at the feeding points F of the microstrip array antenna plate 100, and
0 is connected to the feeding point F.

The conductive pins 220 are covered with an insulating spacer 222 such as Teflon to form a coaxial transmission structure. The position of the center conductor shaft 215 is fixed in the vertical direction by screwing the conductive pin 220, and the amount of protrusion D into the antenna connection waveguide 300 shown in FIG. 4 is defined. The conductive spacer 216 can be moved up and down by warming the set screws 217 and 218. In this state, the distance G between the conductive pin 220 and the conductive pin 220 (see FIG. 4) is adjusted to set a state where the maximum power can be extracted.

The antenna connection guide tube 300 has a flange 301 as shown in FIG. 3 and FIG.
01 is attached to one surface of the circulator 400 shown in FIG. A rectangular window 302 in the center of the flange 301
This window 302 communicates with the flat cavity 303 to form the antenna connection waveguide 300. A high-frequency outlet 304 (see FIG. 5) is formed on the upper surface side of the cavity 303 of the waveguide 300 for antenna connection.
The lower end of the central conductor shaft 215 supported by the rotating shaft 200 is projected to the central conductor shaft 21.
5 and the coaxial transmission structure constituted by the rotating shaft 200 and the antenna connection waveguide 300 are high-frequency coupled,
An operation of transmitting a radio wave provided from circulator 400 to microstrip array antenna plate 100 and an operation of returning a reflected wave induced by microstrip antenna plate 100 to circulator 400 are performed.

Another surface 40 of the circulator 400
1, a transmitter connection waveguide 500 (see FIG. 3) is attached. A waveguide 600 for connecting a receiver is mounted on the opposite surface of the circulator 400. These waveguides 500 and 600 have the same structure as shown in FIGS. 3 and 6, and have a flange 50 for attachment to the circulator 400.
1 (601), and a waveguide window 502 (602) is formed at the center of the flange 501 (601). The window 502 (602) communicates with the cavity 503 (603), and the cavity 503 (603) acts as a waveguide. The cavity 503 is bent by 90 ° and communicates with the upper surface. Transmitter mounting surface 504 (or receiver mounting surface 604) on top
The transmitter 700 and the receiver 800 are mounted on the transmitter mounting surface 504 or the receiver mounting surface 604.

As the transmitter 700, for example, a magnetron can be used. Reference numeral 701 denotes a transmitter driving substrate,
By applying a pulse from the substrate 701 to the magnetron, a high frequency is oscillated during the pulse and the cavity 50
3 to the circulator 400. In the circulator 400, a radio wave input from the window 402 on the surface 401 shown in FIG. 3 is propagated in a counterclockwise direction by 90 ° and emitted to a window formed on a surface orthogonal to the surface 401 by 90 °. On this surface, the antenna connection waveguide 300 described above is provided.
Is connected, the antenna connection waveguide 30
A high-frequency signal is given to the microstrip antenna plate 100 through a coaxial transmission structure constituted by the zero and the rotating shaft 200, and a radio wave is emitted from the microstrip array antenna plate 100.

Microstrip array antenna plate 10
When the reflected wave returns to zero, a high-frequency current is induced at the feeding point F, and this high-frequency current is transmitted to the coaxial transmission structure constituted by the rotating shaft 200 and the antenna connection waveguide 300.
Through the circulator 400. The circulator 400 propagates from the mounting surface of the antenna connection waveguide 300 to the window on the surface rotated in the counterclockwise direction by 90 °, propagates to the receiver mounting waveguide 600, and amplifies at the receiver 800.
Outputs an intermediate frequency signal. An intermediate frequency amplifier is mounted on the substrate 801 to amplify a received signal. The substrate 801 is housed in a shield cover 803,
Cover 802 is put on.

Reference numeral 900 shown in FIG. 3 indicates a metal chassis. Each waveguide 300, 50 is provided in this metal chassis 900.
0,600 are mounted in a state integrated by the circulator 400. The boards 701 and 801 are similarly attached to the metal chassis 900. Metal chassis 90
0 is stored in a housing 950 shown in FIG. The housing 950 includes a lower half 951 and an upper half 955. The lower half 951 is formed in a concave tray shape by an insulating resin, and the metal chassis 900 is screwed by a hole 952 formed in the bottom surface. Four bosses 95 shown in FIG.
Reference numeral 3 denotes a boss in which a screw hole for screwing the metal chassis 900 is formed in the lower half 951.

A waterproof cable extraction tool 960 is attached to the side of the lower half 951, and a cable 970 (FIG. 2) is introduced into the housing through the cable extraction tool 960. A cable 970 is connected to the transmitter board 701, the receiver board 801 and a motor drive circuit. Lower half 95
A waterproof packing 980 is attached to the periphery of the opening 1, and an upper half 955 is put on the upper part with the waterproof packing 980 interposed therebetween. The waterproof packing 980 is tightened between the lower half 951 and the upper half 955 by screwing a screw 954 into a screw hole formed in the upper half through a hole 956 formed around the lower half 951. 900 is sealed with a waterproof structure.

FIG. 8 shows an embodiment of the second invention of this application. In the second invention of this application, a shape of a feed line formed on the microstrip array antenna plate 100 is proposed. Microstrip array antenna plate 1
Reference numeral 00 denotes a dielectric material having a desired dielectric constant. A ground conductive foil is formed on one surface and a strip line is formed on the other surface. Common power supply line 10
3, the branch feed line 104, and the re-branch supply line 10
7 is constituted by a microstrip line.

The common power supply line 103 is a rectangular micro
It is formed along the long side of the strip array antenna plate 100 . When the wavelength of the waveguide formed by the conductor of the radio wave radiated from the antenna and the insulating plate is λ, for example, the common feed line 1 is spaced from the common feed line 103 by one wavelength λ.
Ten or twelve branch power supply lines 104 are branched right and left with respect to a center point X of 03. Branch feed line 1
04 is a microstrip array antenna parallel to each other
It is extended in the short side direction of the plate 100 . Branch feed line 10
8 is selected as 2λ + 3λ / 4 as shown on the right end of FIG. 8, the first re-branch power supply line 107A is branched from the position of 3λ / 4 from the common power supply line 103, and the position of 3λ / 4 is further divided. From the position extended by λ from the second and third
Of the re-branching power supply lines 107B and 107C. These first, second, and third re-branching power supply lines 107
The extension amount of each of A to 107C is selected to be λ / 4.

A rectangular patch 102 is formed at each end of each of the re-branching power supply lines 107A to 107C. Patch 10
The dimension of the other side of the microstrip array antenna plate 100 in the long side direction is selected to be λ / 2, and the dimension B of the other side is the impedance in the direction of the patch 102 at the connection point A, which is the branch feed line 104 and the re-branch feed Line 107
A size matching with each characteristic impedance of A to 107C is selected.

In the second aspect of the present invention, the point where the re-branch power supply lines 107A to 107C are formed in a straight line and the power supply point F
Stub 108 formed separately from common power supply line 103
It is characterized by the structure provided above. By forming the re-branch feed lines 107A to 107C in a straight line parallel to the long side direction of the microstrip array antenna plate 100, the re-branch feed lines 107A to 107C minimize the coupling with the patch 102 and the branch feed line 104. Generation of side lobes can be reduced.

In order to linearize the re-branch power supply lines 107A to 107C, the respective re-branch power supply lines are set so that the impedance when the patch 102 is viewed from the branch power supply line 104 through the respective re-branch power supply lines 107A to 107C has a predetermined value. A pattern width of 107A to 107C is selected. 9 and 10 show the microstrip array antenna plate 1.
A part of the conductive pattern formed at 00 is shown enlarged.
As shown in the drawing, the common power supply line 103 and the branch power supply line 104 have a narrow portion and a wide portion in the pattern width. The dimensions J, K, L, and M of the thin portion shown in FIG.
/ 4, the dimensions N, Q and R of the thick portion are selected to be about 3λ / 4, and the dimensions O and P are selected to be about λ / 4.

Here, particularly, the dimension JJ of the narrow portion existing at the end of the common power supply line 103 is set to a value smaller by about 10% than λ / 4 of the standard dimension J. Further, the dimension JJJ of the central portion near the feeding point F shown in FIG. 10 is set to a value that is about 2 to 3% larger than the standard dimension J. On the other hand, the two branch power supply lines 104 in the central portion
The part that branches off is a thin pattern. The dimension S of the thin pattern portion is set to a value smaller by about 8 to 9% than the standard dimension O of the thick pattern portion.

In this way, the size of each part is set, and the distribution of the power supplied to each patch array is inclined to obtain a sharp directional characteristic. On the other hand, the fourth invention of this application proposes a structure in which a stub 108 formed by a conductive pattern parallel to the common feed line 103 is provided at the center of the microstrip array antenna plate 100, and a feed point F is provided on the stub 108.

That is, the center point of the common power supply line 103 is located at the point X shown in FIG. Therefore, the feed point of the microstrip array antenna plate 100 originally exists at the position of X. Microstrip alean
On the tener plate 100 , the patch array at the right end projects from the right end of the common power supply line 103 by ΔL as shown in FIG. Therefore, when the insulating plate 101 is centered on the point X, there is a disadvantage that the weight distribution is not symmetrical.

For this reason, when the point X is the feeding point, the conventional microstrip array antenna plate 100 shown in FIG.
Is extended from the left end by ΔL, and when the X point is supported as the center of rotation by this extension, the weight distribution is symmetrical to the left and right, so that the rotating shaft 200 is not given any swaying force. However, like this microstrip
When the extension portion is provided at the left end simply by adjusting the weight distribution of the array antenna plate 100 , the microstrip antenna is required.
It is wasteful to add unnecessary portions to the ray antenna plate 100 .

For this reason, the fourth invention of this application has a structure in which the center point of the microstrip array antenna plate 100 can be set as the center of rotation without extending a useless insulating plate to the left end of the microstrip array antenna plate 100. It is a suggestion. According to the fourth invention of this application, the branch conductive pattern 1 extending downward from the center point X of the common power supply line 103.
20, a stub 108 is formed at the tip of the branch conductive pattern 120 by a strip conductive pattern parallel to the common power supply line 103. On the stub 108,
A feed point F is provided at a position corresponding to the center point of the microstrip array antenna plate 100.

As described above, the feed point F is micro-striped while providing impedance matching by providing the stub 108.
By moving the antenna to the center point of the array antenna plate 100 , the position of the feeding point F can be set as the center of rotation of the antenna without adding unnecessary parts to the microstrip array antenna plate 100 . Therefore micro strike
The dimension of the lip array antenna plate 100 in the long side direction can be shortened, and the advantage that the diameter of the housing 950 shown in FIG.

The microstrip array antenna plate
The portions of the common feed line 103 and the branch line 104 formed at 100 which are bent at right angles are formed in a shape cut off at 45 ° as shown in an enlarged manner in FIG. Thus 4
By forming it into a shape cut off at 5 °, it is possible to avoid the occurrence of reflection at a portion bent at a right angle.

[0045]

As described above, according to the present invention, the high-frequency propagation path from the circulator 400 to the microstrip array antenna plate 100 includes the waveguide, the coaxial transmission structure in the rotating shaft 200, and the conductive pin 220. Therefore, the number of paths can be reduced by one compared with the conventional four paths. Therefore, the conversion loss can be reduced at this point,
A high-gain radar antenna can be provided.

Furthermore, inside the rotary shaft 200, a shaft 215 for the central conductor is disposed so as to penetrate from the upper end to the lower end, and the upper end is supported by the conductive spacer 216 and the lower end is supported by the insulating spacer 214. Because of this structure, there is an advantage that the assembly can be easily performed. As a result, it is possible to shorten the time required for assembling, and it is possible to easily perform adjustment for obtaining an antenna having desired characteristics.

According to the present invention, the re-branch feed line 10 constituting the microstrip array antenna plate 100
7 is formed in a linear shape extending in the long side direction of the insulating plate 101, so that the coupling between the re-branch power supply line 107 and the branch power supply line 104 and the re-branch power supply line 104 and the patch 102 can be reduced. . As a result, an antenna having a large gain can be obtained. In addition, since the re-branch power supply line 107 is formed in a straight line, the interval between the patches 102 in the vertical direction does not need to be large, and the insulating plate 101 is not required.
Of the housing 950 can be shortened, and the height dimension of the upper half 955 of the housing 950 can be reduced.

Further, in the present invention, since the feeding point F of the antenna is disposed at the center point of the insulating plate 101, the dimension of the insulating plate 101 constituting the antenna in the long side direction can be shortened. As a result, the diameter of the upper half 955 of the housing 950 can be reduced, and an advantage that the overall shape can be made smaller can be obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing one embodiment of the present invention.

FIG. 2 is an exploded perspective view showing one embodiment of the present invention.

FIG. 3 is an exploded perspective view showing one embodiment of the present invention.

FIG. 4 is a sectional view for explaining an internal structure of a rotary shaft used in the embodiment of the present invention.

FIG. 5 is a cross-sectional view for explaining the structure of the antenna connection waveguide used in the embodiment of the present invention.

FIG. 6 is a cross-sectional view for explaining a structure of a transmitter connection waveguide and a receiver connection waveguide used in the embodiment of the present invention.

FIG. 7 is an exploded perspective view showing an example of a structure of a housing used in the embodiment of the present invention.

FIG. 8 is a front view for explaining the structure of the microstrip array antenna plate used in the embodiment of the present invention.

FIG. 9 is an enlarged front view for explaining the shape of the conductive pattern of the microstrip array antenna plate used in the embodiment of the present invention.

FIG. 10 is an enlarged front view for explaining the shape of the conductive pattern of the microstrip array antenna plate used in the embodiment of the present invention.

FIG. 11 is an enlarged front view for explaining the shape of the conductive pattern of the microstrip array antenna plate used in the embodiment of the present invention.

FIG. 12 is a sectional view for explaining a conventional technique.

FIG. 13 is an enlarged front view for explaining a conventional technique.

[Explanation of symbols]

100 microstrip array antenna plate 1 02 patch 103 common feeder line 104 branch feed line 107 re-branch feed line 200 rotates the shaft 215 around conductor shaft 220 conductive pin 251 motor 300 for antenna connection waveguide 350 support base 351 bearing 400 Circulator 500 Transmitter connection waveguide 600 Receiver connection waveguide 700 Transmitter 800 Receiver 900 Metal chassis 950 Housing 951 Lower half of housing 955 Upper half of housing

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI H01Q 13/08 H01Q 13/08 (56) References JP-A-56-47105 (JP, A) , Y2) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01Q 21/00-21/30 H01Q 13/00-13/28 G01S 7/00-7/46 H01P 1/06 H01P 5 / 12

Claims (4)

(57) [Claims] 1. An antenna connecting waveguide, a rotating shaft, and a microstrip array antenna, wherein the rotating shaft is on one side of the antenna connecting waveguide and substantially perpendicular thereto, and the rotating shaft thereof. The rotary shaft is rotatably mounted on the shaft, and a hollow portion having the same axis is formed in the rotary shaft, and a shaft for the center conductor having the same axis as this is formed at the position of the axis in the hollow portion. A coaxial transmission line is formed by the center conductor shaft and the rotating shaft. An end of the center conductor shaft on the antenna connection waveguide side is formed on a wall surface of the antenna connection waveguide. The coaxial transmission line and the antenna connection waveguide are electromagnetically coupled to each other through the hole formed in the antenna connection waveguide. On the side surface of the end opposite to the antenna connection waveguide, the microstrip array antenna has a plate surface substantially parallel to the axis of the rotating shaft, and the length direction of the microstrip array antenna is At a portion where the microstrip array antenna is mounted on the rotating shaft, a hole is formed in a side surface of the rotating shaft to be connected to the hollow portion, and the hole is formed at a substantially central position of the hole. , the central end of the conductor shaft to the conductive pin is connected held, radar other end of the conductive pin, characterized in that connected to the feed line consisting of microstrip formed on the microstrip array antenna use standard test <br/> Na apparatus. 2. A rectangular insulating plate having a desired dielectric constant, an earth conductor provided in contact with one entire surface of the insulating plate, and one of the rectangular shapes on the other surface of the insulating plate. And a common feed line formed along the long side of the conductive pattern with a length that is an integral multiple of the wavelength of the radio wave radiated, and branch points at intervals of the wavelength of the common feed line. A branch feed line formed by a plurality of strip conductive patterns extending from the branch point in the rectangular short side direction;
/ 4 and from this point at each wavelength interval,
A plurality of re-branching power supply lines linearly extended in the long side direction of the rectangular shape, and a wavelength of a radio wave radiated in the long side direction of the rectangular shape which is electrically connected to a tip end of the re-branching power supply line. about a half of the size, according to claim 1 Symbol mounting radar antenna apparatus characterized the patch formed by the conductive foil, that it is constituted by having a longer dimension than this in the direction perpendicular thereto. 3. A circulator, a transmitter connection waveguide, a receiver connection waveguide, the transmitter, the receiver, and the antenna connection waveguide are supported by a metal chassis. The metal chassis is mounted on a concave tray-shaped lower housing formed of an insulator, and an upper housing is mounted in a waterproof structure on an upper opening of the lower housing, and the microstrip array antenna plate rotates in the upper housing. structure and to a radar antenna system according to claim 1 or claim 2, wherein the was to. 4. A branch conductive pattern formed by branching from the center of the common power supply line in a direction opposite to an extension direction of the branch power supply line, and electrically connected to a tip of the branch conductive pattern and extending in the long side direction. A stub constituted by the formed strip conductive pattern, and a feed point formed at a center point of the insulating plate of the stub.
3. The radar antenna device according to 2.