JPH04256205A - Antenna system for radar - Google Patents

Abstract

PURPOSE:To simplify constitution and to improve a gain by constituting an antenna system for radar with three channels of a waveguide, same rotary transmission structure in a rotary shaft and same rotary transmission structure composed by means of a conductive pin. CONSTITUTION:A micro strip array antenna board 100 is fitted to the upper end part-side of the rotary shaft 200 and the conductive pin 220 which passes through the feeding point of the micro strip array antenna board 100 and the side wall of the rotary shaft 200 and reaches a shaft for center conductor 215 is provided. An insulating body is covered on the outer periphery of the conductive pin 220 and same rotary transmission structure is constituted. The shaft for center conductor 215 is directly connected with the feeding point of the micro strip array antenna board 100 in terms of high frequency by the same rotary transmission structure. Thus, one channel can be reduced compared to conventional four channels and therefore a conversion loss can be reduced and structure can be made simple, whereby the gain can be improved.

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 microstrip array antenna for radar has been put into practical use, 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 serves as a radio wave emission surface. FIG. 12 shows the structure of the main part of a conventional radar microstrip array antenna. In the figure, 100 is a microstrip array antenna plate, 200 is a rotating shaft that supports this microstrip array antenna plate 100, and 300 is a waveguide. Support stand 350 on waveguide 300
is formed, and the rotating shaft 2 is supported by this support stand 350.
00 is rotatably supported. That is, 351 and 352 indicate bearings, 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 rotational speed of approximately
Along with this, the microstrip array antenna plate 100
Rotate.

[0003] The end of the waveguide 300 is connected to a circulator 40.
Connected to 0. The circulator 400 has waveguide connection holes 401 on three sides, and a magnetron (not particularly shown) as a transmitter is inserted into the waveguide connection hole 401 formed on one of the two parallel surfaces. ) and connect the receiver to the waveguide connection hole 401 formed on the other parallel surface.

[0004] The waveguide 300 shown in the figure is connected to a waveguide connection hole formed in the center surface sandwiched between the surfaces connecting the magnetron and the receiver, and the microwaves emitted from the magnetron are introduced into the waveguide 300, the waveguide 3
00 through the rotating shaft 200 to the feeding point F of the microstrip array antenna plate 100, and from this feeding point F, patches are arranged in a matrix by feeding lines of a microstrip structure formed on an insulating plate. Power is supplied to the array, and radio waves are emitted from the array surface of the patch array.

When the radio waves reflected by the target object return, the radio waves are received by the microstrip array antenna plate 100, and the received waves are 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 characteristic of allowing microwaves applied to one waveguide connection hole 401 to propagate in one direction. Therefore, when a received wave is applied to the circulator 400 from the waveguide 300, the received wave propagates to the waveguide connection hole on the opposite side from the waveguide connection hole to which the magnetron is connected, and is input to the receiver.

[0006]

[Problem to be solved by the invention] The radar antenna is
Since the radio wave emitting surface must be rotated, microwaves must be propagated from the fixed part to the rotating part, and vice versa. For this purpose, conventionally, the coupling between the waveguide 300 and the rotating shaft 200 is achieved by insulating the center conductor 201 disposed at the axis of the rotating shaft 200, the cylindrical rotating shaft 200, and one end of the center conductor 201. A supporting insulator 202 forms a coaxial transmission structure, and within the rotating shaft 200, one end of the center conductor 201 is connected to the inner wall of the rotating shaft 200, converting it into a waveguide transmission structure again, and further changing from the waveguide transmission structure. This waveguide transmission structure is converted into a coaxial transmission structure by conductive pins 202 arranged to cross the hollow part, microwaves are guided to the outside of the rotating shaft 200 by this coaxial transmission structure, and the microwaves are transferred to the microstrip. Array antenna board 10
Power is supplied to the power supply point F of 0.

As described above, conventionally, the waveguide 300 is converted three times: coaxial transmission structure - waveguide transmission structure - coaxial transmission structure. Conversion from a waveguide transmission structure to a coaxial transmission structure or from a coaxial transmission structure to a waveguide transmission structure has the disadvantage that loss occurs in the propagation of microwaves. Therefore, it is better to reduce the number of transmission structure conversions as much as possible. Further, in the conventional structure, the center conductor 201 is bent inside the rotating shaft 200 and electrically connected to the inner wall surface of the rotating shaft 200. This part is difficult to assemble and takes time, and the adjustment work to obtain the desired characteristics is also troublesome.

On the other hand, FIG. 13 shows the structure of a conductive pattern of a conventional microstrip array antenna plate 100. In the figure, reference numeral 101 indicates an insulating plate made of a dielectric material having a predetermined dielectric constant. On one side of this insulating plate 101, rectangular patches 102 are arranged in a matrix. patch 1
02 is supplied with power from a power supply line, and radio waves are emitted and received. The power supply lines include a common power supply line 103 formed along the lower side of the insulating plate 101, a branch power supply line 104 branched from this common power supply line 103, and a lead portion 10 branched from this branch power supply line 104.
5, and this lead portion 105 connects the branch power supply line 10.
4 and a λ/4 (λ is the wavelength of the radiated radio wave) matching circuit 106 connected between the patch 102 and the patch 102.

The λ/4 matching circuit 106 has a length of at least λ/4, and has lead portions 1 connected to both ends thereof.
The total length of 05 will be longer than λ/4. For this reason, conventionally, the λ/4 matching circuit 106 is arranged parallel to the branch power supply line 104 as shown in the figure, and the lead portion 105
is extended in the direction of the branch power supply line 104 and the patch 102 to reduce the distance L between the branch power supply line 104 and the patch 102, thereby increasing the overall length LL of the insulating plate 101. is being prevented.

However, in order to reduce the dimension L, λ/
4 matching circuit 106 connects branch power supply line 104 and patch 10
2, it must be placed close to λ/
4 matching circuit 106 and branch power supply line 104 are coupled,
Further, there is a drawback that the λ/4 matching circuit 106 and the patch 102 are coupled, resulting in an impedance mismatch.

To overcome this drawback, a λ/4 matching circuit 1
06 and the branch power supply line 104 and between the λ/4 matching circuit 106 and the patch 102. However, if these dimensions are made larger, the distance between the branch power supply line 104 and the patch 102 becomes larger, resulting in a drawback that the length LL of the insulating plate 101 becomes longer. For this reason, in the past, the λ/4 matching circuit 106 was somewhat coupled to the branch power supply line 104 and the patch 102, and even if an impedance mismatch occurred, the length LL of the insulating plate 101
Priority is given to making it short. As a result, the directivity characteristics of the antenna are somewhat deteriorated. In other words, the generation of side lobes is relatively large compared to the main beam. Further, since the λ/4 matching circuit 106 is extended in the vertical direction, it is necessary to increase the distance between the patches 102 in the vertical direction. Therefore, there is a drawback that the dimension of the insulating plate 101 in the short side direction also becomes large.

The purpose of the present invention is to reduce the number of conversions in the high frequency transmission structure between the circulator and the feeding point of the antenna as much as possible, and to obtain good unidirectional characteristics without increasing the size of the insulating plate. The present invention aims to provide a radar microstrip array antenna that has the following characteristics.

[0013]

[Means for Solving the Problems] In the first invention of this application, a radio wave extraction port is provided on the upper surface of a waveguide for antenna connection, and a cylindrical rotating shaft is mounted on the same axis as this high frequency extraction port. . That is, the hollow part of the rotating shaft is arranged on the same axis as the high-frequency output port, and the central conductor shaft forming the coaxial transmission structure is arranged in this hollow part.

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 form the termination of the coaxial transmission structure. A microstrip array antenna plate is attached to the upper end of the rotating shaft, and a conductive pin is provided that passes through the feeding point of the microstrip array antenna plate and the side wall of the rotating shaft to the center conductor shaft. is covered with an insulator to form a coaxial transmission structure, and this coaxial transmission structure connects the central conductor shaft and the feeding point of the microstrip array antenna plate at high frequency.

Therefore, according to the first invention of this application, the interior of the rotating shaft is constructed only by the coaxial transmission structure, and no conversion of the transmission structure is performed. Therefore, transmission loss can be reduced. Further, the center conductor shaft disposed inside the rotary shaft is disposed over the entire length of the rotary shaft from the lower end to the upper end, and is not bent inside the rotary shaft to form the terminal end of the co-rotating transmission line. Therefore, the structure is simple and assembly is easy.

Furthermore, in the second invention of this application, a linear sub-branch feed line having a length of λ/4 parallel to the long side direction of the insulating plate is provided between the branch feed line of the microstrip array antenna plate and the patch. The structure is connected by According to the second invention, the rebranched power supply line is extended in a direction perpendicular to the branched power supply line, and is further connected in a direction perpendicular to the side of the patch. Therefore, the coupling between the rebranching power supply line and the branch power supply line and the coupling between the rebranching power supply line and the patch can be reduced, and the length of the rebranching power supply line is limited to λ/4. Therefore, a radar microstrip array antenna with excellent directivity can be constructed without increasing the overall length of the insulating plate.

Furthermore, according to the third aspect of the present application, a branch line is 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, and a branch line is formed at the tip of the branch line. The structure is characterized by a stub formed by a thin conductive pattern that is electrically connected and extended in the long side direction of the insulating plate, and a power feeding point provided on the stub at the center point of the insulating plate.

According to the third invention, impedance matching is performed using the stub, so that the feeding point can be placed not at the center of the common feeding line but at the center of the insulating plate. This eliminates the need to provide an extension for impedance matching at the end of the insulating plate, and the length of the insulating plate can also be shortened in this respect.

[0019]

Embodiments FIGS. 1 to 11 show embodiments of the present invention. In the figure, parts corresponding to those in FIGS. 12 and 13 are designated by the same reference numerals. Microstrip array antenna board 100
is attached to a reinforcing plate 110 made of a metal plate, and is attached to the rotating 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,
A branch power supply line 104 and a rebranch power supply line 107 are formed by a microstrip line structure. In other words, the insulating plate 101 is made of a dielectric material having a desired dielectric constant, and a conductive foil is formed on the entire back surface of the insulating plate 101, and this conductive foil is electrically connected to a common potential point to constitute a ground conductor. do.

At the same time, a common power supply line 103, a branch power supply line 104, a repower supply line 107, and a patch 102 having a predetermined width dimension are formed on the front side to constitute a microstrip line. In other words, 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 blocks 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 part is also formed on the back side of the flat part 210, and a protective cover 112 is attached to the flat part on the back side, and the upper end of the rotating shaft 200 is hidden and protected by this protective cover 112. The upper half of the rotating shaft 200 has a prismatic shape to form the above-described flat portion 210, but the lower half has a cylindrical shape, and the inner rings of the bearings 351, 352 are fitted into this cylindrical portion 211. , the outer rings of the bearings 351, 352 are fitted into a support base 350 formed on the antenna connection waveguide 300.

[0023] The bearings 351 and 352 are connected to the holding plate 353.
and 354 are suppressed inside the support base 350. A flange 21 formed on the rotating shaft 200 together with this
A large gear 250 is attached to 2. A pinion 253 attached to a shaft 252 that decelerates the rotation of a motor 251 is engaged with the large gear 250, and the rotary shaft 200 is rotated at a rotation speed of, for example, about 24 revolutions per minute.

A circular hole 213 is provided at the axis of the rotating shaft 200.
is formed by penetrating the top and bottom. An insulating spacer 214 made of an insulator such as Teflon is fitted into the lower end of this circular hole 213. The insulating spacer 214 has a hole in its axis, into which the center conductor shaft 215 is inserted, and the center conductor shaft 215 is connected to the rotating shaft 20.
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 center conductor shaft 215 is inserted into the center 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, thereby forming the terminal end of the coaxial transmission structure. The center conductor shaft 215 has a screw hole 219 in a direction perpendicular to the axis.
is formed, and a conductive pin 220 is screwed into this screw hole 219.

In other words, the flat portion 210 of the rotating shaft 200
A circular hole 221 is formed in the hole 221, and a cylindrical insulating spacer 222 is fitted into the circular hole 221.
The conductive pin 220 is screwed into the center conductor shaft 215 through the center hole 213 of the conductor. The conductive pin 220 is connected to the flat part 21
This protruding conductive pin 220 penetrates a hole formed at the feed point F of the microstrip array antenna plate 100 and is connected to the feed point F of the microstrip array antenna plate 100.

The conductive pin 220 is 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 in the conductive pin 220, and the amount of protrusion D into the antenna connection waveguide 300 shown in FIG. 4 is defined. Further, the conductive spacer 216 can be moved up and down by heating the set screws 217 and 218. In this state, the distance G (see FIG. 4) between the conductive pins 220 is adjusted and set to a state where maximum power can be extracted.

The antenna connection conductive tube 300 has a flange 301 as shown in FIGS. 3 and 5.
01 is attached to one side of the circulator 400 shown in FIG. Rectangular window 302 in the center of flange 301
is formed, and this window 302 communicates with a flat cavity 303 to constitute an antenna connection waveguide 300. A high frequency output port 304 (see FIG. 5) is formed on the upper surface side of the cavity 303 of the antenna connection waveguide 300.
04, the lower end of the center conductor shaft 215 supported by the rotating shaft 200 is projected, and the center conductor shaft 21
5 and a coaxial transmission structure constituted by the rotating shaft 200 and the antenna connection waveguide 300 are high-frequency coupled,
The operations of transmitting radio waves given from the circulator 400 to the microstrip array antenna plate 100 and returning reflected waves induced in the microstrip antenna plate 100 to the circulator 400 are performed.

Another surface 40 of the circulator 400
A transmitter connection waveguide 500 (see FIG. 3) is attached to 1. Further, a receiver connection waveguide 600 is attached to 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 in the center of this flange 501 (601). This window 502 (602) communicates with a cavity 503 (603), and this cavity 503 (603) acts as a waveguide. The cavity 503 is bent at 90° and communicates with the upper surface. A transmitter mounting surface 504 (or receiver mounting surface 604) is formed on the upper surface, and this transmitter mounting surface 504 or receiver mounting surface 60
Attach the transmitter 700 and receiver 800 to 4.

[0029] For example, a magnetron can be used as the transmitter 700. 701 indicates a transmitter driving board;
By applying a pulse to the magnetron from this substrate 701, a high frequency is oscillated during the period of this pulse, and the cavity 50
3 to the circulator 400. In the circulator 400, radio waves input from the window 402 of the surface 401 shown in FIG. On this surface, the antenna connection waveguide 300 described above is provided.
is connected, this antenna connection waveguide 30
A high frequency signal is applied to the microstrip antenna plate 100 through a coaxial transmission structure constituted by a rotating shaft 200 and a rotating shaft 200, and radio waves are emitted from the microstrip array antenna plate 100.

Microstrip array antenna plate 10
When the reflected wave returns to 0, a high frequency current is induced at the feeding point F, and this high frequency current flows through the coaxial transmission structure constituted by the rotating shaft 200 and the antenna connection waveguide 300.
is applied to the circulator 400 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 90 degrees counterclockwise, propagates to the receiver mounting waveguide 600, and is amplified by the receiver 800.
Outputs an intermediate frequency signal. An intermediate frequency amplifier is mounted on the substrate 801, and has a structure for amplifying a received signal. Note that the board 701 is covered with a shield cover 702, and the receiver side board 801 is housed in the shield cover 802.

Reference numeral 900 shown in FIG. 3 indicates a metal chassis. This metal chassis 900 includes waveguides 300 and 50.
0,600 are mounted integrally with the circulator 400. Further, substrates 701 and 801 are similarly attached to metal chassis 900. metal chassis 90
0 is housed in a housing 950 shown in FIG. The housing 950 is composed of a lower half 951 and an upper half 955. The lower half 951 is formed of insulating resin into a concave tray shape, and the metal chassis 900 is fixed with screws through holes 952 formed in the bottom surface. Four bosses 95 shown in FIG.
3 is a boss in which a screw hole for fixing the metal chassis 900 to the lower half 951 is formed.

A waterproof cable puller 960 is attached to the side of the lower half 951, and a cable 970 (FIG. 2) is introduced into the housing through this cable puller 960. A cable 970 is connected to the transmitter board 701, receiver board 801, motor drive circuit, and the like. lower half 95
A waterproof packing 980 is attached to the periphery of the opening of No. 1, and an upper half portion 955 is placed over the waterproof packing 980. By screwing a screw 954 into a screw hole formed in the upper half through a hole 952 formed around the lower half 951, a waterproof packing 980 is tightened between the lower half 951 and the upper half 955, and the housing is closed. 900 is sealed with a waterproof structure.

FIG. 8 shows an embodiment of the second invention of this application. The second invention of this application proposes the shape of the feed line formed on the microstrip array antenna plate 100. The insulating plate 101 is made of a dielectric material having a desired dielectric constant, and a ground conductive foil is adhered to the entire surface of one surface, and a strip line is formed on the other surface. A common power supply line 103, a branch power supply line 104,
The rebranch supply line 107 is constituted by a microstrip line.

[0034] The common power supply line 103 is a rectangular insulating plate 1
It is formed along the long side of 01. If the wavelength of the waveguide composed of a conductor and an insulating plate for the radio waves radiated from the antenna is λ, then from the common feed line 103, for example, from the center point X of the common feed line 103 to the left and right at an interval of one wavelength λ. Ten or twelve branch feed lines 104 are branched, respectively. The branch power supply lines 104 are parallel to each other and are connected to the insulating plates 10.
It is extended in the direction of the short side of 1. The extension amount of the branch power supply line 104 is selected to be 2λ+3λ/4 as shown in the right end of FIG.
The re-branch power supply line 107A is branched, and this
Second and third re-branching power supply lines 107B and 107C are branched from positions extending by λ from position 4. These first, second, and third re-branching power supply lines 107A to 10
The amount of extension of 7C is selected to be λ/4, respectively.

A rectangular patch 102 is formed at each tip of each sub-branch power supply line 107A to 107C. patch 10
The dimension in the long side direction of the insulating plate 101 of No. 2 is selected to be λ/2, and the dimension B of the other side is such that the impedance seen in the direction of the patch 102 at the connection point A is the same as that of the branch power supply line 104 and the sub-branch power supply line 107A~ The dimensions are selected to match each characteristic impedance of 107C.

[0036] In the second invention of this question, the point where the rebranching power supply lines 107A to 107C are formed in a straight line, and the power supply point F
A stub 108 formed separately from the common power supply line 103
It is characterized by a structure provided on the top. By forming the rebranching power supply lines 107A to 107C in a straight line parallel to the long side direction of the insulating plate 101, the rebranching power supply line 1
07A to 107C are patch 102 and branch power supply line 1
04 is minimized, and the generation of side lobes can be reduced.

In order to straighten the sub-branch feed lines 107A to 107C, each sub-branch feed line is connected so that the impedance seen from the patch 102 from the branch feed line 104 through each sub-branch feed line 107A to 107C becomes a predetermined value. Select pattern width from 107A to 107C. Figures 9 and 10 show microstrip array antenna plate 1.
A part of the conductive pattern formed in 00 is shown enlarged. As shown in the figure, the common power supply line 103 and the branch power supply line 104 are formed into a narrow part and a wide part. The dimensions J, K, L, and M of the thin part shown in Figure 9 are approximately λ
/4, the dimensions N, Q, and R of the thick portion are selected to be approximately 3λ/4, and the dimensions O, P are selected to be approximately λ/4.

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

The dimensions of each part are set in this manner, and the distribution of power supplied to each patch array is sloped to obtain sharp directivity characteristics. On the other hand, the third 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 in the center of the microstrip array antenna plate 100, and a feed point F is provided on this stub 108.

In other words, the center point of the common power supply line 103 is located at the point X shown in FIG. Therefore, the feeding point of this microstrip array antenna plate 100 is originally located at the position X. The rightmost patch array on the insulating plate 101 protrudes from the right end of the common power supply line 103 by ΔL, as shown in FIG. Therefore, the insulating plate 101
has the disadvantage that the weight distribution is not symmetrical when centering on point X.

For this reason, when point
With this extension, when the rotating shaft 200 is supported with the point X as the center of rotation, the weight is distributed symmetrically and the rotating shaft 200 is structured not to be subjected to uneven force. However, if the extension portion is provided at the left end of the insulating plate 101 simply by adjusting the weight distribution, an unnecessary portion will be added to the insulating plate 101, which will be wasteful.

Therefore, in the third invention of this application, the insulating plate 1
Insulating plate 10 without extending unnecessary insulating plate to the left end of 01
This paper proposes a structure in which the center point of 1 can be used as the center of rotation. In the third invention of this application, a downward branch conductive pattern 120 is provided from the center point X of the common power supply line 103, and a stub 108 is formed at the tip of this branch conductive pattern 120 by a thin conductive pattern parallel to the common power supply line 103, On this stub 108, a power feeding point F is provided at a position corresponding to the center point of the insulator 101.

By moving the feed point F to the center point of the insulating plate 101 while providing impedance matching by providing the stub 108 in this way, the feed point F can be adjusted without adding unnecessary parts to the insulating plate 101. The position can be the center of rotation of the antenna. Therefore, the dimension in the long side direction of the insulating plate 101 can be shortened, and an advantage can be obtained that the diameter of the housing 950 shown in FIG. 7, especially the upper half portion 955, can be reduced.

[0044] The perpendicularly bent portions of the common power supply line 103 and the branch line 104 formed on the insulating plate 101 are formed in a shape cut at 45° as shown in an enlarged view in FIG. By forming it into a shape cut off at 45 degrees, it is possible to avoid reflections occurring at the portions bent at right angles.

[0045]

As explained above, according to the present invention, the high frequency propagation path from the circulator 400 to the microstrip array antenna plate 100 is formed using a waveguide, a coaxial transmission structure within the rotating shaft 200, and a conductive pin 220. Since the coaxial transmission structure is composed of three passages, the number of passages can be reduced by one compared to the conventional four passages. Therefore, in this respect, conversion loss can be reduced,
A radar antenna with high gain can be provided.

Furthermore, inside the rotating shaft 200, a center conductor shaft 215 is arranged to penetrate from the upper end to the lower end, and the upper end side is supported by a conductive spacer 216, and the lower end side is supported by an insulating spacer 214. This structure has the advantage of easy assembly. As a result, the time required for assembly can be shortened, and adjustments can be easily made to obtain an antenna with desired characteristics.

Further, in the present invention, the rebranching 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, the coupling between the subbranched power supply line 107 and the branched power supply line 104 and between the subbranched power supply line 104 and the patch 102 can be reduced. . As a result, an antenna with large gain can be obtained. Furthermore, since the re-branching power supply line 107 is formed in a straight line, it is not necessary to take a large vertical interval between the patches 102.
This provides the advantage that the dimension in the short side direction of the housing 950 can be shortened, and the height dimension of the upper half portion 955 of the housing 950 can be reduced.

Furthermore, since the present invention adopts a structure in which the feeding point F of the antenna is arranged at the center point of the insulating plate 101, the dimension in the long side direction of the insulating plate 101 constituting the antenna can be shortened. As a result, the diameter of the upper half 955 of the housing 950 can be reduced, providing the advantage that the overall shape can be made smaller.

[Brief explanation of the drawing]

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

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

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

FIG. 4 is a cross-sectional view for explaining the internal structure of the rotating 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 the structure of a transmitter connection waveguide and a receiver connection waveguide used in an embodiment of the present invention.

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

FIG. 8 is a front view for explaining the structure of a microstrip array antenna plate used in an example 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 a conductive pattern of a microstrip array antenna plate used in an example 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 101 Insulating plate 102 Patch 103 Common power supply line 104
Branch power supply line 107
Rebranching power supply line 200 Rotating shaft 215 Center conductor shaft 220 Conductive pin 251 Motor 300 Antenna connection waveguide 35
0 Support stand 351, 352 Bearing 400 Circulator 500
Waveguide 600 for transmitter connection
Receiver connection waveguide 700
Transmitter 800 Receiver

Claims (4)

[Claims] Claim 1: The device has connection ports with waveguides in three directions, and has a characteristic that the high frequency applied to each connection port is propagated in one direction and output to one connection port with the waveguide. A circulator, a transmitter connected to one connection port of the circulator, an antenna connection waveguide for extracting high frequency waves emitted by the transmitter from one connection port of the circulator, and this antenna connection waveguide. a receiver connected to a connection port of the circulator from which received waves inputted to the circulator are output; a high frequency output port formed on one side of the antenna connection waveguide; and the high frequency output hole. A rotary shaft is provided with a hollow portion having the same axis as the rotary shaft, and is rotatably supported by protruding vertically from the top surface of the antenna connection waveguide, and the rotary shaft is disposed at the axis of the hollow portion of the rotary shaft. A center conductor shaft that constitutes a coaxial transmission line together with a rotating shaft, the lower end of which protrudes to the antenna connection waveguide and constitutes a coaxial transmission structure that is high-frequency coupled, and a rotating shaft whose longitudinal direction is connected to the upper end of the rotating shaft. The insulating plate is attached in a direction perpendicular to the axis of the insulating plate, and a plurality of patches are arranged in a matrix on one side of the insulating plate. a microstrip array antenna plate having a structure in which a power supply line is connected to supply power; a hole penetrating from the outer peripheral surface of the rotating shaft toward the hollow part of the rotating shaft; and an insulating tube with a through hole in its axis, which passes through the through hole of the insulating tube, one end is electrically connected to the center conductor shaft, and the other end is connected to the feed point of the microstrip array antenna plate. A radar antenna device comprising: a conductive pin connected to the rotary shaft; and a motor that rotates the rotary shaft at a constant speed. [Claim 2] A ground conductor provided in contact with the entire one surface of a rectangular insulating plate having a desired dielectric constant;
A common power supply line formed of a thin conductive pattern having a length that is an integral multiple of the wavelength of the radio waves emitted along one long side of the rectangular shape on the other surface of the insulating plate; A branch power supply line having a branch point at each interval of the wavelength of the power supply line and configured by a plurality of thin conductive patterns extending from the branch point in the short side direction of the rectangular shape, and the plurality of branch power supply lines. a plurality of sub-branch power supply lines extending linearly from the line in the long side direction of the rectangle;
It is electrically connected to the tip of the rebranched power supply line and has a dimension of about 1/2 of the wavelength of the emitted radio wave in the long side direction of the rectangle, and a longer dimension in the direction perpendicular to this. A radar antenna device comprising: a patch formed of conductive foil; 3. The radar microstrip array antenna according to claim 1, wherein the circulator, a transmitter connection waveguide, a receiver connection waveguide,
A transmitter, a receiver, and a waveguide for antenna connection are supported by a metal chassis, and this metal chassis is attached to a concave tray-shaped lower housing formed of an insulator, and the upper opening of the lower housing is A radar antenna device characterized in that an upper housing is attached with a waterproof structure and the microstrip array antenna plate is rotated within the upper housing. 4. The microstrip array antenna for radar according to claim 2, wherein a branch conductive pattern is formed by branching from the center of the common feed line in a direction opposite to the extension direction of the branch feed line, and a tip of the branch conductive pattern. A radar device comprising: a stub constituted by a thin conductive pattern electrically connected to and extending in the long side direction; and a power feeding point formed at the center point of the insulating plate of the stub. antenna device.