JPH0834382B2 - Planar antenna for automatic tracking - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a planar antenna, and more particularly to a planar antenna that is mounted on a moving object such as a vehicle or a train so that an azimuth angle and a radio wave from a transmission source can always be favorably received. The present invention relates to automatic tracking for adjusting the elevation angle.

[Prior Art] Conventionally, as a planar antenna for automatic tracking as described above, for example, there is one as shown in FIG. This has a main plane antenna 2 whose azimuth angle and elevation angle are adjusted by a driving device (not shown) so that the maximum receiving sensitivity direction is always directed to a transmission source, for example, a communication satellite, and the elevation angle and azimuth angle are adjusted. The main plane antenna 2 is a sub-plane antenna 4a for detecting an upward shift of the elevation angle in which the maximum reception sensitivity direction is shifted upward in the elevation angle direction, and the main plane antenna 2 is located in the maximum reception sensitivity direction in the elevation angle direction. The sub plane antenna 4b for detecting the downward shift of the elevation angle and the sub plane antenna 4c for detecting the azimuth shift to the left in the azimuth direction are shifted to the left in the azimuth direction and the main plane. The antenna 2 has a sub-planar antenna 4d for detecting an azimuth rightward shift in which the direction of maximum receiving sensitivity is shifted to the right in the azimuth direction. In order to make the direction of maximum reception sensitivity different from that of the main plane antenna 2, the sub-plane antennas 4a to 4d are provided so as to be inclined with respect to the main plane antenna 2 by angles δ _{1 to} δ ₄ .

[Problems to be Solved by the Invention] In order to make the receiving sensitivity maximum direction of each sub-planar antenna 4a to 4d different from that of the main plane antenna 2 as described above, each sub-planar antenna 4a to 4d is provided with respect to the main plane antenna 2. Since the main plane antenna 2 and each sub-plane antenna 4a to
4d is not located on the same plane, which makes the structure complicated. Further, since the height dimension H also becomes large as shown in FIG. 13,
It was difficult to mount on the roof of moving objects such as vehicles.

An object of the present invention is to provide a planar antenna for automatic tracking that solves the above problems.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a main plane antenna connectable to a receiving unit and a receiving level detecting unit on a dielectric substrate on the same plane. A plurality of sub-plane antennas that can be connected are provided, and the main plane antenna is formed in a shape having a maximum reception sensitivity direction of an elevation angle that is non-normal to the dielectric substrate surface, and the sub-plane antenna is It includes two antennas for detecting an elevation angle deviation and two antennas for detecting an azimuth angle deviation, and the two antennas for detecting an elevation angle deviation are arranged with respect to the maximum receiving sensitivity direction of the main plane antenna. The two antennas for detecting the azimuth deviation are formed in a shape having maximum receiving sensitivity directions which are deviated from each other by the same angle in the upper direction and the lower direction. Each of them has a shape having a maximum receiving sensitivity direction shifted by the same angle.

[Operation / Effect] According to the present invention, since the main planar antenna and each sub-planar antenna are located on the same plane, the height dimension becomes small, and it is possible to mount the antenna on the roof of a vehicle or the like. . Further, since the main planar antenna and each sub-planar antenna can be configured by one dielectric plate, the structure is simple and the manufacturing can be performed at low cost.

Also, since the shape of the main plane antenna is set so as to beam tilt the direction of maximum reception sensitivity of the main plane antenna, it is possible to receive the radio wave from the transmission source even if the main plane antenna is in a posture close to horizontal. The height of the radome that houses the main planar antenna and each sub-planar antenna can be reduced.

Further, the two sub-plane antennas for detecting the elevation angle deviation, which have a shape in which the maximum receiving sensitivity direction is vertically shifted from the main planar antenna by the same angle, and the maximum receiving sensitivity direction are the same angle left and right with the main planar antenna, respectively. Since two sub-planar antennas for detecting the azimuth shift having a shifted shape are provided, tracking control for always directing the maximum receiving sensitivity direction of the main plane antenna to the transmission source is performed by detecting the two elevation shifts. This can be done by comparing the reception levels of the sub-planar antennas for use with and the reception levels of the two sub-planar antennas for detecting the azimuth deviation. Therefore, the configuration of the tracking control device can be simplified. Moreover, in order to set the reception sensitivity maximum directions of the main plane antenna and the sub-plane antenna as described above, since the shape of each of the above antennas is set, a phase shifter is unnecessary, and the main plane antenna and each A synthesizer for synthesizing the reception outputs of the sub-planar antenna is also unnecessary, and the configuration of the antenna itself can be simplified.

[Embodiment] In FIG. 1, 10 is a main plane antenna, 12a is a sub-plane antenna for detecting a downward shift in elevation angle, 12b is a sub-planar antenna for detecting an upward shift in elevation angle, 12c is a sub-planar antenna for detecting an azimuth right shift, and 12d. Is a sub-plane antenna for azimuth shift detection on the left side, and each is composed of a microstrip plane antenna formed on one horizontal dielectric substrate 14.

Let X be the extension direction of each microstrip line as shown in FIG. 1, Y be the direction orthogonal to this in the antenna plane, and Z be the direction perpendicular to the antenna plane as shown in FIGS. 2 and 3. As shown in FIG. 2, the main plane antenna is beam-tilted so that the maximum receiving sensitivity direction OP forms an elevation angle θ in the XZ plane. Further, the sub-plane antenna 12a for detecting the downward shift of the elevation angle and the sub-plane antenna 12b for detecting the upward shift of the elevation angle are arranged in the maximum receiving sensitivity direction O
R and OQ are beam tilted by θ-α and θ + α.
The azimuth right shift detection sub-plane antenna 12c and the azimuth left shift detection sub-plane antenna 12d have maximum reception sensitivity in the OOP plane as shown in FIG.
It sways by β to the left and right of P respectively.

Adjustment of such directional characteristics is performed by each planar antenna 10, 12
This is performed by adjusting the shapes of a, 12b, 12c, and 12d, for example, the dimensions of each part of each microstrip line 16 shown in FIG. 4 and the length of the feed line 18.

That is, the elevation angle adjustment will be described first. As shown in FIG. 5, the pitch P of one crank of the microstrip line 16 is 2a + (c / 2 + c / 2) = 2a + c. At this time, if the tilt angle is θ _m , the point A
The radio wave emitted from the point A and the radio wave emitted from the point B are delayed by the distance D _e from the point A. This D _e is D _e = (2a + c) cos θ _m . On the other hand, the total length L of the crank is L = 2a + 2b + c. In order for the radio wave radiated from the point A and the radio wave radiated from the point B to have the same phase on the straight line BC, the dielectric substrate 14
Assuming that the wavelength shortening rate above is η and the wavelength of the radio wave radiated from the planar antenna on the dielectric substrate is λ _g , Must be established. However, n is an integer and is usually 2. Thereto, and substituting the values of L and _{D e, (2a + 2b +} c) / η = (2λ g / η) + (2a + c) cos
θ _m , which can be summarized as cos θ _m = (2a + 2b + c−2λ _g ) / η (2a + c). Therefore, in the main planar antenna, θ _m is θ
As shown below,
In the case of a, θ _m becomes θ−α, and in the sub-plane antenna 12b for detecting the upward deviation of the elevation angle, θ _m becomes θ + α,
It suffices to determine a, b, and c.

Next, the adjustment of the azimuth angle will be described. 4 and 6
As shown in FIG. 3A, the signal supplied to the feeding point 20 is supplied to the crank feeding point f ₁ via the feeding lines l ₁ ′ and l ₂ ′, and also through the feeding lines l ₁ ′ and l ₂ Crank feed point
is supplied to f _2, the feed line l ₁ via the and l ₂ 'is supplied to the crank feeding point f _3, it is supplied to the crank feeding point f ₄ via the feed line l ₁ and l _2, each microstrip The line antennas 16, 16 ... Are radiated as radio waves. Assuming that there is a tilt of θ _m to the right as shown in FIG. 6B, the radio waves radiated from the crank feeding point f ₁ and the radio waves at the α point, β point, and γ point are Must be in phase. Therefore, (l ₁ ′ + l ₂ ′) / η = (l ₁ ′ + l ₂ ) / η + dsinθ _m (l ₁ ′ + l ₂ ′) / η = (l ₁ + l ₂ ′) / η + 2 dsinθ _m must hold . Note that d is the distance between the crank feeding points. When these two equations are respectively modified, (l ₂ ′ −l ₂ ) / η = dsin θ _m (l ₁ ′ −l ₁ ) / η = 2 dsin θ _m . Therefore, in the case of the azimuth angle rightward displacement detecting sub-planar antenna 12c having a tilt of β to the right, θ _{m is set} to β
So that each of l ₁ , l ₁ ′, l ₂ and l ₂ ′ satisfies the above equation
Should be designed. In the case of the azimuth right deviation detection sub-planar antenna 12d that has a tilt to the left,
The positions of l ₁ and l ′ _{1 and} the positions of l ₂ and l ₂ ′ shown in FIG. 6 (a) are interchanged, and θ _m is β so that l ₁ , l ₁ ′, It suffices to design l ₂ and l ₂ ′.
Of course, in this case, a, b and c of the microstrip line antennas 16 of the sub plane antennas 12c and 12d for detecting the azimuth shift to the right and the azimuth shift to the left are the same as the a, b and c of the main plane antenna 10. It has the same elevation angle as the main planar antenna 10 in length. In the above description, the case where radio waves are radiated from each plane antenna has been described.
In general, the antenna has reversibility with respect to the transmission and reception of radio waves, and thus the above description naturally holds for the reception.

FIG. 7 shows the main plane antenna 10 thus constructed, the sub plane antennas 12a and 12b for detecting the downward and upward elevation angles.
FIG. 8 is a directional characteristic diagram of the auxiliary plane antennas 12c and 12d for detecting azimuth rightward and leftward shift detection.

As shown in FIG. 9, on the back surface of the dielectric plate 14 on which the respective planar antennas are formed, as shown in FIG.
2, 24, 26, 28 (see FIG. 10) and 30 (see FIG. 10) are provided. And this dielectric plate 14 is a horizontal turntable.
It is locked by an elevation angle rotation shaft 34 provided in 32 along the Y direction. A rack gear 36 is installed near the free end of the dielectric plate 14.
It is locked by 38. The rack gear 36 is moved by a pinion device 42 driven by an elevation angle adjusting motor 40 attached to the horizontal rotary table 32, and the elevation angle θ of the dielectric plate is changed.
change.

The horizontal rotary table 32 is supported on the fixed table 46 by the vertical hollow rotary shaft 43 and the hollow support columns 44 located inside. The hollow rotation shaft 43 has a large diameter gear 48 around it, and a pinion 52 driven by an azimuth angle adjustment motor 50 attached to a fixed base 46 meshes with the gear 48 and is horizontally rotated by the rotation of the azimuth angle adjustment motor 50. The turntable 32 turns. Slip rings 54, 54 ... Are provided around the hollow rotating shaft 43. A brush 55 provided on the fixed base 46 contacts the slip rings 54. Then, inside the hollow rotary shaft 43 and the hollow support column 44, the BS converter received by the main plane antenna 10 is received.
A high frequency rotary coupler 56 is provided for supplying the signal converted into the intermediate frequency signal at 22 to the BS tuner.

FIG. 10 shows a circuit for adjusting the elevation angle and the azimuth angle of the dielectric plate 14, and 58 is a power supply, which supplies a current to the drive circuit 60 of the azimuth angle adjustment motor 50 on the fixed base 46. In addition, current is supplied to the DC-DC inverter 61 on the horizontal rotary table 32 and the drive circuit 62 of the elevation angle adjusting motor 40 via the slip ring 54. The DC-DC inverter 61 supplies the converted direct current to the circuits on the horizontal rotary table 32 as an operating current, and also via the current superimposing circuits 63, 64, 66, 68, 70, the BS converter 22,
Supply operating current to 24, 26, 28, 30.

The intermediate frequency signal of the BS converter 22 of the main plane antenna 10 is transmitted to the fixed base 46 side via the current superposition circuit 63 and the high frequency rotary coupler 56, and is supplied to the BS tuner (not shown) attached to the receiver. To be done. Secondary plane antenna 12b for detecting upward deviation in elevation and secondary plane antenna 12a for downward deviation in elevation angle
The intermediate frequency signals of the converters 26, 24 of the current superimposing circuit 66,
It is supplied to the level detectors 72 and 74 via 64, and the level of the incoming radio wave is detected here. The outputs of the level detectors 72 and 74 are supplied to the elevation angle control circuit 76 for calculation, and the elevation angle upward shift detection sub-plane antenna detected by the level detector 74 is detected.
If the reception level of 12b is higher than the reception level of the sub plane antenna 12a for detecting the downward shift of the elevation angle, the elevation control circuit 7
6 supplies a forward rotation signal to the drive circuit 62, and the elevation angle adjusting motor 4
Rotate 0 forward to increase elevation. On the contrary, if the reception level of the auxiliary plane antenna 12a for detecting the downward angle of elevation detected by the level detector 74 is higher, the elevation angle control circuit 7
6 sends a reverse rotation signal to the drive circuit 62 to reverse the elevation angle adjusting motor 40 and reduce the elevation angle.

Converter 2 of azimuth right deviation detection sub-plane antenna 12c and azimuth left deviation detection sub-plane antenna 12d
The intermediate frequency signals of 8 and 30 are sent to level detectors 76 and 78 via current superposition circuits 68 and 70, and the levels of incoming radio waves are detected. The azimuth control circuit 80 compares these detection levels, and detects the azimuth rightward shift detection sub-plane antenna.
When the reception level of 12c is high, the azimuth adjustment motor 5
A signal for rotating 0 to the right is generated, and when the level of the azimuth angle leftward displacement detecting sub-plane antenna 12d is higher, a signal for rotating the azimuth angle adjusting motor 50 to the left is generated. These signals are supplied to the drive circuit 60 on the fixed base 46 via the slip rings 54, 54 to rotate the azimuth angle adjusting motor 50.

Reference numeral 82 is a microcomputer, which operates by the output of the BS tuner when the received radio wave does not arrive at the main plane antenna 10 when the arrival direction of the radio wave is completely different from the maximum reception sensitivity direction of the antenna, and the elevation angle control is performed based on this. The circuit 76 and the azimuth control circuit 80 generate signals.

In the above embodiment, the sub-planar antennas 12a to 12d are provided on both sides of the main planar antenna 10, respectively.
As shown in FIG. 12, sub planar antennas 12a to 12d may be provided on one side or the lower side of the main planar antenna 10. Of course, although not shown, the sub-planar antennas 12a to 12d may be provided above the main planar antenna 10.

[Brief description of drawings]

FIG. 1 is a plan view of one embodiment of a planar antenna for automatic tracking according to the present invention, and FIG. 2 is a description of the directivity in the elevation angle direction of the main planar antenna and the sub-planar antenna for detecting the upward and downward elevation angles of the same embodiment. 3 and FIG. 3 are explanatory views of directivity in the azimuth direction of the main planar antenna and the sub-plane antennas for detecting the azimuth rightward and leftward deviations in the same embodiment, and FIG. 4 is an enlarged plan view of the main part of the same embodiment. FIG. 5 is an explanatory view of the beam tilt in the elevation angle direction, FIG. 6 is an explanatory view of the beam tilt in the azimuth angle direction, FIG. 7 is a directional characteristic diagram in the elevation angle direction of the same embodiment, and FIG. 8 is the same embodiment. FIG. 9 is a side view of the automatic tracking device using the same embodiment, FIG. 10 is a block diagram of an electric circuit of the automatic tracking device using the same embodiment, and FIG. FIG. 12 is a schematic plan view of another embodiment of the planar antenna for automatic tracking according to the present invention. Furthermore schematic plan view of another embodiment of the automatic tracking planar antenna with, FIG. 13 is a perspective view showing an example of a conventional automatic tracking planar antenna. 10 ... Main plane antenna, 12a to 12d ... Sub plane antenna.

Claims (1)

[Claims] 1. A main plane antenna that is connectable to receiving means and a plurality of sub-plane antennas that are respectively connectable to receiving level detecting means are provided on a dielectric substrate on the same plane, and the main plane is provided. The antenna is formed in a shape having a maximum reception sensitivity direction of an elevation angle which is non-normal to the surface of the dielectric substrate, and the sub-planar antenna includes two antennas for detecting an elevation angle deviation and an antenna for detecting an azimuth deviation. And two antennas for detecting the deviation in the elevation angle direction, the two receiving antennas having the same receiving angle are shifted by the same angle in the upper direction and the lower direction with respect to the receiving sensitivity maximum direction of the main plane antenna. And a shape having a maximum receiving sensitivity direction in which the two antennas for detecting the azimuth deviation are offset by the same angle in the right direction and the left direction from the maximum receiving sensitivity direction of the main plane antenna. Automatic tracking for a flat antenna that was.