JPS61169003A - Antenna device - Google Patents

Abstract

PURPOSE:To move an antenna beam in an optional direction by providing a dielectric through which a radio wave radiated from plural array elements irradiating the radio wave of the phase is transmitted in a different phase to each array element. CONSTITUTION:A signal incoming from a terminal 19 is distributed to primary radiation array elements 9a-9c in a signal distributor 14 is the same amplitude and same phase. A dielectric 17 is provided in the front face of the elements 9a-9c and when the radio wave passes through into the dielectric 17, the phase is retarded. In using the dielectric arranging the phase face in a desired direction while the radio wave passes through in the dielectric, the antenna beam is varied in its direction. The dielectric constant of the dielectric 17 is controlled by an external control section to vary the antenna beam in an optional direction.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an array antenna.

[Conventional technology]

Traditionally, the A and -Hl Maknt systems in the has diagram, or the X-Y Maknt system in Figure 6, have been often used as Maknt systems for rounding tracking of large antennas such as satellite communications or rocket tracking. In addition, the Polar Makunt shown in Figure 7 is used for astronomical observation.

In Figure 5, 11+ is A, axis, +! 1l-jEL axis,
In Figure 6, +31flX axis, (41 is Y axis, 7th
In the figure, 11) haem, axis, (61#:tl)]
This is the ffct axis.

The Mz-111 Makunt system shown in Figure S is a system in which the M2 axis is installed perpendicular to the ground and the III axis is installed horizontally.This system uses There is a problem with growing bigger.

The X-Y Makunt formula in Figure 6 consists of an X-axis horizontal to the ground and a Y-axis perpendicular to it. The axis itself rotates with the X axis. This is mechanically difficult because both wheels are placed high above the ground.

The Polar Makunt method shown in Figure 7 is widely used in astronomical telescopes to track stars by rotating only the -axis, with the -axis (H-axis) parallel to the Earth's polar axis, and the The axis (DZC axis) is installed perpendicular to the IIIA axis.

This is because the rotational speed of the HA axis increases when tracking a satellite moving near the polar axis, and the HA axis is tilted with respect to the ground unless it is installed at the poles or the equator. There are some difficulties in tracking the structure.

The Makant method shown in FIGS. 5 and 7 has the disadvantage that the antenna inevitably becomes mechanically large due to rounding in which the entire antenna rotates around both axes (i orthogonal axes) for tracking.

On the other hand, in the case of an antenna with a very small tracking movable range, as shown in FIG. As shown in the figure, by moving the focusing reflectors α8a) to (13d) t- which constitute the primary radiation system, the antenna beams (lla) to (lIC) t-
There is a method to move it to aim at the target.

In the gs diagram and Fig. 9, (7) is the main reflector, (8) is the sub-reflector, (9) is the horn constituting the -order radiator, and (1
01#: feed @ path, (lla) ~ (llc) is the direction of the movable antenna beam, (l'IJ is the wavefront of the antenna beam, (18a - 18 (1) #'f-order radiator The converging reflecting mirror (plane or single curved mirror) 'lHf.

On the other hand, the array antenna method shown in FIG. 6 is a method in which the beam movement operation is performed electronically. After each array element (9a) to (9d), the phase shifter (11Sa) to (
15(1) is connected, and the phase amount of each phase shifter (15a) to (15a) is controlled by the phase shifter controller to control the phase wavefront of the array elements (9a) to (9b)! (Antenna beam f: (lla
) to (11(1)).

In FIG. 6, (9a) to (9d) are array elements, (l
1a) to (111) are the wavefronts of the moved antenna beams, .alpha. is a signal distributor, 15a to 15d are 9-phase phase shifters, and a is a controller for controlling the variable phase shifter.

[Problem that the invention seeks to solve]

As described above, the Ma-Kund method shown in Figs. 5 to γ moves the entire antenna, and is used for relatively large antennas. The movable beam method has the drawback that even though the movable range is relatively small, the antenna must be larger than a certain extent due to its configuration.

The movable beam method shown in Figure 1θ can also be moved electronically in all directions, but the phase shifter configuration and controller are extremely complex, making it unapplicable to devices that require simple tracking. The present invention eliminates these drawbacks and allows the antenna beam to be easily moved using a simple device.

[Means for solving problems]

In this invention, a dielectric is arranged in front of the array element of the play antenna, and the shape of the dielectric changes the dielectric constant, thereby changing the direction of the antenna beam with a simple device configuration. - [Operation] Radio waves emitted with the same phase from each array element transmit through a dielectric material, but if the thickness or permittivity of the dielectric material is varied, the wavefronts of the transmitted radio waves will differ. Therefore, it is possible to change the direction of the antenna beam.

[Embodiments of the invention]

Examples of the present invention will be described below.

Figure 1 shows a general configuration example of this embodiment (9a) to (9C).
is a group of -order radiation arrays, (lla) to (110) are the moved antenna beams, (12+ is the wavefront of the antenna beam, 04 is the signal splitter, and 0η is the dielectric that performs wavefront conversion. This will be explained as a system (transmission system) in which radio waves are transmitted from an antenna. First, signals coming from terminal - are sent to array elements (9a) to (9C) in signal distributor 04.
) with the same amplitude and phase. At this time, dielectric 1
In the absence of η, as shown in Figure 2, the equal-phase wavefronts of each array element will be equal in the front direction of the antenna, as shown by Ql, and the antenna beam will emerge in the positive direction of the antenna, resulting in h. . Therefore, if you want to change the antenna beam in this state, you have to make the entire antenna movable. However, returning to FIG. 1, if the dielectric 0η exists in front of the array element, the phase of the radio wave will be delayed when it passes through the dielectric compared to when there is no dielectric.

Therefore, if the dielectric material is such that the phase wavefront is aligned in the desired direction while the radio wave passes through the dielectric material (for example, wavefront number 4 in Figure 1), the antenna beam will be varied in that direction. , tracking can be performed without moving the antenna.

Figure js8 shows an embodiment of the present invention, in which the dielectric aη is +
12) The shape of the dielectric material is tapered so that the wavefront becomes an equal wavefront in the direction of 12), and the dielectric constant has a gradient.

In the thick part of the dielectric 0η, the phase is delayed, so the wavefront (12
becomes as shown.

In this case, it is difficult to change the wavefront (I), but the width is wide (
If a beam with a broad width is generated, even if the target to be tracked moves slightly, it will remain within the width of the beam, so there is no need to change the wavefront α, so there is no problem.

The dielectric material should preferably have a high dielectric constant and low loss.

An example of such a material is quartz glass.

Although the shape of the #-tm electric body in FIG. 3 is tapered, it is also possible to have a uniform shape and change the dielectric constant itself.

The dielectric constant of the dielectric material is controlled by an external control unit α, and the wavefront of the antenna beam is made to have the same phase in any direction. In this case, the antenna body and the The antenna beam can be moved while the dielectric also remains completely stationary.

Even in this case, the method of changing the permittivity of the dielectric using the external control unit +I11 is to directly change the permittivity itself without changing the shape of the dielectric, or to change the shape of the dielectric to equivalently change the dielectric constant. The method of changing the rate is called shipping.

As the dielectric used for this purpose, a piezoelectric element whose dielectric constant changes depending on the applied voltage may be used, and the applied voltage may be partially changed.

〔Effect of the invention〕

As described above, according to the present invention, the antenna beam can be moved in any direction by loading a dielectric material on the front surface of the antenna aperture and changing its dielectric constant, thereby making it possible to perform very simple tracking.

[Brief explanation of drawings]

FIG. 1 is a general configuration diagram of the present invention, FIG. 3 is a phase diagram,
FIGS. 8 and 4 show embodiments of the present invention. Figures 5 to 7 are schematic diagrams of the conventional antenna Makant system, and Figures aI8 to 1 (Figure 1 is an explanatory diagram of the conventional movable beam system.
t axis, (3) C X axis, (4) Y axis, f511iHA
axis, (61 is the DEC axis, (7) is the main reflector, (8) is the sub-reflector, (9) is the array element. 1101 is the feeding section, (Ill is the antenna beam, (+
21 is the wavefront of the antenna beam, atr is the focusing reflector, 0
4] is a distributor, lJ@ is a variable phase shifter, a*n variable phase shifter controller, aηtI′i dielectric, α11 is a dielectric controller, and 4 is a signal terminal. Note that the same reference numerals and numbers in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] An antenna device comprising a plurality of array elements that radiate radio waves with the same phase and a dielectric body that transmits the radio waves radiated from these array elements with different phases to each array element.