JPH03280702A - Mirror surface correction antenna - Google Patents

Abstract

PURPOSE:To obtain a highly accurate desired shape beam with one reflection mirror only by providing ruggedness corresponding to a shaped beam having a desired characteristic to one reflecting mirror face only so as to ensure the shaped beam. CONSTITUTION:Contour lines shown in solid lines are projection contour lines applied to a reflecting mirror 1 regarded as an ideal mirror surface in the unit of mm, and dotted lines show recessed contour lines. How projecting and recessed contour lines applied to the mirror surface of the reflecting mirror 1 work is calculated in advance corresponding to the characteristic of the shaped beam at a cross section at a right angle to the travelling direction of a radio wave radiating from the reflecting mirror 1 as a second source. The phase distribution of the radio wave subject to second radiation from an aperture of the mirror surface of the reflecting mirror 1 provided with projection and recessed parts varies with projection and recessed parts of the mirror surface and a desired characteristic of the shaped beam is attained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a mirror-modified antenna, and in particular, the mirror surface of a reflector antenna is modified so that the beam shape in a cross section perpendicular to the direction of radio wave propagation has desired characteristics. This invention relates to a mirror-modified antenna that obtains a shaped beam.

[Conventional technology]

Traditionally, mirror-modified antennas to obtain this type of highly shaped beam have used multiple reflectors. (For example, 363 Institute of Electronics, Information and Communication Engineers Spring National Conference 5B-1-2 [Advanced Shaped Beam Antenna with Mirror Surface Modification] "Shogen, Oumaru, NHKJ
) In a double-reflector type mirror-modified antenna, the amplitude distribution on the main reflecting mirror surface is changed by modifying the sub-reflector, and the phase distribution on the main reflecting mirror aperture is controlled by making the main reflecting mirror surface uneven. A highly shaped beam radiation pattern was obtained.

[Problem to be solved by the invention]

Since the conventional mirror-finished antenna described above is a double-reflector type antenna, a sub-reflector is required in addition to the main reflector.

In particular, when a conventional mirror-finishing antenna is mounted on an artificial satellite, a sub-reflector and mounting hardware for attaching it to the satellite body are required, resulting in an increase in weight. Another disadvantage is that alignment is complicated when attaching a conventional antenna to a satellite body.

[Means to solve the problem]

The mirror-modified antenna of the present invention is a mirror-modified antenna in which mirror modification is performed so that the antenna radiation beam in a plane perpendicular to the direction of propagation of radio waves becomes a shaped beam having desired characteristics. It has a configuration that provides unevenness corresponding to the shaped beam having desired characteristics to ensure the shaped beam.

Further, the mirror-finished antenna of the present invention has a configuration in which the mirror-finished antenna is composed of only one reflecting mirror surface and a feeding horn.

Further, the mirror-finished antenna of the present invention has a configuration in which the mounting body is an artificial satellite.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a perspective view showing the overall configuration of a mirror-finished antenna according to the present invention. The mirror-finished antenna of this embodiment includes one reflecting mirror 1 whose surface is roughened to obtain desired shaped beam characteristics, and a feeding horn 2 that radiates primary radio waves to the reflecting mirror 1.
The whole thing is attached to an artificial satellite.

FIG. 2 is a contour diagram showing an example of the amount of unevenness applied to the reflecting mirror 1 of FIG. 1. FIG. The special high-speed line shown as a solid line in Figure 2 is
m
The dotted lines indicate the contour lines of the concavities.The contour lines of the concavities and convexities on the mirror surface of the reflecting mirror 1 are determined by the cross section perpendicular to the direction of propagation of the radio waves secondarily radiated from the reflecting mirror 1. is pre-calculated corresponding to the characteristics of the beam formed at . The phase distribution of the radio waves secondarily radiated from the aperture of the mirror surface of the reflecting mirror 1 provided with such an unevenness changes in accordance with the unevenness of the mirror surface, and the characteristics of the formed beam can be made desired. . FIG. 3 is a 1 2 GHz phase distribution contour map on the mirror surface of the reflecting mirror 1 provided with the uneven contour lines of FIG. 2. FIG. In FIG. 3, solid lines and dotted lines are phase contour lines that represent the lead and lag relative to the reference phase in degrees, respectively.

FIG. 4 is a diagram showing the secondary radiation pattern at 12 GHz of the reflecting mirror 1 with the uneven contour lines of FIGS. 2 and 3.
This shows the state in which the Japanese archipelago can be efficiently irradiated on board an artificial satellite, and the numerical values shown by the contour lines indicate the amplitude characteristics of the shaped beam of the secondary radiation.

〔Effect of the invention〕

As explained above, the present invention achieves a
This has the advantage that a highly desired shaped beam can be obtained with only one reflecting mirror.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the overall configuration of an embodiment of the mirror-finished antenna of the present invention, and FIG. 2 is the amount of unevenness deviation from the ideal mirror surface when the reflecting mirror 1 of FIG. 1 is viewed from the aperture direction. Figure 3 is a contour map of the 12GH2 phase distribution on the modified reflecting mirror shown in Figure 2, and Figure 4 shows the Japanese archipelago based on the secondary radiation pattern at 12 GHz of the modified reflecting mirror shown in Figure 2. It is a figure showing irradiation. 1... Modified reflector, 2... Power supply horn.

Claims (1)

[Claims] 1. In a mirror-modified antenna that is mirror-modified so that the antenna radiation pattern in a plane perpendicular to the direction of propagation of radio waves becomes a shaped beam with desired characteristics, only one reflective mirror surface is used. A mirror-finished antenna characterized in that the shaped beam is secured by providing irregularities corresponding to the shaped beam having desired characteristics. 2. The mirror-finished antenna according to claim 1, wherein the mirror-finished antenna is composed of only one reflecting mirror surface and a feeding horn. 3. Claim 1 characterized in that the mounting body is an artificial satellite.
Mirror-finished antenna as described.