JPS59230304A - Satellite antenna - Google Patents

Abstract

PURPOSE:To increase the degree of freedom for distribution of tracking radiation elements by combining the communication radiation elements and those elements distributed newly adjacently to said communication elements to obtain a primary radiator for tracking. CONSTITUTION:For the signals received by radiation elements 12 and 13 among those 11-14 serving as a communication horn, only the beacon frequency signals are extracted by demultiplexers 17 and 18. These signals are synthesized with the output signal of a radiation element 15 added newly through a magic T20. In the same way, the signals of radiation elements 13 and synthesized by a magic T19. Then these two signals are synthesized by magics T21 and T22, and therefore the directional characteristics are obtained at output terminals 23 and 24. Thus good tracking radiation beams are obtained. The radiation elements 12 and 13 for communication constitute a radiation element for tracking together with tracking elements 15 and 16. Thus, the degree of freedom for distribution of tracking radiation elements is increased and the good tracking characteristics are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a satellite-mounted antenna having a self-tracking signal detection function.

[Description of prior art]

Conventionally, in order to match the irradiation area of a satellite-mounted antenna with a predetermined communication area on the ground, this satellite-mounted antenna receives a beacon signal sent from a reference earth station on the ground. Four or an integer multiple of primary radiators were provided to detect the antenna's steering signal. Furthermore, these secondary radiators were either completely shared with the radiating element of the primary radiator provided for communications, or were provided completely separately.

However, in a primary radiator where the tracking horn is completely shared with the communication horn, the arrangement of all the primary radiating elements is determined according to the communication area with various shapes, so it is difficult to find the optimal one for the tracking horn. There was a drawback that there was no flexibility in the arrangement, and that tracking directional characteristics for obtaining good tracking accuracy could not be obtained.

In addition, when the tracking radiator is provided completely separately from the communication radiator, the two primary radiators are offset near the focal point of the main reflector by at least the geometric shape of the two. Because of the location, the two radiation directions for communication and tracking are different, which has the disadvantage that the earth station for transmitting beacon waves must be installed at a point away from the communication area of the antenna.

On the other hand, the present inventors believe that when the irradiation area of radio waves from a satellite is long and narrow, the radiating element of the communication radiator is also generally arranged on a long and narrow curve. The present invention was completed by focusing on the fact that a part of the radiating element of the secondary radiator can also be used as part of the components of the tracking radiator.

[Purpose of the invention]

Based on the above consideration, the present invention configures a tracking radiator by a part of the plurality of radiating elements of the communication radiator and a newly added radiating element, and radiates the communication radiator. It is an object of the present invention to provide a satellite-mounted antenna equipped with a small primary radiator that has not only directional characteristics but also good tracking radiation directional characteristics that point in a desired direction.

SUMMARY OF THE INVENTION An object of the present invention is to provide a satellite-mounted antenna that has a small number of radiating elements in the -order radiator and has a large degree of freedom in designing a tracking peaker.

[Summary of the invention]

The present invention provides a method for tracking by using a part of the radiating element of the next radiator for communication and a newly provided radiating element without changing the arrangement of the radiating element of the first radiator for communication to define a desired communication area. −
The second radiator is configured to obtain a good tracking radiation beam within the communication area.

[Explanation based on examples]

Next, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is a vertical cross-sectional view of an antenna according to an embodiment of the present invention.

The satellite-mounted antenna has one main reflector 1 directed toward the earth station, and is arranged near the focal point of this main reflector 1,
It is composed of a primary radiator 2 having a plurality of radiating elements that irradiates the main reflecting mirror 1.

FIG. 2 is a front view of this primary radiator 2. In FIG. 2, the -order radiator 2 is composed of radiating elements 11-16. These radiating elements 11 to 14 constitute a second-order radiator for communication, and when signals of the same amplitude and the same phase are simultaneously supplied to these radiating elements 11 to 14, the electric field strength as shown in Fig. 3 The communication area of the distribution is obtained.

A characteristic configuration of the present invention is that the radiating elements 12 and 13
Radiating elements 15 and 16 are newly arranged adjacent to the radiating element 15 or 16 and the radiating element 12 or 1.
In combination with 3, a tracking radiator is constructed. The radiating elements 12 and 13 are shared for tracking and communication.

In an antenna with such a configuration, if signals with the same amplitude and 180° phase difference are supplied to the radiating elements 12 and 15, the radiation direction shown by the solid line in FIG. 4 will be on line AA' in FIG. characteristics are obtained. The directivity characteristics shown by this solid line are the same for the radiating elements 13 and 16 as shown in FIG.
4. Therefore, if signals of the same phase and the same amplitude are supplied to the radiating elements 12 and 15 and the radiating elements 13 and 16, the result in FIG. 4 is increased by 3 dB on the cc' line in FIG. A radiation directivity characteristic indicated by a broken line is obtained.

In exactly the same way, radiating elements 13 and 15 and radiating element 12
and 16 with the same amplitude and a 180" phase difference, and when their outputs are synthesized under the same phase relationship, the directional characteristics shown by the broken line in Figure 4 will be the 2nd one.
This occurs on line DD' in the figure. In this case, ca in Figure 1
It is desirable that the 'line and the DD' line are orthogonal to each other, but since the arrangement of the radiating elements 12 and 13 is determined to ensure the desired communication area, the ca' line and the DD' line are generally orthogonal. do not.

However, since the accuracy of self-tracking is determined by the depth of the valley in the directivity characteristics shown in FIG. 4, the intended purpose of tracking can be fully satisfied. Further, the direction in which this valley appears can be designed to exist within the communication area.

The method of supplying and detecting the communication signal and tracking signal described above will be explained using an example of the block configuration of the primary radiator 2 in FIG. 5.

In FIG. 5, 17 and 18 are branching filters, 19 to 22
is a magic tee, and 23 to 28 are output terminals.

The branching filters 17 and 18 constitute a branch circuit 29, and the magic tees 19 to 22 constitute a combining circuit 30.

The output of the radiating element 12 is connected to the input of the duplexer 17.

An output terminal 27 is connected to one output of the duplexer 17, and one input of the magic tee 20 is connected to the other output. Further, the output of the radiating element 13 is connected to the input of the duplexer 18. An output terminal 28 is connected to one output of the duplexer 18, and one input of the magic tee 19 is connected to the other output. Magic tee 1 above
The outputs of the radiating elements 16 and 15 are connected to the other inputs of the radiating elements 9 and 20, respectively. The E arms of the magic tees 19 and 20 are connected to the input of the magic tee 21, and the H arms of the magic tees 19 and 20 are connected to the input of the magic tee 22.

The {circle around (2)} arm of the magic tee 21 is connected to the output terminal 23, and the E arm of the magic tee 22 is connected to the output terminal 24.

In the primary radiator having such a configuration, the signals received by the radiating elements 12 and 13 of the radiating elements 11 to 14, which are communication horns, are extracted by the demultiplexers 17 and 18, which demultiplex only the beacon frequency signal. . The signal detected by the demultiplexer 17 is transmitted to the newly provided radiating element 15.
When combined with the output signal of the magic tee 20, the E arm of the magic tee 20 has the directivity characteristics shown in FIG. In exactly the same way, the signals of radiating elements 13 and 16 are obtained from the E arm of Magic Tee 19, so when these signals are combined by Magic Tee 21, the combined directional characteristics shown in Fig. 4 are obtained in the arm. can get.

On the other hand, the 2 obtained in each arm of Masic Tea 19 and 20
When the signals of E are synthesized by the magic tee 22, the E
The arm has the directional characteristics shown in FIG. 4. As shown in Figure 4, the respective characteristics obtained at the output terminals 23 and 24 in the orthogonal direction are generally not the same, but the difference in characteristics does not matter for tracking performance, so the desired purpose is achieved. can do.

In the above example, the antenna was explained from the direction of transmitting radio waves as a transmitting antenna, but it can also be applied to the case of receiving radio waves as a receiving antenna according to the reversible theory of electromagnetic fields. Therefore, the terms "irradiation" or "radiation" used in the above description do not limit the invention to transmitting antennas.

In the above explanation, it was stated that the primary radiator is placed near the focal point of the main reflecting mirror, but at this focal point, there are multiple focal points formed by using sub-reflecting mirrors, and other effective focal points of the main reflecting mirror. It includes everything that works.

〔Effect of the invention〕

As described above, according to the present invention, a small number of radiating elements are newly provided in addition to the plurality of radiating elements constituting the existing communication radiator, and this new radiating element and the plurality of radiating elements are By configuring the tracking-order radiator with a part of the radiating element of Directional characteristics for tracking can be obtained, and it can also be used for communication.
Secondary radiator and tracking - By arranging the secondary radiator near the focal point of the main reflector, (c) the shape and weight of the main reflector can be reduced;
This has the excellent effect of allowing the earth station for transmitting beacon waves to be installed in the communication area of the antenna.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view of an antenna according to an embodiment of the present invention. Figure 2 is a front view of the primary radiator of this antenna. FIG. 3 is a diagram showing the electric field distribution in the irradiation area of the communications radiator. FIG. 4 is a diagram showing the electric field distribution in the irradiation area of the tracking radiator. FIG. 5 is a block diagram of a -order radiator of an antenna according to an embodiment of the present invention. 1... Main reflecting mirror, 2... -order radiator, 11-16.
... Radiation element, 17.18 ... Branching filter, 19-22-
...Magic tee, 23-28...-output terminal, 29.
...Branch circuit, 3゜...Synthesis circuit. Nao Takashi Ide, Patent Attorney Representative for Patent Applicant Figure 1 0 Figure 2 Tome-no-no-fusuma-ku Mi

Claims (1)

[Claims] (1) In a satellite-mounted antenna equipped with one main reflector directed toward the earth station and a communications radiator composed of multiple radiating elements that irradiate the main reflector. ,
A part of the radiating element, a small number of radiating elements provided separately from the radiating element, a K number of tracking radiators, and a part of the radiating element of the communication radiator. A branch circuit provided in the signal path for branching the tracking signal, and a predetermined tracking antenna that combines the tracking signal of the tracking-next radiator and the tracking signal branched by the branch circuit. - A satellite-mounted antenna characterized by being equipped with a synthesis circuit for obtaining beam characteristics.