JP2838569B2 - How to receive radio waves from geostationary satellites - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for receiving radio waves from geosynchronous satellites, and more particularly, to a method for receiving radio waves from a plurality of geosynchronous satellites to a single parabolic reflector by using a plurality of primary radiators. And a method of receiving.

[Related Art] Conventionally, when receiving radio waves from a plurality of geostationary satellites,
A parabolic antenna with one parabolic reflector and one primary radiator is provided for each geostationary satellite,
Adjust the azimuth and elevation of each parabolic antenna so that radio waves from the corresponding geostationary satellite can be received well,
Further, the polarization was adjusted so that the cross polarization was minimized. Here, the polarization adjustment means that the waveguide connected to the primary radiator is orthogonal to the cross polarization so that the cross component is not guided into the waveguide so that the waveguide is rotated about the axis. To maximize the main polarization output and minimize the cross polarization output.

[Problems to be Solved by the Invention] However, such a receiving method requires the same number of parabolic antennas as the number of geosynchronous satellites to be received.
In addition, the azimuth and elevation must be adjusted so that each parabolic antenna can receive radio waves from the corresponding geostationary satellite well. This requires a large installation area and increases the cost. there were.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a first stationary radiator fixed at or near the focal position of one parabolic reflector, and a first stationary radiator. Receiving the main polarization signal from the satellite and adjusting the elevation and azimuth of the parabolic reflector to maximize it; and receiving the cross-polarization signal from the first geostationary satellite and minimizing it. Adjusting the reception polarization so that the elevation angle and the azimuth angle of the parabolic reflector are finely adjusted, and movably provided at a position near the focal point where radio waves from the second geostationary satellite can be received. Receiving the cross-polarized signal from the second geosynchronous satellite with the second primary radiator, adjusting the received polarization such that the cross-polarized signal is minimized, and adjusting the position of the second primary radiator. And

[Operation] According to the receiving method of the present invention, the first and second primary radiators adjust the elevation angle and the azimuth angle of the parabolic reflector to a position where the main polarized wave from the first geostationary satellite can be satisfactorily received. Then
The main polarization from the second geostationary satellite is also installed at a position where it can be well received. When the elevation and azimuth of the parabolic reflector have been adjusted to a position where the main polarized signal from the first geosynchronous satellite can be received well, the cross-polarized signal is received by the first primary radiator and received. The polarization is adjusted and the azimuth and elevation of the parabolic reflector are finely adjusted to minimize cross-polarization so that the level of the main polarization signal is not lowered. In this state, the cross-polarized signal from the second geosynchronous satellite is received, and the movement of the second primary radiator and the adjustment of the received polarization are performed to minimize the cross-polarized signal.

[Embodiment] As shown in FIG. 4, this embodiment is located on the same satellite orbit 2 at an interval of 4 ° from the center of the earth (an interval of about 4.5 ° from the center in Japan). Among the four geostationary satellites A to D, the present invention is applied to the case where radio waves from adjacent B and C are received, and uses an apparatus having the following configuration. That is, the apparatus has one center-feed or offset-feed, positive or elliptical parabolic reflector 4, which is configured so that its elevation and azimuth can be changed, and its focal position. In the vicinity of F,
As shown in FIGS. 1 to 3, two primary radiators 6 and 8 are provided so as to sandwich the focal point position F therebetween. FIG. 1 and FIG. 3 are viewed from the parabola reflector 4 side from the respective geostationary satellites A to D side. The primary radiator 6 is for receiving radio waves from the geostationary satellite B, and the primary radiator 8 is for receiving radio waves from the geostationary satellite C. The primary radiator 6 is a parabolic reflector 4
In a state where the elevation angle and the azimuth angle of the parabolic reflector 4 are adjusted so that the focal position F of the satellite B points to the intermediate position between the geostationary satellites B and C, the radio wave from the geostationary satellite B can be satisfactorily received. The radiator 8 is similarly arranged at a position where radio waves from the geostationary satellite C can be satisfactorily received. Therefore, the primary radiator 6 is disposed in a position theta ₁ inclined upwardly relative to the horizontal plane as shown in Figure 1. This is because, as shown in FIG. 4, since the angle formed by the horizontal line of the receiving point and a line connecting the geostationary satellite B and geostationary satellite C is theta _1, the polarization plane of the radio wave geostationary satellite C is geostationary satellite B because it is offset by theta ₁ than radio waves deviation surface. Further, the primary radiator 6 is configured to be movable on a straight line a connecting the primary radiator 8 and the primary radiator 8 and in a direction of a straight line b substantially perpendicular to the straight line. The primary radiator 8 is fixed so that its installation position does not move. further,
These primary radiators 6, 8 are configured so that their received polarization can be adjusted, that is, the waveguides connected to these primary radiators can be rotated.

Using this device, radio waves from geostationary satellites B and C are received. That is, the primary radiator 8 receives the main polarization signal from the geostationary satellite C. And to maximize this,
The azimuth and elevation of the parabolic reflector 4 are adjusted. In this state, while receiving the cross-polarized signal from the geostationary satellite C and adjusting the received polarization, the elevation angle and the azimuth angle of the parabolic reflector 4 are finely adjusted in a minute range, for example, in the range of 0.1 ° to 0.2 °. , And minimize the cross polarization component.

In this state, the geostationary satellite B is
Check if the main polarized wave from the receiver can be received.
When the elevation angle and the azimuth of the parabolic reflector 4 are adjusted to the position where the primary radiator 8 can receive the main polarization signal from the geostationary satellite C at the maximum, the primary radiator 6 converts the main polarization signal from the geostationary satellite B into the primary radiator 8. Since the primary radiator 6 is installed at a position where it can be well received, it is not necessary to adjust the elevation angle and azimuth of the parabolic antenna 4 in order to properly receive the main polarized signal from the geostationary satellite B. When it can be checked that the main polarization signal from the geostationary satellite B can be received, the primary radiator 6 receives the cross-polarization signal from the geostationary satellite B, and sets the primary radiator 6 so that the cross-polarization component is minimized. Is moved along the directions of the straight lines a and b, and the received polarization is adjusted.

FIG. 5 shows the reception levels of the main polarization signal and the cross polarization signal of the primary radiators 6 and 8 after the adjustment as described above, and the solid line indicates the main polarization signal of the primary radiator 6, The dashed line is the cross-polarized signal of the primary radiator 6, the dotted line is the main polarized signal of the primary radiator 8, and the two-dot chain line is the cross-polarized signal of the primary radiator 8. As is apparent from the above, the elevation and azimuth adjustments are performed only for one geostationary satellite, so that the main polarization signals from the two geostationary satellites B and C can be satisfactorily received. The signal can be minimized.

In the above embodiment, since the radio waves from two geostationary satellites are received, the primary radiators 6 and 8 are provided near the focal point F of the parabolic reflector 4, but three geostationary satellites, for example, B , C and D, the primary radiator for receiving the radio waves from the geostationary satellite C is fixed at the focal point F, and the primary radiator for receiving the radio waves from the geostationary satellites B and D is used. What is necessary is just to provide a container on both sides of the focal point F so that the position can be changed.

[Effects of the Invention] As described above, according to the receiving method of the present invention, one primary radiator is fixed, and the other primary radiator is movable. Even with a parabolic antenna provided with a radiator, each of the main polarized waves from each of the geostationary satellites can be received at the maximum level, and each of the cross-polarized waves can be minimized. Therefore, radio waves from a plurality of geosynchronous satellites can be satisfactorily received using such a parabolic antenna, so that the installation space can be reduced and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an enlarged front view of a part of a parabolic antenna used in an embodiment of a receiving method according to the present invention, FIG. 2 is a plan view of the parabolic antenna, FIG. 3 is a front view of the parabolic antenna, FIG. FIG. 5 is a diagram showing the relationship between the orbital position of each geostationary satellite and the parabolic antenna shown in FIG. 1, and FIG. 5 is a characteristic diagram of the parabolic antenna shown in FIG. 4 ... parabolic reflector, 6, 8 ... primary radiator.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01Q 3/00-3/46 H01Q 15/00-19/32

Claims (1)

(57) [Claims] 1. A main polarized signal from a first geosynchronous satellite is received by a first primary radiator fixed at or near a focal position of one parabolic reflector, and the parabolic signal is maximized. Adjusting the elevation and azimuth of the reflector; receiving the cross-polarized signal from the first geostationary satellite, adjusting the received polarization so as to minimize the cross-polarized signal, and adjusting the elevation and azimuth of the parabolic reflector; And a second primary radiator movably provided at a position near the focal position, which is a position where radio waves from the second geostationary satellite can be received. Receiving the signal, adjusting the received polarization such that the signal is minimized, and adjusting the position of the second primary radiator.