JPS5915308A - Antenna device for marine satellite communication - Google Patents

Abstract

PURPOSE:To prevent a communication fault due to mixture of a structure material of a ship into a high frequency transmission line connecting an antenna and a communication satellite, by shifting the anntenna along a guide rail fixed on the ship. CONSTITUTION:An antenna shift guide rail 11 is fixed on the deck of a ship. An antenna shift stage 13 holding an antenna fixing stage 14 for a parabola antenna 15 moves along the rail 11. Therefore the antenna 15 can change its position on the deck. If a mast or funnel of the ship gets into a high frequency transmission line connecting a communication satellite and the antenna 15 to produce a communication fault, the antenna 15 is moved along the rail 11 up to a position where no communication fault arises.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a maritime satellite communication antenna device mounted on a ship.

In recent years, there has been an increasing number of ships adopting maritime satellite communication systems from the standpoint of improving the efficiency of communication means. This communication is carried out between a land-based earth station and a ship earth station mounted on a ship, or between a ship earth station and a ship earth station, via a communication satellite stationary on the equator.

Traditionally, maritime satellite communication antenna systems installed on ships have a parabolic antenna installed on a fixed base at a predetermined position on the ship, and an automatic tracking device ensures that the parabolic antenna points in the direction of the communication satellite at any time. .

However, the conventional maritime satellite communication antenna device described above has the following drawbacks.

(1) High-frequency transmission line (hereinafter referred to as RF line) connecting the ship's 5-Labora antenna, which is a ship's earth station antenna, and the communication satellite.Substantially, the apex angle is 10 degrees from the center of the parabolic antenna to the communication satellite. If a structure that interferes with radio waves enters the cone of a radio wave, it will interfere with communication (generally speaking, it is said that if the sensitivity loss due to the obstacle exceeds 6 dB, communication becomes impossible). A case in which such a communication failure occurs will be explained with reference to FIG. In the figure, 1 is a ship, and a parabolic antenna 3 is installed at a predetermined position on the ship 1 by means of a fixed base 2. Also, ship 1
Above is radar mast 4, which is higher than Lapira antenna 3.
Alternatively, a chimney 5 or the like is provided. On the other hand, S in the figure is a geostationary communication satellite stationary above the equator. At point A on the sea, the radar mast 4 and chimney 5 do not enter the RF line between the antenna 3 and the geostationary communication satellite S, so no interference occurs. However, ship 1
As the satellite moves over the sea, the Norizera antenna 3 tracks the communication satellite S, and at point B on the sea, within the RF line between the Norizera antenna 3 and the communication satellite S (such as the radar mast 4 or the chimney 5) Telegraph failures occur due to interference.

(2) The drawback of (1) above can be avoided by turning the ship's steering when communicating from the ship to land.

This will be explained with reference to FIGS. 2(,) and (b).

In other words, as shown in Figure 2 (IL), the first power of the ship - the first
For example, if you are at point B in the figure, the chimney 5 is in the RF line between the Ladera antenna 3 and the communication satellite S, but if you are at point B in the figure, If the ship 1 is steered to change its direction, the chimney 5 can be removed from the RF line, thereby avoiding communication interference. However, turning the ship every time a communication failure occurs will result in a significant drop in operational efficiency.

(3) Especially for emergency lines, as there is a possibility that the structure of the ship may be inside the RF line when communicating from land to ship. There is a point that there are times when communication is not possible.

(4) It is expected that the drawbacks of (1) to (3) above can be overcome by focusing only on the Via communication characteristics (by installing the laboratory antenna near the top of the ship).

However, if the parazer antenna is sterilized in a high position on a ship, it will require measures to prevent vibrations, which increases costs, and the work for installation and maintenance must be done at heights, which is dangerous.

The present invention was made in order to eliminate the above-mentioned drawbacks, and it is possible to move the antenna horizontally on a ship,
Antenna system for maritime satellite communications that can prevent ship structures from entering the R and F lines without installing the antenna high on the ship, leading to a decrease in operational efficiency. This is what we are trying to provide.

Embodiments of the present invention will be described below with reference to FIGS. 3 and 4.

Reference numeral 11 in FIG. 3 is an antenna moving platform guide fixed on the deck of a ship and having a square cross section and a cable carrier rail 12 on the side surface. A table 13 is placed on a movable edible table along the upper surface of the guide plate 1. This antenna moving table 1
An antenna fixing base 14, which is taller than a conventional antenna fixing base, is fixed on the antenna fixing base 3. Furthermore, on this antenna fixing base 14, height H: 200 to 220 Crn, diameter D: 180 to 200 cm, weight W: 200 to 30
A ladera antenna 15 is fixed. Note that the antenna moving table guide 11 and the antenna moving table 1
3 is the weight of Noyaradera antenna 15 and /-? It has enough strength to withstand the wind pressure and the like that the laboratory antenna 15 receives. 16 in the figure) is an antenna cable that connects the 9 laboratories antenna 15 and the onboard marine satellite communication unit, and is connected along the cable 1 wire rail 12 provided on the side of the antenna moving platform guide 11. It is suspended by a plurality of movably provided cable carriers 17, . . . and introduced into the ship through a deck penetrating fitting 18.

In the antenna device for maritime satellite communication described above, the para-pillar antenna 15 fixed on the antenna moving table 13 by the antenna fixing table 14 can be moved by moving the antenna moving table 13 along the upper surface of the antenna moving table guide 11.
You can change your position on the ship's deck. The power for moving the antenna moving table 13 may be manual, electric, hydraulic, pneumatic, or the like. In addition, the antenna cable 16 is moved from one end of the antenna 1 to the other end as the cable carriers 17, . . . move along the cable carrier rail 12 as the antenna moving table 13 moves. It can be expanded smoothly.

The effects of the above-mentioned maritime satellite communication antenna device are shown in Figure 4
This will be explained with reference to IL) and (b) e. That is, as shown in FIG. 4(,), in the ship 21 equipped with the above-mentioned maritime satellite communication antenna device, the Noyara gelatin antenna 15 is located on the port side of the ship 21, and the chimney is higher than the Lagera antenna 15. Even if a structure such as 22 enters the RF line between communications satellite S...
), the chimney 22 can be removed from the RF line by moving the antenna moving base (not shown) along the antenna moving base guide 1 and positioning the ladera antenna 15 on the starboard side of the vessel 21. As a result, communication failures can always be prevented without causing a decrease in operational efficiency due to steering, unlike ships equipped with conventional devices. -! Just in case, the communication satellite S is stationary, and the ship's current location can be known from astronomical measurements and navigational instruments, and the direction in which the communication satellite S is seen from the ship can be determined in advance. If the antenna 15 is moved to an appropriate position on the ship,
There is no possibility that communication will become impossible during emergency communication from land to ship.

-! In addition, in satellite communication systems, radio waves called TDM carriers are constantly emitted from communication satellites, and ship earth station receivers are equipped with level meters that can monitor the strength of TDM carriers. It is also possible to move the para-pillar antenna 15 to an appropriate position on the ship when the level drops.

Note that the maritime satellite communication antenna device of the present invention can be applied to any of a manual type, a remote control type, and an automatic radio interference removal type.

In the case of a manual type, a roller mechanism is incorporated into the antenna moving base 13 shown in FIG. A locking mechanism may be provided between 13 and the antenna moving table guide.

In addition, in the case of a remote control type, when the level drops by looking at the TDM level meter on the receiver of the satellite communication system,
The antenna moving table 13 may be moved using a remote control switch installed near the receiver. The power source at this time may be electricity, air, hydraulic pressure, or the like.

Further, in the automatic radio wave interference removal method, the antenna moving table 13 is automatically moved depending on the level of the TDM carrier from the communication satellite.

That is, as shown in FIG. 5, the TDM carrier from the communication satellite is received by the paradela antenna 15 and monitored by the TDM carrier level monitor 31. A signal is sent to the antenna moving table drive circuit 34 to move the antenna moving table 13, and the movement is stopped when the reception level falls within 6 dB.

The power source for this movement may be electricity, air, hydraulic pressure, or the like.

Furthermore, the antenna moving table guide or antenna moving table in the antenna device for maritime satellite communication of the present invention is not limited to the structure as in the above embodiments, but may be an I? Other structures may be used as long as the laboratory antenna can be moved in the horizontal direction.

As detailed above, according to the present invention, it is possible to completely prevent the structure of the ship from entering the RF line without installing the antenna at a high place on the ship, and it is possible to maintain good operation at all times without causing a decrease in operational efficiency. It is possible to provide an antenna device for maritime satellite communication that is capable of communication.

[Brief explanation of drawings]

FIGS. 1 and 2 (a) and (b) are explanatory diagrams showing the drawbacks of conventional maritime satellite communication antenna devices, and FIG. 3 is a partially exploded view of the maritime satellite communication antenna device according to an embodiment of the present invention. FIGS. 4(a) and 4(b) are perspective views showing the effects of the antenna device for satellite communication in accordance with the embodiment of the present invention, and FIG. FIG. 3 is a block diagram illustrating the operation of the antenna device for use in the mobile phone. 11... Antenna moving base guide, 12... Cable carrier rail, 13... Antenna moving base, 14...
...Antenna fixing stand, 15...Para-pillar antenna, 1
6... Antenna cable, 17... Cable carrier, 18... Deck penetration fitting, 2... Ship, 22...
...Chimney, 31...70M carrier level monitor, 3
2...TDM level meter, 33...TDM level comparator, 34...Antenna moving platform drive circuit, S...Communication satellite.

Claims (1)

[Claims] An antenna moving base guide fixed on a ship, an antenna moving base movably disposed along the antenna moving base guide, and a 7-magnitude bora antenna fixed on the antenna moving base. An antenna device for maritime satellite communication characterized by the following.