JPS61152101A - Horizontal planar nondirectional antenna for float - Google Patents

Abstract

PURPOSE:To eliminate the influence due to the fluctuation of a float by supporting movably an antenna main body and setting the moving direction so as to intersect orthogonally with the longitudinal direction of the float. CONSTITUTION:The antenna main body 1 of a dipole stack-type horizontal planar nondirectional antenna P is movably supported by a uniaxial gimbal 2 fitted on the top of a radome 1. Thus, the main body 1 can be vertically held even without fail if the vessel equipped with the radome 3 rolls and pitches. A cable 5 is connected to the top of the main body 1 through a connector 4. When the antenna P is fitted on the mast 11A of the float 11, in light of the fluctuating characteristic of the float 11, the antenna P is provided so that the fluctuating direction Y can be orthogonally intersected with the longitudinal direction (bow-stern direction) of the float 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a dipole stack type horizontal omnidirectional antenna that is attached to a floating body such as a buoy or a ship.

(Background of the invention) Horizontal omnidirectional antennas are known as
Coaxial dipole antenna (dipole stack antenna) is described in P. 138 of ``Antenna Engineering Handbook''. According to this document, dipole stack antenna is made by cutting a circumferential slot in the outer conductor of the coaxial feed line. This is an antenna type antenna with a cylindrical dipole antenna attached to its periphery, and this antenna has a characteristic of having uniform directivity in the horizontal plane.

When trying to obtain a high gain using a dipole stack antenna (hereinafter referred to as an antenna) as described above, the beam width in the vertical direction may become narrow. Therefore, when the antenna 2 is fixed to the ball of the floating body 110 in the communication system between the floating body 11 and the fixed or moving body 14 located at a fixed position above the water surface as shown in FIG. When the floating body 11 and the antenna 12 are in a horizontal stable state, the fixed or moving body 14 is within the range of the antenna beam 13.

However, as shown in FIG. Because of the existence of the floating body 11 and the fixed or moving body 14, mutual communication becomes impossible.
In order to avoid this situation, even if the floating body 11 oscillates as shown in FIG. 1(C), the antenna 12 must be
), maintaining a level safety state is a fixed point.
It is possible to place the moving object 14 within the range of the antenna beam 13 as shown in FIG. A signal is generated, and this signal drives a hydraulic servo or the like to correct the fluctuation of the antenna. As a result, the amount of hardware/software increases, which not only increases the size and weight of the stabilizer 2-ize mechanism, but also poses a risk of lowering reliability.

[Purpose of the invention]

In view of the above points, the present invention provides a floating horizontal omnidirectional antenna that is small in size and has a simple structure, and is capable of automatically correcting oscillations and maintaining a stable horizontal state at all times. The purpose is to

[Summary of the Invention] In order to achieve the above object, the present invention supports a dipole stack type horizontal omnidirectional antenna so that its antenna body can swing, and the direction of the swing is perpendicular to the longitudinal direction of the floating body. It is characterized by being set to .

[Embodiments of the invention]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before explaining one embodiment of the present invention with reference to the drawings, the principle of the present invention will be described below.

An example of the specifications of a dipole stack type horizontal plane omnidirectional antenna is shown in the table below.

According to the table above, if the vertical beam width is 10°, the maximum amplitude in the pitch direction of the floating body is limited to ±5°, and if the maximum amplitude in the pitch direction can be suppressed to ±5°, the oscillation correction can be made in the roll direction. can be limited to. In other words, it is easily understood that the oscillation correction only needs to work on one axis.

Based on the above, if a dipole stack type horizontal omnidirectional antenna is suspended in a pendulum shape so that it oscillates only in the -axis direction, the axis of the antenna is held in the vertical direction and the antenna is always stabilized in the horizontal plane. It is possible to do so.

The unusual configuration of this embodiment based on the above-mentioned principle is explained in detail in FIG. 2. This FIG. 2 is a partially cutaway perspective view of the antenna of this embodiment.
The dipole stack type horizontal omnidirectional antenna P
An antenna main body 1 is swingably supported by a uniaxial gimbal 2 mounted on the top inside a radome 5. In other words, since the antenna main body 1 is suspended by the -axis gimbal 2 and held in a pendulum state, the antenna body 1 is suspended from the -axis gimbal 2 and held in a pendulum state, so that the radome 3 is attached to the ship body (see FIG.

Even if the antenna (not shown) is shaken, the antenna body 1 is always connected.

It is possible to hold it in a vertical position.

A cable 5 is connected to the top end of the antenna body 10 via a connector 4, but depending on the frequency etc., a rotary joint and a flexible waveguide may be used in place of the component 4.5.

A horizontal omnidirectional antenna P having the structure described above.
When the antenna P is attached to the floating body 11 (mass) 11A as shown in FIG. It is provided so as to be perpendicular to the longitudinal direction (fare-stern direction) x-x' of the body 11.

The radome 3 prevents the antenna body 1 from shaking due to the influence of rain, wind, etc., and also prevents the hull 11 from moving beyond the design standard.
It serves as a stopper and mounting legs in case of movement.

〔Effect of the invention〕

As explained above, according to the present invention, even if the floating body oscillates, it is possible to automatically correct the oscillation and maintain it in a stable horizontal state at all times due to the small and simple structure. A horizontal omnidirectional antenna can be provided. Therefore, according to the present invention, in maritime mobile communication by a floating object, the lit! Has the effect of eliminating the influence of 揖0

[Brief explanation of drawings]

Figures 1 (α) to (C) are explanatory diagrams of a communication system between a floating body and a fixed or moving body, and Figure 2 is an example of a horizontal omnidirectional antenna for mounting on a floating body according to the present invention. The partially cutaway perspective view shown in FIG. 5(α) and FIG. 5(A) are a plan view and a front view illustrating a state in which the embodiment shown in FIG. 2 is attached to a floating body.

Claims (1)

[Claims] A dipole stack type horizontal omnidirectional antenna for a floating object, characterized in that the antenna body is supported so as to be swingable, and the direction of the swing is set perpendicular to the longitudinal direction of the floating object. antenna.