JPH0652214U - Dual frequency antenna - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a dual-band dual-antenna that operates in the dual-frequency band specific to the radio buoy and the L-band for GPS reception. A L-band helical antenna 6 is attached to a lower end of a loading coil 4 of a center loading antenna 2 used in the medium wave band.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a radio buoy antenna used for fisheries or for ocean observation.

[0002]

[Prior art]

 Conventionally, the frequency band used for radio buoys for fisheries has often been a medium frequency band capable of long-distance notification, and the antenna has also been adapted to that. In some cases, such as ocean current surveys, a position measuring device such as a Loran receiver is installed in the same radio buoy, but since the frequency used is close to that of the radio buoy, the antenna is shared as is. I was able to.

[0003]

[Problems to be solved by the device]

 However, when a GPS (Global Positioning System) receiver operating at an L-band frequency is used as a position measuring device incorporated in a radio buoy, the two frequencies cannot be shared because they are far from each other. In order to operate the GPS receiver effectively, it is desirable to install the antenna as high as possible on the sea surface, but there is no room to install two antennas on a small radio buoy floating on the sea surface. There is.

The present invention has been made in order to solve such a problem, and it is an object of the present invention to cover two widely separated frequency bands with a single antenna.

[0005]

[Means for Solving the Problems]

 In the dual-frequency band antenna according to the present invention, the helical antenna operating in the L band is attached to the lower end of the loading coil of the center loading antenna operating in the medium frequency band.

[0006]

[Action]

 According to the dual frequency band antenna of the present invention, the antennas for the medium wave band and the L band can be configured by one antenna, and the sea level required for GPS reception can be increased.

[0007]

【Example】

 An embodiment of the dual frequency band antenna according to the present invention will be described below with reference to the drawings. FIG. 4 is a diagram showing a configuration of a conventional radio buoy and an antenna, 1 is a radio buoy main body, and 2 is a center loading antenna for the medium wave band. The center loading antenna 2 includes a lower rod 3, a loading coil 4, and an upper rod 5, which are fitted with screws. FIG. 1 is a view showing the structure of a dual-band antenna according to the present invention. Reference numeral 6 denotes an L-band helical antenna portion, which is fitted between the lower rod 3 and the loading coil 4 with a screw. FIG. 2 is a diagram showing the structure of the helical antenna section 6, where 7 is an outer cylinder coated with FRP for reinforcement, 8 is a helical antenna body, 9 is a fitting screw, and 10 is a coaxial plug. A cable for transmitting GPS signals to the buoy body is connected. Reference numeral 11 denotes a conductive wire that directly connects the lower rod 3 and the loading coil 4.

Further, although the helical antenna unit 6 is described as a single unit in the above embodiment, it may be integrated with the loading coil 4 as shown in FIG.

[0009]

[Effect of device]

 As described above, according to the present invention, a single antenna can be used for the antenna operating in the two bands of the medium wave band specific to the radio buoy and the L band for GPS reception.

[Brief description of drawings]

FIG. 1 is a structural diagram of a dual frequency band antenna according to the present invention.

FIG. 2 is a structural view of a helical antenna unit according to the present invention.

FIG. 3 is a structural diagram of a case where a helical antenna unit and a loading coil according to the present invention are integrated.

FIG. 4 is a diagram showing a configuration of a radio buoy and a center loading antenna.

[Explanation of symbols]

1 Radio buoy body 2 Center loading antenna 3 Lower rod 4 Loading coil
5 Upper Rod 6 Helical Antenna 7 Outer Cylinder 8 Helical Antenna Main Body 9 Screw 10 Coaxial Plug 11 Conductor

Claims (1)

[Scope of utility model registration request] 1. A dual frequency band antenna, wherein an L band helical antenna is attached to a lower end of a center loading coil of the medium frequency band antenna.