JPS5814762B2 - antenna cable - Google Patents

Description

[Detailed description of the invention] The present invention relates to improvements in cable construction.

When performing wireless communication at a frequency of 1 MHz or less near a cable that has been laid for a certain purpose, conventionally the cable and antenna wire were laid separately and used for each purpose, as shown in Figure 1. was.

In this case, it takes twice a lot of effort to install the cable and the antenna, and depending on the location, the aesthetics can be seriously impaired.

In FIG. 1, 1 is a cable, 2 is an antenna, 3 is a power supply device, and 4 is a receiver.

SUMMARY OF THE INVENTION An object of the present invention is to reduce costs, shorten the time required for installation, and improve the aesthetic appearance by manufacturing the cable body and the antenna wire in an integrated manner.

The gist of the present invention is to utilize the longitudinally attached or spirally wound conductor as an antenna wire by vertically attaching or spirally winding a conductor to a cable body and feeding a signal from near the middle of the state diagram.

The structure of the present invention will be specifically explained with reference to FIGS. 2 and 3 showing embodiments.

(1) As shown in FIG. 2, one conductor 5 is attached vertically to the outside of the cable body 1.

The conductor 5 is cut near the middle and the power supply device 3 is placed.

The approximate length of the vertical conductor that radiates radio waves most efficiently can be determined by the following formula.

l≒c/2f—(1) However, l=vertical conductor length (m),
c: constant (3 x 108 m/s), f: frequency (Hz) of the signal to be fed.

(2) As shown in Figure 3, multiple conductors are attached vertically to the outside of the cable body.

When used as an antenna, one of the plurality of conductors is cut near the middle and a signal is fed from this.

Both terminals of the vertical conductor are short-circuited. At this time, the approximate length of the vertically attached conductor through which radio waves are radiated most efficiently is shown in (1) above.
Determined from the formula.

That is, they operate as a 1/2 wavelength dipole antenna or a folded dipole antenna.

By using the cable of the present invention, the cost of the cable including the antenna is reduced, and by installing the cable only once, it is possible to simultaneously achieve the intended use of the cable and wireless communication in the vicinity of the installed cable.

If the vertically connected conductor does not resonate at the frequency of the signal being fed, the length of the vertically connected conductor can be electrically adjusted by inserting a coil or capacitor in the middle or at both ends of the vertically connected conductor. It can emit radio waves.

Further, in FIGS. 2 and 3, the longitudinally attached conductor 5 may not be in a straight line but may be in a spiral shape with respect to the cable 1.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the configuration of wireless communication when conventional antenna wires are installed independently; FIG. 2 is an explanatory diagram showing an embodiment of the present invention in which a single conductor is attached vertically to a cable; FIG. 3 is an explanatory diagram of one embodiment of the present invention in which a plurality of conductors are attached vertically to a cable. 1: Cable body, 2: Antenna, 3: Power supply device (transmitter), 4: Receiver, 5: Vertical conductor.

Claims (1)

[Claims] 1. The cable body and the cable body to be used as an antenna wire are insulated and consist of a conductor attached vertically or spirally wound on the outside of the cable body, and a power supply device installed near the center of the conductor. A cable with an antenna characterized by: