JPS639205A - Telescopic multi-stage antenna - Google Patents

Abstract

PURPOSE:To radiate a radio wave efficiently at the expansion by providing a flexible radiation element in the inside of an outer tube constituted telescopically in a way that a radiation part and a shield part are formed alternately and fixing the upper part of the radiation element to the upper part of the outer tube. CONSTITUTION:The outer tube 1 is constituted in a way that radiation parts 2, 3, 4, 5 made of a low dielectric substance and shield parts 6, 7, 8 made of a metal or the like are arranged alternately telescopically by a slide member 9. A flexible radiation element 11 connected to a coaxial feeder 10 is penetrated in the inside of the outer tube 1 and the outer tube 1 and the element 11 are formed coaxially. In gripping a top 12 by a hand and drawing it out, the antenna is expanded as shown in figure and in pushing down the top, the antenna is contracted to minimiaturize The radio wave on the element 11 is shielded by the shield parts 6, 7, 8, the radiated phase of the radiation parts 2, 3, 4, 5 is in phase to attain the efficient radiation of the radio wave. The length of the radiation parts and the shield parts is nearly lambda2 electric length and the length of the radiation part 5 is nearly lambda4 electric length.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an invention for configuring a multi-stage antenna in a telescopic manner.

To specifically describe the embodiments of the present invention, 1 is a general term for the telescoping portion of the outer tube. The configuration of the outer tube 1 is 2,
The radiating parts 3, 4, and 5 (this part consists of tubes made of insulators with a low dielectric constant) and the shielding parts 6, 7, and 8 (this part consists of metal tubes made of materials that prevent the radiation of radio waves). consists of a radiation part 2 and a shielding part 6, a shielding part 6 and a radiation part 3, and a radiation part 3.
and shielding part 7, shielding part 7 and radiation part 4, radiation part 4 and shielding part 8
The shielding part 8 and the radiation part 5 are respectively combined in a telescopic manner and configured to slide and expand and contract by a sliding part machine 9. A flexible radiating element 11 connected to the coaxial feeder line 10 is penetrated into the inside of this retractable outer tube 1, and the outer tube 1 and the radiating element 11 are connected to each other.
are formed coaxially. Further, the tip of the flexible radiating element 11 is fixed to a top 12 fixed above the radiating section 2 . Further, if the radiating section 2 has a radiating element fixed therein, the tip of the flexible radiating element 11 may be coupled to the lower end of the radiating element fixed at the bottom of the radiating section 2. In this explanation, the radiating element 11 will be explained using the polyethylene coating 13 and core wire 14 of the coaxial feeder line 10,
If this is made into a space-wound coil spring-like radiating element, the present invention has an element that becomes a multi-stage antenna having an extension circuit. The reason why the radiating element 11 is made flexible is to satisfy the requirement that the radiating element 11 becomes coiled and can be housed without any trouble when the outer tube 1 is retracted into the cable storage part, which will be described later. The radiating element 11 includes radiating parts 2, 3, 4, and 5 and a shielding part 6,
Stabilizers 15 provided at the bottom of the outer tubes 7 and 8 allow the extended region of the outer tube 1 to be located at the center of the outer tube 1 when retracted. Reference numeral 16 denotes an outer tube, which, as shown in FIG. 2, consists of a portion 17 that also accommodates the telescoping outer tube 1 when retracted, and a cable accommodating portion 18 that accommodates the coaxial feeder line 10 and the flexible radiating element 11 in a coiled manner.A bulkhead 19 It is distinguished by Coaxial feed line 10
The boundary point (usually the feeding point) between the outer conductor 20 (blade) of the coaxial feeding line 10 and the radiating element 11 is folded back to have an electrical length of about 2/4 of the target frequency to measure impedance matching. It is desirable to cover the surface of this folded portion with a heat shrinkable tube such as polyolefin.

Although not shown, as another matching method, a stub or the like may be installed in the trap area. The other end of the coaxial feeder line 10 is connected to a receptacle 21 provided at an appropriate position in the cable accommodating portion 18 of the outer tube 16. If a super top is installed at the position of this receptacle 21, impedance matching can be measured without the need to fold back the electrical length of the external conductor 20 of the coaxial feed line 10. Although not shown, a connector is connected to this receptacle 21 to a conjunction communication device. The outer tube 16 is configured to be attached to an attachment portion 23 by an attachment member 22 provided outside the outer tube 16 .

In the explanation of this embodiment, the cable accommodation section 18 was used. However, if the cable accommodation section 18 is not provided and the retractable multi-stage antenna of the present invention is attached to the cowl near the trunk of a car, for example, If the coaxial feeder line 10 and the flexible radiating element 11 are housed in the trunk, the cable accommodation section 18 can be made unnecessary.

As shown in this embodiment, according to the present invention, when the top 12 is pulled out by hand, it expands as shown in FIG. 1, and when it is pushed down, the outer tube 1 contracts as shown in FIG. 2, thereby reducing the size. be. The electrical equivalent circuit when the retractable multi-stage antenna in this explanation is extended is the third one.
With something like the one shown in the figure, the radio waves riding on the flexible radiating element are shielded by the shielding parts 6, 7, and 8, and the radiation phases of the radiating parts 2, 3, 4, and 5 are in the same phase, resulting in efficient radio waves. Radiation can be measured. For reference, the dimensions of the radiating part and shielding part of the telescoping outer tube 1 in the experiment are radiating parts 2, 3, 4 and shielding parts 6, 7, 8.
The length of the radiating portion 5 is approximately ■ electrical length, and the length of the radiation portion 5 is approximately ■ electrical length. In this case, a gain of about 7 db was obtained in dipole ratio.

In this explanation, the radiating parts 2, 3, 4, 5 and the shielding parts 6, 7, 8 of the telescoping outer tube 1 are set for each section and have a constant frequency. Even if the radiating part is provided in a part of the shielding part instead of each section, or by changing the length relationship of the radiating parts 2, 3, 4, 5 and the shielding parts 6, 7, 8, it can be configured as a multi-frequency antenna. I can do it. In this explanation, there are four radiating sections, but it is also possible to have more or fewer radiating sections. In addition, in this explanation, manual expansion and contraction has been explained, but if the flexible radiating element 11 is electrically driven by a drive device and the telescoping outer tube 1 is extended and contracted, the telescoping multi-stage antenna of the present invention can be realized. It is even more convenient to use.

The present invention is based on the telescopic co-linear antenna of Japanese Patent Application No. 1983-256130, which was previously discussed, and its effects and features are limited only to the accuracy of the length relationship between the radiating part and the shielding part of the retractable outer tube. The first thing is that the frequency characteristics can be obtained and the short tube (
Since it is manufactured by expanding and contracting a tube with a low dielectric constant and a metal or similar tube, there is no difficulty in manufacturing and it can be easily manufactured, from small antennas (for mobile stations) to long antennas that were previously unimaginable. Since there is no electrical contact with the radiating element located at the center coaxially with the outer tube, there is little dielectric loss and the radiation efficiency is extremely good. Combined with this, it is possible to form an antenna with unprecedented high gain. Also, any type of radiating element can be formed into a multi-stage antenna, so if you use the linear radiating element described in this explanation as the radiating element, or the space-wound coil spring-shaped element described in the previous explanation, you can create a multi-stage antenna with an extension circuit. A high gain antenna can also be formed. As described above, according to the present invention, by selecting the flexible radiating elements to be installed inside the outer tube as necessary, it is possible to configure a telescopic multi-stage antenna with freely adjustable characteristics. In addition, the elasticity of the present invention is compact, making it convenient to transport and easy to handle.In use, it can be retracted when not in use, so it does not get in the way, and when installed in a car, etc., it is easy to wash the car. It is very convenient because there is no need to remove it when putting it in the garage or when putting it in the garage.

Since radio frequencies are moving to higher frequencies in the future, it is natural that antennas will be in an era of higher gain, and from this point of view as well, the telescopic multi-stage antenna of the present invention can bring convenience to society.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an extended state of a telescoping multi-stage antenna according to an embodiment of the present invention, FIG. 2 is a sectional view showing its retracted state, and FIG. 3 is an electrical equivalent circuit. 1... Telescoping outer tube, 2, 3, 4, 5... Radiation part, 6
, 7, 8... Shielding part, 9... Sliding part machine, 10...
Coaxial feeder line, 11... Flexible radiation element, 12... Top, 13... Polyethylene coating, 14... Core wire,
DESCRIPTION OF SYMBOLS 15... Stabilizer, 16... Outer cylinder, 17... Outer tube storage part, 18... Cable storage part, 19... Partition wall, 2
0...Outer conductor, 21...Receptacle, 22...
・Mounting part machine, 23...Mounting part

Claims (1)

[Claims] A flexible radiating element is installed inside an extensible outer tube with alternating radiating parts and shielding parts, and the outer tube and the radiating element are coaxially arranged. A retractable multi-stage antenna configured by fixing.