CN101140817A

CN101140817A - Leaky coaxial cable

Info

Publication number: CN101140817A
Application number: CNA2006100375313A
Authority: CN
Inventors: 寿伟春; 邹智; 吴欣欣
Original assignee: ZHUHAI HANSEN INDUSTRIES Corp
Current assignee: ZHUHAI HANSEN INDUSTRIES Corp
Priority date: 2006-09-06
Filing date: 2006-09-06
Publication date: 2008-03-12
Anticipated expiration: 2026-09-06
Also published as: CN100483567C

Abstract

The invention relates to the communication field, especially relating to a leaky coaxial cable, which comprises in turn from interior to exterior an inner conductor extending along the longitudinal axis of the cable, an insulant, an outer conductor and a sheath. The insulant separates the inner conductor from the outer conductor around which punched with V-shape slotted hole. The V-shape slotted hole is 135 to 145 degrees in flare angle, 80 to 85 mm in length, 4.5 to 5.0 mm in width and 110 to 115 mm in half-pitch. The leaky coaxial cable provided in the invention changes the notch shape on the outer conductor with slot hole of the prior leaky coaxial cable, wherein the U-shape and the inverted V-shape slot in prior technology are replaced by the V-shape slot. By the structure of the slotted holes and high-precision thin copper belt punching technology, the leaky coaxial cable with the outer conductor with V-shape slot offered in the invention guarantees the consistency of the cable radiation characteristic alongst and improves the relay amplifying distance as well as the multipath fading characteristic.

Description

A kind of leaky coaxial cable

Technical field

The present invention relates to communication field, relate in particular to a kind of leaky coaxial cable.

Background technology

In recent years, foreign railway has used the GSM-R system in a large number, it is that International Union of Railways is the technical standard of European railway wireless mobile communication exploitation of new generation, be to utilize to be widely used in the upgrading system of the GSM of public mobile communication, form by the interface of wireless network, switching network and other communication networks at the railroad train wireless dispatch system.Because train dispatching system is with respect to the requirements at the higher level of public mobile communication, particularly fail safe and ageing aspect requirement we can say very harsh.At the use frequency range of GSM-R leaky coaxial cable is optimized design like this, specially and becomes very necessary.At present, though the GSM-R of different manufacturers production has their own characteristics each with leaky coaxial cable, but the technological means of basic principle and employing is roughly the same, mainly is made up of four parts such as the outer conductor in inner wire (2,2`), insulating barrier (5,5`), trough of belt hole (1,1`) and sheaths (4,4`) referring to Fig. 1 and Fig. 2 product.By on outer conductor, opening one group of periodically difform slotted eye in advance, make different coupling losses minimum in the regulation frequency range with vertical transmission attenuation, reduce the dynamic range of incoming level; Simultaneously, can introduce radiofrequency signal Anywhere underground again, and can be in place that it is passed by to external radiation or received RF signal, just as a continuous antenna, thereby realize underground mobile communication, existing GSM-R mostly is U type 3 ', splayed configuration 3 or ellipse with the outer conductor slotted eye of leaky coaxial cable, and the multipath fading characteristic of coaxial cable with these shape slotted eyes is not ideal enough.

Summary of the invention

The present invention has overcome shortcoming of the prior art, provides a kind of multipath fading characteristic better leaky coaxial cable.

In order to solve the problems of the technologies described above, be achieved through the following technical solutions:

A kind of leaky coaxial cable, it comprises an inner wire from inside to outside successively, it extends along the longitudinal axis of cable; One insulating material, an outer conductor and sheath, this insulating material separates internal and external conductor, has slotted eye in the outer conductor outside, and wherein, described slotted eye is a V-type.

This V-type groove subtended angle is 135～145 degree, and the V-type slot length is 80～85mm, and the V-type well width is 4.5～5mm, and V-type groove half-section distance is 110～115mm.

Leaky coaxial cable of the present invention has changed the notch shape of trough of belt hole outer conductor in the existing leaky coaxial cable, replaces U type groove of the prior art or splayed configuration groove with V-shaped groove.V-type groove outer conductor leaky coaxial cable of the present invention is by the improvement of slotted hole structure and high-precision thin copper belt punching technology, guaranteed cable radiation characteristic consistency in the longitudinal direction, the relaying hyperplastic distance that has improved cable from, also improved the multipath fading characteristic of cable.

Description of drawings

Fig. 1 is a splayed configuration groove outer conductor leaky coaxial cable structural representation in the prior art;

Fig. 2 is a U type groove outer conductor leaky coaxial cable structural representation in the prior art;

Fig. 3 is splayed configuration groove outer conductor leaky coaxial cable coupling loss and probability of acceptance figure in the prior art;

Fig. 4 is U type groove outer conductor leaky coaxial cable coupling loss and probability of acceptance figure in the prior art;

Fig. 5 is a V-type groove outer conductor leaky coaxial cable structural representation of the present invention;

Fig. 6 is V-type groove outer conductor leaky coaxial cable coupling loss of the present invention and probability of acceptance figure.

Embodiment

Referring to Fig. 5, a kind of novel V-type groove outer conductor leaky coaxial cable, it comprises inner wire 12, insulating barrier 15, V-type groove punched copper tape vertical bag outer conductor 11 and 14 4 parts of sheath; Compare with the leaky coaxial cable of different slots hole shapes such as traditional U type groove (see figure 2), splayed configuration groove (see figure 1), leaky coaxial cable outer conductor 11 of the present invention has adopted V-type slotted eye 13 project organizations that improve the multipath fading amplitude, this V-type slotted eye 13 subtended angle A are 135～145 degree, V-type slot length L is 80～85mm, V-type well width H is 4.5～5mm, and V-type groove half-section is 110～115mm apart from S.

The radiation mode of outer conductor 11 is most important for the signal radiation of leaky cable.After signal sews out, when arriving receiving equipment, can produce multipath fading from the slotted eye 13 of leaky cable outer conductor 11, the coupling loss amplitude fluctuation situation in the longitudinal direction that this index can qualitative corresponding leaky cable through different paths.Referring to Fig. 3 and Fig. 4, usually traditional leaky coaxial cable coupling loss index amplitude fluctuation in the longitudinal direction all more than 20dB, have in addition reach 40dB.Referring to Fig. 6, this project is by adopting the structural design of special V-type slotted eye 13, improve the multipath fading performance of product greatly, made coupling loss amplitude fluctuation in the longitudinal direction be controlled at 10dB even littler, improved the communication quality in the actual use.

" leaky coaxial cable of specification is an example, and when 900MHz, the concrete coupling loss index of the leaky coaxial cable amplitude fluctuation situation in the longitudinal direction of V-type groove, splayed configuration groove, three kinds of difformity slotted eyes of U type groove is seen Fig. 3, Fig. 4, Fig. 6 respectively with 7/8.

The system design of leaky coaxial cable not only will be considered the landform situation in field strength coverage territory, the actual requirement of radiation areas area, but also to consider some important electric parameters of leaky coaxial cable: transmission attenuation and coupling loss, satisfy the specification requirement of engineering design to guarantee up, the descending signal transmission of leaky coaxial cable." leaky coaxial cable of specification is an example, and V-type groove, splayed configuration groove, the concrete maximum attenuation of leaky coaxial cable of three kinds of difformity slotted eyes of U type groove, the specific targets of coupling loss see Table 1 with 7/8.

Table 1: the leaky coaxial cable maximum attenuation of difformity slotted eye, coupling loss index

Know from last table and Fig. 3, Fig. 4, Fig. 6, outer conductor adopts the particular design of V-type groove, can optimize the combination property of leaky coaxial cable in 800～900MHz frequency range, make product have advantages such as the multipath fading characteristic is excellent, the coupling loss fluctuation is little, radiation field intensity is even, electric property is stable.Therefore, in the GSM-R system, adopting V-type groove outer conductor leaky coaxial cable is to solve the leaky coaxial cable field intensity to cover stable, inhomogeneity optimal path.

For radial leak coaxial cable, its another key technology is that flat indulging wrapped the copper strips outer conductor layer that one deck has slotted eye with covering in the insulating barrier outside.The present invention is by to the The Automation Design of punching technology, make this equipment outside on the conductor copper strips according to the physical dimension that designs in advance, high accuracy is automatically gone out specific slotted eye.Simultaneously, by research and design and optimization to vertical bag link, make the metal sheet band that has slotted eye very flatly to indulge with covering and wrap in surface of insulating layer, and guaranteed the integrality and the consistency of slotted hole structure effectively, thereby further guaranteed the stability of the coupling loss index of whole cable.

V-type groove outer conductor leaky coaxial cable of the present invention adopts the slotted hole structure designing technique of improving multipath fading amplitude and radiation characteristic, make radiofrequency signal can be equably spread out of by slotted eye and import into, thereby in these signal limitation zones, realize radio communication along cable.This product has advantages such as multipath fading is excellent, the coupling loss fluctuation is little, radiation field intensity is even, electric property is stable.Using this product can improve the coverage of radio wave widely, eliminate transmission blind spot, is one of vitals the most suitable in the present GSM-R system.

The only unrestricted technical scheme of the present invention in order to explanation is more than described.Any modification or partial replacement that does not break away from spirit and scope of the invention all should be encompassed in the middle of the claim scope of the present invention.

Claims

1. leaky coaxial cable, it comprises an inner wire from inside to outside successively, it extends along the longitudinal axis of cable; One insulating material, an outer conductor and sheath, this insulating material separates internal and external conductor, has slotted eye in the outer conductor outside, it is characterized in that, and described slotted eye is a V-type.

2. leaky coaxial cable according to claim 1 is characterized in that, described outer conductor is the vertical bag of a copper strips outer conductor.

3. leaky coaxial cable according to claim 1 is characterized in that, described V-type groove subtended angle is 135～145 degree.

4. leaky coaxial cable according to claim 1 is characterized in that, described V-type slot length is 80～85mm.

5. leaky coaxial cable according to claim 1 is characterized in that, described V-type well width is 4.5～5mm.

6. according to any described leaky coaxial cable among the claim 1-5, it is characterized in that described V-type groove half-section distance is 110～115mm.