CN209675489U - A kind of crotch type groove low-loss leakage coaxial cable - Google Patents

Abstract

The utility model relates to a kind of leakage coaxial cable, related fields is field of telecommunications cables, is mainly used for the closing occasion such as mine, coal mine, is also widely applied at present in particular surroundings such as market place builet below the ground, subways.Its structure of the utility model leakage coaxial cable successively includes inner conductor, four insulator, outer conductor and sheath parts from inside to outside.Its structure of the inner conductor is corrugated copper tube, and outer conductor is made of surface smooth copper band embossing longitudinal wrap, and slot shape is designed as hook type by the utility model, and U-type groove leakage cable is compared after improved has lower coupling loss, and transmission loss meets national standard.It can be applied to the occasion for having tightened up requirement to coupling loss.

Description

A kind of crotch type groove low-loss leakage coaxial cable

Technical field

The utility model relates to communication cable technical field, in particular to a kind of low-loss leakage coaxial cable.

Background technique

The development of modern society's communication technology and computer technology is very fast, the requirement of people couple and communication quality It is higher and higher.Although the current communication technology can make most of area realize high quality communication, but still have Communication blind district exists, such as the environment such as city underground, high-speed rail and tunnel, mining area, biography of the radio magnetic wave in these environment It is difficult to broadcast, and leakage coaxial cable is exactly a good answer for solving this problem.

The composition of leakage coaxial cable includes that central inner conductor and the closely coupled dielectric of inner conductor and insulation are situated between Matter closely coupled outer conductor and sheath.Regularly there are some slots according to some cycles in outer conductor surface, by leading outside Slot on body can be by electromagnetic wave signal to external radiation, while extraneous electromagnetic wave signal can also be entered by slot and be sewed The inside of cable, therefore leaky cable has the dual property of transmission line and dual-mode antenna.By laying leakage coaxial cable come It is pretty good to solve the communication blind districts effects such as tunnel, high-speed rail and interior.

There is the slit of series of regular on leakage coaxial cable outer conductor, enables coupling loss and transmission loss Reach minimum on its working frequency range, and to external radiation or electromagnetic wave signal can be received in its coverage area, it so can be real The communication work of present blind area.The outer conductor structure of leakage coaxial cable is the key that determine its main performance, and outer conductor is opened Slot mode is to determine one of the principal element of leakage coaxial cable performance.Other influences factor includes slot size and slot Arrangement mode etc..

The relatively common slot of leaky cable has elliptical slot, "-" type slot, splayed slot and type III so far Slot, U-type groove, the leakage coaxial cable of this structure are the main forces of current leakage coaxial cable by studying and practicing for many years. Predict that leakage coaxial cable will be in later communication work according to the development of subway, high-speed rail and three big operators Play the part of prior position, therefore can be higher to the performance requirement of leakage coaxial cable.

For the slot of leaky cable outer conductor, if slot is the rectangular slot along leakage cable axial direction, along slot side Equal in magnitude contrary on the both sides of notch to vertical electric field component, resulting radiation field will be canceled out, therefore The rectangular slot of leakage cable axial direction will not generate radiation.If want generate radiation, need to continue by rectangle slot add perpendicular to The slot of cable axial direction is leaked, this is widely used U-type groove leakage coaxial cable currently on the market.U-type groove structure destroys original The symmetry of horizontal rectangle slot electric field component becomes mark so that forming one direction radiation field at leakage cable axial direction slot Quasi- radial leak coaxial cable.For U-type groove, the size of slot axial component is the main decision of its radiation characteristic Factor, the main function of the axially vertical component of slot are the symmetry in order to destroy electric field component.It is devised according to this principle Hook type slot leakage coaxial cable increases the axial component length of slot, and making the cable under the same conditions can have more Low coupling loss.

Summary of the invention

It is analyzed according to the production principle of above-mentioned U-type groove leakage coaxial cable coupling loss, the utility model devises one kind The leakage coaxial cable of novel slot further reduces the coupling loss of leaky cable under the same conditions.

A kind of novel leakage coaxial cable of the present utility model successively includes that inner conductor, solid are exhausted from inside to outside Edge, five part of slot, outer conductor and sheath, the inner conductor structure are corrugated copper tube, and the outer conductor is by surface smooth copper Band embossing longitudinal wrap is constituted.To solve the above problems, slot is designed to hook type by the utility model, electricity is compared to U-type groove Axially parallel component is more for cable, and the coupling loss of leaky cable can be smaller.

Further, the outer conductor slot is the corrugated copper tape after embossing.Through groove milling process, milled out on outer conductor big Small consistent slot.

Further, the slot is hook type.Leakage coaxial cable slot size is as shown in Figure 2.Slot right end length a It is 20-32mm for 70-82mm, left end length b, axial groove width c is 2.5-4mm, and vertical axial groove width d is 1-5mm, and slot is whole Width e is 8-10mm, and the axial distance f of the adjacent two crotch type groove is 24-40mm, and hook type slot boundary radius of corner is 2mm。

Further, the inner conductor is trough 14.5mm, wave crest 17.3mm, with a thickness of the spiral corrugated copper of 0.35mm Pipe, outer insulation diameter 42.5mm, it for 1.2, loss tangent is 1.7 × 10 that insulating materials, which uses relative dielectric constant,^-5Hair Steep polyethylene.

The utility model keeps the covering of leakage coaxial cable signal equal by the design to leaky cable slotted hole structure and size Even, fluctuation range is small, effectively increases the transmission performance of leaky cable.When working frequency is 900MHz, national Specification The coupling loss of leaky cable should be in 74dB hereinafter, the coupling of U-type groove leakage coaxial cable under this condition on the market at present Loss is generally 70-72dB or so, and hook type leaky cable can achieve 67.87dB in the coupling loss of 900MHz after tested, It is 3-5dB lower than U-type groove leaky cable.

Detailed description of the invention

Fig. 1 is the overall structure diagram of embodiment provided by the utility model.

Fig. 2 is the structural schematic diagram of leaky cable slot in Fig. 1.

Fig. 3 is embodiment coupling loss test result figure.

Specific embodiment

In order to allow the purpose of this utility model, technical solution and advantage to be more clearly understood, below with reference to embodiment and attached Figure, is described in further detail the utility model.

In specific embodiment provided by the utility model, the structure of leakage coaxial cable mainly include inner conductor, with The close-connected insulating layer of inner conductor and with the allo outer conductor of insulating layer.

The main function of inner conductor is the transmission of axial current or signal inside cable, and the main function of insulating layer is internal Conductor insulate, and inner conductor and external conductor is prevented to constitute circuit.

Effect of the outer conductor in leakage coaxial cable is the largest.In outer conductive surface according to certain rule setting one The slot of series, each slot can regard a wave electromagnetic radiation source as, signal while along cable transmission, electromagnetic energy A part is radiated by slot to exterior space, and the electromagnetic field environment for meeting particular requirement is formed, and is reached and is increased signal covering Effect.

Leakage coaxial cable provided by the utility model, in axial direction setting is at least one set of on the surface of outer conductor The crotch type groove of even arrangement, each group of crotch type groove are at least two.In every group of slot, two adjacent slot centers pair Claim, is conducive to the processing of outer conductor in this way, keeps structure simpler.

Leakage coaxial cable slot size provided by the utility model is as shown in Figure 2.Slot right end length a is 70-82mm, Left end length b is 20-32mm, and axial groove width c is 2.5-4mm, and vertical axial groove width d is 1-5mm, and slot overall width e is 8- 10mm, the axial distance f of the adjacent two crotch type groove are 24-40mm, and hook type slot boundary radius of corner is 2mm.Inside lead Body uses trough 14.5mm, wave crest 17.3mm, with a thickness of the spiral corrugated copper pipe of 0.35mm, outer insulation diameter 42.5mm, insulation It for 1.2, loss tangent is 1.7 × 10 that material, which uses relative dielectric constant,^-5Polyethylene foamed.

When working frequency is 900MHz, the coupling loss of national Specification leaky cable should be in 74dB hereinafter, at present The coupling loss of U-type groove leakage coaxial cable under this condition on the market is generally 70-72dB or so.It is chosen in embodiment 42 test points being evenly distributed test its coupling loss, after tested hook type leaky cable the coupling loss of 900MHz can be with Reach 67.87dB, it is 3-5dB lower than U-type groove leaky cable.

The above leaky cable slot parameter is only with the technical solution of the utility model is illustrated, if any requirement of engineering, slot Length and width can also be adjusted.It finds after tested, within the specified scope left and right end edge long a, b of hook type slot and leakage The coupling loss for letting out cable is inversely proportional, axial groove width and vertical axial groove width c, d are directly proportional to the coupling loss of leaky cable. If you need to realize lower coupling loss in working frequency range, can be obtained according to the size of changing rule appropriate adjustment crotch type groove Obtain better performance.

Claims (8)

1. a kind of leakage coaxial cable successively includes inner conductor (1), solid insulation (2), slot (3), outer conductor from inside to outside (4) and (5) five part of sheath, it is characterised in that: the inner conductor structure is corrugated copper tube, and the outer conductor is smooth by surface Copper strips embossing longitudinal wrap is constituted, and on the outer conductor surface, has at least one set of evenly distributed crotch type groove along its axial direction, respectively Group includes at least two crotch type grooves, and the notch of the adjacent two crotch type groove is centrosymmetric in each group.

2. leakage coaxial cable according to claim 1, which is characterized in that the right end length of the crotch type groove is 70- 82mm, left end length are 20-32mm.

3. leakage coaxial cable according to claim 1, which is characterized in that the axial groove width of the crotch type groove is 2.5- 4mm, vertical axial groove width 1-5mm.

4. leakage coaxial cable according to claim 1, which is characterized in that the crotch type groove integral channel width is 8- 10mm, the axial distance of adjacent two crotches type groove are 24-40mm.

5. leakage coaxial cable according to claim 1, which is characterized in that the hook type slot boundary radius of corner is 2mm。

6. leakage coaxial cable according to claim 1, which is characterized in that the inner conductor trough is 14.5mm, wave crest For 17.3mm, with a thickness of the spiral corrugated copper pipe of 0.35mm.

7. leakage coaxial cable according to claim 1, which is characterized in that the outer conductor diameter is 42.5mm.

8. leakage coaxial cable according to claim 1, which is characterized in that leaky cable further includes the outer conductor and shield Set, the effect of sheath is to prevent mechanical damage, and the outer wall of the outer conductor is close to the inner wall surface of the sheath.