CN103700914A

CN103700914A - Rectangular waveguide covered with dielectric layer

Info

Publication number: CN103700914A
Application number: CN201410005640.1A
Authority: CN
Inventors: 王均宏; 张冲; 陈美娥; 张展; 李铮
Original assignee: Beijing Jiaotong University
Current assignee: Beijing Jiaotong University
Priority date: 2014-01-06
Filing date: 2014-01-06
Publication date: 2014-04-02

Abstract

The invention discloses a rectangular waveguide covered with a dielectric layer in the technical field of communication cables. A waveguide structurally comprises the rectangular waveguide and the dielectric layer, wherein the dielectric layer is arranged on the rectangular waveguide; the wall of the rectangular waveguide is provided with a slot array formed by a plurality of slots at uniform intervals along the axis direction. The dielectric layer is added on the rectangular slot waveguide, and the electric field intensity of a working area on the surface of the rectangular slot waveguide is obviously improved; the divergence degree of an electromagnetic field is reduced; meanwhile, proper thickness and dielectric constant of the dielectric layer are selected, and the radiation intensity of a working area of a rectangular slot waveguide cable can be controlled. The rectangular waveguide can be applied to a communications based train control (CBTC) railway mobile communication system, the near field intensity on the upper side of the rectangular slot waveguide is improved, the space convergence of an electric field is improved, and the system has the best working condition.

Description

A kind of rectangular waveguide of blanket dielectric layer

Technical field

The invention belongs to telecommunication cable technical field, relate in particular to a kind of rectangular waveguide of blanket dielectric layer.

Background technology

Rectangular aperture waveguide is mainly opened series of periodic gap by the appropriate location at wave guide wall and direction, thus radiation and reception radio wave effectively, and distant place electric wave is not impacted, be not subject to the interference of general electric wave at a distance yet.At present, in the moving block system based on radio communication (CBTC), the two-way continuous communiction between car ground is mainly realized by rectangular aperture waveguide.Current, the main 2.4GHz open frequency range that adopts of car-ground radio transmission of moving block system, the rectangular aperture waveguide that is wherein applied to 2.4GHz can be transmitted main energy, in transmitting procedure only in the cable very little part energy of radiation in certain limit around, form a radio wave passage that radial extension is limited, can extend with limited energy the operating distance of electric wave so as far as possible, thereby improve communication quality.

The electric field that typical rectangular aperture waveguide antenna goes out presents and disperses relaxation phenomenon when away from rectangular waveguide, and after receiver is apart from rectangular aperture waveguide top certain distance, the level receiving cannot meet receiver sensitivity requirement.And the two-way communication of waiting for bus between ground for existing CBTC, effective service range of rectangular aperture waveguide is generally in 50cm.Meanwhile, rectangular aperture waveguide during as reception antenna, can be received transmitting of train antenna, can receive the interference signal from other electronic equipments again; Conversely, when train antenna is as reception antenna, rectangular aperture waveguide is during as transmitting antenna, and train antenna also can be received the interference from the electronic equipment except rectangular aperture waveguide.

Summary of the invention

The present invention is directed near field intensity and the space convergence that how can improve rectangular aperture waveguide antenna electric field, thereby improve the resolution that receives useful signal, and reduce the problem of the interference of other signals, proposed a kind of rectangular waveguide of blanket dielectric layer.

A rectangular waveguide for blanket dielectric layer, is characterized in that, described waveguide comprises rectangular waveguide and dielectric layer; Described dielectric layer is placed on rectangular waveguide.

On described rectangular waveguide wall, along axis direction, equally spaced have some gaps and form gap array.

The span of described thickness of dielectric layers is between zero-sum reception antenna and the distance of rectangular waveguide.

The span of the dielectric constant of described dielectric layer is the dielectric constant that is greater than air.

The fluting of described gap array is rectangular channel, U-lag or the Eight Character trough.

The invention has the beneficial effects as follows compared with prior art, in rectangular aperture waveguide, add dielectric layer, significantly increase the electric field strength of rectangular aperture waveguide surface service area; Reduce the degree of divergence of electromagnetic field; Simultaneously by selecting thickness and the dielectric constant of suitable dielectric layer, radiation field intensity that can control rectangle gap waveguide cable service area, makes system reach optimum Working.

Accompanying drawing explanation

Fig. 1 is the overall construction drawing of the rectangular aperture waveguide embodiment 1 of a kind of dielectric layer covering provided by the invention;

Fig. 2 is rectangular aperture waveguide center gap actinal surface distribution map of the electric field when frequency 2.4GHz that a kind of dielectric layer provided by the invention covers;

Fig. 3 is the rectangular aperture waveguide center gap actinal surface distribution map of the electric field when frequency 2.4GHz that does not have dielectric layer to cover provided by the invention;

Fig. 4 be the rectangular aperture waveguide that covers of a kind of dielectric layer provided by the invention when frequency 2.4GHz apart from the center gap distribution map of the electric field in 1/4th cycles;

Fig. 5 be provided by the invention do not have rectangular aperture waveguide that dielectric layer covers when frequency 2.4GHz apart from the center gap distribution map of the electric field in 1/4th cycles;

Fig. 6 be the rectangular aperture waveguide that covers of a kind of dielectric layer provided by the invention when frequency 2.4GHz apart from the center gap distribution map of the electric field in 1/2nd cycles;

Fig. 7 be provided by the invention do not have rectangular aperture waveguide that dielectric layer covers when frequency 2.4GHz apart from the center gap Electric Field Distribution in 1/2nd cycles;

Fig. 8 is a kind of rectangle vertical clearance gap leaky waveguide blanket dielectric layer provided by the invention distribution map of the electric field in axial direction when frequency 2.4GHz;

Fig. 9 is rectangular aperture waveguide that dielectric layer the covers distribution map of the electric field in axial direction when frequency 2.4GHz that do not have provided by the invention;

Wherein, 101-rectangular waveguide; 102-gap array; 103-dielectric layer; 104-center gap.

Embodiment

Below in conjunction with accompanying drawing, preferred embodiment is elaborated.Should be emphasized that following explanation is only exemplary, rather than in order to limit the scope of the invention and to apply.

Fig. 1 is the overall construction drawing of the rectangular waveguide embodiment 1 of a kind of dielectric layer covering provided by the invention.Described in Fig. 1, waveguide specifically can comprise rectangular waveguide 101 and cover the dielectric layer 103 on rectangular waveguide, wherein, on described rectangular waveguide 101 walls, along this axis direction interval, evenly has several gap arrays 102.Rectangular waveguide 101 is the communication rectangular waveguide that general outer conductor is slotted, and in transmitting energy, to external radiation Homogeneous Electromagnetic Wave, wherein, gap array 102 flutings can be the multiple gap structures such as rectangular channel, U-lag or the Eight Character trough; Dielectric layer 103 is dielectric-slab, for restraining and strengthen entering to inject the electromagnetic field of dielectric-slab.The thickness of dielectric-slab and dielectric constant are determined according to specific needs.

Discuss the effect of dielectric layer 103:

While there is no dielectric layer 103 outside rectangular waveguide 101, the field giving off from gap array 102 is freedom of entry space directly, and electric field is dispersed and decay fast in the vertical direction.

Inventor herein has noticed this point, therefore, creatively on described rectangular waveguide 101, covers one deck dielectric layer, and dielectric layer can change its dielectric constant and thickness according to actual needs.When dielectric layer 103 covers rectangular aperture surface, the dielectric constant of dielectric layer is greater than the dielectric constant of air, and the electromagnetic wave that rectangular aperture waveguide antenna goes out is after entering dielectric layer, and refraction angle reduces, electric field convergence; Meanwhile, the introducing of electric capacity and lens effect also makes field intensity concentrate to dielectric layer one side.Therefore the present invention can solve rectangular aperture waveguide electric field and leave the waveguide surface problem of decay rapidly.

To sum up, tool of the present invention has the following advantages:

1) can restrain rectangular aperture Waveguide near-field;

2) can solve rectangular aperture Waveguide near-field attenuation ratio problem faster;

With reference to Fig. 1, in a kind of application example of the present invention, the standard BJ22 waveguide that is operated in 2.4GHz frequency range of take is example, and vertical clearance gap array 102 comprises 13 vertical clearance gap, vertical clearance gap width and length are respectively w=3mm and l=19mm, and the spacing between each vertical clearance gap is P=61mm.The dielectric constant of dielectric layer is ε=10, and the height of dielectric layer 103 is 100mm.

With reference to Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8 and Fig. 9 show respectively rectangular aperture waveguide cable not blanket dielectric layer and blanket dielectric layer respectively when frequency 2.4GHz apart from center gap 104 0, electric field tangential distribution figure in the XOZ plane of P/4, P/2, wherein P is the cycle between gap.

Can find out, under above-mentioned parameter, when rectangular aperture waveguide blanket dielectric layer, apart from center gap 104 0, the XOZ plane electric fields of P/4, P/2 is with respect to the situation of blanket dielectric layer not, the localization effects of electric field strength in medium block and medium block superjacent air space is all obvious, and convergence strengthens.

Can find out, under above-mentioned parameter, the structure of dielectric layer covering rectangular aperture waveguide meets the requirement of mobile communication system, in Waveguide near-field direction, electric field is had and is significantly concentrated and convergence effect.

The above; be only the present invention's embodiment preferably, but protection scope of the present invention is not limited to this, is anyly familiar with in technical scope that those skilled in the art disclose in the present invention; the variation that can expect easily or replacement, within all should being encompassed in protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claim.

Claims

1. a rectangular waveguide for blanket dielectric layer, is characterized in that, described waveguide comprises rectangular waveguide and dielectric layer; Described dielectric layer is placed on rectangular waveguide.

2. waveguide according to claim 1, is characterized in that, on described rectangular waveguide wall, along axis direction, equally spaced has some gaps and forms gap array.

3. waveguide according to claim 1, is characterized in that, the span of described thickness of dielectric layers is zero distance to reception antenna and rectangular waveguide.

4. waveguide according to claim 1, is characterized in that, the span of the dielectric constant of described dielectric layer is the dielectric constant that is greater than air.

5. waveguide according to claim 2, is characterized in that, the fluting of described gap array is rectangular channel, U-lag or the Eight Character trough.