CN203232943U - Cavity filter - Google Patents

Abstract

The utility model relates to a cavity filter which comprises a cavity body, a connector and a harmonic oscillator. The connector is integrated into the cavity body, and the harmonic oscillator is arranged in the cavity to form a resonant cavity. The harmonic oscillator comprises a medium body, a concave hole which curves in towards the inner part of the medium body is arranged in the surface of the medium body, and a conductive lay is arranged on a part of or the whole surface of the inner wall of the concave hole and/or on a part of or the whole surface of the outer side wall of the medium body. The conductive lay arranged on a part of or the whole surface of the inner wall of the concave hole and/or on a part of or the whole surface of the outer side wall of the medium body helps reduce the resonant frequency of the resonant cavity where the harmonic oscillator are arranged, thereby greatly reducing the size of the resonant cavity.

Description

Cavity body filter

Technical field

The utility model relates to the filter of the communications field, especially relates to a kind of cavity body filter.

Background technology

In the communications field, especially in the field of radio frequency communication, cavity body filter is widely used as a kind of frequency selection device.For example in the base station, cavity body filter is used for selecting signal of communication, clutter or interference signal that the filtering communication signal frequency is outer.

Cavity body filter adopts cavity body structure, and a cavity can equivalence become the inductance shunt capacitance, so just forms a resonance level, reaches filter function.Harmonic oscillator also is set, to determine the resonance frequency of filter in the cavity of cavity body filter.

The existing type of the harmonic oscillator of cavity body filter can comprise metal harmonic oscillator and dielectric resonance.The volume of metal harmonic oscillator is little, and can realize the resonance of lower frequency, but the little meeting of volume causes bearing higher power.Dielectric resonance can bear high power, but if realize low-frequency resonant, then the volume of the volume of dielectric resonance and resonant cavity can be bigger, do not satisfy the demand of filter miniaturization.Therefore, how designing and a kind ofly have that resonance frequency is low, volume is little and the filter of anti-high power characteristics concurrently, is the problem that this area needs to be resolved hurrily.

The utility model content

Technical problem to be solved in the utility model provides that a kind of resonance frequency is low, volume is little and anti-high-power cavity body filter.

The utility model is that to solve the problems of the technologies described above the technical scheme that adopts be to propose a kind of cavity body filter, comprises cavity, connector and harmonic oscillator.This connector and this cavity are one-body molded, and this harmonic oscillator is located at this inside cavity and is formed resonant cavity; This harmonic oscillator comprises a medium body, offers on this medium body surface to the shrinkage pool of this medium body interior depression, and the part or all of surface of the part or all of surface of the inwall of this shrinkage pool and/or the lateral wall of this medium body is provided with conductive layer.

In an embodiment of the present utility model, the part or all of surface of the part or all of surface of the inwall of this shrinkage pool and/or the lateral wall of this medium body directly is attached with conductive layer.

In an embodiment of the present utility model, the part or all of surface of the part or all of surface of the inwall of this shrinkage pool and/or the lateral wall of this medium body is connected with conductive layer by connecting media.

In an embodiment of the present utility model, this conductive layer is metal cylinder, and this medium body is tubular and is enclosed within outside this metal cylinder.

In an embodiment of the present utility model, this shrinkage pool is through hole or blind hole.

In an embodiment of the present utility model, this harmonic oscillator is located at this cavity bottom by a supporting base.

In an embodiment of the present utility model, this medium body is made greater than 1 material by dielectric constant.

In an embodiment of the present utility model, this conductive layer is to be attached to one or more on the medium body surface to have geometric conductive structure.

In an embodiment of the present utility model, this cavity comprises a lateral wall, and this connector is positioned on this lateral wall.

In an embodiment of the present utility model, this connector is cylinder type, inner hollow.

The harmonic oscillator that cavity body filter of the present utility model has because lateral wall or shrinkage pool inwall are provided with conductive layer, are conducive to reduce the resonance frequency of harmonic oscillator place resonant cavity, thereby dwindle the volume of resonant cavity greatly.So cavity body filter of the present utility model has concurrently, and resonance frequency is low, volume is little and anti-high-power advantage.

Description of drawings

For above-mentioned purpose of the present utility model, feature and advantage can be become apparent, below in conjunction with accompanying drawing embodiment of the present utility model is elaborated, wherein:

Fig. 1 illustrates the partial schematic diagram of the cavity body filter of the utility model one embodiment;

Fig. 2 illustrates the vertical view of the harmonic oscillator of the utility model first embodiment;

What Fig. 3 illustrated harmonic oscillator shown in Figure 2 partly cuts open front view;

Fig. 4 illustrates the structural representation of the harmonic oscillator of the utility model second embodiment;

What Fig. 5 illustrated harmonic oscillator shown in Figure 4 partly cuts open front view;

Fig. 6 is the front view of variation example of the harmonic oscillator of the utility model second embodiment;

Fig. 7 illustrates the structural representation of the harmonic oscillator of the utility model the 3rd embodiment;

What Fig. 8 illustrated cavity connector among the utility model one embodiment partly cuts open vertical view;

Fig. 9 be cavity connector shown in Figure 8 partly cut open front view.

Embodiment

Fig. 1 illustrates the partial schematic diagram of the cavity body filter of the utility model one embodiment.With reference to shown in Figure 1, cavity body filter 100 comprises cavity 110 and connector 120.Chamber lid (scheming not shown) is housed on the openend of cavity 110, thereby cavity 110 is enclosed a sealed hollow 112.Connector 120 is connected in cavity 110, and is used for being connected with the antenna of base station system.

More particularly, have lateral wall 114 outside the cavity 110, connector 120 is connected in the lateral wall 114 of cavity 110.Connector 120 can be cylinder type, inner hollow.Correspondingly, lateral wall 114 is provided with perforation with the junction of connector 120, and this perforation communicates with hollow bulb in the connector 120, forms unified hollow bulb, for assembling connector assembly.Connector 120 has screw thread 122 at the end away from cavity 110, is used for being spirally connected with aforesaid antenna.

In preferred embodiment, connector 120 is formed in one with cavity 110.Like this, the water resistance of cavity body filter 100 will obviously be promoted, and be better than the structure that existing connector with split is installed to cavity body filter.

For instance, the cavity 110 of cavity body filter 100 and connector 120 can be formed through technologies such as die casting, machinings in the lump by same blank.The material of blank can be selected metallic aluminium.

In the present embodiment, cavity body filter 100 also comprises harmonic oscillator 113, is positioned in the cavity 112 of cavity 110.The characteristics of this harmonic oscillator 113 are, can be so that formed resonant cavity has low-down resonance frequency.Therefore under identical resonance frequency, the volume of the resonant cavity of the cavity body filter 100 of present embodiment can be more much smaller than the resonant cavity of existing cavity body filter.Thus, can effectively reduce the weight of cavity body filter equally.The different embodiment of harmonic oscillator 113 will be described below.

Fig. 2 illustrates the vertical view of the harmonic oscillator of the utility model first embodiment; What Fig. 3 illustrated harmonic oscillator shown in Figure 2 partly cuts open front view.With reference to Fig. 2 and shown in Figure 3, the harmonic oscillator 130 of an embodiment comprises medium body 131.Be provided with shrinkage pool 132 at medium body 131.This shrinkage pool 132 from the outer surface of medium body 131 to medium body 131 inner recess.The part or all of surface of shrinkage pool 132 inwalls is provided with conductive layer 133.

Medium body 131 can select for use any dielectric constant greater than 1 material.Usually, the material that dielectric constant is more high, loss angle tangent is more little more is conducive to electromagnetic resonance and reduces resonance frequency.In certain embodiments, the material of medium body 131 for example is polytetrafluoroethylene, epoxy resin, FR4 material etc.More preferably, select ceramic material for use, aluminium oxide for example also can be BaTi for example ₄O ₉, Ba ₂Ti ₉O ₂₀, MgTiO ₃-CaTiO ₃, BaO-Ln ₂O ₃-TiO ₂System, Bi ₂O ₃-ZnO-Nb ₂O ₅Microwave-medium ceramics such as system.Certainly, above-mentioned material only is purpose for example, all can be used to make medium body 131 so long as have the material of higher dielectric constant and lower loss (dielectric constant is greater than 30 usually, and loss angle tangent is less than 0.01).

Although in Fig. 2, medium body 131 is the rectangle square column, and four rib roundings, and the utility model is not limited to this shape.In embodiment of the present utility model, medium body 131 can be the shape that existing any one harmonic oscillator has, for example cylindrical, square shape sheet, truncated cone-shaped, square halfpace, or other any regular or irregularly shaped, this does not have influence on the characteristic of harmonic oscillator of the present utility model.

Shrinkage pool 132 shown in Figure 2 is through hole, and namely shrinkage pool 132 is penetrated into another surface from a surface of medium body 131.

The through hole of present embodiment can be cylindrical hole, and preferably the center line of this cylindrical hole is positioned on the central shaft of medium body 131.The advantage of Bu Zhiing is like this, can be so that the electromagnetic field in the cavity is symmetrically distributed when harmonic oscillator is placed on resonant cavity central authorities.

In other embodiments, through hole also can be cylindrical, square column type, truncated cone-shaped, square halfpace, taper or other rule or irregular shape, thereby or with the conformal thick structure such as 131 one-tenth of medium bodies that makes of the outline of medium body 131.

Certainly, this shrinkage pool 132 is not defined as through hole, can be blind hole yet, does not namely penetrate into another surperficial hole.This blind hole can also can be other shapes such as hemisphere, tetrahedroid etc. for, just height short shape identical with any shape of above-mentioned through hole, and the utility model is not restricted.

The conductive layer 133 that the inwall of shrinkage pool 132 adheres to is made of the material that can conduct electricity.The electric conducting material preferable alloy, for example silver, copper or gold perhaps are the alloy that contains two or three in silver, copper or the gold.Certainly, electric conducting material also can be other metal materials or other metal alloy electric conducting materials.In addition, electric conducting material also can be can conduct electricity nonmetal, for example electrically conductive graphite, indium tin oxide or Al-Doped ZnO.

Certainly, conductive layer 133 also can be other version, for example for Direct Electroplating or evaporation or be splashed to metal level on the medium body 131, also can have geometric conductive structure for being attached to one or more on the medium body surface, random geometries such as the split ring resonator that this conductive structure can constitute for I-shaped metal wire, metal wire, rectangular metal sheet.

In embodiment of the present utility model, conductive layer 133 can be attached directly on the inwall of shrinkage pool 132, also can be arranged on shrinkage pool 132 inside by connecting media.Connecting media for example adopts viscose glue bonding; Perhaps can use an end to be connected with conductive layer 133, the other end and shrinkage pool 132 inwalls are fixedly coupled bar, and this makes and is separated with air layer between conductive layer 133 and shrinkage pool 132 inwalls; The material that perhaps can also add other low-losses, low dielectric between conductive layer 133 and shrinkage pool 132 fixes these two, etc.

Fig. 4 illustrates the structural representation of the harmonic oscillator of the utility model second embodiment; What Fig. 5 illustrated harmonic oscillator shown in Figure 4 partly cuts open front view.With reference to Fig. 4 and shown in Figure 5, the harmonic oscillator 130a of present embodiment is identical with most of structure of last embodiment, difference is, be called first conductive layer except the part or all of surface at the inwall of shrinkage pool 132 arranges conductive layer 133(at this), on the part or all of surface of medium body lateral wall conductive layer 134(is set also and is called second conductive layer at this).

Certain first conductive layer 133 can adopt identical electric conducting material with second conductive layer 134, also can adopt electric conducting material together.As previously mentioned, the electric conducting material preferable alloy, for example silver, copper or gold perhaps are the alloy that contains two or three in silver, copper or the gold.Electric conducting material also can be other metal materials or other metal alloy electric conducting materials.In addition, electric conducting material also can be can conduct electricity nonmetal, for example electrically conductive graphite, indium tin oxide or Al-Doped ZnO.

Simultaneously, first conductive layer 133 can be the conductive foil of a slice integral body, also can be a plurality of conductive foil structures with certain what shape, for example be a plurality of at interval strips, criss-cross, disc, circle etc. successively, perhaps other complicated shapes, for example snowflake type shown in Figure 6 also can be " worker " font.These paillon foil structures can rule arrange, but also random arrangement.Second conductive layer 134 also is like this.The paillon foil structure of the two can arrange regularly, and for example parallel, symmetry etc. also can arrange at random.

Fig. 7 illustrates the structural representation of the harmonic oscillator of the utility model the 3rd embodiment.With reference to shown in Figure 7, among the present embodiment harmonic oscillator 130b, medium body 131a is the cylindrical shape of even uniform thickness, and the shrinkage pool 132 in the middle of the medium body 131 is through hole.Conductive layer 133b is for having certain thickness metal cylinder, and the bottom is provided with flange 135.Like this, medium body 131 is enclosed within conductive layer 133b bottom surface outer and medium body 131a and can just be placed on the flange 135.

Certainly, metal cylinder can not have flange 135.Conductive layer 133b can fix by bonding or other modes and cavity bottom.Preferred conductive layer 133b directly is electrically connected and ground connection with cavity bottom.

In aforesaid each embodiment, the scope that conductive layer (for example 133,134,133b) covers can be the part surface of shrinkage pool inwall for the whole inner wall surface of shrinkage pool (for example 132).For example, conductive layer only covers the side of shrinkage pool inwall, the also inner wall section that namely is connected with the shrinkage pool open end, and do not cover the bottom surface of shrinkage pool, i.e. relative with the shrinkage pool open end and the inner wall section (if shrinkage pool has the words of bottom surface) that is not connected with this openend.Perhaps, conductive layer also can only cover the bottom surface of shrinkage pool; Or conductive layer can cover the subregion of side and the subregion of bottom surface simultaneously.

The advantage of harmonic oscillator of the present utility model is described below in conjunction with harmonic oscillator role in the cavity connector.

What Fig. 8 illustrated cavity connector among the utility model one embodiment partly cuts open vertical view; Fig. 9 be cavity connector shown in Figure 8 partly cut open front view.With reference to Fig. 8, shown in Figure 9, for example cavity 110 shown in Figure 1, for example harmonic oscillator 130 shown in Figure 2 and extra tuning plug 150 have been formed resonant cavity.Connector 120 is set on the lateral wall of cavity 110.This connector 120 can be formed in one with cavity 110.The chamber lid is housed on the openend of cavity 110, cavity is enclosed a sealed hollow.Harmonic oscillator 130 is positioned at cavity, and its bottom can be supported by the supporting base that a low-loss material (as aluminium oxide etc.) made.Tuning plug 150 is contained in the chamber and covers, and the end of tuning plug 150 stretches in the cavity and stretches at least in part in the shrinkage pool 132 of harmonic oscillator.The end of tuning plug 150 can directly contact with shrinkage pool 132 inwalls or conductive layer 133.

Tuning plug 150 typically is metal screw, is contained in the chamber by nut and covers, and stretch into adjustable length in the chamber, thereby regulate the resonance frequency of resonant cavity among a small circle.In other embodiments, tuning plug 150 also can be made by ceramic material, or rod outer surface coated metal, pottery or other high dielectric constant materials made at a low-loss material and make.

Tuning plug 150 also can be made by other nonmetallic materials, needs only its dielectric constant greater than 1, the certainly preferred higher material of dielectric constant.The utility model is not done any restriction to material and the shape of tuning plug 150, thereby can the interior electromagnetic field distribution of perturbation cavity influence resonance frequency as long as it stretches in the cavity 110.

When shrinkage pool 132 was through hole, the bottom surface that contacts with cavity 110 of medium body 131 can arrange the conductor articulamentum.This conductor articulamentum is made by the electric conducting material identical or different with conductive layer 133, and couples together with that a part of conductive layer 133 on the through-hole wall.This moment, this conductor articulamentum can be fixed with one by hot pressing or welding or other known interconnection techniques and cavity 110.

In order to strengthen the frequency reducing effect, can be provided with two or more than two shrinkage pool 132, one of them shrinkage pool 132 is provided with a tuning plug 150 on the medium body 131.Certainly, in order to increase perturbation quantity, can a tuning plug 150 all be set in each shrinkage pool 132 relative position.

Cavity connector of the present utility model can have at least one resonant cavity, and wherein at least one resonant cavity is above-mentioned resonant cavity.Cavity connector of the present utility model can have the device of filter function for band pass filter, band stop filter, high pass filter, low pass filter or multiband filter, duplexer or other.

To use the advantage of the resonant cavity of harmonic oscillator of the present utility model by concrete experimental data explanation below.Be Comparative Examples with a single chamber resonant cavity with pure ceramic dielectric harmonic oscillator, this resonant cavity cavity is square column type, this ceramic dielectric harmonic oscillator adopts the cylindrical microwave media ceramic, be of a size of external diameter 24mm, internal diameter 8mm, high 19mm, internal diameter corresponds to through hole, the resonance frequency that experiment records the resonant cavity with this dielectric resonance is 1.642GHz, and the average power of this resonant cavity is 275W.

If according to embodiment of the present utility model, adopt identical cavity and dielectric resonance (being that above-mentioned pure ceramic dielectric harmonic oscillator is as the medium body of harmonic oscillator in this example), and plate silver (being the conductive layer in this example) at the through hole (being the shrinkage pool in this example) of this harmonic oscillator, experiment records the resonance frequency of the resonant cavity with this harmonic oscillator and is down to 0.875GHz, and average power is 335W.

This shows, adopt harmonic oscillator of the present utility model, with respect to simple dielectric resonance, resonance frequency can be reduced about 800MHz, be essentially half of original resonance frequency.This means that when preparing the resonant cavity of identical resonance frequency, cavity volume will reduce significantly, and little to the influence of power.

In another Comparative Examples, adopt identical cavity, dielectric resonance is replaced by shape, metal harmonic oscillator that volume is identical, namely the metal harmonic oscillator is the cylindrical shape of external diameter 24mm, internal diameter 8mm, high 19mm, and material is fine copper.The resonance frequency that experiment records the resonant cavity with this metal harmonic oscillator is 1.569GHz, and average power is 54W.

This shows, adopt harmonic oscillator of the present utility model, the metal harmonic oscillator with respect to simple still can provide lower resonance frequency, and average power has improved greatly then.

In sum, the harmonic oscillator that has of cavity body filter of the present utility model had both had the anti-high-power advantage of dielectric resonance, the advantage that the resonance frequency that has the metal harmonic oscillator simultaneously concurrently is low, the resonant cavity volume is little as can be known.So cavity body filter of the present utility model has concurrently, and resonance frequency is low, volume is little and anti-high-power advantage.

Though the utility model is described with reference to current specific embodiment, but those of ordinary skill in the art will be appreciated that, above embodiment illustrates the utility model, under the situation that does not break away from the utility model spirit, also can make variation or the replacement of various equivalences, therefore, as long as in connotation scope of the present utility model in the scope to the variation of above-described embodiment, claims that modification all will drop on the application.

Claims (9)

1. a cavity body filter comprises cavity, connector and harmonic oscillator, it is characterized in that, this connector and this cavity are one-body molded, and this harmonic oscillator is located at this inside cavity and is formed resonant cavity; This harmonic oscillator comprises a medium body, offers on this medium body surface to the shrinkage pool of this medium body interior depression, and the part or all of surface of the part or all of surface of the inwall of this shrinkage pool and/or the lateral wall of this medium body is provided with conductive layer.

2. cavity body filter according to claim 1 is characterized in that, the part or all of surface of the part or all of surface of the inwall of this shrinkage pool and/or the lateral wall of this medium body directly is attached with conductive layer.

3. cavity body filter according to claim 1 is characterized in that, the part or all of surface of the part or all of surface of the inwall of this shrinkage pool and/or the lateral wall of this medium body is connected with conductive layer by connecting media.

4. cavity body filter according to claim 1 is characterized in that, this conductive layer is metal cylinder, and this medium body is tubular and is enclosed within outside this metal cylinder.

5. cavity body filter according to claim 1 is characterized in that, this shrinkage pool is through hole or blind hole.

6. cavity body filter according to claim 1 is characterized in that, this harmonic oscillator is located at this cavity bottom by a supporting base.

7. cavity body filter according to claim 1 is characterized in that, this conductive layer is to be attached to one or more on the described medium body surface to have geometric conductive structure.

8. according to each described cavity body filter of claim 1 to 7, it is characterized in that this cavity comprises a lateral wall, this connector is positioned on this lateral wall.

9. according to each described cavity body filter of claim 1 to 7, it is characterized in that this connector is cylinder type, inner hollow.

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