CN203617409U

CN203617409U - Broadband dielectric filter

Info

Publication number: CN203617409U
Application number: CN201320812829.2U
Authority: CN
Inventors: 苗青雷
Original assignee: ANHUI XRF TECHNOLOGY Co Ltd
Current assignee: ANHUI XRF TECHNOLOGY Co Ltd
Priority date: 2013-12-12
Filing date: 2013-12-12
Publication date: 2014-05-28
Anticipated expiration: 2023-12-12

Abstract

The utility model provides a broadband dielectric filter. The broadband dielectric filter comprises a dielectric filter body and a shield shell body which sleeves the periphery of the dielectric filter body. The dielectric filter body comprises a square ceramic dielectric with a plurality of through holes. One side surface of the dielectric is equipped with an input electrode and an output electrode. Loading layers are arranged at the peripheries of the through holes in the upper end surface of the dielectric. The loading layers at two ends of the dielectric are connected with the input electrode and the output electrode through S-shaped coupling wires respectively and a direct coupling electrode is formed. The input electrode and the output electrode are connected with the loading layers at the peripheries of the through holes at the two ends through S-shaped coupling wires respectively to form a direct coupling electrode, wire and therefore electrode time delay of the dielectric filter can be decreased. Through enhancement of capacitance coupling or inductance coupling between two through holes, the pass band of the filter is broadened. Through arrangement of cross coupling between separated holes, the rectangle coefficient of the filter is good. The broadband dielectric filter has advantages of small size, good rectangle coefficient, wide frequency band and the like.

Description

A kind of Wide-band dielectric filter

Technical field

The utility model relates to a kind of filter, relates in particular to a kind of Wide-band dielectric filter.

Background technology

In microwave communication field, filter has can allow useful signal zero-decrement passing through as far as possible, the large as far as possible decay of unwanted signal is eliminated to the device of jamming incoherent signal, and it is subject to production firm as a kind of important communication apparatus and more and more payes attention to.

In recent years, volume is little, Insertion Loss is low, the feature of good stability because having for dielectric filter, has both been widely used in mobile communication system, satellite communication system and cable television system, also for specific communication engineering.This just proposes, outside high standard, also its packaging technology, reliability etc. to be proposed to requirements at the higher level to the electrical property of filter, requires filter to have high inhibition, wideband filtering.Dielectric filter generally divides and is structure as a whole and the large type of Split type structure two, and wherein the Wide-band dielectric filter of Split type structure exists the poor defect of squareness factor, and the dielectric filter of integrative-structure exists relative bandwidth less, all can not meet demand.

Utility model content

The utility model will solve above-mentioned deficiency exactly, and the Wide-band dielectric that a kind of volume is little, squareness factor is good filter is provided.

In order to reach above-mentioned effect, the utility model provides a kind of Wide-band dielectric filter, comprise dielectric filter body and the shield shell that is set in dielectric filter body periphery, described dielectric filter body comprises the square ceramic dielectric that offers multiple through holes, and a side of described dielectric is provided with input, output electrode; The bore periphery that is positioned at dielectric upper surface is equipped with loading layer; The loading layer that is positioned at dielectric two ends is connected and forms direct-coupling electrode with described input, output electrode by S shape coupling line respectively.

The live width of described S shape coupling line is not less than 0.2mm.

Loading layer below in the middle of being positioned at arranges a coupling horizontal line and forms cross coupling capacitor.

Half frame structure that described shield shell is made up of top board, header board and biside plate, welds between itself and dielectric filter body.

The dielectric constant of the ceramic dielectric body in the utility model is 20; Described input electrode, output electrode, S shape coupling line, loading layer, coupling horizontal line are to be plated in dielectric surface by silver layer to form.

The utility model medium filter body is to be formed by the ceramic dielectric body sintering that is provided with multiple through holes, and its outer surface is silver coated.Carve formation loading layer around each through hole at the upper surface of dielectric silver layer by laser machine; Between the loading layer in two holes, directly relatively form capacitive coupling; Between the loading layer in two holes, have vertical line be separated by form inductive coupled; A coupling horizontal line is set below middle loading layer, makes to form cross coupling capacitor between this coupling horizontal line head and the tail loading layer.Side engraving at dielectric forms input, output electrode, and input, output electrode are connected and form direct-coupling electrode with the loading layer around being positioned at dielectric two ends through hole by S shape coupling line respectively.

Dielectric filter body is fixedly arranged on by welding in the shield shell of half framework, and shield shell is to be formed by packfong pressing and bending.

The silver layer size of the electrode time delay size of dielectric filter of the present utility model and S shape coupling line and input, output electrode has relation, specific as follows:

(1) size of the length of S shape coupling line, live width size determining electrode time delay, S shape coupling line is more carefully longer, and electrode time delay is less; Otherwise electrode time delay is larger;

(2) the silver layer size of input, output electrode is directly proportional to electrode time delay size, and its area is larger, and electrode time delay is larger; Otherwise electrode time delay is less.

So the beneficial effects of the utility model:

1, be connected with input, output electrode by S shape coupling line respectively owing to being positioned at dielectric two ends through hole loading layer around, thereby make two ends loading layer and input, output electrode be connected to form direct-coupling electrode, have the advantages that obviously reduce electrode time delay, electrode can be increased, thereby the passband width of filter can be increased by adding the mode of close coupling.

2, a coupling horizontal line is established in middle loading layer below, forms cross capacitance coupling, has the advantages that to improve squareness factor, respectively forms a flex point at upper lower sideband, thus the suppress sideband of drawing near-end.

3, between the through hole of dielectric filter of the present utility model loading layer around, capacitive coupling and inductance coupling high are set, make it have two suppress sideband symmetries.

4, to be designed to serpentine shape be the length in order to increase lines to S shape coupling line, and width is made as that to be not less than 0.2mm be in order to make line thickness as much as possible little, thereby reduces the electrode time delay of this dielectric filter.

Accompanying drawing explanation

Below in conjunction with the drawings and specific embodiments, the utility model is described in further detail.

Fig. 1 is the utility model structural representation;

Fig. 2 is shield shell structural representation in the utility model;

Fig. 3 is the utility model medium filter body construction schematic diagram;

Fig. 4 is the upper end surface structure schematic diagram of the utility model medium filter body;

Fig. 5 is the side structure schematic diagram of the utility model medium filter body;

Fig. 6 is equivalent circuit diagram of the present utility model;

Fig. 7 is measured waveform figure of the present utility model.

Embodiment

A Wide-band dielectric filter as shown in Figure 1, 2, comprises dielectric filter body 1 and shield shell 2, and dielectric filter body 1 is fixedly arranged on by welding in the shield shell 2 of half framework; Dielectric filter body 1 is to be formed by ceramic dielectric body sintering, and its outer surface is silver coated; Carve on dielectric end face silver layer by laser machine, and form coupling pattern, i.e. input electrode, output electrode, S shape coupling line, coupling horizontal line.Shield shell 2 is to be formed by packfong pressing and bending.

As shown in Fig. 3,4,5, dielectric filter body 1 comprises the square ceramic dielectric that offers seven through holes, and a side 1-2 of described dielectric is provided with input electrode 1-21, output electrode 1-22; Seven bore periphery that are positioned at dielectric upper surface are equipped with loading layer, and the two ends through hole loading layer 1-13, the 1-19 that are positioned at dielectric upper surface 1-1 are connected to form direct-coupling electrode by S shape coupling line 1-11 and input electrode 1-21, output electrode 1-22 respectively; The second through hole loading layer 1-14 is provided with coupling horizontal line 1-12 to the below of fifth hole loading layer 1-17, make between the second through hole loading layer 1-14 and fifth hole loading layer 1-17 formation intersect capacitive coupling; The first through hole loading layer 1-13 and the second through hole loading layer 1-14, fourth hole loading layer 1-16 and fifth hole loading layer 1-17, between the 6th through hole loading layer 1-18 and the 7th through hole loading layer 1-19, be equipped with coupling vertical line 1-20, make to be between them inductance coupling high; Between the second through hole loading layer 1-14 and third through-hole loading layer 1-15, third through-hole loading layer 1-15 and fourth hole loading layer 1-16, fifth hole loading layer 1-17 and the 6th through hole loading layer 1-18, be capacitive coupling.

The equivalent circuit diagram of the utility model Wide-band dielectric filter as shown in Figure 6, C1 and L1, C2 and L2 in figure ..., C7 and L7 form respectively seven resonance frequencies, i.e. seven resonant cavitys; L12, L45, L67 are respectively coupling reactance between the first through hole and the second through hole, fourth hole and fifth hole, the 6th through hole and the 7th through hole; C23, C34, C56 are respectively coupling capacitance between the second through hole and third through-hole, third through-hole and fourth hole, fifth hole and the 6th through hole; C25 is the cross coupling capacitor between the second through hole and fifth hole; L01, L02 are input, the outputting inductance that input, output electrode and the first hole, seven apertures in the human head form by S shape coupling line.

Be illustrated in figure 7 measured waveform figure of the present utility model, its frequency 2130MHz, center loss is less than 1.5dB, and BW-0.5dB is 350 MHz, and f0 ± 350 MHz inhibition degree is greater than 55dBc.

Above embodiment is not limited only to protection range of the present utility model, all modify based on basic thought of the present utility model or change all belong to protection range of the present utility model.

Claims

1. a Wide-band dielectric filter, comprise dielectric filter body and the shield shell that is set in dielectric filter body periphery, it is characterized in that: described dielectric filter body comprises the square ceramic dielectric that offers multiple through holes, a side of described dielectric is provided with input, output electrode; The bore periphery that is positioned at dielectric upper surface is equipped with loading layer; The loading layer that is positioned at dielectric two ends is connected and forms direct-coupling electrode with described input, output electrode by S shape coupling line respectively.

2. Wide-band dielectric filter according to claim 1, is characterized in that: the live width of described S shape coupling line is not less than 0.2mm.

3. Wide-band dielectric filter according to claim 1, is characterized in that: the loading layer below in the middle of being positioned at arranges a coupling horizontal line and forms cross coupling capacitor.

4. Wide-band dielectric filter according to claim 1, is characterized in that: half frame structure that described shield shell is made up of top board, header board and biside plate, welds between itself and dielectric filter body.