Background technology
In recent years, along with the developing rapidly of microminiaturization of mobile communication, satellite communication and Defensive Avionics System, high-performance, low cost and miniaturization have become the developing direction of microwave current/RF application, all have higher requirement to the performance of microwave filter, size, reliability and cost.In some national defence tip device, present use frequency range is quite full, so the tip device such as satellite communication develop towards millimeter wave band, so microwave and millimeter wave band filter has become the critical electronic parts in this band reception and transmitting branch, the leading indicator describing this component capabilities has had: passband operating frequency range, stop band frequency range, pass band insertion loss, stopband attenuation, passband input/output voltage standing-wave ratio, insertion phase shift and delay/frequency characteristic, temperature stability, volume, weight, reliability etc.But having in particular cases, screening signal being carried out to different frequency proposes new requirement, so bank of filters provides stable outstanding application in this situation system.
LTCC is a kind of Electronic Encapsulating Technology, adopts multi-layer ceramics technology, passive component can be built in medium substrate inside, and also active element can be mounted on substrate surface makes passive/active integrated functional module simultaneously.LTCC technology all shows many merits in cost, integration packaging, wiring live width and distance between centers of tracks, low impedance metal, design diversity and flexibility and high frequency performance etc., has become the mainstream technology of passive integration.The advantages such as it has high q-factor, is convenient to embedded passive device, and thermal diffusivity is good, and reliability is high, high temperature resistant, punching shake, utilize LTCC technology, can well process size little, precision is high, and tight type is good, the microwave device that loss is little.Because LTCC technology has the integrated advantage of 3 D stereo, be widely used for manufacturing various microwave passive components at microwave frequency band, the height realizing passive component is integrated.Based on the stack technology of LTCC technique, can realize three-dimensional integrated, thus size is little, lightweight, performance is excellent, reliability is high, batch production performance consistency is good and the plurality of advantages such as low cost to make various micro microwave filter have, utilize its three-dimensional integrated morphology feature, the bank of filters in the present invention can be realized.
But up to the present, still there is very large development space in the technology of bank of filters, the more high performance bank of filters of development need of modern communication.Such as, the scope of application that power is large not, standing wave poor performance can affect SHF band filter group is born, the development of restriction filter group.
Summary of the invention
Screen freely under the object of the present invention is to provide a kind of Neng Dui mono-road signal to carry out different frequency range, and the SHF wave band high performance filter group based on LTCC and DGS technology that insertion loss is little, standing wave performance is good, Out-of-band rejection is high.
The technical scheme realizing the object of the invention is: a kind of SHF wave band high performance filter group based on LTCC and DGS technology, comprises single-pole double-throw switch (SPDT) chip Switch, the first microwave filter Filter1 and the second microwave filter Filter2; Described single-pole double-throw switch (SPDT) chip Switch comprises signal input port RFIn, the first signal output port RFOut1, secondary signal output port RFOut2, first exports and selects control end V1, second to export selection control end V2 five ports; Wherein the first signal output port RFOut1 is connected with the input port of the first microwave filter Filter1, and secondary signal output port RFOut2 is connected with the input port of the second microwave filter Filter2;
Wherein the first microwave filter Filter1 and the second microwave filter Filter2 all adopts defect ground structure DGS and LTCC LTCC technology, and described microwave filter includes input port, input lead inductance, Pyatyi parallel resonance unit, output lead inductance, output port, two screens, Z-shaped interstage coupling unit and two grounding ports; Every grade of resonant element is formed by the upper and lower two-layer strip line of parallel placement, and second layer strip line is positioned at below ground floor strip line, and wherein the first screen is arranged at below second layer strip line, and secondary shielding layer is arranged at above ground floor strip line; At grade, and one end of resonant element ground floor strip line at different levels is connected with the first grounding ports, the other end is opened a way for the ground floor strip line of described input lead inductance, resonant element at different levels, output lead inductance; Second layer strip line one end is connected with the second grounding ports, the other end is opened a way, input port is connected with in the middle part of the ground floor strip line of first order parallel resonance unit by input lead inductance, be connected with output port by output lead inductance in the middle part of the ground floor strip line of level V parallel resonance unit, Z-shaped interstage coupling unit is positioned at the below of resonant element at different levels, the top of the first screen, and Z-shaped interstage coupling unit one end is connected with the first grounding ports, the other end is connected with the second grounding ports.
Compared with prior art, its remarkable advantage is in the present invention: (1) achieves the advantage that filter frequencies selectivity is good, passband response is smooth, transition band is precipitous, Out-of-band rejection is good, return loss is little, insertion loss is little; (2) microwave switch Insertion Loss is achieved little, the advantage that standing wave is good; (3) present invention employs DGS technology, to the suppression of high order harmonic component well; (4) volume of the present invention is little, lightweight, reliability is high, excellent electrical property, implementation structure are simple, cost is low, can realize production in enormous quantities.
Embodiment
Below in conjunction with accompanying drawing, the present invention is described in further detail.
The present invention is based on the SHF wave band high performance filter group of LTCC and DGS technology, comprise single-pole double-throw switch (SPDT) chip Switch, the first microwave filter Filter1 and the second microwave filter Filter2; Described single-pole double-throw switch (SPDT) chip Switch comprises signal input port RFIn, the first signal output port RFOut1, secondary signal output port RFOut2, first exports and selects control end V1, second to export selection control end V2 five ports; Wherein the first signal output port RFOut1 is connected with the input port of the first microwave filter Filter1, and secondary signal output port RFOut2 is connected with the input port of the second microwave filter Filter2;
Wherein the first microwave filter Filter1 and the second microwave filter Filter2 all adopts defect ground structure DGS and LTCC LTCC technology, and described microwave filter includes input port, input lead inductance, Pyatyi parallel resonance unit, output lead inductance, output port, two screens, Z-shaped interstage coupling unit and two grounding ports; Every grade of resonant element is formed by the upper and lower two-layer strip line of parallel placement, and second layer strip line is positioned at below ground floor strip line, and wherein the first screen is arranged at below second layer strip line, and secondary shielding layer is arranged at above ground floor strip line; At grade, and one end of resonant element ground floor strip line at different levels is connected with the first grounding ports, the other end is opened a way for the ground floor strip line of described input lead inductance, resonant element at different levels, output lead inductance; Second layer strip line one end is connected with the second grounding ports, the other end is opened a way, input port is connected with in the middle part of the ground floor strip line of first order parallel resonance unit by input lead inductance, be connected with output port by output lead inductance in the middle part of the ground floor strip line of level V parallel resonance unit, Z-shaped interstage coupling unit is positioned at the below of resonant element at different levels, the top of the first screen, and Z-shaped interstage coupling unit one end is connected with the first grounding ports, the other end is connected with the second grounding ports.
The model that described single-pole double-throw switch (SPDT) chip Switch adopts is WKD0016H.Described first microwave filter Filter1 is identical with the second microwave filter Filter2 structure, but size is different, and is operated in different frequency ranges.
Composition graphs 1 (a) ~ (c), the present invention is a kind of based on the SHF wave band high performance filter group of LTCC (LTCC) with defect ground structure (DGS) technology, described first microwave filter Filter1 comprises surface-pasted 50 ohmage first input end mouth P1, first input lead inductance L in1, first order parallel resonance unit L11, L12, second level parallel resonance unit L21, L22, third level parallel resonance unit L31, L32, fourth stage parallel resonance unit L41, L42, level V parallel resonance unit L51, L52, first output lead inductance L out1, surface-pasted 50 ohmage first output port P2, the screen DGS1 of two defect ground structures, DGS2, the grounding ports Gnd1 of a first Z-shaped interstage coupling unit ZL1 and two Surface Mount structure and Gnd2, every grade of resonant element is formed by the upper and lower two-layer strip line of parallel placement, and second layer strip line is positioned at below ground floor strip line, and wherein the first screen DGS1 is arranged at below second layer strip line, and secondary shielding layer DGS2 is arranged at above ground floor strip line, first order parallel resonance unit L11, L12 is by the first strip line L11 of ground floor, second strip line L12 of the second layer is formed in parallel, second level parallel resonance unit L21, L22 is by the 3rd strip line L21 of ground floor, 4th strip line L22 of the second layer is formed in parallel, third level parallel resonance unit L31, L32 is by the 5th strip line L31 of ground floor, 6th strip line L32 of the second layer is formed in parallel, fourth stage parallel resonance unit L41, L42 is by the 7th strip line L41 of ground floor, 8th strip line L42 of the second layer is formed in parallel, level V parallel resonance unit L51, L52 is by the 9th strip line L51 of ground floor, tenth strip line L52 of the second layer is formed in parallel, at grade, and one end of resonant element ground floor strip line L11, L21, L31, L41, L51 at different levels is connected with the first grounding ports Gnd1, the other end is opened a way for the ground floor strip line of described first input lead inductance L in1, resonant element at different levels, the first output lead inductance L out1, second layer strip line L12, L22, L32, L42, L52 one end is connected with the second grounding ports Gnd2, the other end is opened a way, first input lead inductance L in1 one end is connected with the middle part of the first strip line L11, the other end is connected with first input end mouth P1, and one end of the first output lead inductance L out1 is connected with in the middle part of the 9th strip line L51, the other end is connected with the first output port P2, first Z-shaped interstage coupling unit ZL1 is positioned at the below of resonant element at different levels, the top of the first screen DGS1, and first Z-shaped interstage coupling unit ZL1 one end is connected with the first grounding ports Gnd1, the other end is connected with the second grounding ports Gnd2,
Second microwave filter Filter2 comprises surface-pasted 50 ohmage second input port P3, second input lead inductance L in2, 6th grade of parallel resonance unit L13, L14, 7th grade of parallel resonance unit L23, L24, 8th grade of parallel resonance unit L33, L34, 9th grade of parallel resonance unit L43, L44, tenth grade of parallel resonance unit L53, L54, second output lead inductance L out2, surface-pasted 50 ohmage second output port P4, the screen DGS3 of two defect ground structures, DGS4, the grounding ports Gnd3 of a second Z-shaped interstage coupling unit ZL2 and two Surface Mount structure, Gnd4, wherein every grade of resonant element is formed by the upper and lower two-layer strip line of parallel placement, and second layer strip line is positioned at below ground floor strip line, and the 3rd screen DGS3 is arranged at below second layer strip line, and the 4th screen DGS4 is arranged at above ground floor strip line, 6th grade of parallel resonance unit L13, L14 is by the 11 strip line L13 of ground floor, 12 strip line L14 of the second layer is formed in parallel, 7th grade of parallel resonance unit L23, L24 is by the 13 strip line L23 of ground floor, tenth strip line L24 of the second layer is formed in parallel, 8th grade of parallel resonance unit L33, L34 is by the 15 strip line L33 of ground floor, 16 strip line L34 of the second layer is formed in parallel, 9th grade of parallel resonance unit L43, L44 is by the 17 strip line L43 of ground floor, 18 strip line L44 of the second layer is formed in parallel, tenth grade of parallel resonance unit L53, L54 is by the 19 strip line L53 of ground floor, 20 strip line L54 of the second layer is formed in parallel, at grade, and one end of resonant element ground floor strip line L13, L23, L33, L43, L53 at different levels is connected with the 3rd grounding ports Gnd3, the other end is opened a way for the ground floor strip line of described second input lead inductance L in2, resonant element at different levels, the second output lead inductance L out2, second layer strip line L14, L24, L34, L44, L54 one end is connected with the 4th grounding ports Gnd4, the other end is opened a way, second input lead inductance L in2 one end is connected with the middle part of the 11 strip line L13, the other end is connected with the second input port P3, and one end of the second output lead inductance L out2 is connected with in the middle part of the 19 strip line L53, the other end is connected with the second output port P4, second Z-shaped interstage coupling unit ZL2 is positioned at the below of resonant element at different levels, the top of the 3rd screen DGS3, and second Z-shaped interstage coupling unit ZL2 one end is connected with the 3rd grounding ports Gnd3, the other end is connected with the 4th grounding ports Gnd4.
Described first microwave filter Filter1 and the second microwave filter Filter2 all adopts multilayer LTCC technique to realize, owing to being the realization of employing multilayer LTCC technique, its low-temperature co-burning ceramic material and metallic pattern sinter and form at about 900 DEG C of temperature, so have extreme high reliability and temperature stability, because structure adopts, 3 D stereo is integrated to be grounded with multilayer folding structure and outer surface metallic shield and to encapsulate, thus volume is significantly reduced.
Embodiment 1
The size that the present invention is based on the SHF wave band high performance filter group filter segment of LTCC and DGS technology is only 3.23mm × 3.23mm × 1.53mm and 1.63mm × 3.23mm × 1.53mm, single-pole double-throw switch (SPDT) chips W KD0016H, frequency range is 6-18GHz, insertion loss is 2dB, isolation is 40dB, input vswr is 1.3:1, and overall dimension is 1.1mm*1.4mm*0.1mm.Composition graphs 2 ~ 5, the present embodiment is as follows based on the performance of the SHF wave band high performance filter group of LTCC and DGS technology: pass band width is respectively 7.5-10GHz and 11.5-14GHz, the amplitude-frequency characteristic of two output ports in passband is better, and input port return loss is better than 16dB.As shown in Figure 2, the Insertion Loss of the first microwave filter Filter1 in 7.5-10GHz is less; As shown in Figure 3, switch connect first output select control end V1 time input standing wave reach below-17dB; As shown in Figure 4, the Insertion Loss of the second microwave filter Filter2 in 11.5-14GHz is less.As shown in Figure 5, switch connect second output select control end V2 time input standing wave reach below-16dB.
The present invention combines the excellent properties such as the insertion loss of two filters is little, passband fluctuation is little, transition band is precipitous, Out-of-band rejection is good, and good stability, electrical property are reliable, can be used in and the different frequency part in a road signal is carried out in separating treatment or other the occasion having rigors and corresponding system.