CN102136615A - LTCC-based miniaturized X-wave band band-pass filter - Google Patents
LTCC-based miniaturized X-wave band band-pass filter Download PDFInfo
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- CN102136615A CN102136615A CN2011100030840A CN201110003084A CN102136615A CN 102136615 A CN102136615 A CN 102136615A CN 2011100030840 A CN2011100030840 A CN 2011100030840A CN 201110003084 A CN201110003084 A CN 201110003084A CN 102136615 A CN102136615 A CN 102136615A
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Abstract
The invention discloses a low temperature co-fired ceramic (LTCC)-based miniaturized X-wave band band-pass filter. The filter comprises a grounded metal shell and a plurality of layers of metal plates connected with forward or backward metal wires, wherein stripline feed ends on different layers are led to a surface microstrip line for transmitting, namely inputting and outputting in a microstrip line mode, through metal through holes; and a ceramic dielectric material is filled on the periphery of devices in the metal shell and the periphery of a microstrip line below the grounded metal shell and the metal through holes. In the LTCC-based miniaturized X-wave band band-pass filter, an LTCC process-based multilayer composite right/left-handed transmission line structure equivalent lumped parameter element is adopted, and out-band rejection and high-frequency performance are improved very well by designed upper and lower sideband transmission zero points; and finally, a novel X-wave band LTCC band-pass filter with a simple structure, a small size, high tightness, small band-pass insertion loss and a high out-band rejection degree is disclosed.
Description
Technical field
The invention belongs to microwave technical field, relate to a kind of band pass filter, more particularly, relate to a kind of miniaturization X-band Design of Bandpass method based on LTCC technology.
Background technology
Microwave filter is the two-port network of control system frequency response characteristic in the microwave system, and its performance directly influences the performance of whole system.Traditional filter little band or resonant cavity forms of adopting realize though can realize low-loss, often having bigger planar dimension more.Modern communication systems to during miniaturization and high performance requirement improve constantly, in order to solve the contradiction between size of devices and the transmission characteristic, people such as Yasushi Horri proposed multilayer (Multilayered, ML) CRLH TL structure in 2005.ML TL structure makes electromagnetic wave propagate along the vertical direction perpendicular to horizontal plane, and use horizontal andante electric capacity to replace plane capacitance commonly used in the planar microstrip line structure perpendicular to the direction of propagation, electromagnetic transmission direction and moulded dimension change direction are placed on two dimensions respectively.Such ML TL structure biggest advantage is to obtain less physical size and short length of transmission line under bigger electrical length.
LTCC (LTCC) is a kind of of Electronic Packaging technology, adopts the multi-layer ceramics technology, can also active element can be mounted on substrate surface simultaneously and make the integrated functional module of have no chance/having chance with the passive component embedded set in medium substrate inside.The LTCC technology all shows numerous advantages at cost, integrated encapsulation, wiring live width and distance between centers of tracks, Low ESR metallization, the diversity of design and good aspects such as high frequency performance, has become passive integrated mainstream technology.Application in microwave regime in recent years receives increasing concern, has high Q value, is convenient to embedded passive device, and thermal diffusivity is good, the reliability height, high temperature resistant, dash advantages such as shake, utilize the LTCC technology, it is little to process size, the precision height, and compactness is good, the microwave device that loss is little.
Summary of the invention
The objective of the invention is to propose that a kind of size is little, compactness good, logical in-band insertion loss is little and the method for designing of the novel miniaturization X-band LTCC band pass filter that the outer inhibition degree of band is high, based on LTCC technology, utilize multilayer composite left-and-right-hand transmission line structure to realize equivalent lumped-parameter element, and designed last lower sideband transmission zero.
The objective of the invention is to be achieved by the following technical programs, a kind of miniaturization X-band LTCC band pass filter based on LTCC, four faces have grounded metal enclosure before and after about comprising one, and wherein the top and bottom of grounded metal enclosure connect by metallic vias; The grounded metal enclosure inside seven horizontally disposed metallic plates that be arranged in parallel up and down, described seven metallic plates comprise seven measure-alike flat boards, name first flat board to the, seven flat boards from bottom to top respectively; The banded line of the first dull and stereotyped input that connects, the 7th dull and stereotyped output strip line that connects are guided to microstrip line by the metallic vias of passing metal shell respectively, with the input and output of microstrip line form; Fill ceramic medium material around the device and around grounded metal enclosure below microstrip line and the metallic vias in the grounded metal enclosure.
The further technical scheme of the present invention is that in described seven metal plates that be arranged in parallel up and down, first flat board connects the first forward direction metal wire that links to each other previously with grounded metal enclosure simultaneously except that connecting the input strip line; The second dull and stereotyped second forward direction metal wire that links to each other previously with grounded metal enclosure that connects; The 3rd dull and stereotyped connect with grounded metal enclosure link to each other later first afterwards to metal wire; The 5th dull and stereotyped connect with grounded metal enclosure link to each other later second afterwards to metal wire; The 6th dull and stereotyped the 3rd forward direction metal wire that links to each other previously with grounded metal enclosure that connects, described the 3rd forward direction metal wire and the second forward direction metal wire are up and down and be arranged in parallel, and be continuous by two metallic vias; Described the 7th flat board connects the 4th forward direction metal wire that links to each other previously with grounded metal enclosure simultaneously except that connecting the input strip line.
Described adjacent panels realizes the left hand series capacitance; The left hand shunt inductance is realized to metal wire in forward direction metal wire, back.The metallic vias of described connection forward direction metal wire has realized the upper sideband transmission zero; Capacitive coupling between the adjacent forward direction metal wire has realized the lower sideband transmission zero.
The metallic vias of described connection input, output strip line and microstrip line forms accurate coaxial line structure with the metallic vias that is connected metal grounding shell top and bottom, and the feed port translation that makes antarafacial is a co-planar ports.
The invention has the beneficial effects as follows: with existing invention relatively, the present invention is based on LTCC technology, proposed a kind of simple in structure, size is littler, logical in-band insertion loss is littler, the method for designing of the X-band band pass filter of the outer Du Genggao of inhibition of band.The present invention has adopted multilayer composite left-and-right-hand transmission line structure, and the transmission direction and the moulded dimension change direction of electromagnetic field is placed on two dimensions respectively, has effectively reduced size of devices; Simultaneously based on LTCC technology, multilayer transmission line structure equivalence lumped-parameter element, the transmission zero of the last lower sideband of designing has well been improved outer inhibition of band and high frequency performance.
Description of drawings
Fig. 1 is the structural representation of the miniaturization X-band band pass filter based on LTCC of the present invention;
Fig. 2 is the front view of the miniaturization X-band band pass filter based on LTCC of the present invention;
Fig. 3 is the vertical view of the miniaturization X-band band pass filter based on LTCC of the present invention;
Fig. 4 is the left view of the miniaturization X-band band pass filter based on LTCC of the present invention;
Fig. 5 is the amplitude-frequency characteristic simulation result of the described miniaturization X-band band pass filter based on LTCC of the specific embodiment of the invention;
Fig. 6 is the group delay characteristic simulation result of the described miniaturization X-band band pass filter based on LTCC of the specific embodiment of the invention;
Fig. 7 is the periodic unit equivalent circuit diagram of the miniaturization X-band band pass filter based on LTCC of the present invention.
Wherein: 1 is first metallic plate; 2 is second metallic plate; 3 is the 3rd metallic plate; 4 is the 4th metallic plate; 5 is the 5th metallic plate; 6 is the 6th metallic plate; 7 is the 7th metallic plate; 8 is grounded metal enclosure; 9 is first metallic vias; 10 is second metallic vias; 11 is the 3rd metallic vias; 12 is first little band; 13 is second little band; 14 is the 4th metallic vias; 15 is ceramic medium material; 1a is first flat board; 1b is the banded line of input; 1c is first pad; 1d is the first forward direction metal wire; 2a is second flat board; 2b is the second forward direction metal wire; 2c is second pad; 3a is the 3rd flat board; 3b is that first back is to metal wire; 4a is Siping City's plate; 5a is the 5th flat board; 5b second back is to metal wire; 6a is the 6th flat board; 6b is the 3rd forward direction metal wire; 6c is the 3rd pad; 7a is the 7th flat board; 7b is the output strip line; 7c is the 4th pad; 7d is the 4th forward direction metal wire.
Tool is stopped execution mode
Below in conjunction with accompanying drawing the present invention is described in further detail.
As shown in Figure 1, a kind of miniaturization X-band band pass filter based on LTCC, four faces in front and back have grounded metal enclosure 8 up and down, and wherein the top and bottom of grounded metal enclosure connect by first metallic vias 9; Inside, the chamber seven horizontally disposed metallic plates that be arranged in parallel up and down, bottom-up first metallic plate 1, second metallic plate 2, the 3rd metallic plate 3, the 4th metallic plate 4, the 5th metallic plate 5, the 6th metallic plate 6, the 7th metallic plate 7 of being respectively; Seven metallic plates comprise seven measure-alike flat boards, name the first dull and stereotyped 1a, the second dull and stereotyped 2a, the 3rd dull and stereotyped 3a, the plate 4a of Siping City, the 5th dull and stereotyped 5a, the 6th dull and stereotyped 6a, the 7th dull and stereotyped 7a from bottom to top respectively; The banded line 1b of the input that the first dull and stereotyped 1a connects, be connected to first microstrip line 12 by second metallic vias 10 of passing metal shell 8, the output strip line 7b that the 7th dull and stereotyped 7a connects, be connected to second microstrip line 13 by the 3rd metallic vias 11 of passing metal shell 8, described second metallic vias 10, the 3rd metallic vias 11 and first metallic vias 9 that is connected the grounded metal enclosure top and bottom form accurate coaxial line structure, and making the antarafacial port translation is co-planar ports; The first dull and stereotyped 1a connects the first forward direction metal wire 1d that links to each other previously with grounded metal enclosure, and the banded line 1b of input connects the first pad 1c; The second dull and stereotyped 2a connects the second forward direction metal wire 2b that links to each other previously with grounded metal enclosure; The 3rd dull and stereotyped 3a connect with grounded metal enclosure link to each other later first afterwards to metal wire 3b; The 5th dull and stereotyped 5a connect with grounded metal enclosure link to each other later second afterwards to metal wire 5b; The 6th dull and stereotyped 6a connects the 3rd forward direction metal wire 6b that links to each other previously with grounded metal enclosure; The 7th dull and stereotyped 7a connects the 4th forward direction metal wire 1d that links to each other previously with grounded metal enclosure, and output strip line 7b connects the 4th pad 7c; Connect by the 4th metallic vias 14 between the second forward direction metal wire 2b and the 3rd forward direction metal wire 6b, the bottom of described the 4th metallic vias 14 connects the second pad 2c, the top connects the 3rd pad 6c; Device fills ceramic medium material 15 on every side and around grounded metal enclosure 8 below microstrip lines 12,13 and the metallic vias 10,11 in the grounded metal enclosure 8.
In this structure, left hand shunt inductance L
LProvide left hand series capacitance C by the second forward direction metal wire 2b, the 3rd forward direction metal wire 6b and first back to metal wire 5b to metal wire 3b, second back
LBy among the dull and stereotyped 1a-7a in twos the spacing between the adjacent panels provide.Connect the 4th metallic vias 14 of the second forward direction metal wire 2b and the 3rd forward direction metal wire 6b, equivalence is the feedback inductance of non-conterminous inter-stage, has realized the transmission zero of high stopband; Capacitive coupling between capacitive coupling between the first forward direction metal wire 1d and the second forward direction metal wire 2b, the 3rd forward direction metal wire 6b and the 4th forward direction metal wire 7d, equivalence is the electric capacity between adjacent level, has realized the transmission zero of low stopband.
Filter operation principle of the present invention: the left-and-right-hand transmission line equivalent electric circuit generally has ω in order to obtain effective bandwidth as shown in Figure 7
L＜＜ω
R, during engineering is used during more simple CRLH TL balance the cut-off frequency expression formula be
In the formula:
ω
L---the left hand frequency variable,
ω
R---right hand frequency variable,
ω
CL---left hand hop cut-off frequency;
ω
CR---right hand hop cut-off frequency;
As can be seen, the cut-off frequency of centre frequency and decision amount of bandwidth is by C
L, L
L, C
R, L
RDecision.Be used to provide the structural parameters of right-hand man's transmission characteristic electric capacity, inductance value by adjustment, can reach the purpose that changes frequency characteristic.
Mini filter often can not be avoided being coupled between resonant cavitys at different levels bigger, the outer problem that suppresses difference of band.Near band connection frequency, realize several transmission zeros, the band that often can reduce in the band segment suppresses outward.
The formation main cause of transmission zero is the obstruct of energy, and in two kinds of situation: total reflection and energy are shorted to other branch roads.When signal process parallel network Y, the admittance of Y is that infinity is short-circuited, and energy is all passed to ground, thereby forms transmission zero; When signal was infinitely great through the impedance of series network Z, signal can't pass through, and forms a transmission zero.
Connect two metallic vias of the second forward direction metal wire and the 3rd forward direction metal wire in this patent, equivalence is the feedback inductance of non-conterminous inter-stage, has realized the transmission zero of high stopband; Capacitive coupling between adjacent forward direction metal wire has realized the transmission zero of low stopband.By regulating model structure parameter, change equivalent inductance, capacitance, can regulate transmission zero easily.
LTCC metal that technology adopts is a gold among the present invention, the medium substrate material is a Ferro-A6 type LTCC ceramic material, its relative dielectric constant is 5.9, dielectric loss is 0.002, dielectric-slab thickness d=127um before the sintering, whole filter is totally 20 layers of dielectric-slab thickness, and the entire device volume only is 4.5mm * 3.6mm * 1.93mm.
This filter model amplitude-frequency characteristic simulation result as shown in Figure 5, this band pass filter works in 9.24GHz-10.03GHz, logical in-band insertion loss is less than 1.2dB, return loss is greater than 13.3dB in the passband, there are two transmission zeros at lower sideband 7.41GHz, 8.5GHz place, there are two transmission zeros at upper sideband 11.63GHz, 14.47GHz place, and band is outer in the very big frequency range below the 7.9GHz suppresses greater than 35dB, and band is outer in the very big frequency range more than the 11.4GHz suppresses greater than 35dB.
This filter model group delay characteristic simulation result changes band pass filter in working frequency range as shown in Figure 6, and group delay is between 0.48ns-0.63ns, and Group Delay Ripple is only less than 0.15ns in the passband.
In sum, the X-band Design of Bandpass method that the present invention proposes has adopted multilayer left-right-hand composite transmission line structure, and the transmission direction and the moulded dimension change direction of ripple is placed on two dimensions respectively, has effectively reduced size of devices; Simultaneously based on LTCC technology, multilayer transmission line structure equivalence lumped-parameter element, the transmission zero of the last lower sideband of designing has well been improved outer inhibition of band and high frequency performance.Designed a kind of simple in structure, size is littler, in-band insertion loss is littler, the X-band band pass filter of the outer Du Genggao of inhibition of band, this band pass filter can be widely used in the microwave telecommunication system.
Above content is to further describing that the present invention did in conjunction with concrete preferred implementation; can not assert that the specific embodiment of the present invention only limits to this; for the general technical staff of the technical field of the invention; without departing from the inventive concept of the premise; can also make some simple deduction or replace, all should be considered as belonging to the present invention and determine scope of patent protection by claims of being submitted to.
Claims (6)
1. the miniaturization X-band band pass filter based on LTCC is characterized in that, four faces in front and back have grounded metal enclosure up and down, and wherein the top and bottom of grounded metal enclosure connect by metallic vias.
2. a kind of miniaturization X-band band pass filter according to claim 1 based on LTCC, it is characterized in that, described grounded metal enclosure inside seven metallic plates that be arranged in parallel up and down, every metallic plate are and are horizontally disposed with, and name first metallic plate to the, seven metallic plates from bottom to top respectively; Described seven metallic plates comprise seven measure-alike flat boards, name first flat board to the, seven flat boards from bottom to top respectively.
3. a kind of miniaturization X-band band pass filter according to claim 1 and 2 based on LTCC, it is characterized in that, the banded line of the described first dull and stereotyped input that connects, the 7th dull and stereotyped output strip line that connects, guide to microstrip line by the metallic vias of passing grounded metal enclosure respectively, with the input and output of microstrip line form, described metallic vias forms accurate coaxial line structure with the metallic vias that is connected the metal shell top and bottom, and making the antarafacial port translation is co-planar ports.
4. a kind of miniaturization X-band band pass filter according to claim 1 and 2 based on LTCC, it is characterized in that, in described seven measure-alike flat boards, first dull and stereotyped the removing connects the banded line of input, connects the forward direction metal wire that links to each other previously with grounded metal enclosure simultaneously; The second dull and stereotyped forward direction metal wire that links to each other previously with grounded metal enclosure that connects; The 3rd dull and stereotyped connect with grounded metal enclosure link to each other later back to metal wire; The 5th dull and stereotyped connect with grounded metal enclosure link to each other later back to metal wire; The 6th dull and stereotyped forward direction metal wire that links to each other previously with grounded metal enclosure that connects; The 7th dull and stereotyped banded line of the input that connects that removes connects the forward direction metal wire that links to each other previously with grounded metal enclosure simultaneously.
5. according to claim 1 or 4 described a kind of miniaturization X-band band pass filters, it is characterized in that the forward direction metal wire that described second flat board, the 6th flat board are connected is up and down and be arranged in parallel, link to each other by two metallic vias based on LTCC.
6. according to claim 1 or 3 described a kind of miniaturization X-band band pass filters based on LTCC, it is characterized in that, fill ceramic medium material in the described grounded metal enclosure around the device, fill ceramic medium material around grounded metal enclosure below microstrip line and the metallic vias.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103413997A (en) * | 2013-08-01 | 2013-11-27 | 南京理工大学 | Vertical interdigital LTCC band-pass filter |
| CN106129556A (en) * | 2016-08-28 | 2016-11-16 | 戴永胜 | A kind of cutting back line style LTCC ultra wide band bandpass filter |
| CN108565531A (en) * | 2018-03-23 | 2018-09-21 | 南京邮电大学 | Small narrow band low-temperature co-fired ceramics bandpass filter |
| CN107453727B (en) * | 2017-08-07 | 2021-01-15 | 大连海事大学 | Low-insertion-loss negative group time delay microwave circuit |
| US11245168B2 (en) | 2020-03-30 | 2022-02-08 | Industrial Technology Research Institute | Filter |
| CN117938182A (en) * | 2024-01-11 | 2024-04-26 | 安徽蓝讯通信科技有限公司 | Miniaturized receiving module based on LTCC |
Citations (1)
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| CN101888003A (en) * | 2010-07-07 | 2010-11-17 | 西安交通大学 | Bandpass filter with LTCC multilayer composite left-and-right-hand transmission line structure |
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| CN101888003A (en) * | 2010-07-07 | 2010-11-17 | 西安交通大学 | Bandpass filter with LTCC multilayer composite left-and-right-hand transmission line structure |
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103413997A (en) * | 2013-08-01 | 2013-11-27 | 南京理工大学 | Vertical interdigital LTCC band-pass filter |
| CN103413997B (en) * | 2013-08-01 | 2015-11-04 | 南京理工大学 | Vertical interdigital LTCC band pass filter |
| CN106129556A (en) * | 2016-08-28 | 2016-11-16 | 戴永胜 | A kind of cutting back line style LTCC ultra wide band bandpass filter |
| CN106129556B (en) * | 2016-08-28 | 2020-06-02 | 深圳波而特电子科技有限公司 | Short-section line type LTCC ultra-wideband band-pass filter |
| CN107453727B (en) * | 2017-08-07 | 2021-01-15 | 大连海事大学 | Low-insertion-loss negative group time delay microwave circuit |
| CN108565531A (en) * | 2018-03-23 | 2018-09-21 | 南京邮电大学 | Small narrow band low-temperature co-fired ceramics bandpass filter |
| US11245168B2 (en) | 2020-03-30 | 2022-02-08 | Industrial Technology Research Institute | Filter |
| CN117938182A (en) * | 2024-01-11 | 2024-04-26 | 安徽蓝讯通信科技有限公司 | Miniaturized receiving module based on LTCC |
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Application publication date: 20110727 |