CN114335941B - Flexible band-pass filter of stretching - Google Patents
Flexible band-pass filter of stretching Download PDFInfo
- Publication number
- CN114335941B CN114335941B CN202111613858.1A CN202111613858A CN114335941B CN 114335941 B CN114335941 B CN 114335941B CN 202111613858 A CN202111613858 A CN 202111613858A CN 114335941 B CN114335941 B CN 114335941B
- Authority
- CN
- China
- Prior art keywords
- pass filter
- band
- microstrip
- flexible
- line
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Control Of Motors That Do Not Use Commutators (AREA)
Abstract
The invention provides a flexible stretchable band-pass filter, and belongs to the technical field of flexible electronic devices. The flexible stretchable band-pass filter prepared by the invention comprises a patterned band-pass filter circuit, a flexible medium substrate, a patterned metal grounding plate and a compensation coupling capacitor, wherein a traditional rigid medium substrate is replaced by the flexible medium substrate, and the patterned band-pass filter circuit, the compensation coupling capacitor and the patterned metal grounding plate are used for guiding the propagation of electromagnetic waves together, so that the stretchable function of the band-pass filter circuit is realized, and the pass band and stop band characteristics are kept stable in the process of stretching to 20%.
Description
Technical Field
The invention belongs to the technical field of flexible electronic devices, and particularly relates to a flexible stretchable band-pass filter.
Background
With the rapid development of modern wireless communication technology, radio frequency microwave devices have gained wide attention and intensive research by scholars at home and abroad. The band-pass filter has the function of screening or isolating signals in a specific frequency range, the performance of the band-pass filter directly affects the quality of the whole wireless communication system and a signal processing circuit, and the band-pass filter is a key front-end device in the signal processing circuit. At present, wearable devices attract wide attention in related fields, and the flexible band-pass filter has the advantages of being soft, bendable, stretchable, convenient to attach to a human body and the like, and has a good application prospect.
However, the conventional flexible band-pass filter has only flexibility but not stretchability, and the usage scenario thereof is limited. For example, zhao M et al [1] A flexible band-pass filter based on open-circuit and short-circuit branch lines is disclosed, which is prepared by preparing the filter on a flexible LCP substrate; wang T et al [2] A5-7 GHz band-pass filter based on DGS is disclosed, and the filter and the bending characteristics are realized by manufacturing the filter on a flexible LCP substrate; yu L et al [3] A hairpin bandpass filter is disclosed, byThe filter is prepared on the flexible LCP substrate, so that the filtering and bending characteristics are realized; ying Y et al [4] A flexible band-pass filter based on a J/K converter is disclosed, and stable filtering performance can be still maintained when the filter is bent to 70 degrees by manufacturing the filter on a flexible LCP substrate; zhao M et al [5] A hairpin flexible band-pass filter is disclosed, which is prepared on a flexible LCP substrate, has an operating frequency of 5.15-5.875GHz, and is suitable for WLAN application.
Therefore, the flexible stretchable band-pass filter has important practical significance in research and manufacture.
[1]Zhao M,Zhang Y,Liu S,et al.UWB flexible filter with low loss and exc ellent stopband performance[J].Microwave&Optical Technology Letters,2017,59(1):194-197.
[2]Wang T,Wang Z,Zhao M,et al.A Compact Implantable Flexible Filter with Low loss[J].IEICE Electronics Express,2017,14(17):20170802-20170802.
[3]Yu L,Xu Y,Wang C,et al.Flexible microwave filters on ultra thin Liquid Crystal Polymer substrate[C]//Microwave Symposium.IEEE,2015.
[4]Ying Y,Ping G,Ding K,et al.Aflexible bandpass filter based on Liquid C rystal Polymer substrate[C]//Microwave Conference.IEEE,2016.
[5]Zhao M,Yong Z.A Compact Wearable 5-GHz Flexible Filter[J].Electronics Le tters,2017,53(10):661-663.
Disclosure of Invention
In view of the problems of the background art, it is an object of the present invention to provide a flexible and stretchable band pass filter. The flexible stretchable band-pass filter comprises a patterned band-pass filter circuit, a flexible medium substrate, a patterned metal grounding plate and a compensation coupling capacitor, wherein a traditional rigid medium substrate is replaced by a flexible medium substrate, and electromagnetic wave propagation is guided by the patterned band-pass filter circuit, the compensation coupling capacitor and the patterned metal grounding plate together, so that the stretchable function of the band-pass filter circuit is realized, and the band-pass filter function is kept stable in the stretching deformation process.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a flexible and stretchable band-pass filter sequentially comprises a graphical band-pass filter circuit, a flexible medium substrate and a graphical metal grounding plate from top to bottom;
the graphical band-pass filter circuit comprises two microstrip line units and a compensation coupling capacitor, wherein the two microstrip line units are symmetrical about a vertical middle axis of the flexible medium substrate, each microstrip line unit consists of a linear microstrip line and a runway-type microstrip resonance ring, and the linear microstrip line is arranged on one side, away from the symmetrical axis (the vertical middle axis of the flexible medium substrate), of the runway-type microstrip resonance ring; a notch is arranged in the center of a straight line part of one side of the runway type microstrip resonance ring, which is close to the symmetry axis, the side is connected with a section of bent line, the other end of the bent line is provided with a welding area, and two welding areas of the graphical band-pass filter circuit are welded with compensation coupling capacitors;
the patterned metal ground plate comprises two rectangular ground plates, the two rectangular ground plates are directly connected through bent lines, the width of each rectangular ground plate is larger than that of a microstrip line unit in the patterned band-pass filter circuit, and the distance between each rectangular ground plate and a straight line part of a runway type microstrip resonance ring in the microstrip line unit, which is close to one side of a symmetry axis, is not smaller than that of the straight line part of the runway type microstrip resonance ring.
Further, the circumference of the runway-type microstrip resonance ring is the wavelength lambda of the gated electromagnetic wave g Half, the width being determined by the coupling impedance.
Furthermore, the linear microstrip line is connected with a straight line part of the runway-type microstrip resonance ring, and a bent line is arranged at the connection position of the circular arc part and the straight line part of one side of the runway-type microstrip resonance ring, which is close to the symmetry axis.
Further, the bend line is preferably a serpentine line.
Furthermore, the larger the distance between two microstrip line units in the graphical band-pass filter circuit is, the smaller the coupling effect of the circuit is, and the distance between the microstrip line units should make the circuit have no coupling effect.
Further, the capacitance value of the compensation coupling capacitor is selected according to actual requirements.
Further, the flexible medium layer is made of silicon rubber, specifically Ecoflex or PDMS; the graphical band-pass filter circuit and the graphical metal grounding plate are made of polyimide copper clad plates.
The mechanism of the invention is as follows:
the two symmetrical resonant rings realize the conduction effect on the electromagnetic wave with the specific frequency through the coupling effect of the adjacent electromagnetic field, specifically, one resonant ring generates resonance on the input electromagnetic wave with the certain frequency in the working process, the adjacent electromagnetic field excites the resonance of the other resonant ring through electromagnetic induction on the other resonant ring, and the electromagnetic wave with other frequencies cannot generate resonance, so that the gating on the electromagnetic wave with the specific frequency is realized. The resonant ring resonates only for electromagnetic fields of a specific frequency determined by the electrical length of the resonant ring (the circumference of the resonant ring) which is the wavelength λ of the gated electromagnetic wave g Half of the wavelength of the light (half the operating wavelength), wherein,
where C is the speed of light, f is the center frequency, ε eff Is the microstrip line equivalent dielectric constant, the center frequency of the band pass filter is therefore dependent on the electrical length of the resonant ring.
In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:
1. according to the invention, through the design of the patterned band-pass filter circuit and the patterned metal grounding plate structure, the band-pass filter realizes the stretching function, and meanwhile, the band-pass filter function of the filter can be kept stable in the process that the stretching deformation of the device is up to 20%.
2. The device has simple structure, is easy for industrial production and preparation, has light weight, is easy to integrate and is convenient to combine with a human body.
Drawings
FIG. 1 is a schematic diagram of a flexible and stretchable band-pass filter according to the present invention;
the device comprises a flexible dielectric substrate 1, a graphical band-pass filter circuit 2, a graphical metal grounding plate 3 and a compensation coupling capacitor 4.
Fig. 2 is a schematic diagram of a specific structure of the patterned bandpass filter circuit according to the present invention.
FIG. 3 is a schematic diagram of a serpentine interconnect of the patterned bandpass filter circuit according to the present invention.
Fig. 4 is a schematic structural diagram of a patterned metal ground plate according to the present invention.
Fig. 5 is a schematic diagram of a specific structure of a serpentine interconnect of the patterned metal ground plate according to the present invention.
Fig. 6 is an equivalent circuit diagram of the flexible and stretchable band-pass filter of the present invention.
FIG. 7 shows the different stretching degrees (0% stretching, 10% stretching, 20% stretching) S of the flexible and stretchable band pass filter of example 1 11 And (6) carrying out parameter real mapping.
FIG. 8 shows the different stretching degrees (0% stretching, 10% stretching, 20% stretching) S of the flexible and stretchable band pass filter of example 1 21 And (6) carrying out parameter real-time mapping.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the following embodiments and accompanying drawings.
A flexible and stretchable band-pass filter is shown in figure 1, and comprises a graphical band-pass filter circuit 2, a flexible dielectric substrate 1 and a graphical metal grounding plate 3 from top to bottom in sequence;
the schematic structural diagram of the graphical band-pass filter circuit is shown in fig. 2, and the graphical band-pass filter circuit is composed of two microstrip line units which are axisymmetrical about a vertical middle axis of the flexible medium substrate, wherein each microstrip line unit is composed of a linear microstrip line and a runway-shaped microstrip resonance ring, and the linear microstrip line is arranged on one side of the runway-shaped microstrip resonance ring, which is far away from the symmetry axis, and is preferably connected with a linear part of the runway-shaped microstrip resonance ring; a notch is arranged in the center of the straight line part on one side, close to the symmetry axis, of the runway-type microstrip resonance ring, a snake-shaped line is further arranged at the joint of the arc part and the straight line part, a welding area is arranged at the other end of the snake-shaped line, a compensation coupling capacitor is welded and arranged on the two welding areas of the graphical band-pass filter circuit, and the structure of the snake-shaped interconnection line is shown in figure 3;
in the stretching process of the two runway type microstrip resonance rings, as the distance is gradually increased, the adjacent coupling effect of the two runway type microstrip resonance rings is gradually reduced until zero, so that the device keeps the coupling effect by introducing a coupling compensation capacitor, thereby stabilizing the filtering performance of the device. However, because the required total coupling effect is a certain value, and the required compensation capacitance is gradually increased along with the reduction of stretching adjacent coupling, in order to avoid the instability of the filter performance of the device in the stretching process, a large interval is arranged between the two runway-type microstrip resonance rings, so that the adjacent coupling between the resonance rings is eliminated, the coupling effect is completely from the compensation capacitance, the compensation capacitance change caused by the adjacent coupling effect change is avoided, and a larger stretching limit can be brought.
The schematic structural diagram of the graphical metal ground plate is shown in fig. 4, and the graphical metal ground plate comprises two rectangular ground plates which are directly connected through a bent line, the width of each rectangular ground plate is larger than the width of a microstrip line unit in the graphical band-pass filter circuit, the distance between the rectangular ground plate and a straight line part of a runway-type microstrip resonance ring on one side close to a symmetry axis in the microstrip line unit is not smaller than the width of the straight line part of the runway-type microstrip resonance ring, and the specific structure of a snake-shaped interconnection line between the rectangular ground plates is shown in fig. 3.
FIG. 6 is an equivalent circuit diagram extracted using a microstrip line equivalent model, which is divided into four parts, where L is L, to make the equivalent circuit diagram accurate a ，C a Corresponding to the straight line segment, L, of the upper half part of the resonance ring close to the symmetry axis b ，C b L corresponding to the upper arc part of the resonance ring and the straight line part of the input port to the upper arc c ，C c Corresponding to the lower arc part of the resonant ring and the straight line part from the input port to the lower arc, L d ，C d Corresponding to the straight line segment of the lower half part of the resonance ring close to the symmetrical shaft side, C is a compensation coupling capacitor, and Port1 and Port2 are respectively an input Port and an output Port.
Example 1
In this embodiment, the line width of the coupling loop is 1mm because the center frequency of the filter is 1GHz, the length of the resonance loop is 100mm, and impedance matching is considered.
The substrate of the flexible and stretchable band-pass filter of the present embodiment is Ecoflex (aliphatic aromatic random copolyester) with a thickness of 1mm; the materials used by the graphical band-pass filter circuit and the graphical metal grounding plate are polyimide copper clad plates with the thickness of 58 mu m, wherein the thickness of the polyimide layer is 40 mu m, and the thickness of the copper layer is 18 mu m.
As shown in fig. 2, in the patterned bandpass filter circuit: width W of linear microstrip line 1 =2.8mm, length L 1 =5.0mm, width W of central gap of straight line part of track type microstrip resonance ring 2 =1mm, length L of lower half straight part near symmetrical axis side 2 =16.5mm, length L of straight line on upper half portion on side close to axis of symmetry 3 =15.2mm, length L of straight line portion on side away from symmetry axis 4 =26mm, outer diameter of circular arc portion R 1 =6mm, inner diameter R 2 ＝5mm。
As shown in FIG. 3, in the serpentine interconnection line of the patterned bandpass filter circuit, each serpentine line comprises two connecting lines, three straight lines and two arcs, and the width W of the serpentine line 1 =0.3mm, length of straight portion L 1 =3mm, the first section of connecting line is connected with the runway-type microstrip resonance ring, the second section of connecting line is connected with the bonding pad, and the inner diameter R of the arc line 1 =0.5mm, outer diameter R 3 =0.7mm, the pad is square, the side length L 3 =1.5mm, pitch L of pads 2 ＝1mm。
As shown in fig. 4, in patterning the metallic ground plate: ground plate length W 1 =18.4mm, position L of interconnect line connection 1 =32.1mm, ground plane width L 2 =67mm. As shown in fig. 5, in the serpentine interconnection line of the patterned metal ground plate: length L of straight line part 1 =10mm, inner diameter of circular arc portion R 1 =2mm, outer diameter R 2 =2.5mm, radius R of connecting structure of interconnecting line and metal plate 3 ＝1.2mm。
The flexible and stretchable band pass filters described in the examples were stretched to 0%, 10%, and 20%, respectively, and the performance thereof was tested. FIG. 7 is a graph of the S11 parameter versus frequency for the flexible stretchable band pass filter of the embodiment after stretching to different degrees (0% stretched, 10% stretched, 20% stretched); fig. 8 is a graph of the S21 parameter versus frequency for the flexible, stretchable band-pass filter of an embodiment after stretching to different degrees (0% stretch, 10% stretch, 20% stretch). S11 is a reflection coefficient, and S21 is a transmission coefficient. The smaller the reflection coefficient, the larger the transmission coefficient, indicating that the majority of the electromagnetic energy reaches the output port from the input port without being substantially reflected back to the input port. In this embodiment, S11 and S21 respectively achieve the aforementioned effects only in the vicinity of 0.99GHz, indicating that electromagnetic energy passes through the filter almost without loss at this frequency. At other frequencies, electromagnetic energy is substantially reflected back to the input port and does not reach the output port, thereby embodying bandpass filtering, i.e., when the flexible, stretchable bandpass filter of an embodiment is stretched to 20%, its operating frequency is stabilized at 0.99GHz, and the passband and stopband characteristics remain stable. Therefore, the flexible stretchable band-pass filter provided by the invention still has good stability under certain tensile strength, and is suitable for the field of wearable microwave devices.
While the invention has been described with reference to specific embodiments, any feature disclosed in this specification may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise; all of the disclosed features, or all of the method or process steps, may be combined in any combination, except mutually exclusive features and/or steps.
Claims (7)
1. A flexible and stretchable band-pass filter comprises a graphical band-pass filter circuit, a flexible dielectric substrate and a graphical metal grounding plate from top to bottom in sequence,
the graphical band-pass filter circuit comprises two microstrip line units which are axisymmetric about the vertical middle axis of the flexible medium substrate and a compensation coupling capacitor; the microstrip line unit consists of a linear microstrip line and a runway-type microstrip resonance ring, the linear microstrip line is arranged on one side of the runway-type microstrip resonance ring, which is far away from the vertical middle bobbin of the flexible medium substrate, the center of a straight line part of the runway-type microstrip resonance ring, which is close to one side of the vertical middle bobbin of the flexible medium substrate, is provided with a notch, the side is connected with a first bending line, and the other end of the first bending line is provided with a welding area; two ends of the compensation coupling capacitor are respectively connected with two welding areas of the graphical band-pass filter circuit;
the patterned metal ground plate comprises two rectangular ground plates, the two rectangular ground plates are connected through a second bent line, the width of each rectangular ground plate is larger than that of a microstrip line unit in the patterned band-pass filter circuit, and the distance between each rectangular ground plate and a straight line part, close to one side of a vertical middle line shaft of the flexible medium substrate, of a runway-type microstrip resonance ring in each microstrip line unit is not smaller than the width of the straight line part of the runway-type microstrip resonance ring.
2. The band pass filter of claim 1, wherein the racetrack microstrip resonant ring has a perimeter of half a wavelength of the gated electromagnetic wave and a width determined by the coupling impedance.
3. The bandpass filter according to claim 1, wherein the linear microstrip line is connected to a straight line portion of the racetrack microstrip resonant ring, and a meander line is provided at a junction between an arc portion and the straight line portion of the racetrack microstrip resonant ring on a side of the racetrack microstrip resonant ring close to the vertical centerline axis of the flexible dielectric substrate.
4. The bandpass filter according to claim 1, wherein the first and second meander lines are each preferably serpentine lines.
5. The bandpass filter according to claim 1, wherein the distance between two microstrip line elements in the patterned bandpass filter circuit is such that the circuit has no coupling effect.
6. The bandpass filter according to claim 1, wherein the capacitance of the compensation coupling capacitor is selected according to actual requirements.
7. A bandpass filter as recited by claim 1, wherein the flexible dielectric layer material is silicone rubber, in particular Ecoflex or PDMS; the graphical band-pass filter circuit and the graphical metal grounding plate are made of polyimide copper clad plates.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111613858.1A CN114335941B (en) | 2021-12-27 | 2021-12-27 | Flexible band-pass filter of stretching |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111613858.1A CN114335941B (en) | 2021-12-27 | 2021-12-27 | Flexible band-pass filter of stretching |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114335941A CN114335941A (en) | 2022-04-12 |
| CN114335941B true CN114335941B (en) | 2022-10-14 |
Family
ID=81013385
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111613858.1A Active CN114335941B (en) | 2021-12-27 | 2021-12-27 | Flexible band-pass filter of stretching |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114335941B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108901123A (en) * | 2018-07-24 | 2018-11-27 | 武汉电信器件有限公司 | A kind of circuit board and electronic equipment |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006287527A (en) * | 2005-03-31 | 2006-10-19 | Sony Corp | Communication device |
| US8772772B2 (en) * | 2006-05-18 | 2014-07-08 | Intermolecular, Inc. | System and method for increasing productivity of combinatorial screening |
| US7744717B2 (en) * | 2006-07-17 | 2010-06-29 | E. I. Du Pont De Nemours And Company | Process for enhancing the resolution of a thermally transferred pattern |
| US20140035698A1 (en) * | 2012-08-03 | 2014-02-06 | Dielectric, Llc | Microstrip-Fed Crossed Dipole Antenna Having Remote Electrical Tilt |
| CN106549687B (en) * | 2016-10-31 | 2019-08-30 | 努比亚技术有限公司 | A kind of signal transmission system and mobile terminal based on serpentine |
| CN113078426A (en) * | 2021-03-12 | 2021-07-06 | 钱塘科技创新中心 | Low-pass filter and manufacturing method thereof |
-
2021
- 2021-12-27 CN CN202111613858.1A patent/CN114335941B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108901123A (en) * | 2018-07-24 | 2018-11-27 | 武汉电信器件有限公司 | A kind of circuit board and electronic equipment |
Non-Patent Citations (1)
| Title |
|---|
| 《氧化物功能薄膜材料在柔性传感器件中的应用》;潘泰松，廖非易，姚光，王宇轩，高敏，林媛;《中国科学:信息科学》;20180606;第48卷(第6期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114335941A (en) | 2022-04-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101694899B (en) | Microstrip bandpass filter with sector open-circuit structure | |
| CN112993498B (en) | Suspension strip line ultra-wideband adjustable zero-point band-pass filter | |
| CN102299697B (en) | Composite left/right handed transmission line and design method thereof as well as duplexer based on transmission line | |
| CN104659450B (en) | A kind of broadband bandpass filter based on cross resonator | |
| CN101777678B (en) | Double-mode double-band band-pass filter based on hexagonal ring resonator | |
| CN101609915A (en) | A kind of LTCC bandpass filter with image suppression | |
| CN1874056B (en) | Left hand microstrip transmission line, and time delay line structured based on the transmission line | |
| CN114335941B (en) | Flexible band-pass filter of stretching | |
| CN110556615A (en) | multi-frequency band-pass filter based on coupling symmetrical short-circuit branch multimode resonator | |
| CN113764850A (en) | Grounded coplanar waveguide-rectangular waveguide filtering transition structure | |
| WO2024108858A1 (en) | Balun-based spoof surface plasmon on-chip dual-mode transmission line | |
| CN112072235A (en) | Microstrip-probe structure feed dual-mode SIW balance band-pass filter | |
| CN201332134Y (en) | Multiple-circular arc resonant cavity double-mode band-pass filter | |
| CN201408828Y (en) | LTCC image frequency suppression band-pass filter | |
| US7532918B2 (en) | Superconductive filter having U-type microstrip resonators with longer and shorter parallel sides | |
| CN110534852A (en) | Multifrequency band-pass filter based on in-parallel coupling splitted construction multimode resonator | |
| Xiao et al. | Multi-mode bandstop filter using defected equilateral triangular patch resonator | |
| CN105896008A (en) | Compact-type band-pass filter comprising transmission zero points at high and low frequencies | |
| CN101901951A (en) | Bent dual-band bandpass filter applying defected ground level waveguide technology | |
| CN201408829Y (en) | LTCC harmonic suppression band-pass filter | |
| CN210468059U (en) | Dual-frequency band-pass filter based on microstrip system | |
| JPS61159803A (en) | Transmission line coupler for antenna | |
| CN202534756U (en) | Compact type dual mode open circuit loop band pass filter | |
| CN209747694U (en) | Low-pass filter with complementary split resonant ring and U-shaped groove defected ground | |
| Keriee et al. | Millimeter-Wave Bandpass Filter By Open Loop Elliptical Ring Resonators |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |