CN1601902A - Micromechanical capacitance microwave switch based on Nano dielectric film - Google Patents
Micromechanical capacitance microwave switch based on Nano dielectric film Download PDFInfo
- Publication number
- CN1601902A CN1601902A CN 200410067330 CN200410067330A CN1601902A CN 1601902 A CN1601902 A CN 1601902A CN 200410067330 CN200410067330 CN 200410067330 CN 200410067330 A CN200410067330 A CN 200410067330A CN 1601902 A CN1601902 A CN 1601902A
- Authority
- CN
- China
- Prior art keywords
- dielectric film
- nano dielectric
- nano
- film
- switch
- 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.)
- Pending
Links
Landscapes
- Micromachines (AREA)
Abstract
Microwave switch includes lower pole, upper Nano dielectric thin film, movable pole, and non-static micro driver. Lower pole is a layer of electric metal thin film, and Nano dielectric thin film is on lower pole. The movable pole, which is self supported movable pole, positioned on Nano dielectric thin film is connected to non-static micro driver. Non-static micro driver drives the movable pole to close with or depart from the upper pole to make parallel plate capacitor generate change so as to realize on/off of switch. Nano dielectric film in very thin thickness is adopted in the invention as insulating medium of tunable capacitance. Thus, maximum value of capacitance is raised remarkably so as to raise on/off ratio of capacitance type switch, and improve operational characteristics of switch.
Description
Technical field
The present invention relates to a kind of microwave switch, exactly, relate to a kind of micromechanical capacitance microwave switch based on Nano dielectric film.Be used for the automatic control technology field.
Background technology
Tunable capacitor in the adjusting microwave circuit is one of groundwork mode of MEMS microwave switch control signal transmission to realize connecting or disconnecting of transmission line, and this class switch is called as the capacitive character microwave switch.Capacitive switch comprises moving electrode, fixed electrode usually and is clipped in above-mentioned dielectric film between the two, forms MIM (Metal-Insulator-Metal) structure.Above-mentioned mim structure constitutes an adjustable parallel plate capacitor, changes the parallel-plate spacing by handling moving electrode, can change the MIM capacitance significantly, reaches the purpose of connecting or cutting off the microwave circuit signal.Wherein, closure with disconnect the make-to-break ratio that the maximum that can realize under the two states and the ratio of position of minimum capacitance are called switch, be the key technical index of capacitive character microwave switch.
For polyphone capacitance microwave switch (in parallel opposite), in principle, increase between the motor area of travelling electrode, reduce the thickness of dielectric barrier layer and adopt the dielectric film of high-k all to help to improve the make-to-break ratio of switch, wherein, increase the response speed that the moving electrode displacement not only can influence switch, and driving mechanism had higher requirement, often cause the actuating force deficiency, perhaps driving voltage is too high; Reduce dielectric film thickness and adopt high dielectric constant then not have pronounced side effects, therefore, from improving the angle of switch overall performance, improve the dielectric constant of dielectric film, reduce its thickness, be only the technological approaches of more efficiently raising switch performance.Present capacitive character microwave switch, majority Si
3N
4, SiC, Al
2O
3, Ta
2O
5Deng the insulating barrier of thin-film material as mim structure, thickness more than 300 nanometers, minimum 150 nanometers that reach.
Find by prior art documents, people such as J.Y.Park are at " Proceedings of the IEEEMEMS2000 " 639-44,2000, deliver on the Japan (" Institute of Electrical and Electric Engineers MEMS proceeding in 2000 ") " Electroplated RF MEMS capacitive switches; " (electroplating the RF MEMS capacitance switch of preparation), barium strontium titanate (BST) film of high-k is adopted in trial in the microwave switch of static driven, the thickness minimum reaches 190nm, and in common static electricity driving capacitor formula construction of switch, the both sides of dielectric film will apply higher driving voltage usually, therefore, too thin insulating barrier tends to cause electric charge accumulation and overload to puncture, so, do not see the research report that successfully adopts Nano dielectric film in the MEMS microwave switch is arranged, if can adopt the dielectric of Nano dielectric film, can significantly improve the make-to-break ratio of switch as tunable capacitor.
Summary of the invention
The objective of the invention is to overcome deficiency of the prior art, propose a kind of micromechanical capacitance microwave switch, make it can reach higher switch on and off ratio, improve the service behaviour of microwave switch based on Nano dielectric film.
The present invention is achieved by the following technical solutions, the present invention includes: the microdrive of non-static, moving electrode, bottom electrode and on Nano dielectric film, bottom electrode is one deck conductive metal film, generally adopts precious metal materials such as Pt/Ti combination.Nano dielectric film is positioned on the bottom electrode, keeps appropriate insulation, and its thickness is less than 100 nanometers.Moving electrode is positioned on the Nano dielectric film, is connected with non-static microdrive, and it is the movable member of self-supporting, so certain thickness and structural strength will be arranged.Non-static microdrive driving moving electrode is close or leave top electrode, thereby plane-parallel capacitor is changed, and realizes the break-make of switch.
Control moving electrode with non-static microdrive,, constitute the bigger micromechanics adjustable condenser of a kind of adjustable range with transportable moving electrode with the dielectric of Nano dielectric film as tunable capacitor.This adjustable condenser can parallel connection or series connection go into microwave circuit, realize break-make control by control capacittance to circuit.Because the characteristic of low voltage of non-static driven, and voltage no longer is applied directly to the both sides of dielectric film, so can adopt the dielectric of the Nano dielectric film of very thin thickness as tunable capacitor, significantly improve the maximum capacitor value, thereby improve the make-to-break ratio of capacitance-type switch, improve the operating characteristic of switch.Nano dielectric film as dielectric can adopt high-permittivity microwave mediums such as barium strontium titanate, tantalum pentoxide or aluminium oxide.The non-static microdrive that is used to control moving electrode can adopt electromagnetic type or hot mechanical microdrive, piezo-electric micro driver.
Compare with general capacitive character microwave switch, the present invention adopts non-static microdrive to realize the break-make of switch as driver, adopt the dielectric of Nano dielectric film as tunable capacitor, significantly improved the make-to-break ratio of switch, therefore in microwave integrated circuit, obtain to use widely, can significantly reduce the loss of radio-frequency phase shifter.
Description of drawings
Fig. 1 structural representation of the present invention
The signal of Fig. 2 capacitive character microwave switch general structure
The structural representation of Fig. 3 tandem capacitive character microwave switch
The structural representation of the parallel capacitive character microwave switch of Fig. 4
Embodiment
Below in conjunction with accompanying drawing the present invention is done detailed statement, it is to be noted: the dimension scale of each several part might not optimization structure size according to the invention among the figure, only represents the mutual alignment relation of each several part.
As shown in Figure 1, 2, the present invention includes bottom electrode 1, Nano dielectric film 2 on it, moving electrode 3 and the non-static microdrive 4 that is connected with moving electrode 3.The characteristics of above-mentioned each part below make introductions all round:
Bottom electrode 1 is that one deck is positioned at the conductive metal film under the Nano dielectric film 2 because preparation high-k Nano dielectric film needs high-temperature process, so bottom electrode can only adopt precious metal materials such as Pt/Ti combination, thickness in hundreds of nanometers to micron dimension.
The thickness of Nano dielectric film 2 is keeping the appropriate insulation characteristic less than 100 nanometers, and under the prerequisite of the dielectric constant of not appreciable impact simultaneously, thickness should be as far as possible little.The size of film preparing technology and dielectric constant is the foundation that material is selected, and takes all factors into consideration with common high-frequency dielectrics such as barium strontium titanate (BST), tantalum oxide, aluminium oxide and is advisable.
Moving electrode 3 is that one deck is positioned at the metal film on the dielectric film, owing to can manage to avoid high-temperature process, thus not necessarily to use precious metal material, but it is the movable member of self-supporting, so certain thickness and structural strength will be arranged.In addition, this self-supporting film structure should be able to keep higher evenness, closely contacts to guarantee that whole and dielectric film 2 are surperficial, make and bottom electrode 1 between the gap minimize.Comparatively speaking, the nickel-base alloy film of electro-deposition, copper film ratio are easier to satisfy above-mentioned requirements.The aluminium of physical vapour deposition (PVD) also is better selection, because have the comparative advantages of light weight.
Non-static microdrive 4 manipulation moving electrodes 3 leave or close bottom electrode 1, thereby plane-parallel capacitor is changed, the weakness of static driven is that higher driving voltage directly is added in the both sides of plane-parallel capacitor, cause and produce very high electric field strength in the dielectric, cause easily puncturing, so reducing, the thickness of dielectric layer 2 has been subjected to certain restriction, adopt non-electrostatic actuator 4, it mainly is the driving voltage that is carried in the dielectric film both sides in order to reduce, electromagnetic type, heat machinery and piezo-electric micro driver all might satisfy above-mentioned designing requirement, wherein not only driving voltage is lower for the microdrive of electromagnetism and hot mechanical schemes, and driving voltage directly is not added in the both sides of dielectric film 2, but be added on drive coil or the thermal expansion medium, the anti-breakdown characteristics of dielectric film 2 is required to hang down very low, using in the adjustable capacitance type switch for Nano dielectric film provides possible.Utilize adjustable micro-mechanical capacitor structure microwave switch, existing parallel design also has serially connected design.
Among the serially connected design principle figure shown in Figure 3, stay breach in the middle of the microwave signal transmission line 6 as bottom electrode, transmission line 6 upper surfaces of breach both sides constitute tunable capacitor 5 with moving electrode 3 respectively by Nano dielectric film 2, realize the break-make switching of holding wire by the size of control capacittance 5.Lift the position when moving electrode 3 is in, electric capacity 5 diminishes, and holding wire is in off-state, and the total capacitance of this moment is Coff, and when moving electrode 3 is pressed close to Nano dielectric film 2, electric capacity 5 becomes big, and holding wire is in conducting state, and the total capacitance of this moment is Con.Transmission line herein both can be the holding wire of co-planar waveguide, also can be microstrip line.
In the parallel structure shown in Figure 4, as 6 and 7 of bottom electrode is respectively the holding wire and the earth connection of co-planar waveguide, and they and top electrode 3 constitutes tunable capacitors 5 by Nano dielectric film 2, when moving electrode 3 is in when lifting the position, electric capacity 5 diminishes, coplanar waveguide transmission line is interference-free substantially, is in pass-through state, when moving electrode near Nano dielectric film 2, electric capacity 5 becomes big, to cause holding wire and earth connection to be linked up, signal will be by bypass, and switch is in off-state.
Claims (4)
1, a kind of micromechanical capacitance microwave switch based on Nano dielectric film, comprise: bottom electrode (1) and on Nano dielectric film (2), moving electrode (3) and non-static microdrive (4), it is characterized in that, bottom electrode (1) is one deck conductive metal film, Nano dielectric film (2) is positioned on the bottom electrode (1), moving electrode (3) is positioned on the Nano dielectric film (2), be connected with non-static microdrive (4), it is the movable member of self-supporting, non-static microdrive (4) drive moving electrode (3) near or leave top electrode, thereby plane-parallel capacitor is changed, realize the break-make of switch.
2, the micromechanical capacitance microwave switch based on Nano dielectric film according to claim 1 is characterized in that, non-static microdrive (4) is an electromagnetic type micro driver, perhaps hot mechanical microdrive, perhaps piezo-electric micro driver.
3, the micromechanical capacitance microwave switch based on Nano dielectric film according to claim 1 is characterized in that, bottom electrode (1) is that one deck is positioned at the conductive metal film under the Nano dielectric film (2), thickness in hundreds of nanometers to micron dimension.
4, the micromechanical capacitance microwave switch based on Nano dielectric film according to claim 1 is characterized in that, Nano dielectric film (2) adopts the microwave-medium film of high-k, as bst thin film, five oxidation two tantalum film, aluminum oxide film, thickness is less than 100 nanometers.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410067330 CN1601902A (en) | 2004-10-21 | 2004-10-21 | Micromechanical capacitance microwave switch based on Nano dielectric film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410067330 CN1601902A (en) | 2004-10-21 | 2004-10-21 | Micromechanical capacitance microwave switch based on Nano dielectric film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1601902A true CN1601902A (en) | 2005-03-30 |
Family
ID=34666581
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200410067330 Pending CN1601902A (en) | 2004-10-21 | 2004-10-21 | Micromechanical capacitance microwave switch based on Nano dielectric film |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1601902A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108306633A (en) * | 2018-01-17 | 2018-07-20 | 陕西师范大学 | A kind of logic switch based on the transmission of graphene micro-nano structure array |
| CN111146705A (en) * | 2020-01-20 | 2020-05-12 | 张金辉 | Automatic flicking self-protection power distribution cabinet based on capacitance change |
| CN111884644A (en) * | 2020-06-28 | 2020-11-03 | 深圳清华大学研究院 | Parallel RF MEMS switch based on structure ultra-smoothness |
| WO2022000122A1 (en) * | 2020-06-28 | 2022-01-06 | 深圳清华大学研究院 | In-plane sliding parallel capacitive radio frequency switch based on floating potential |
-
2004
- 2004-10-21 CN CN 200410067330 patent/CN1601902A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108306633A (en) * | 2018-01-17 | 2018-07-20 | 陕西师范大学 | A kind of logic switch based on the transmission of graphene micro-nano structure array |
| CN108306633B (en) * | 2018-01-17 | 2021-05-25 | 陕西师范大学 | Logic switch based on graphene micro-nano structure array transmission |
| CN111146705A (en) * | 2020-01-20 | 2020-05-12 | 张金辉 | Automatic flicking self-protection power distribution cabinet based on capacitance change |
| CN111884644A (en) * | 2020-06-28 | 2020-11-03 | 深圳清华大学研究院 | Parallel RF MEMS switch based on structure ultra-smoothness |
| WO2022000122A1 (en) * | 2020-06-28 | 2022-01-06 | 深圳清华大学研究院 | In-plane sliding parallel capacitive radio frequency switch based on floating potential |
| JP7388667B2 (en) | 2020-06-28 | 2023-11-29 | 深▲せん▼清華大学研究院 | In-plane sliding parallel capacitor radio frequency switch |
| CN111884644B (en) * | 2020-06-28 | 2024-04-19 | 深圳清华大学研究院 | Parallel RF MEMS switch based on structure ultra-slip |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4834443B2 (en) | Piezoelectric drive MEMS actuator | |
| JP4763358B2 (en) | Micro electromechanical variable capacitor | |
| US8319393B2 (en) | Reduced voltage MEMS electrostatic actuation methods | |
| CN101093966B (en) | Piezoelectric driven mems device | |
| KR101424297B1 (en) | Electronic element, variable capacitor, micro switch, method for driving micro switch, mems type electronic element, micro actuator and mems optical element | |
| US7439117B2 (en) | Method for designing a micro electromechanical device with reduced self-actuation | |
| KR101529731B1 (en) | Mems switch with improved standoff voltage control | |
| US20070183116A1 (en) | Micro-electro-mechanical variable capacitor for radio frequency applications with reduced influence of a surface roughness | |
| WO2007072407A2 (en) | Arrangement of mems devices having series coupled capacitors | |
| JP2004172504A (en) | Variable capacitor, package provided therewith, and method for manufacturing the same | |
| CN1601902A (en) | Micromechanical capacitance microwave switch based on Nano dielectric film | |
| US20060146472A1 (en) | Micro-electromechanical device and module and method of manufacturing same | |
| CN102683770A (en) | Variable filter and communication apparatus | |
| WO2005117042A1 (en) | Variable capacitor and process for fabricating the same | |
| WO2003015128A2 (en) | An electromechanical switch and method of fabrication | |
| CN100521030C (en) | Micro-electromechanical device and module and method of manufacturing same | |
| US6400550B1 (en) | Variable capacitors including tandem movers/bimorphs and associated operating methods | |
| Aghaei et al. | A low voltage vertical comb RF MEMS switch | |
| CN2657214Y (en) | Silicon base cascade MEMS phase shifter | |
| Dehoff et al. | Piezoelectric actuated MEMS for use in microwave switching and filtering applications | |
| CN201414121Y (en) | Capacitive switch of dielectric adjustable radio-frequency micro electromechanical system | |
| CN1206669C (en) | Electrostatic driven micromachine changeable inductor | |
| EP1675148B1 (en) | Method for designing a micro electromechanical device with reduced self-actuation | |
| Ramli et al. | Design and modelling of a digital MEMS varactor for wireless applications | |
| Sarkar et al. | Design of a low voltage rf mems capacitive switch with low spring constant |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |