WO2022247064A1

WO2022247064A1 - High-reliability capacitive rf mems switch

Info

Publication number: WO2022247064A1
Application number: PCT/CN2021/118203
Authority: WO
Inventors: 向小健; 杨德智; 黄轩宇; 白玉蝶; 郑泉水
Original assignee: 深圳清华大学研究院; 清华大学
Priority date: 2021-05-25
Filing date: 2021-09-14
Publication date: 2022-12-01
Also published as: CN113035650A; CN113035650B

Abstract

The present invention provides a high-reliability capacitive RF MEMS switch, comprising a substrate, a driving member provided inside the substrate, a sliding member provided on the substrate, and a transmission member provided in the substrate. The sliding member is driven by the driving member to move; the transmission member comprises an input portion and an output portion; the sliding member moves between an input side and an output side. In the high-reliability capacitive RF MEMS switch provided by the present invention, a traditional cantilever beam type capacitive switch is changed into an in-plane sliding type capacitive switch, and on-off of a radio frequency signal is realized by utilizing the change of coupling capacitance between the sliding member and the transmission member, thereby avoiding the problem of adhesion failure caused by adhesive force, impact damage, surface effect and the like, and prolonging the service life. Moreover, spatial decoupling of the driving member and the transmission member can be achieved by means of the horizontal driving mode, the isolation degree and the operating power of the switch are remarkably improved, and the problem of crosstalk of a driving member circuit to signal output of the transmission member is solved.

Description

High Reliability Capacitive RF MEMS Switches

technical field

The invention belongs to the technical field of radio frequency devices, and more specifically relates to a highly reliable capacitive RF MEMS switch.

Background technique

The RF switch is used to switch and route one or several RF signals, including switching between receiving and transmitting, switching between different frequency bands, sharing antennas, etc. It is one of the most commonly used devices in the RF path. It is widely used in radio frequency test instrument, automatic test system (ATE), radio frequency wireless communication system (mobile phone, base station), radar communication system, satellite communication system and other fields.

Among them, compared with traditional semiconductor switches, RF MEMS radio frequency switches have excellent characteristics such as high linearity, low loss, high isolation, small volume, etc., and low energy consumption due to the use of mechanical switching to control the on and off of radio frequency signals. It will become the mainstream solution of radio frequency switches in the future, and has the potential to become one of the key technologies for advanced electronic equipment in national defense and civilian fields such as next-generation mobile communication terminals and systems, satellite communication systems, and high-performance phased array radars.

Although RF MEMS switches have many advantages, breakthroughs in reliability are urgently needed to achieve large-scale applications. Capacitive RF MEMS switches in the prior art generally adopt a two-end or multi-end beam structure. The beam supports the pole plate and is erected above the electrode element. The electrode element can drive the pole plate or the beam to realize vertical movement by using its own deflection. The pole plate and the electrode Capacitance is formed between the components, and the magnitude of the capacitance changes with the movement of the plates. However, since most electrode elements need to realize driving and transmission at the same time, there is a physical coupling relationship between the electrode elements and the transmission parts, which restricts the isolation and operating power capability of the capacitive switch RF switching device, and the polar plate will be in contact with the dielectric layer when it moves vertically And impact occurs, resulting in adhesion and impact damage, affecting the reliability and life of the entire RF MEMS switch.

The Chinese patent application with publication number CN105788971A discloses a compact MEMS capacitive radio frequency switch based on silicon substrate and its preparation method, which includes a section of interdigitated coplanar waveguide transmission line, movable plate, silicon substrate and insulating medium , the movable plate is above the fixed plate in the interdigitated coplanar waveguide transmission line, and the fixed plate is used as the signal line of the interdigitated coplanar waveguide transmission line, which is connected to the external radio frequency circuit; A bias voltage is set between the fixed pole plate and used to control the on and off of the switch, thereby controlling the on and off of the external radio frequency signal.

In the above scheme, the isolation is increased by separating the signal line from the bias voltage, but all the circuits of this structure are still placed on the same plane. At this time, there will still be a certain coupling force between the bias voltage and the movable plate. If Increasing the distance between the movable plate and the signal line, due to the square relationship between the bias voltage and the distance, the driving voltage of the switch will increase sharply, and the response time will also decrease accordingly.

Therefore, to overcome key core technical problems such as high reliability and high isolation of capacitive RF MEMS switches, it is necessary to seek thorough solutions from multiple levels such as design, structure, and materials.

technical problem

The purpose of the present invention is to provide a highly reliable capacitive RF MEMS switch to solve the technical problems of poor reliability, low isolation and low power in the prior art.

technical solution

In order to achieve the above object, the technical solution adopted by the present invention is: provide a highly reliable capacitive RF MEMS switch, including a substrate, a driving part arranged inside the substrate and a sliding part arranged on the substrate, so The sliding part is driven by the driving part, and it is characterized in that it also includes a transmission part, the transmission part is arranged in the base, the transmission part includes an input part and an output part, and the two sides of the base are respectively An input side and an output side, the input part is located on the input side, the output part is located on the output side, and the sliding member moves between the input side and the output side.

Further, the transmission part further includes a transmission ground wire, and the transmission ground wire is located outside the driving part and the sliding part.

Further, the driving part includes a first driving assembly and a second driving assembly, the first driving assembly is located on the input side, the second driving assembly is located on the output side, and the sliding parts are respectively controlled by the The first drive assembly and the second drive assembly drive motion.

Further, the second driving component is in conduction with the output part.

Further, the length of the input part is greater than the length of the first drive assembly, and the length of the output part is greater than the length of the second drive assembly.

Further, both the first driving component and the second driving component include at least two driving electrodes, and the driving electrodes are respectively located on both sides of the input part or on both sides of the output part, and the first All the driving electrodes of a driving component are connected, and all the driving electrodes of the second driving component are connected.

Further, the first drive assembly also includes first connection electrodes for connecting all the drive electrodes of the first drive assembly, and the second drive assembly also includes first connection electrodes for connecting all the drive electrodes of the second drive assembly. The second connection electrode of the electrode.

Further, the first connection electrode and the second connection electrode extend between the input part and the output part, and the width of the first connection electrode and the second connection electrode is greater than 0.1 μm.

Further, the driving part further includes a ground electrode, and the ground electrode is located between the first driving assembly and the second driving assembly.

Further, the sliding part includes a capacitive plate, the capacitive plate is located on the base, and the capacitive plate is in super-slidable contact with the base.

Further, the sliding component includes a capacitor plate and a sliding frame, and the sliding frame is mounted on the base and drives the capacitor plate to move.

Further, the capacitive plate is made of metal conductor or semiconductor material, and the thickness of the capacitive plate is 0.6 μm to 20 μm.

Further, the gap between the lower surface of the capacitor plate and the upper surface of the substrate is 0.1 μm to 10 μm.

Further, the sliding frame includes at least four supporting blocks, the supporting blocks are connected to the capacitor plate, and at least one super-sliding sheet is placed on the bottom of the supporting blocks.

Further, a sliding groove is provided on the base, the support block is located in the sliding groove and slides in the sliding groove, and the bottom surface of the sliding groove is an atomic level flat surface.

Further, the sliding slot is located inside the transmission ground wire.

Further, an insulating layer is further provided on the substrate, and the insulating layer is located on the driving component and the transmission component.

Further, the insulating layer has a thickness of 20nm to 100nm.

Further, the side of the output part close to the input part is provided with an extension part, and the extension part communicates with the output part; or, the side of the input part close to the output part is provided with an extension part , the extension part communicates with the input part.

Beneficial effect

1. Changing the traditional vertical-driven capacitive switch into an in-plane sliding type can fundamentally realize the decoupling of the driving signal and the transmission signal, avoid crosstalk between signals, increase the operating power, and utilize the gap between the sliding part and the transmission part The change of the coupling capacitance realizes the on-off of the radio frequency signal. Since there is no damage to the dielectric layer, and the problem of adhesion failure caused by adhesion, impact damage, and surface effects is avoided, the capacitive RF MEMS switch based on the super-slip structure can achieve a high service life. At the same time, the The driving part is separated from the transmission part, the driving part is only used to drive the movement of the sliding part, and the transmission part is used to couple the capacitance change with the sliding part to realize the opening and closing control of the RF MEMS switch, which has higher isolation and higher operating power.

2. Structurally separate the drive part from the transmission part, the electrical signal in the drive part will not interfere with the transmission signal, affect the transmission of radio frequency signals, and at the same time increase the driving force of the drive part to the sliding part and reduce the drive voltage. Speed up your reaction time.

3. A bistable drive structure is formed on the input side and the output side. When there is no external drive, the sliding part can be stabilized at the current position, and no external force is required to keep the position of the sliding part stable, which can greatly reduce energy consumption. At the same time, the charge accumulation on the insulating layer is greatly reduced to achieve ultra-long life.

4. The first driving part and the second driving part are respectively arranged on both sides of the RF MEMS switch, and the first driving part and the second driving part respectively drive the reciprocating motion of the sliding part to realize the opening and closing of the switch. The first driving part and the second driving part are arranged around the input part and the output part, which can ensure that it is always opposite to the transmission part during the movement process, and at the same time can ensure that it always has a certain driving force.

5. Both the first drive assembly and the second drive assembly are provided with a first connection electrode and a second connection electrode, and both the first connection electrode and the second connection electrode extend between the input part and the output part. At this time, it is possible to drive The sliding part is farther away from the output part or the input part, so that its isolation can be enhanced, and a larger isolation can be enhanced according to the needs, and the output of the capacitor will not be affected.

6. A super-sliding sheet is placed on the bottom of the support block, and the bottom surface of the sliding groove is an atomically flat surface. The super-sliding sheet and the sliding groove realize super-sliding contact, and there is no wear between the HOPG super-sliding sheet and the insulating layer during the switching process , low friction, and impact-free sliding, which can completely avoid impact damage, and at the same time overcome the problem of adhesion failure caused by van der Waals force, surface tension, etc., and significantly improve the operating life of RF MEMS switches.

7. An extension part is set on one side of the output part or the input part, so that the cross-sectional areas of the input part and the output part are not completely equal. When the sliding part is in the middle area, that is, in a steady state, the capacitance formed by the input part and the output part is not the same. Exactly the same, can increase capacitance and reduce insertion loss.

Description of drawings

Fig. 1 is the structural representation of the highly reliable capacitive RF MEMS switch that the embodiment of the present invention 1 provides;

Fig. 2 is the structural representation of the highly reliable capacitive RF MEMS switch that the embodiment of the present invention 2 provides;

Fig. 3 is the structural representation of the high reliability capacitive RF MEMS switch that the embodiment of the present invention 3 provides;

Fig. 4 is a schematic diagram of a side sectional structure of a high-reliability capacitive RF MEMS switch provided by an embodiment of the present invention;

FIG. 5 is a schematic diagram of a side sectional structure of a high-reliability capacitive RF MEMS switch provided by an embodiment of the present invention;

6 is a schematic diagram of a side sectional structure of a high-reliability capacitive RF MEMS switch provided by an embodiment of the present invention;

FIG. 7 is a schematic diagram of a side sectional structure of a high-reliability capacitive RF MEMS switch provided by an embodiment of the present invention;

Fig. 8 is the upper-state capacitance simulation diagram of the highly reliable capacitive RF MEMS switch provided by the embodiment of the present invention;

Fig. 9 is the insertion loss figure of the highly reliable capacitive RF MEMS switch provided by the embodiment of the present invention;

FIG. 10 is an isolation diagram of a highly reliable capacitive RF MEMS switch provided by an embodiment of the present invention.

Wherein, each reference sign in the figure:

1. Base; 2. Driving part; 3. Transmission part; 4. Sliding part; 11. Input side; 12. Output side; 13. Insulation layer; 14. Sliding groove; 21. First driving component; 22. Second Drive assembly; 23, ground electrode; 211, first connection electrode; 222, second connection electrode; 31, input part; 32, output part; 33, transmission ground wire; 34, extension part; 41, capacitor plate; 42, Sliding frame; 421, support block; 422, super sliding sheet.

BEST MODE FOR CARRYING OUT THE INVENTION

Please refer to FIG. 1 and FIG. 4 together, and now the highly reliable capacitive RF MEMS switch provided by the present invention will be described. The high-reliability capacitive RF MEMS switch includes a substrate 1, a driving part 2 arranged inside the substrate 1, a transmission part 3 and a sliding part 4 arranged on the substrate 1, and the sliding part 4 consists of The driving part 2 is driven to realize plane movement on the base 1 . Both the driving component 2 and the transmission component 3 are arranged inside the base 1 , and the driving component 2 and the transmission component 3 are located at the same height of the base 1 . Preferably, the driving component 2 and the transmission component 3 need to be arranged alternately in the horizontal layout, and the two cannot overlap each other, so as not to affect the driving or capacitive coupling.

Wherein, the two sides of the substrate 1 are respectively the input side 11 and the output side 12, and the other two sides are all provided with a transmission ground wire 33, and the transmission ground wire 33 is surrounded by the outside of the driving part 2, and can be connected with the input part 31 and the output part 32. Cooperate to realize the coupling output of the capacitor.

Among them, the substrate 1 is generally made of high-resistance silicon, silicon oxide or silicon nitride, and the driving part 2 and the transmission part 3 are metal conductive elements buried inside the substrate 1 or located above or below the substrate 1. The driving part 2 Connected to an external circuit, the transmission part 3 is used to conduct radio frequency signals, and forms a series capacitor with the capacitor plate 41 .

Compared with the prior art, the highly reliable capacitive RF MEMS switch provided by the present invention has a horizontal layout structure that can fundamentally decouple the driving part 2 and the transmission part 3, and separate the driving part 2 and the transmission part 3 , the driving part 2 is only used to drive the movement of the sliding part 4, through the change of the coupling capacitance between the transmission part 3 and the capacitor plate 41, the opening and closing control of the RF MEMS switch is realized, the isolation is higher, and the operating power is larger. At the same time, the wear-free super-slip sliding in the plane can achieve almost infinite operating life.

Further, as a specific embodiment of the highly reliable capacitive RF MEMS switch provided by the present invention, the transmission part 3 includes an input part 31 and an output part 32, and the input part 31 is located at the input side 11, The output part 32 is located on the output side 12 , and the sliding part 4 can move between the input side 11 and the output side 12 driven by the driving part 2 . The drive component 2 includes a first drive assembly 21 and a second drive assembly 22, the first drive assembly 21 is located on the input side 11, and the second drive assembly 22 is located on the output side 12, that is, the first drive assembly 21 The assembly 21 is disposed on either side or opposite sides of the input portion 31 , and the second driving assembly 22 is disposed on either side or opposite sides of the output portion 32 .

Preferably, the length of the input part 31 is greater than the length of the first drive assembly 21, and one end of the first drive assembly 21 close to the output part 32 is flush with the input part 31 or protrudes from the input part 31; The length of the portion 32 is greater than that of the second drive assembly 22 , and the end of the second drive assembly 22 close to the input portion 31 is flush with the output portion 32 or protrudes from the output portion 32 . At this time, it can be ensured that the first driving assembly 21 and the second driving assembly 22 can be activated in cooperation to realize the reciprocating motion of the sliding member 4 . Of course, in other embodiments, the length of the input portion 31 may also be less than or equal to the length of the first driving assembly 21 .

Further, as a specific implementation of the highly reliable capacitive RF MEMS switch provided by the present invention, the first drive assembly 21 and the second drive assembly 22 each include at least two separate drive electrodes, and The driving electrodes are arranged around the input part 31 or the output part 32, and the two driving electrodes are respectively located on both sides of the input part 31 or the two sides of the output part 32, and can drive the sliding part 4 on the input part 31 or the output part 32. 32's upper movement.

Wherein, all the driving electrodes of the first driving assembly 21 are connected, preferably, all the driving electrodes are connected through the first connecting electrode 211, and the first connecting electrode 211 can extend to between the input part 31 and the output part 32 , and at the same time connect the driving electrodes on both sides of the input part 31, the setting of the first connecting electrode 211 can extend the maximum drivable distance of the sliding part 4, and the sliding part 4 can be driven not to face the input part 31 when necessary, So as to achieve a better isolation effect.

All the driving electrodes of the second driving assembly 22 are also connected to each other, and the connection between all driving electrodes is realized through the second connecting electrode 222 , which cooperates with the first connecting electrode 211 to achieve a better isolation effect.

Preferably, both the first connecting electrode 211 and the second connecting electrode 222 have a certain line width, and the first connecting electrode 211 and the second connecting electrode 222 cooperate with other driving electrodes to achieve the effect of pushing the sliding part 4 to move, Therefore, its line width needs to be larger than 0.2 μm, or the driving voltage should be increased.

The drive part 2 also includes a ground electrode 23, the ground electrode 23 is located between the first drive assembly 21 and the second drive assembly 22, and the ground electrode 23 is connected to the first drive assembly 21 or the second drive assembly 22. are connected, so as to realize bias on both sides of the sliding part 4, and then drive the movement of the sliding part 4.

Further, referring to Fig. 1 and Fig. 4, as a kind of embodiment of the capacitive RF MEMS switch of high reliability provided by the present invention, described sliding component 4 comprises capacitive plate 41 and sliding frame 42, and described sliding frame 42 Erected on the base 1 and drives the capacitive plate 41 to move, the lower surface of the capacitive plate 41 is not in contact with the base 1 , which can avoid friction between the capacitive plate 41 and the base 1 . At least one super-sliding sheet 422 can be placed under the capacitor plate 41, so that the super-sliding sheet 422 is in contact with the substrate 1, and the capacitor plate 41 can slide on the substrate 1 with zero wear, which can achieve extremely low friction and no wear. slide. At the same time, the bistable pull-in can greatly reduce the charge accumulation on the insulating layer 13 , and at the same time greatly reduce the energy consumption, and achieve super long life.

Preferably, the sliding frame 42 includes at least four support blocks 421, the support blocks 421 are connected to the capacitor plate 41, and a plurality of support blocks 421 are respectively arranged on the bottom of the capacitor plate 41, and can support the entire capacitor plate after being combined. 41 , so that there is a certain gap between the capacitive plate 41 and the substrate 1 , preventing the capacitive plate 41 from directly contacting the substrate 1 . Preferably, the supporting blocks 421 are respectively arranged at four sides or corners of the capacitor plate 41 .

Further, please refer to FIG. 1 and FIG. 5 , a sliding groove 14 is opened on the base 1, and the support block 421 is located in the sliding groove 14 and slides in the sliding groove 14. At this time, the bottom surface of the sliding groove 14 It is an atomic level flat surface, and the super-sliding piece 422 at the bottom of the support block 421 is in super-sliding contact with the bottom surface of the sliding groove 14, and the moving direction of the sliding part 4 is limited by electrostatic energy to prevent the sliding part 4 from deflecting.

Preferably, the sliding groove 14 provided on the base 1 is generally arranged inside the transmission ground wire 33 , at this time, capacitive coupling between the transmission ground wire 22 and the capacitor plate 41 can be avoided, thereby affecting the insertion loss of the switch.

Preferably, the capacitor plate 41 is made of a metal material, and the metal material can be made of aluminum, copper, nickel or other alloys with better conductivity and lighter weight; the capacitor plate 41 can also directly use a whole piece of lightweight graphite Sheets or other super-slippery sheets of lightweight semiconducting material. The thickness of the capacitor plate 41 is 0.1 μm to 50 μm, and the gap between the capacitor plate 41 and the substrate 1 is 0.05 μm to 8 μm.

Further, please refer to Fig. 1, Fig. 4 and Fig. 5, as a kind of embodiment of the highly reliable capacitive RF MEMS switch provided by the present invention, described substrate 1 is also provided with insulating layer 13, and described insulating layer The layer 13 is located on the driving component 2 and the transmission component 3 , and the arrangement of the insulating layer 13 can prevent the driving component 2 and the transmission component 3 from being in direct contact with the capacitor plate 41 . Preferably, the insulating layer 13 is only applied directly above the driving part 2 and the transmission part 3, and the inside of the sliding groove 14 is not provided with the insulating layer 13, and the inner surface of the sliding groove 14 is an atomic level flat surface; or, the sliding groove The inside of 14 is also filled with an insulating layer 13, and the insulating layer 13 in this region satisfies atomic level flatness.

At this time, the sliding groove 14 may not be provided, and the super-sliding sheet 422 at the bottom of the support block 421 is in direct super-sliding contact with the insulating layer 13 . Preferably, the thickness of the insulating layer 13 is 10nm to 80nm, and the thickness of the insulating layer 13 is relatively thin, which can prevent the gap between the transmission component 3 and the capacitor plate 41 from being too large, thereby weakening the driving force and affecting its reaction speed.

In other embodiments of the present invention, the sliding part 4 of the capacitive RF MEMS switch can also only include a capacitive plate 41, the lower surface of the capacitive plate 41 has an ultra-slippery surface, and the upper surface of the substrate 1 is an atomic level flat surface. When the capacitive plate 41 is directly arranged on the base 1 , and the capacitive plate 41 and the base 1 are in super-slidable contact and slide, no sliding frame 42 is required.

Preferably, when the sliding frame 42 is not provided, the size of the capacitive plate 41 is generally on the order of microns. Of course, the size of the capacitive plate 41 can also be on the order of millimeters or centimeters according to actual conditions and specific needs. The upper surface of the substrate 1 is provided with an insulating layer 13 , the insulating layer 13 can avoid contact between the transmission component 3 and the capacitor plate 41 , and can form a capacitive gap between the transmission component 3 and the capacitor plate 41 .

For RF switches, isolation and insertion loss are the two most important indicators for determining RF switches, while the up-state capacitance (C _up ) and capacitance ratio (C _down /C _up ) are the main constraints affecting the above characteristics. The input part 31 The capacitance between the capacitor plate 41 and the capacitor plate 41 is C ₁ , and the capacitor between the output part 32 and the capacitor plate 41 is C ₂ ; for a capacitive RF MEMS switch, when it is required to be disconnected, C _p approaches 0, and when it is turned on C _p is a few picofarads; capacitance C ₁ is:

Capacitor _C2 is:

The total capacitance C _p of the driving system is:

Total electrostatic energy of drive system:

Horizontal driving force F _x :

Wherein, _ε0 is the vacuum permittivity;

ε _r is the relative permittivity of the dielectric layer;

g is the thickness of insulating layer 13;

x is displacement;

W _a is the width of the ground electrode 23;

W _b is the width of the driving electrode;

a is the length of the ground electrode 23;

V is the driving voltage.

It can be seen from the formula that the horizontal driving force gradually decreases with the displacement x, and the velocity decreases quadratically. When x=0, i.e. the initial position, the horizontal driving force has a maximum value

The initial maximum value is determined by the air gap g, the driving electrode length W _b and the driving voltage V. That is, the smaller the air gap g is, the larger the driving electrode width W _b is, and the larger the initial driving force is.

in,

Under the design size, the upper-state capacitance simulation diagram is shown in Figure 8, the insertion loss diagram is shown in Figure 9, and the isolation diagram is shown in Figure 10. This high-reliability capacitive RF MEMS switch has excellent radio frequency characteristics , the upper-state capacitance is at least 2.5fF, and the lower-state/upper-state capacitance ratio is as high as 235. Different from the traditional vertical driving structure, the signal switching is realized by sliding the sliding part 4. When a direct current is applied between the ground electrode 23 and the driving electrode When paranoid, the sliding part 4 slides to coincide with the transmission part 3 under the action of the horizontal electrostatic force, so as to control the change of the coupling capacitance between the sliding part 4 and the transmission part 3, and realize the on-off of the radio frequency signal. Since there is no suspended structure, and there is no wear, low friction, and no impact sliding between the sliding part 4 and the insulating layer 13 during the switching process, it can completely avoid impact damage, and at the same time, the bistable driving method can greatly reduce the charge of the insulating layer accumulated, significantly improving the operational lifetime of RF MEMS switches.

As an alternative embodiment of the present invention, in other embodiments of the present invention, the drive part 2 and the transmission part 3 are located at different heights of the base 1, and the transmission part 3 is located above the drive part 2, and the drive part 2 and the transmission part 3 Interlaced settings on the horizontal layout, there is no overlapping or only a few interlaced parts.

As an alternative embodiment of the present invention, in other embodiments of the present invention, referring to FIG. 6, a separate sliding groove 14 may not be provided, and the bottom of the support block 421 may directly contact the upper surface of the base 1 or the top surface of the insulating layer 13. The upper surfaces are in contact with each other. At this time, the upper surface of the substrate 1 is an atomically flat surface, and the super-slip sheet 422 at the bottom of the support block 421 is in super-slip contact with the substrate 1 .

As an alternative embodiment of the present invention, in other embodiments of the present invention, please refer to FIG. 6 , the insulating layer 13 may not be provided, and the driving component 2 and the transmission component 3 are both embedded in the base 1 or arranged on the base 1 , the upper surface of the entire substrate 1 satisfies atomic-level flatness, and at this time the sliding component 4 directly slides on the surface of the substrate 1 .

As an alternative embodiment of the present invention, in other embodiments of the present invention, referring to Fig. 7, the sliding part 4 of this capacitive RF MEMS switch can also only include a capacitive plate 41, and the lower surface of the capacitive plate 41 has an ultra-slip surface. On the surface, the upper surface of the substrate 1 is an atomically flat surface. At this time, the capacitor plate 41 is directly arranged on the substrate 1 or the insulating layer 13, and the capacitor plate 41 and the substrate 1 or the insulating layer 13 are in super-slip contact and slide, and there is no need to set the sliding Rack 42.

Preferably, the size of the capacitive plate 41 is generally on the order of microns. Of course, the size of the capacitive plate 41 may also be on the order of millimeters or centimeters according to actual conditions and specific needs. The upper surface of the substrate 1 is provided with an insulating layer 13 , the insulating layer 13 can avoid contact between the transmission component 3 and the capacitor plate 41 , and can form a capacitive gap between the transmission component 3 and the capacitor plate 41 .

Embodiments of the present invention

The present invention will be described in detail through specific examples below.

Example 2:

Please refer to Fig. 2, as another specific embodiment of the highly reliable capacitive RF MEMS switch provided by the present invention, the difference between this embodiment and Embodiment 1 is: the second driving assembly 22 and the output part 32 phase conduction, the first drive assembly 21 and the input part 31 are separated, at this time the second drive assembly 22 and the output part 32 are the same part, which can realize simultaneous processing, the structure is simpler, and the process difficulty is lower. At the same time, the areas of the first driving component 21 and the second driving component 22 are different, the coupling capacitance is increased, the operating frequency range of the RF MEMS switch is widened, and the insertion loss is reduced.

Example 3:

Referring to Fig. 3, as another kind of embodiment of the highly reliable capacitive RF MEMS switch provided by the present invention, the difference between this embodiment and Embodiment 1 is: the output part 32 is close to a part of the input part 31 An extension part 34 is provided on the side, and the extension part 34 communicates with the output part 32; or, the side of the input part 31 close to the output part 32 is provided with an extension part 34, and the extension part 34 is connected to the output part 32. The input unit 31 is connected. An extension part 34 is set on one side of the output part 32 or the input part 31, so that the cross-sectional areas of the input part 31 and the output part 32 are not completely equal. Part 32 forms capacitances that are not exactly the same in magnitude, which can increase transmission capacitance and reduce insertion loss.

Industrial Applicability

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the claims of the present invention shall fall within the scope of the claims of the present invention.

Claims

A high-reliability capacitive RF MEMS switch, comprising a substrate (1), a driving part (2) arranged inside the substrate (1) and a sliding part (4) arranged on the substrate (1), The sliding part (4) is driven to move by the driving part (2), and is characterized in that it also includes a transmission part (3), the transmission part (3) is arranged in the base (1), and the transmission part (3) The component (3) includes an input part (31) and an output part (32), the two sides of the base (1) are respectively the input side (11) and the output side (12), and the input part (31) is located on the On the input side (11), the output part (32) is located on the output side (12), and the sliding part (4) moves between the input side (11) and the output side (12).
The capacitive RF MEMS switch of high reliability as claimed in claim 1, is characterized in that: described transmission part (3) also comprises transmission ground wire (33), and described transmission ground wire (33) is positioned at described driving part (2) and the outside of the sliding part (4).
The capacitive RF MEMS switch of high reliability as claimed in claim 1, is characterized in that: described driving part (2) comprises first driving assembly (21) and second driving assembly (22), and described first driving assembly The component (21) is located on the input side (11), the second drive component (22) is located on the output side (12), and the sliding part (4) is respectively controlled by the first drive component (21) and The second drive assembly (22) drives motion.
The high-reliability capacitive RF MEMS switch according to claim 3, characterized in that: the second driving component (22) is in conduction with the output part (32).
The capacitive RF MEMS switch of high reliability as claimed in claim 3, is characterized in that: the length of described input part (31) is greater than the length of described first driving assembly (21), and described output part (32) The length is greater than the length of the second drive assembly (22).
The capacitive RF MEMS switch of high reliability as claimed in claim 3, is characterized in that: described first driving assembly (21) and described second driving assembly (22) all comprise at least two driving electrodes, and the The drive electrodes are respectively located on both sides of the input part (31) or both sides of the output part (32), all the drive electrodes of the first drive assembly (21) are connected, and the second drive All said drive electrodes of the assembly (22) are connected.
The capacitive RF MEMS switch of high reliability as claimed in claim 6, is characterized in that: described first driving assembly (21) also comprises the first driving electrode that is used to connect first driving assembly (21) A connection electrode (211), the second drive assembly (22) further includes a second connection electrode (222) for connecting all the drive electrodes of the second drive assembly (22).
The capacitive RF MEMS switch of high reliability as claimed in claim 7, is characterized in that: described first connection electrode (211) and described second connection electrode (222) extend to described input part (31) and Between the output parts (32), the width of the first connection electrode (211) and the second connection electrode (222) is greater than 0.1 μm.
The capacitive RF MEMS switch of high reliability as claimed in claim 3, is characterized in that: described driving part (2) also comprises grounding electrode (23), and described grounding electrode (23) is positioned at described first driving assembly (21) and the second drive assembly (22).
The capacitive RF MEMS switch of high reliability as claimed in claim 2, is characterized in that: described sliding part (4) comprises capacitance plate (41), and described capacitance plate (41) is positioned at described substrate (1) , and the capacitor plate (41) is in superslip contact with the substrate (1).
The capacitive RF MEMS switch of high reliability as claimed in claim 2, is characterized in that: described sliding part (4) comprises capacitance plate (41) and sliding frame (42), and described sliding frame (42) is erected on The base (1) drives the capacitance plate (41) to move.
The capacitive RF MEMS switch of high reliability as claimed in claim 11, is characterized in that: described capacitive plate (41) is made of metal conductor or semiconductor material, and the thickness of described capacitive plate (41) is 0.6 μ m to 20 μm.
The high-reliability capacitive RF MEMS switch according to claim 11, characterized in that: the gap between the lower surface of the capacitor plate (41) and the upper surface of the substrate (1) is 0.1 μm to 10 μm.
The capacitive RF MEMS switch of high reliability as claimed in claim 11, is characterized in that: described sliding frame (42) comprises at least four support blocks (421), and described support block (421) and described capacitance plate (41) are connected, and the bottom of the support block (421) is padded with at least one ultra-sliding sheet (422).
The capacitive RF MEMS switch of high reliability as claimed in claim 14, is characterized in that: described substrate (1) is provided with sliding groove (14), and described supporting block (421) is positioned at described sliding groove (14) ) and slide in the sliding groove (14), the bottom surface of the sliding groove (14) is an atomic level flat surface.
The high-reliability capacitive RF MEMS switch according to claim 15, characterized in that: the sliding groove (14) is located on the inner side of the transmission ground wire (33).
The high-reliability capacitive RF MEMS switch as claimed in any one of claims 1 to 16, characterized in that: the substrate (1) is also provided with an insulating layer (13), and the insulating layer (13) is located at on the drive part (2) and the transmission part (3).
The high-reliability capacitive RF MEMS switch according to claim 17, characterized in that: the thickness of the insulating layer (13) is 20nm to 100nm.
The high-reliability capacitive RF MEMS switch according to any one of claims 1 to 16, characterized in that: the output portion (32) is provided with an extension portion (34) near the input portion (31) ), the extension part (34) communicates with the output part (32); or, the input part (31) is provided with an extension part (34) near the side of the output part (32), and the The extension part (34) communicates with the input part (31).