Microwave power sensor with high overload level and control method thereof

Abstract

The application discloses a microwave power sensor with high overload level and a control method thereof. The sensor is composed of a substrate, a coplanar waveguide transmission line, a cantilever beam, a preset anchor point and a capacitor plate. The preset anchor point is arranged between the fixed anchor point of the cantilever beam and the coplanar waveguide transmission line, and the capacitor plate is arranged below the cantilever beam and is arranged on the two sides of the coplanar waveguide transmission line with the preset anchor point. An output end is connected with the capacitor plate for detecting the capacitance. When the microwave signal enters, the capacitance changes, and the power of the microwave signal can be indirectly obtained by measuring the change value. The sensor adopts a variable-length cantilever beam structure, overcomes the problem that the overload power is too small due to the improvement of the sensitivity of the traditional cantilever beam structure, greatly improves the overload power of the sensor, expands the range of the sensor, and due to the increase of the anchor point, the cantilever beam can be protected to a certain extent to avoid the structural collapse caused by the excessive input power.

Description

Technical Field

[0001] This invention relates to the field of MEMS micromechanical sensors, and in particular to a microwave power sensor with a high overload level and its control method. Background Technology

[0002] The development of microwave technology based on microelectromechanical systems (MEMS) has become an important indicator of a country's scientific and technological level. In research on all aspects of microwave signal generation, transmission, and reception, microwave power measurement is an essential fundamental testing technique. Currently, due to the influence of gravity, the overload power of traditional cantilever beam structures decreases continuously with increasing sensitivity, resulting in extremely small measurement ranges for capacitive microwave power sensors and limiting their application scenarios. In recent years, with the continuous development of MEMS fabrication processes, microwave power sensors based on variable-length cantilever beams have become possible. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a microwave power sensor with a high overload level and its control method.

[0004] To address the problems of existing technologies, this invention discloses a microwave power sensor with a high overload level, comprising a ground wire, a coplanar waveguide transmission line, an anchor region, a preset anchor point, a cantilever beam, and a capacitor plate. Two ground wires are respectively located on opposite sides of the coplanar waveguide transmission line. One ground wire is connected to the cantilever beam via the anchor region. The coplanar waveguide transmission line is located below the cantilever beam. The preset anchor point is located between the anchor region and the coplanar waveguide transmission line. During the downward pulling process, the cantilever beam contacts the preset anchor point at a certain moment. The capacitor plate is located between the ground wire and the coplanar waveguide transmission line on the other side. Both the preset anchor point and the capacitor plate are located below the cantilever beam.

[0005] Furthermore, it also includes a substrate, and ground lines, coplanar waveguide transmission lines, anchor areas, preset anchor points, cantilever beams and capacitor plates are all disposed on the substrate.

[0006] Furthermore, the substrate is made of gallium nitride.

[0007] Furthermore, both the anchor zone and the preset anchor point are located at the upper end of the ground wire.

[0008] Furthermore, the side of the capacitor plate is connected to the ground wire.

[0009] Accordingly, a control method for a microwave power sensor with a high overload level employs the aforementioned microwave power sensor with a high overload level.

[0010] When the microwave signal enters, electrostatic force is generated to bend the cantilever beam, thereby causing the distance between the cantilever beam and the lower capacitor plate to decrease, so that the capacitance changes, and the microwave power is obtained by measuring the change amount of the capacitance.

[0011] Correspondingly, a control method of the microwave power sensor with a high overload level adopts the microwave power sensor with a high overload level described above.

[0012] The cantilever beam is pulled down to contact the preset anchor point, so that the equivalent length of the cantilever beam is reduced, the stiffness of the cantilever beam is thus improved, the overload power of the cantilever beam is improved, and the range of the sensor is expanded.

[0013] The present application has the beneficial effects that:

[0014] The present application detects the microwave signal by using the capacitance type, is online, compared with the traditional terminal pyroelectric microwave power sensor, and does not completely consume the microwave signal, can be continuously used by the subsequent process, has the advantages of high sensitivity, wide measurement range, etc.

[0015] The present application detects the microwave signal by using the length-variable cantilever beam, compared with the traditional capacitance type microwave power sensor, the overload power is significantly improved, has the advantages of wide range, high sensitivity, etc. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a top view of the microwave power sensor of the present application.

[0017] Figure 2 It is a front view of the microwave power sensor of the present application.

[0018] Among them, 1-ground wire, 2-coplanar waveguide transmission line, 3-anchor area, 4-pre-set anchor point, 5-cantilever beam, 6-capacitor plate. EMBODIMENT

[0019] The present application will be further described below in conjunction with the drawings. The following examples are only used to more clearly illustrate the technical solutions of the present application, and cannot be used to limit the protection scope of the present application.

[0020] As shown in the drawings, Figure 1 A microwave power sensor with a high overload level of the present application is composed of a ground wire 1, a coplanar waveguide transmission line 2, an anchor area 3, a pre-set anchor point 4, a cantilever beam 5, and a capacitor plate 6. The coplanar waveguide transmission line 2 is arranged in the middle, the pre-set anchor point 4 and the capacitor plate 6 are respectively arranged on the two sides of the coplanar waveguide transmission line 2, one ground wire 1 is respectively arranged on the outer side of the pre-set anchor point 4 and the capacitor plate 6, the anchor area 3 is arranged on the ground wire 1 on the side of the pre-set anchor point 4, and the cantilever beam 5 is connected to the anchor area 3.

[0021] As shown in the drawings, Figure 2As shown, the substrate, the ground wire 1, the coplanar waveguide transmission line 2, the anchor area 3, the preset anchor point 4, the cantilever beam 5 and the capacitor plate 6 are all arranged on the substrate, wherein the ground wire 1 is arranged on both sides of the upper end of the substrate, the coplanar waveguide transmission line 2 is arranged in the middle of the upper end of the substrate, the preset anchor point 4 and the capacitor plate 6 are arranged on both sides of the coplanar waveguide transmission line 2 respectively, and the cantilever beam 5 is suspended above the coplanar waveguide transmission line 2, the preset anchor point 4 and the capacitor plate 6 through the anchor area 3.

[0022] The capacitor is formed between the cantilever beam 5 and the capacitor plate 6. The microwave power transmitted on the coplanar waveguide transmission line 2 will generate a downward electrostatic force on the cantilever beam 5, causing the cantilever beam 5 to deform and displace, thereby changing the capacitance between the cantilever beam 5 and the capacitor plate 6. The size of the microwave power transmitted on the coplanar waveguide can be obtained through a capacitance measurement circuit. Compared with the traditional cantilever beam structure, the length-variable cantilever beam shortens the equivalent length of the beam during the pull-down process, thus improving the stiffness of the beam structure, and greatly improving the overload power of the system.

[0023] The capacitive microwave power sensor has the characteristics of good input matching, low transmission loss, and compatibility with CMOS technology. The impedance matching design of the coplanar waveguide can improve the microwave characteristics, the preset anchor point 4 can change the equivalent length of the beam structure during the operation of the cantilever beam 5, and the anchor area 3 is placed outside the coplanar waveguide transmission line 2 to remove the influence of parasitic capacitance and provide more accurate capacitance measurement.

[0024] The capacitive sensor has higher overload power due to the application of the length-variable cantilever beam, while maintaining good resolution and high sensitivity. It can measure higher power microwave signals and has good overload resistance.

[0025] In summary, the microwave power sensor based on the length-variable cantilever beam adopts the MEMS planar processing technology, has the advantages of small size, high integration and high sensitivity. In addition, by using the length-variable cantilever beam, not only can the power range of the measured microwave signal be greatly improved, and the cantilever beam structure has good resolution, which greatly improves the accuracy of the detection signal and the sensitivity of the system itself. In summary, the microwave power sensor based on the length-variable cantilever beam has the advantages of high precision, large measurement range and high sensitivity.

[0026] It is to be understood that the terminology used herein such as first and second, and the like, is only intended to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Also, in the description of the present application, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are used only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present application. In the drawings of the present application, the filling patterns are only for distinguishing layers, and do not have any other limitations.

[0027] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, alternatives, and variations can be made in the embodiments without departing from the spirit and scope of the present application as defined by the appended claims and their equivalents.

Claims

1. A microwave power sensor of high overload level, characterized in that, The application relates to a high-overload-level microwave power sensor, which comprises ground wires (1), coplanar waveguide transmission lines (2), anchor areas (3), preset anchor points (4), cantilever beams (5) and capacitor plates (6).

2. The high overlaod level microwave power sensor of claim 1, wherein, The application further comprises a substrate, and the ground wires (1), the coplanar waveguide transmission lines (2), the anchor areas (3), the preset anchor points (4), the cantilever beams (5) and the capacitor plates (6) are arranged on the substrate.

3. The high overlaod level microwave power sensor of claim 2, wherein, The substrate is made of gallium nitride.

4. The high overlaod level microwave power sensor of claim 1, wherein, The anchor areas (3) and the preset anchor points (4) are arranged on the upper ends of the ground wires (1).

5. The high overlaod level microwave power sensor of claim 1, wherein, The capacitor plates (6) are connected to the side surfaces of the ground wires (1).

6. A method of controlling a microwave power sensor at high levels of overdrive, characterized by, The application discloses a high-overload-level microwave power sensor. When microwave signals enter, electrostatic force is generated to bend the cantilever beam (5), thereby reducing the distance between the cantilever beam (5) and the capacitor plate (6) below, changing the capacitance, and obtaining the microwave power by measuring the change amount of the capacitance.

7. A method of controlling a microwave power sensor at high levels of overdrive, characterized by, The application discloses a high-overload-level microwave power sensor. The cantilever beam (5) is pulled down to contact the preset anchor point (4), so that the equivalent length of the cantilever beam (5) is reduced, the rigidity of the cantilever beam (5) is improved, the overload power of the cantilever beam (5) is improved, and the range of the sensor is expanded.

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