CN111044796B - Symmetrical thermoelectric MEMS microwave standing wave meter and preparation method thereof - Google Patents
Symmetrical thermoelectric MEMS microwave standing wave meter and preparation method thereof Download PDFInfo
- Publication number
- CN111044796B CN111044796B CN201911412946.8A CN201911412946A CN111044796B CN 111044796 B CN111044796 B CN 111044796B CN 201911412946 A CN201911412946 A CN 201911412946A CN 111044796 B CN111044796 B CN 111044796B
- Authority
- CN
- China
- Prior art keywords
- mems
- transmission line
- port
- cpw
- microwave
- 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
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/08—Measuring electromagnetic field characteristics
- G01R29/0864—Measuring electromagnetic field characteristics characterised by constructional or functional features
- G01R29/0878—Sensors; antennas; probes; detectors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
- B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
- B81B7/02—Microstructural systems; Auxiliary parts of microstructural devices or systems containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS]
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
- B81C1/00436—Shaping materials, i.e. techniques for structuring the substrate or the layers on the substrate
- B81C1/00523—Etching material
- B81C1/00539—Wet etching
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R21/00—Arrangements for measuring electric power or power factor
- G01R21/02—Arrangements for measuring electric power or power factor by thermal methods, e.g. calorimetric
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Electromagnetism (AREA)
- Computer Hardware Design (AREA)
- Manufacturing & Machinery (AREA)
- Micromachines (AREA)
Abstract
The symmetrical thermoelectric MEMS microwave standing wave meter of the invention forms a symmetrical directional coupler by symmetrically distributing signal lines of ACPS transmission lines at two ends on the upper and lower sides of a main transmission line, and respectively extracts incident and reflected microwave power to a coupling end and an isolation end of an upper branch and a lower branch; the tail ends of each CPW transmission line of the upper branch and the lower branch are respectively connected with a thermoelectric MEMS microwave power sensor to measure the microwave power of each port of the two branches, and the measured output hot voltage is averaged to obtain more accurate incident and reflected microwave power so as to obtain the size of the standing-wave ratio; if one branch stops working, the other branch can still work normally, namely the MEMS microwave standing wave meter can still measure, and the failure rate is reduced; the symmetrical thermoelectric MEMS microwave standing wave meter improves the reliability of the MEMS microwave standing wave meter, and adopts a fully passive structure, thereby having the characteristics of zero direct current power consumption and being compatible with a gallium arsenide monolithic microwave integrated circuit process.
Description
Technical Field
The invention relates to a microwave standing wave meter for detecting standing wave ratio on line and a preparation method thereof, in particular to a symmetrical thermoelectric MEMS (Micro-Electro-Mechanical-System) microwave standing wave meter based on MEMS technology and a preparation method thereof.
Background
In a modern microwave high-density integrated micro system, a microwave standing wave meter is a key element of a microwave system module self-detection application and is used for representing the size of a standing wave ratio in the microwave system. The microwave high-density integrated micro system requires high integration of modules such as an antenna and a TR component, and is used for micro detection, interference, frequency detection and the like. Along with the fact that the size of a microwave system is smaller and the integration degree is higher and higher, the highly integrated microwave system is large in performance difference, difficult to disassemble and measure, and prone to component failure caused by long-term work and environmental influence, and therefore the standing-wave ratio of the microwave system is important to achieve on-line detection. At present, there are two main methods for measuring standing-wave ratio of microwave system: one is based on network analyzer measurements, which can provide relatively accurate and complete signal measurements, but which are only suitable for systems that are not operating, and which require manual operation of the instrument each time to complete a single test. For many modules that often need to be tested, measuring the reliability of a microwave system in this way is significantly more cumbersome. The other is based on microwave standing wave meter measurement, the method embeds a microwave standing wave meter between an amplifier and an antenna, can perform measurement when a microwave system is in an operating state, and can perform continuous test. The measurement is convenient and quick, is especially suitable for large-scale detection, and has small influence on a microsystem. Generally, a microwave standing wave meter mainly includes two parts: the microwave signal extracting part is the microwave signal extracting part, and the microwave signal detecting part is the microwave signal extracted part. For the extraction part of the microwave signal, the structure can be divided into a structure based on a multi-port annular junction, a structure based on a sampling transmission line, a structure based on a directional coupler and the like; the detection section from which the microwave signal is extracted generally employs a diode, a logic circuit, a thermistor, and the like. However, these standing wave meters exhibit disadvantages of large volume, active detection, hybrid integration, and the like. Therefore, it is urgently needed to develop a microwave standing wave meter with miniaturization, low power consumption, integration, low cost and on-line detection standing wave ratio, so as to be embedded into a microwave high-density integrated micro-system, thereby realizing the self-detection of the microwave micro-system. With the intensive research of the MEMS technology, it becomes possible to develop a symmetrical thermoelectric MEMS microwave standing wave meter that realizes the above functions based on the MEMS technology.
Disclosure of Invention
The technical problem is as follows: in order to overcome the defects in the prior art, the invention provides a symmetrical thermoelectric MEMS microwave standing wave meterThe microwave signal is input from a coplanar waveguide (CPW) transmission line at a first port, is transmitted to a CPW transmission line at a second port through a main transmission line of a symmetrical directional coupler and is output, so that the structure does not consume direct current power and is an online device; in the symmetrical directional coupler, two sections of asymmetrical coplanar strip line (ACPS) transmission lines are symmetrically arranged on the upper side and the lower side of a main transmission line, two ends of the two sections of ACPS transmission lines are respectively connected to CPW transmission lines at three, four, five and six ports to form the symmetrical directional coupler with two coupling ends and two isolation ends, wherein the three port and the five port are coupling ends, and the four port and the six port are isolation ends; the tail ends of the third port, the fourth port, the fifth port and the sixth port are respectively connected with a thermoelectric MEMS microwave power sensor, so that the microwave power output from the ports can be measured; because the coupling degree of the directional coupler is far greater than the isolation degree, the microwave power measured at the coupling ends (the third port and the fifth port) can obtain the incident microwave power on the main transmission line, the microwave power measured at the isolation ends (the fourth port and the sixth port) can obtain the reflected microwave power on the main transmission line, and then the standing-wave ratio when the microwave system is in a working state is obtained, so that the function of detecting the standing-wave ratio on line of the symmetrical thermoelectric MEMS microwave standing-wave meter is realized; connecting the divided CPW ground lines by placing four identical MEMS air bridges at the CPW transmission line and ACPS transmission line connection nodes of the symmetrical type directional coupler; the MEMS air bridge crosses over the CPW signal line, two ends of the MEMS air bridge are respectively fixed on the CPW ground lines at two sides of the CPW signal line through anchor areas, and the CPW signal line is covered with silicon nitride (Si)3N4) An insulating dielectric layer; by adopting optimized materials and optimizing the simulation structure for many times in the processing process, the symmetrical thermoelectric MEMS microwave standing wave meter has smaller microwave loss and chip area, and the preparation method is compatible with the gallium arsenide-based monolithic microwave integrated circuit process; therefore, the symmetrical thermoelectric MEMS microwave standing wave meter provided by the invention has the characteristics of miniaturization, low power consumption, integration, low cost and on-line detection of standing wave ratio.
The technical scheme is as follows: the symmetrical thermoelectric MEMS microwave standing wave meter adopts gallium arsenide (GaAs) as a substrate, a CPW transmission line, an ACPS transmission line, a symmetrical directional coupler, four same MEMS air bridges and four same thermoelectric MEMS microwave power sensors are arranged on the GaAs substrate, and an MEMS substrate film structure is designed on the substrate near a load resistor:
the CPW transmission line is horizontally arranged on the GaAs substrate and used as the input and the output of the MEMS microwave standing wave meter; and the CPW transmission line at the coupling port and the isolation port is used for realizing the transmission of the coupled microwave signals. The input port on the left side is a port one, the output port on the right side is a port two, the coupling port on the left side above is a port three, the isolation port on the right side above is a port four, the coupling port on the left side below is a port five, and the isolation port on the right side below is a port six. The CPW transmission line is composed of a signal line and two ground lines, wherein the ground lines are located on both sides of the signal line. In order to realize microwave matching between the port and the outside, the characteristic impedance of the port of the CPW transmission line is usually designed to be 50 Ω.
Two sections of ACPS transmission lines are placed on the GaAs substrate, each section of ACPS transmission line is composed of a signal line and a ground line, and the signal line of the ACPS transmission line is used as a secondary transmission line of a symmetrical directional coupler in the MEMS microwave standing wave meter. The signal lines of the two sections of ACPS transmission lines are symmetrically positioned at the upper side and the lower side of the main transmission line in the symmetrical directional coupler, and the lengths of the signal lines are quarter wavelengths. In the symmetrical directional coupler, two ends of each section of auxiliary transmission line are respectively a coupling end and an isolation end, wherein the coupling end is close to the input end, and the isolation end is close to the output end. In order to realize microwave matching in connection with the CPW transmission line, the characteristic impedance of the ACPS transmission line is designed to be 50 Ω.
The symmetrical directional coupler is positioned among input, output, coupling and isolating ports of the MEMS microwave standing wave meter and mainly comprises a section of main transmission line and two sections of auxiliary transmission lines, wherein the two sections of auxiliary transmission lines are positioned on the upper side and the lower side of the main transmission line, and the distances from the two sections of auxiliary transmission lines to the main transmission line are equal. The coupling degree and the isolation degree of the upper section of the auxiliary transmission line and the lower section of the auxiliary transmission line of the symmetrical directional coupler are equal. The two ports on the left side are coupling ends, and the two ports on the right side are isolation ends.
Each thermoelectric MEMS microwave power sensor mainly comprises a CPW transmission line and Si3N4The device comprises an insulating medium layer, a pressure welding block, two load resistors, a thermopile and an MEMS substrate film structure.
Eight same load resistors are placed in pairs at the two coupling ports and the two isolation ports. The coupling port and the isolation port are designed by adopting a CPW transmission line. Each coupling port and each isolation port are connected with two load resistors in parallel, and the resistance value of each load resistor is 100 omega.
Four identical thermopiles are placed close to, but not in contact with, the load resistors at the two coupled ports and the two isolated ports, respectively. Each thermopile is formed by connecting ten pairs of thermocouples in series, wherein each pair of thermocouples comprises a semiconductor arm and a metal arm, and are connected at one end by using a metal connecting wire. And a plurality of pairs of thermocouples are connected in series, so that the sensitivity of measuring the temperature can be increased. The semiconductor arm, the metal arm and the load resistor are covered with Si3N4And the insulating medium layer is used for playing a role in protecting in the preparation process. When the load resistor absorbs microwave power to generate heat, the temperature of one end of the thermopile close to the load resistor is increased, and the end is called the hot end of the thermopile; and the temperature of the other end of the thermopile far away from the load resistor is almost kept constant and is the ambient temperature, namely the cold end of the thermopile. When the load resistor absorbs microwave power to generate heat, the temperature of the hot end and the cold end of the thermopile is different, based on the Seebeck effect, the thermopile generates output hot voltage, and the hot voltage reflects the temperature of the load resistor. In order to improve the transmission efficiency of heat from the load resistor to the hot end of the thermopile and further improve the temperature difference between the hot end and the cold end of the thermopile, the GaAs substrate near the lower part of the load resistor is etched and thinned by a body etching technology to form an MEMS substrate film structure. The temperature of the load resistor at the moment can be obtained by measuring the thermal voltage on the pressure welding blocks on the two sides of the thermopile, and the microwave signal power of the port can be further obtained.
Each MEMS air bridge is a suspended solid support beam structure provided with through holes at equal intervals.
The four same MEMS air bridges cross over the signal line of the CPW transmission line, and two ends of each MEMS air bridge are fixed on the CPW ground lines on two sides of the CPW signal line through anchor areas; the through holes on the MEMS air bridge are beneficial to releasing in the manufacturing process of the MEMS air bridge. Design Si3N4The insulating medium layer covers the signal wire of the CPW transmission line below the MEMS air bridge, so that the MEMS air bridge is isolated from the direct current of the signal wire of the CPW transmission line.
In the mechanical structure, the CPW transmission line, the ACPS transmission line, the symmetrical directional coupler, the thermoelectric MEMS microwave power sensor, the MEMS air bridge and the pressure welding block are positioned on the same GaAs substrate.
The symmetrical thermoelectric MEMS microwave standing wave meter is formed by adopting a full passive structure, the input microwave power on a main transmission line is coupled to a port III and a port V of a coupling end through two sections of ACPS auxiliary transmission lines, and the reflected microwave power is coupled to a port IV and a port VI of an isolation end; the four same thermoelectric MEMS microwave power sensors are respectively positioned at the tail ends of the third port, the fourth port, the fifth port and the sixth port and are used for measuring the coupled microwave power at the ports, so that a symmetrical thermoelectric MEMS microwave standing wave meter is formed; the detection of the thermoelectric MEMS microwave power sensor is based on the principle of microwave power-heat-electricity conversion; the method comprises the steps that four identical MEMS air bridges are respectively placed at connecting nodes of a CPW transmission line and an ACPS transmission line of a symmetrical directional coupler to connect disconnected CPW ground lines; the MEMS air bridge spans the CPW signal line, and two ends of the MEMS air bridge are fixed on CPW ground lines on two sides of the CPW signal line below the MEMS air bridge through anchor areas; covering a layer of Si on the CPW signal line below the MEMS air bridge3N4And an insulating dielectric layer. When the MEMS microwave standing wave meter works, microwave power incident from the first port and reflected from the second port is coupled to the two coupling ends and the isolation end in a certain proportion through the symmetrical directional coupler, and due to the characteristics of directivity and isolation of the coupler, the microwave power extracted from the first port is transmitted to the third port and the fifth port, the microwave power extracted from the second port is transmitted to the fourth port and the sixth port, the microwave power transmitted to the third port and the fifth port are equal, and the microwave power transmitted to the fourth port and the fifth port are transmitted to the fourth port and the fifth portThe microwave power of the sixth port is equal, the coupled microwave power is completely consumed by the load resistors at the third, fourth, fifth and sixth ports and generates heat, the temperature around the load resistors is increased, the thermopile placed near the load resistors detects the temperature change, the temperature change is converted into output thermal voltage based on the Seebeck effect, the measurement of the microwave power incident at the first port and the microwave power reflected at the second port is realized, and the standing-wave ratio can be obtained; during detection, only a certain proportion of microwave power is coupled for measurement, and most of the microwave power is available, so that the standing-wave ratio of online detection is realized; the directional coupler usually has only one section of ACPS auxiliary transmission line, one coupling end and one isolation end, but the measurement accuracy of the microwave standing wave meter can be improved by adopting a multi-measurement mode through designing two symmetrical coupling branches. For example, when two branches of the symmetrical directional coupler work normally, the average value of the measured thermal voltages at two coupling ends (isolation ends) is taken as a final value; when the upper half branch or the lower half branch of the symmetrical directional coupler can not work normally, the other branch which works normally can still measure the standing-wave ratio, thereby obviously improving the reliability of the MEMS microwave standing-wave meter. The symmetrical thermoelectric MEMS microwave standing wave meter is prepared by adopting a gallium arsenide monolithic microwave integrated circuit and an MEMS process, and the preparation method comprises the following specific processing steps:
(1) selecting a gallium arsenide epitaxial wafer as a substrate, wherein the gallium arsenide substrate is semi-insulating, and the square resistance of the epitaxial layer is 100-130 omega; coating photoresist, removing the photoresist in the region outside the semiconductor arm of the thermocouple, etching the front epitaxial layer, and then removing the photoresist to form the semiconductor arm of the thermopile;
(2) sputtering AuGeNi/Au, forming a metal arm and a pressure welding block of the thermopile by adopting a stripping process, and then carrying out rapid thermal annealing to ensure that the semiconductor arm and the metal arm have good ohmic contact;
(3) etching the semiconductor arm of the thermopile to reduce the thickness of the semiconductor arm, so that the resistance of the thermopile is increased to about 300K omega;
(4) coating photoresist on the GaAs substrate obtained in the step (3), removing the photoresist at the position where the load resistor is to be manufactured, sputtering to grow TaN, and stripping to form the load resistor with the square resistance of 25 omega;
(5) coating photoresist on the GaAs substrate obtained in the step (4), removing the photoresist at the positions where the CPW transmission line, the ACPS transmission line and the pressure welding block are to be manufactured, growing a layer of Ti/Pt/Au/Ti in an evaporation mode, and preliminarily forming the CPW transmission line, the ACPS transmission line and the pressure welding block by adopting a stripping process;
(6) growing a layer of Si 2300A thick by a plasma enhanced chemical vapor deposition process3N4Insulating dielectric layer, photoetching and etching Si3N4An insulating dielectric layer, Si remaining on the CPW signal line below the semiconductor arm, the metal arm, the load resistor and the MEMS air bridge3N4An insulating dielectric layer;
(7) spin-coating a polyimide sacrificial layer with the thickness of 1600nm, photoetching and etching the polyimide sacrificial layer, and reserving the polyimide sacrificial layer below the MEMS air bridge to be manufactured;
(8) evaporating the seed layer titanium/gold/titanium for electroplating, photoetching and removing the photoresist at the position to be electroplated;
(9) growing a layer of Au on the seed layer obtained in the step (8) in an electroplating mode, removing photoresist in an area which does not need to be electroplated, reversely etching titanium/gold/titanium, and corroding bottom gold to completely form structures such as a CPW transmission line, an ACPS transmission line, an MEMS air bridge, a pressure welding block and the like;
(10) coating a layer of photoresist on the front surface of the substrate for protection, and carrying out operation on the back surface of the GaAs substrate;
(11) coating a layer of photoresist on the back of the GaAs substrate, photoetching the photoresist, removing the photoresist below the load resistor and the hot end of the thermopile, reserving the region except the region below the load resistor and the hot end of the thermopile, and carrying out wet etching on the back of the substrate to form an MEMS substrate film structure, wherein the thickness of the MEMS substrate film structure is less than 20 microns;
(12) and (3) removing the front protection material, scribing the front of the substrate, corroding the sacrificial layer manufactured in the step (7) by using a developing solution, releasing the MEMS air bridge, slightly soaking by using deionized water, dehydrating by using absolute ethyl alcohol, volatilizing at normal temperature, and airing.
Has the advantages that:
compared with the prior art, the symmetrical thermoelectric MEMS microwave standing wave meter and the preparation method thereof provided by the invention have the following advantages:
(1) the symmetrical thermoelectric MEMS microwave standing wave meter is formed by adopting a fully passive structure, and the measurement of the standing-wave ratio is realized by adopting a symmetrical directional coupler and a thermoelectric MEMS microwave power sensor.
(2) In the structure, by designing a symmetrical directional coupler, incident microwave power is respectively coupled to a third port and a fifth port of a coupling end, and reflected microwave power is respectively coupled to a fourth port and a sixth port of an isolation end; on one hand, a twice measurement mode is adopted, and the average value of the thermal voltages measured at two coupling ends (isolation ends) is taken as a final value, so that the measurement accuracy of the microwave standing wave meter is improved; on the other hand, if the upper half branch or the lower half branch of the symmetrical directional coupler can not work normally, the other branch which works normally can still carry out standing wave ratio measurement.
(3) In the structure, four same thermoelectric MEMS microwave power sensors are used for converting the extracted incident microwave power and the extracted reflected microwave power into direct-current thermal voltages respectively, so that the microwave power is measured; the method has the characteristics of zero direct current power consumption, high power, high sensitivity, good linearity and the like.
(4) The MEMS microwave standing wave meter adopts a symmetrical directional coupler based on CPW and ACPS transmission lines to replace the traditional microstrip line-based structure, realizes the extraction of incident microwave power and reflected microwave power, can ensure that the standing wave meter has lower microwave loss in higher frequency bands, and is convenient for connecting other devices in series and in parallel because a signal line and a ground line are on the same plane.
(5) The symmetrical thermoelectric MEMS microwave standing wave meter is an online device, and most microwave signals can still be used in the measurement process, so that the on-line self-detection standing wave ratio is realized; the preparation method is compatible with a gallium arsenide monolithic microwave integrated circuit.
Drawings
FIG. 1 is a schematic diagram of a symmetrical pyroelectric MEMS microwave standing wave meter;
FIG. 2 is a cross-sectional view A-A of a symmetrical pyroelectric MEMS microwave standing wave meter;
FIG. 3 is a B-B cross-sectional view of a symmetrical pyroelectric MEMS microwave standing wave meter;
the figure includes: CPW transmission line (1), ACPS transmission line (2), symmetrical directional coupler (3), thermoelectric MEMS microwave power sensor (4), MEMS air bridge (8), Si3N4The MEMS device comprises an insulating medium layer (12), a metal arm (13), a semiconductor arm (14), a load resistor (15), a pressure welding block (16), a GaAs substrate (21), an MEMS substrate membrane structure (22), a first port (31), a second port (32), a third port (33), a fourth port (34), a fifth port (35) and a sixth port (36).
Detailed Description
The specific implementation scheme of the symmetrical thermoelectric MEMS microwave standing wave meter is as follows:
the GaAs substrate (21) is provided with a CPW transmission line (1), an ACPS transmission line (2), a symmetrical directional coupler (3), four same MEMS air bridges (8) and four same thermoelectric MEMS microwave power sensors (4), and the substrate near a load resistor (15) is designed with an MEMS substrate film structure (22):
the CPW transmission line (1) is horizontally arranged on the GaAs substrate (21) and used as the input and the output of the MEMS microwave standing wave meter; and the CPW transmission line (1) at the coupling port and the isolation port is used for realizing the transmission of the coupled microwave signals. The left input port is port one (31), the right output port is port two (32), the upper left coupled port is port three (33), the upper right isolated port is port four (34), the lower left coupled port is port five (35), and the lower right isolated port is port six (36). The CPW transmission line (1) is composed of a signal line and two ground lines, wherein the ground lines are positioned at two sides of the signal line. In order to realize microwave matching of the port and the outside, the port characteristic impedance of the CPW transmission line (1) is usually designed to be 50 Ω.
Two sections of ACPS transmission lines (2) are placed on the GaAs substrate, each section of ACPS transmission line (2) is composed of a signal line and a ground line, and the signal line of the ACPS transmission line (2) is used as a secondary transmission line of a symmetrical directional coupler (3) in the MEMS microwave standing wave meter. The signal lines of the two sections of ACPS transmission lines (2) are symmetrically positioned at the upper side and the lower side of a main transmission line in the symmetrical directional coupler (3), and the lengths of the signal lines are quarter wavelengths. In the symmetrical directional coupler (3), two ends of each section of auxiliary transmission line are respectively a coupling end and an isolation end, wherein the coupling end is close to the input end, and the isolation end is close to the output end. In order to realize microwave matching in connection with the CPW transmission line (1), the characteristic impedance of the ACPS transmission line (2) is designed to be 50 Ω.
The symmetrical directional coupler (3) is positioned among input, output, coupling and isolating ports of the MEMS microwave standing wave meter and mainly comprises a section of main transmission line and two sections of auxiliary transmission lines, wherein the two sections of auxiliary transmission lines are positioned on the upper side and the lower side of the main transmission line, and the distances from the two sections of auxiliary transmission lines to the main transmission line are equal. The coupling degree and the isolation degree of the upper and lower sections of auxiliary transmission lines of the symmetrical directional coupler (3) are equal. The two ports on the left side are coupling ends, and the two ports on the right side are isolation ends.
Each thermoelectric MEMS microwave power sensor (4) mainly comprises a CPW transmission line (1) and Si3N4The device comprises an insulating medium layer (12), a pressure welding block (16), two load resistors (15), a thermopile and an MEMS substrate film structure (22).
Eight identical load resistors (15) are placed in pairs at the two coupling ports and the two isolation ports. The coupling port and the isolation port are designed by adopting a CPW transmission line (1). Wherein each coupling port and each isolation port are connected with two load resistors (15) in parallel, and the resistance value of each load resistor (15) is 100 omega.
Four identical thermopiles are placed close to, but not in contact with, the load resistors (15) placed at the two coupled and two isolated ports, respectively. Wherein each thermopile is formed by ten pairs of thermocouples connected in series, each pair of thermocouples comprising a semiconductor arm (14) and aMetal arms (13) are supported and connected at one end by a metal connecting wire. And a plurality of pairs of thermocouples are connected in series, so that the sensitivity of measuring the temperature can be increased. The semiconductor arm (14), the metal arm (13) and the load resistor (15) are covered with Si3N4And the insulating medium layer (12) is used for playing a role in protection in the preparation process. When the load resistor (15) absorbs microwave power to generate heat, the temperature of one end of the thermopile close to the load resistor (15) is increased, and the end is called the hot end of the thermopile; and the temperature of the other end of the thermopile far away from the load resistor is almost kept constant and is the ambient temperature, namely the cold end of the thermopile. When the load resistor (15) absorbs microwave power to generate heat, the temperature of the hot end and the cold end of the thermopile can be caused to be different, based on the Seebeck effect, the thermopile generates output hot voltage, and the hot voltage reflects the temperature of the load resistor (15). In order to improve the heat transfer efficiency from the load resistor (15) to the hot end of the thermopile and further improve the temperature difference between the hot and cold ends of the thermopile, the GaAs substrate (21) near the lower part of the load resistor is etched and thinned by a bulk etching technology to form a MEMS substrate film structure (22). By measuring the thermal voltage on the pressure welding blocks (16) on the two sides of the thermopile, the temperature of the load resistor (15) at the moment can be obtained, and the microwave signal power of the port can be further obtained.
Each MEMS air bridge (8) is a suspended solid support beam structure provided with through holes at equal intervals.
The four same MEMS air bridges (8) cross over the signal lines of the CPW transmission line (1), and two ends of each MEMS air bridge (8) are fixed on the CPW ground lines on two sides of the CPW signal line through anchor areas; the through holes on the MEMS air bridge (8) are beneficial to releasing in the manufacturing process. Design Si3N4The insulating medium layer (12) covers the signal line of the CPW transmission line (1) below the MEMS air bridge (8), so that the MEMS air bridge (8) is isolated from the direct current of the signal line of the CPW transmission line (1).
In the mechanical structure, the CPW transmission line (1), the ACPS transmission line (2), the symmetrical directional coupler (3), the thermoelectric MEMS microwave power sensor (4), the MEMS air bridge (8) and the pressure welding block (16) are positioned on the same GaAs substrate.
The symmetrical thermoelectric MEMS microwave standing wave meter is formed by adopting a full passive structure, the input microwave power on a main transmission line is coupled to a port III and a port V of a coupling end through two sections of ACPS auxiliary transmission lines, and the reflected microwave power is coupled to a port IV and a port VI of an isolation end; the four same thermoelectric MEMS microwave power sensors (4) are respectively positioned at the tail ends of the third port, the fourth port, the fifth port and the sixth port and are used for measuring the coupled microwave power at the ports, so that a symmetrical thermoelectric MEMS microwave standing wave meter is formed; the detection of the thermoelectric MEMS microwave power sensor is based on the principle of microwave power-heat-electricity conversion; four same MEMS air bridges (8) are respectively placed at the connecting nodes of the CPW transmission line (1) and the ACPS transmission line (2) of the symmetrical directional coupler to connect the disconnected CPW ground wires; the MEMS air bridge (8) spans the CPW signal line, and two ends of the MEMS air bridge (8) are fixed on CPW ground lines on two sides of the CPW signal line below the MEMS air bridge (8) through anchor areas; a layer of Si is covered on the CPW signal wire below the MEMS air bridge (8)3N4An insulating dielectric layer (12). When the MEMS microwave standing wave meter works, microwave power incident from a port I (31) and reflected from a port II (32) couple a certain proportion of microwave power to two coupling ends and two isolation ends through a symmetrical directional coupler (3), due to the characteristics of directivity and isolation of the coupler, the microwave power extracted from the port I (31) is transmitted to a port III (33) and a port V (35), the microwave power extracted from the port II (32) is transmitted to a port IV (34) and a port VI (36), the microwave power transmitted to the port III (33) and the port V (35) is equal, the microwave power transmitted to the port IV (34) and the port VI (36) is equal, the coupled microwave power is completely consumed by load resistors at the ports III, IV, V, VI (33, 34,35, 36) and generates heat, and the temperature around the load resistor (15) is increased, the thermopile placed near the load resistor (15) detects the temperature change, converts the temperature change into output thermal voltage based on Seebeck effect, and realizes microwave power incident at a first port (31) and micro-reflected at a second port (32)Measuring the wave power, and further obtaining the standing-wave ratio; during detection, only a certain proportion of microwave power is coupled for measurement, and most of the microwave power is available, so that the standing-wave ratio of online detection is realized; the directional coupler usually has only one section of ACPS auxiliary transmission line, one coupling end and one isolation end, but the measurement accuracy of the microwave standing wave meter can be improved by adopting a multi-measurement mode through designing two symmetrical coupling branches. For example, when two branches of the symmetrical directional coupler work normally, the average value of the measured thermal voltages at two coupling ends (isolation ends) is taken as a final value; when the upper half branch or the lower half branch of the symmetrical directional coupler can not work normally, the other branch which works normally can still measure the standing-wave ratio, thereby obviously improving the reliability of the MEMS microwave standing-wave meter. The symmetrical thermoelectric MEMS microwave standing wave meter is prepared by adopting a gallium arsenide monolithic microwave integrated circuit and an MEMS process, and the preparation method comprises the following specific processing steps:
(1) selecting a gallium arsenide epitaxial wafer as a substrate, wherein the gallium arsenide substrate is semi-insulating, and the square resistance of the epitaxial layer is 100-130 omega; coating photoresist, removing the photoresist in the region outside the semiconductor arm of the thermocouple, etching the front epitaxial layer, and then removing the photoresist to form the semiconductor arm (14) of the thermopile;
(2) sputtering AuGeNi/Au, forming a metal arm (13) and a pressure welding block (16) of the thermopile by adopting a stripping process, and then carrying out rapid thermal annealing to ensure that the semiconductor arm (14) and the metal arm (13) have good ohmic contact;
(3) etching the semiconductor arm (14) of the thermopile to reduce the thickness thereof, so that the resistance of the thermopile is increased to about 300K omega;
(4) coating photoresist on the GaAs substrate (21) obtained in the step (3), removing the photoresist at the position where the load resistor (15) is to be manufactured, sputtering to grow TaN, and stripping to form the load resistor (15) with the square resistance of 25 omega;
(5) coating photoresist on the GaAs substrate (21) obtained in the step (4), removing the photoresist at the positions of preparing the CPW transmission line (1), the ACPS transmission line (2) and the pressure welding block (16), growing a layer of Ti/Pt/Au/Ti in an evaporation mode, and preliminarily forming the CPW transmission line (1), the ACPS transmission line (2) and the pressure welding block (16) by adopting a stripping process;
(6) growing a layer of Si 2300A thick by a plasma enhanced chemical vapor deposition process3N4Insulating dielectric layer, photoetching and etching Si3N4An insulating dielectric layer, Si remaining on the CPW signal line below the semiconductor arm (14), the metal arm (13), the load resistor (15) and the MEMS air bridge (8)3N4An insulating dielectric layer (12);
(7) spin-coating a polyimide sacrificial layer with the thickness of 1600nm, photoetching and etching the polyimide sacrificial layer, and reserving the polyimide sacrificial layer below the MEMS air bridge (8) to be manufactured;
(8) evaporating the seed layer titanium/gold/titanium for electroplating, photoetching and removing the photoresist at the position to be electroplated;
(9) growing a layer of Au on the seed layer obtained in the step (8) in an electroplating mode, removing photoresist in an area which does not need to be electroplated, reversely etching titanium/gold/titanium, and corroding bottom gold to completely form structures such as a CPW transmission line (1), an ACPS transmission line (2), an MEMS air bridge (8), a pressure welding block (16) and the like;
(10) coating a layer of photoresist on the front surface of the substrate for protection, and carrying out operation on the back surface of the GaAs substrate (21);
(11) coating a layer of photoresist on the back of a GaAs substrate (21), removing the photoresist below the load resistor (15) and the hot end of the thermopile, reserving the region outside the lower parts of the load resistor (15) and the hot end of the thermopile, and performing wet etching on the back of the substrate to form an MEMS substrate film structure (22), wherein the thickness of the MEMS substrate film structure is less than 20 um;
(12) and (3) removing the front protection material, scribing the front of the substrate, corroding the sacrificial layer manufactured in the step (7) by using a developing solution, releasing the MEMS air bridge (8), slightly soaking by using deionized water, dehydrating by using absolute ethyl alcohol, volatilizing at normal temperature, and airing.
The criteria for distinguishing whether this structure is present are as follows:
(1) the transmission of microwave signals is realized by adopting a CPW transmission line (1) and an ACPS transmission line (2) which are horizontally arranged;
(2) a symmetrical directional coupler (3) is adopted to couple a main transmission line to two sections of ACPS auxiliary transmission lines, couple input signals to two coupling ends and couple reflected signals to two isolation ends;
(3) arranging four MEMS air bridges (8) at the connecting junction of a CPW transmission line (1) and an ACPS transmission line (2) of the symmetrical directional coupler;
(4) four MEMS microwave power sensors (4) are respectively arranged at the tail ends of the two coupling ends and the two isolation ends;
(5) at the MEMS air bridge (8) structure: the MEMS air bridge (8) spans the CPW signal line, and two ends of the MEMS air bridge are fixed on the CPW ground line through anchor areas;
(6) at a MEMS microwave power sensor (4) structure: a load resistor (15) is arranged at the tail end of the CPW transmission line, a thermopile structure consisting of a metal arm (13) and a semiconductor arm (14) is arranged close to the outer side of the load resistor (15), pressure welding blocks (16) are arranged at two ends of the thermopile, and an MEMS substrate film structure (22) is designed at the load resistor (15) and the hot end of the thermopile;
(7) si is covered on the CPW signal line (1) below the load resistor (15), the metal arm (13), the semiconductor arm (14) and the MEMS clamped beam3N4An insulating dielectric layer (12);
the structure satisfying the above conditions is regarded as the symmetrical thermoelectric MEMS microwave standing wave meter of the present invention.
Claims (4)
1. Symmetrical thermoelectric MEMS microwave standing wave meter, its characterized in that: the MEMS microwave power sensor comprises a GaAs substrate (21), wherein a CPW transmission line (1), an ACPS transmission line (2), a symmetrical directional coupler (3), four MEMS air bridges (8), a pressure welding block (16) and four thermoelectric MEMS microwave power sensors (4) are arranged on the GaAs substrate (21); the symmetrical directional coupler (3) is composed of a main transmission line and two auxiliary transmission lines, wherein the two auxiliary transmission lines are positioned in parallel at two sides of the main transmission lineSide, and equal distance to the main transmission line; microwave power is transmitted to a main transmission line of the symmetrical directional coupler (3) from an input port, incident microwave power of a port I (31) is coupled to a port III (33) and a port V (35) through two auxiliary transmission lines respectively, and reflected microwave power of a port II (32) is coupled to a port IV (34) and a port VI (36) respectively; the coupling end and the isolation end of the symmetrical directional coupler (3) are respectively connected with a thermoelectric MEMS microwave power sensor (4) to form a symmetrical thermoelectric MEMS microwave standing wave meter; the thermoelectric MEMS microwave power sensor (4) is based on the microwave power-heat-electricity principle, and can obtain the size of the standing-wave ratio by measuring the microwave power at the coupling end and the isolation end of the symmetrical directional coupler (3), so that the on-line detection of the standing-wave ratio is realized; each MEMS air bridge (8) spans on the CPW signal wire, two ends of each MEMS air bridge are respectively fixed on the CPW ground wires at two sides of the CPW signal wire through anchor areas, and the CPW signal wire below the air bridge is covered with Si3N4An insulating dielectric layer (12); connecting the divided CPW ground wires by placing four MEMS air bridges (8) at the CPW transmission line and ACPS transmission line (2) connection nodes of the symmetrical directional coupler; each thermoelectric MEMS microwave power sensor (4) comprises a CPW transmission line (1), Si3N4The MEMS device comprises an insulating medium layer (12), a pressure welding block (16), two load resistors (15), a thermopile and an MEMS substrate film structure (22).
2. The symmetrical thermoelectric MEMS microwave standing wave meter of claim 1, wherein: the symmetrical directional coupler (3) comprises a CPW transmission line (1) and two ACPS transmission lines (2), wherein a signal line of the CPW transmission line (1) forms a main transmission line of the symmetrical directional coupler (3), and two signal lines of the two ACPS transmission lines (2) form two auxiliary transmission lines of the symmetrical directional coupler (3); the signal lines of the two sections of ACPS transmission lines (2) are symmetrically distributed on the upper side and the lower side of the main transmission line, wherein the length of each section of ACPS transmission line (2) is one quarter wavelength.
3. The symmetrical thermoelectric MEMS microwave standing wave meter of claim 1, wherein: the four thermoelectric MEMS microwave power sensors (4) are identical, and the four MEMS air bridges (8) are identical.
4. A preparation method for manufacturing the symmetrical thermoelectric MEMS microwave standing wave meter of claim 1 is characterized by comprising the following steps:
(1) selecting a gallium arsenide epitaxial wafer as a substrate, wherein the gallium arsenide substrate is semi-insulating, and the square resistance of the epitaxial layer is 100-130 omega; coating photoresist, removing the photoresist in the region outside the semiconductor arm of the thermocouple, etching the front epitaxial layer, and then removing the photoresist to form the semiconductor arm (14) of the thermopile;
(2) sputtering AuGeNi/Au, forming a metal arm (13) and a pressure welding block (16) of the thermopile by adopting a stripping process, and then carrying out rapid thermal annealing to ensure that the semiconductor arm (14) and the metal arm (13) have good ohmic contact;
(3) etching the semiconductor arm (14) of the thermopile to reduce the thickness thereof, so that the resistance of the thermopile is increased to about 300K omega;
(4) coating photoresist on the GaAs substrate (21) obtained in the step (3), removing the photoresist at the position where the load resistor (15) is to be manufactured, sputtering to grow TaN, and stripping to form the load resistor (15) with the square resistance of 25 omega;
(5) coating photoresist on the GaAs substrate (21) obtained in the step (4), removing the photoresist at the positions of preparing the CPW transmission line (1), the ACPS transmission line (2) and the pressure welding block (16), growing a layer of Ti/Pt/Au/Ti in an evaporation mode, and preliminarily forming the CPW transmission line (1), the ACPS transmission line (2) and the pressure welding block (16) by adopting a stripping process;
(6) growing a layer of Si 2300A thick by a plasma enhanced chemical vapor deposition process3N4Insulating dielectric layer, photoetching and etching Si3N4An insulating dielectric layer (12) remaining on the semiconductor arm (14), the metal arm (13), the load resistor (15) and the MEMS air bridge (18) Si on the lower CPW signal line3N4An insulating dielectric layer (12);
(7) spin-coating a polyimide sacrificial layer with the thickness of 1600nm, photoetching and etching the polyimide sacrificial layer, and reserving the polyimide sacrificial layer below the MEMS air bridge (8) to be manufactured;
(8) evaporating the seed layer titanium/gold/titanium for electroplating, photoetching and removing the photoresist at the position to be electroplated;
(9) growing a layer of Au on the seed layer obtained in the step (8) in an electroplating mode, removing photoresist in an area which does not need to be electroplated, reversely etching titanium/gold/titanium, and corroding bottom gold to completely form a CPW transmission line (1), an ACPS transmission line (2), an MEMS air bridge (8) and a pressure welding block (16) structure;
(10) coating a layer of photoresist on the front surface of the substrate for protection, and carrying out operation on the back surface of the GaAs substrate (21);
(11) coating a layer of photoresist on the back of a GaAs substrate (21), removing the photoresist below the load resistor (15) and the hot end of the thermopile, reserving the region outside the lower parts of the load resistor (15) and the hot end of the thermopile, and performing wet etching on the back of the substrate to form an MEMS substrate film structure (22), wherein the thickness of the MEMS substrate film structure is less than 20 um;
(12) and (3) removing the front protection material, scribing the front of the substrate, corroding the sacrificial layer manufactured in the step (7) by using a developing solution, releasing the MEMS air bridge (8), slightly soaking by using deionized water, dehydrating by using absolute ethyl alcohol, volatilizing at normal temperature, and airing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911412946.8A CN111044796B (en) | 2019-12-31 | 2019-12-31 | Symmetrical thermoelectric MEMS microwave standing wave meter and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911412946.8A CN111044796B (en) | 2019-12-31 | 2019-12-31 | Symmetrical thermoelectric MEMS microwave standing wave meter and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111044796A CN111044796A (en) | 2020-04-21 |
| CN111044796B true CN111044796B (en) | 2022-03-29 |
Family
ID=70242672
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911412946.8A Active CN111044796B (en) | 2019-12-31 | 2019-12-31 | Symmetrical thermoelectric MEMS microwave standing wave meter and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111044796B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1925348A (en) * | 2006-10-10 | 2007-03-07 | 华为技术有限公司 | Standing-wave ratio detecting method and device |
| CN102375090A (en) * | 2011-09-22 | 2012-03-14 | 东南大学 | Micromechanical cantilever beam switch online microwave power detector and manufacturing method thereof |
| CN102435837A (en) * | 2011-09-22 | 2012-05-02 | 东南大学 | Online detector for micro electro mechanical system (MEMS) coupling degree-reconfigurable microwave power and preparation method thereof |
| JP2012220407A (en) * | 2011-04-12 | 2012-11-12 | Yokogawa Electric Corp | Magnetic measuring device |
| CN103531909A (en) * | 2013-10-16 | 2014-01-22 | 北京理工大学 | Terahertz frequency-scanning H-plane sectoral horn antenna and preparation method thereof under bulk silicon MEMS (micro-electromechanical system) process |
| CN103777066A (en) * | 2014-01-03 | 2014-05-07 | 南京邮电大学 | Microelectronic mechanical dual channel microwave power detection system and preparation method thereof |
| CN104467988A (en) * | 2014-12-15 | 2015-03-25 | 天津七一二通信广播有限公司 | Portable standing-wave meter applied to wireless transmitting radio station |
| CN104868868A (en) * | 2015-04-28 | 2015-08-26 | 中国电子科技集团公司第五十五研究所 | Micro-electromechanical system (MEMS) stepping type digital attenuator |
| CN107611541A (en) * | 2017-08-28 | 2018-01-19 | 北京理工大学 | Terahertz waveguide duplexer based on bulk silicon MEMS technique and preparation method thereof |
| CN109932561A (en) * | 2019-03-27 | 2019-06-25 | 南京邮电大学 | Microwave power detector based on compound arched girder |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7382213B2 (en) * | 2005-01-28 | 2008-06-03 | Northrop Grumman Corporation | Monolithically integrated switchable circuits with MEMS |
-
2019
- 2019-12-31 CN CN201911412946.8A patent/CN111044796B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1925348A (en) * | 2006-10-10 | 2007-03-07 | 华为技术有限公司 | Standing-wave ratio detecting method and device |
| JP2012220407A (en) * | 2011-04-12 | 2012-11-12 | Yokogawa Electric Corp | Magnetic measuring device |
| CN102375090A (en) * | 2011-09-22 | 2012-03-14 | 东南大学 | Micromechanical cantilever beam switch online microwave power detector and manufacturing method thereof |
| CN102435837A (en) * | 2011-09-22 | 2012-05-02 | 东南大学 | Online detector for micro electro mechanical system (MEMS) coupling degree-reconfigurable microwave power and preparation method thereof |
| CN103531909A (en) * | 2013-10-16 | 2014-01-22 | 北京理工大学 | Terahertz frequency-scanning H-plane sectoral horn antenna and preparation method thereof under bulk silicon MEMS (micro-electromechanical system) process |
| CN103777066A (en) * | 2014-01-03 | 2014-05-07 | 南京邮电大学 | Microelectronic mechanical dual channel microwave power detection system and preparation method thereof |
| CN104467988A (en) * | 2014-12-15 | 2015-03-25 | 天津七一二通信广播有限公司 | Portable standing-wave meter applied to wireless transmitting radio station |
| CN104868868A (en) * | 2015-04-28 | 2015-08-26 | 中国电子科技集团公司第五十五研究所 | Micro-electromechanical system (MEMS) stepping type digital attenuator |
| CN107611541A (en) * | 2017-08-28 | 2018-01-19 | 北京理工大学 | Terahertz waveguide duplexer based on bulk silicon MEMS technique and preparation method thereof |
| CN109932561A (en) * | 2019-03-27 | 2019-06-25 | 南京邮电大学 | Microwave power detector based on compound arched girder |
Non-Patent Citations (2)
| Title |
|---|
| Broadband RF Adaptive Antenna with Automatic SWR Control by using MEMS-RF Technology and Microcontroller Process;N. Nistor 等;《IEEE 24thInternational Symposium for Design and Technology in Electronic Packaging》;20181231;第335-338页 * |
| 一种新型的在线式微波功率传感器;韩磊 等;《半导体学报》;20070731;第28卷(第7期);第1145-1148页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111044796A (en) | 2020-04-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102360039B (en) | Five-port micromachine cantilever-based capacitance type microwave power sensor and manufacturing method thereof | |
| CN102243268B (en) | Micro-electro-mechanical directional coupling microwave power sensor and preparation method thereof | |
| CN102323475B (en) | Three-channel micromechanical clamped beam indirect microwave power sensor and preparation method | |
| CN102385001A (en) | Three-channel micro-mechanical cantilever beam indirect-type microwave power sensor and preparation method | |
| CN111044799B (en) | MEMS microwave standing wave meter based on thermoelectric and capacitive dual-channel online detection | |
| Dehe et al. | Broadband thermoelectric microwave power sensors using GaAs foundry process | |
| Han et al. | A micromachined inline-type wideband microwave power sensor based on GaAs MMIC technology | |
| CN102411086B (en) | Five-port capacitance type microwave power sensor based on micro mechanical clamped beam | |
| CN111044800B (en) | State-controllable symmetrical thermoelectric MEMS microwave standing wave meter and preparation method | |
| CN111044798B (en) | MEMS microwave power sensor capable of realizing online self-detection and preparation method thereof | |
| CN111044796B (en) | Symmetrical thermoelectric MEMS microwave standing wave meter and preparation method thereof | |
| CN111273089B (en) | Symmetrical MEMS directional microwave power coupler with online self-detection function | |
| CN111044797B (en) | MEMS integrated microwave standing wave meter capable of tuning frequency state and preparation method thereof | |
| CN102338825A (en) | 120-degree three-channel micro electro mechanical microwave power sensor and preparation method thereof | |
| CN102411087B (en) | 90-degree angle four-input micro electromechanical microwave power sensor and preparation method thereof | |
| CN102411088B (en) | Four-input micromechanical clamped beam thermoelectric microwave power sensor and preparation method thereof | |
| CN1128366C (en) | Microbridge structured thermalcouple type microwave power sensor | |
| CN106645920B (en) | Clamped beam T junction indirect heating type microwave signal detector | |
| Zhang et al. | A Novel Inline Near-Zero Thermopile RF MEMS Power Sensor | |
| CN102645579B (en) | Four-input micro mechanical cantilever beam thermoelectric microwave power sensor and preparation method | |
| KR20000014835A (en) | Millimeter wave sensing apparatus and fabricating method of sensing sensor | |
| CN115327236A (en) | Reconfigurable frequency MEMS standing wave meter based on multi-port annular junction and preparation method | |
| CN106802370B (en) | Silicon substrate unknown frequency slot-coupled formula indirect type millimeter wave phase detectors | |
| CN106841788B (en) | The online given frequency microwave phase detector device of clamped beam T junction indirect heating | |
| CN106872796B (en) | The indirect type millimeter-wave signal detector of silicon substrate slot-coupled formula |
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 |