CN117792323B - Impedance matching circuit and radio frequency power supply device - Google Patents

Abstract

The application provides an impedance matching circuit and radio frequency power supply equipment, wherein the impedance matching circuit is provided with a detection node which is selectively connected with a radio frequency power supply, and the impedance matching circuit also comprises an impedance matching unit, a capacitance value detection unit and a voltage value acquisition unit; the impedance matching unit comprises a first matching capacitor connected with the detection node; the capacitance value detection unit comprises a detection capacitance module and a detection power supply, one end of the detection capacitance module is connected with the detection power supply, and the other end of the detection capacitance module is selectively connected with the detection node; the impedance matching circuit has a self-checking state, in the self-checking state, the detection node is disconnected with the radio frequency power supply, the detection capacitor module is connected with the detection node, the detection power supply outputs detection voltage, the voltage value acquisition unit acquires the voltage value of the detection node, and the capacitance value of the detection capacitor module, the detection voltage of the detection power supply and the voltage value of the detection node are used for calculating to obtain the capacitance value of the first matching capacitor. The application can detect the capacitance value of the capacitor device.

Description

Impedance matching circuit and radio frequency power supply device

Technical Field

The present application relates to the field of radio frequency technologies, and in particular, to an impedance matching circuit and a radio frequency power supply device having the same.

Background

Currently, with the popularization of Radio Frequency (RF) technology, RF power supplies are increasingly used in various fields. When the radio frequency power supply is used for outputting a load, the impedance matching of the radio frequency power supply and the load is indispensable, and when the radio frequency power supply is matched with the load impedance, the occurrence of reflected power can be effectively reduced, and a better output effect is obtained.

However, when the impedance matching circuit is used for impedance matching between the rf power supply and the load, the capacitance value of the capacitor in the impedance matching circuit cannot be known, and it is difficult to accurately detect the capacitance value of the capacitor in the impedance matching circuit, so that the impedance matching circuit cannot perform relatively accurate impedance matching between the rf power supply and the load, and therefore, how to detect the capacitance value of the capacitor in the impedance matching circuit before the impedance matching circuit performs impedance matching between the rf power supply and the load becomes a problem to be considered.

Disclosure of Invention

The application provides an impedance matching circuit and radio frequency power supply equipment, which can detect the capacitance value of a capacitor device in the impedance matching circuit.

In a first aspect, an impedance matching circuit is provided, the impedance matching circuit is used for performing impedance matching on a radio frequency power supply and a load, the impedance matching circuit is provided with a detection node, and the impedance matching circuit further comprises an impedance matching unit, a capacitance value detection unit and a voltage value acquisition unit; the impedance matching unit at least comprises a first matching capacitor, and the first matching capacitor is connected with the detection node; the capacitance value detection unit comprises a detection capacitance module and a detection power supply, wherein the detection capacitance module is provided with a capacitance value, the detection power supply comprises an output end for outputting a detection voltage, one end of the detection capacitance module is connected with the output end of the detection power supply, and the other end of the detection capacitance module is selectively connected with the detection node; the voltage value acquisition unit is at least used for acquiring the voltage value of the detection node; wherein the detection node is selectively connected with the radio frequency power supply; the impedance matching circuit is provided with a self-checking state, the detection node is disconnected with the radio frequency power supply in the self-checking state, the detection capacitor module is connected with the detection node to form a detection loop comprising the detection power supply, the detection capacitor module and the first matching capacitor, the detection power supply outputs detection voltage and transmits the detection voltage to the detection node through the detection capacitor module, and the voltage value acquisition unit acquires the voltage value of the detection node, wherein the capacitance value of the detection capacitor module, the detection voltage of the detection power supply and the voltage value of the detection node are used for calculating and obtaining the capacitance value of the first matching capacitor.

In a possible implementation manner, the impedance matching circuit further has an operating state, in which the detection node is connected to the radio frequency power supply, the detection capacitor module is disconnected from the detection node, and the impedance matching circuit performs impedance matching on the radio frequency power supply and the load at least through the first matching capacitor of the impedance matching unit.

In a possible implementation manner, the first matching capacitor is an adjustable capacitor with a first capacitance value range, and the impedance matching circuit further comprises a first adjusting unit, wherein the first adjusting unit is matched with the first matching capacitor and used for adjusting the capacitance value of the first matching capacitor; in the self-checking state, the first adjusting unit adjusts the first matching capacitor at least once, and the calculated capacitance value of the first matching capacitor comprises the capacitance value of the first matching capacitor before adjustment and the capacitance value of the first matching capacitor after each adjustment; after the first adjusting unit adjusts the first matching capacitor at least once, when the capacitance value of the first matching capacitor obtained by current calculation is equal to the maximum value and the minimum value of a first capacitance value range, the adjustment amount of the first adjusting unit before adjustment, and the accumulated adjustment amount of the first adjusting unit respectively adjusted to the maximum value and the minimum value of the first capacitance value range are used for correspondingly obtaining a first adjustment amount range of the first adjusting unit; or after the first adjusting unit adjusts the first matching capacitor at least once, calculating to obtain a capacitance change value of the first matching capacitor before and after adjustment, so as to calculate a first adjustment amount range of the first adjusting unit through the capacitance value of the first matching capacitor before adjustment, the adjustment amount of the first adjusting unit before adjustment, the single adjustment amount of the first adjusting unit, the capacitance change value of the first matching capacitor and a first capacitance value range; in the working state, the first adjusting unit adjusts the capacitance value of the first matching capacitor in a first adjusting quantity range so as to match the radio frequency power supply with the load impedance.

In a possible implementation manner, the impedance matching circuit further includes a control unit and a switch unit, where the switch unit is at least used to connect or disconnect the connection between the detection node and the radio frequency power supply, and connect or disconnect the connection between the other end of the detection capacitor module and the detection node, and the control unit is at least used to control the switch unit to connect or disconnect the connection between the detection node and the radio frequency power supply, and control the switch unit to connect or disconnect the connection between the other end of the detection capacitor module and the detection node; when the self-checking state is adopted, the control unit controls the switch unit to disconnect the connection between the detection node and the radio frequency power supply, and to conduct the connection between the other end of the detection capacitor module and the detection node, and controls the detection power supply to output detection voltage, and receives the voltage value of the detection node output by the voltage value acquisition unit, so that the capacitance value of the first matching capacitor is calculated according to the capacitance value of the detection capacitor module, the detection voltage value of the detection power supply and the voltage value of the detection node; in the working state, the control unit controls the switch unit to conduct connection between the detection node and the radio frequency power supply, and disconnect connection between the other end of the detection capacitor module and the detection node, and impedance matching is performed on the radio frequency power supply and the load at least through the first matching capacitor of the impedance matching unit.

In a possible implementation manner, the first matching capacitor is connected between the detection node and ground, and the switch unit comprises a first switch and a second switch; the first switch is connected between the radio frequency power supply and the detection node, and is connected or disconnected so that the detection node is connected or disconnected with the radio frequency power supply; the second switch is connected between the other end of the detection capacitor module and the detection node, and is turned on or turned off so that the other end of the detection capacitor module is connected with or disconnected from the detection node; in the self-checking state, the first switch is disconnected, the second switch is connected, and the first matching capacitor is connected with the detection capacitor module in parallel so as to calculate and obtain the capacitance value of the first matching capacitor; in the working state, the second switch is disconnected, the first switch is connected, and the first matching capacitor performs impedance matching on the radio frequency power supply and the load.

In a possible implementation manner, the first matching capacitor is connected between the radio frequency power supply and the detection node, the switch unit comprises a first switch, a second switch and a third switch, and the impedance matching circuit further comprises a shielding node, and the shielding node is arranged between the radio frequency power supply and the first matching capacitor; the first switch is connected between the radio frequency power supply and the shielding node, and is connected or disconnected so that the shielding node is connected or disconnected with the radio frequency power supply; the second switch is connected between the shielding node and the ground, the first matching capacitor is connected with the ground through the second switch, and the second switch is turned on or off so that the first matching capacitor is connected with the ground or disconnected; the third switch is connected between the other end of the detection capacitor module and the detection node, and is turned on or turned off so that the other end of the detection capacitor module is connected with or disconnected from the detection node; in the self-checking state, the first switch is disconnected, the second switch and the third switch are connected, and the first matching capacitor is connected with the detection capacitor module in parallel so as to calculate and obtain the capacitance value of the first matching capacitor; in the working state, the second switch and the third switch are disconnected, the first switch is connected, and the first matching capacitor performs impedance matching on the radio frequency power supply and the load.

In a possible implementation manner, the first matching capacitor is selectively connected with the detection node, and the impedance matching unit further comprises a second matching capacitor, and the second matching capacitor is selectively connected with the detection node; before the capacitance value of the first matching capacitor is calculated or after the first adjustment amount range of the first adjustment unit is calculated in the self-checking state, the first matching capacitor is disconnected from the detection node, the second matching capacitor is connected with the detection node, the detection node is disconnected from the radio frequency power supply, the detection capacitor module is connected with the detection node to form a detection loop comprising the detection power supply, the detection capacitor module and the second matching capacitor, the detection power supply outputs detection voltage, and the voltage value of the detection node is obtained through the voltage value obtaining unit, wherein the capacitance value of the detection capacitor module, the detection voltage of the detection power supply and the voltage value of the detection node are used for calculating the capacitance value of the second matching capacitor; in the working state, the first matching capacitor and the second matching capacitor are used for matching to carry out impedance matching on the radio frequency power supply and the load.

In a possible implementation manner, the second matching capacitor is an adjustable capacitor with a second capacitance value range, and the impedance matching circuit further comprises a second adjusting unit, wherein the second adjusting unit is matched with the second matching capacitor and used for adjusting the capacitance value of the second matching capacitor; in the self-checking state, the second adjusting unit adjusts the second matching capacitor at least once, and the calculated capacitance value of the second matching capacitor comprises the capacitance value of the second matching capacitor before adjustment and the capacitance value of the second matching capacitor after each adjustment; after the second adjusting unit adjusts the second matching capacitor at least once, when the capacitance value of the second matching capacitor obtained by current calculation is equal to the maximum value and the minimum value of the second capacitance value range, the adjustment amount of the second adjusting unit before adjustment, and the accumulated adjustment amount of the second adjusting unit respectively adjusted to the maximum value and the minimum value of the first capacitance value range are used for correspondingly obtaining the second adjustment amount range of the second adjusting unit; or after the second adjusting unit adjusts the second matching capacitance at least once, calculating to obtain a capacitance change value of the second matching capacitance after adjustment and before adjustment, so as to calculate a second adjustment amount range of the second adjusting unit through the capacitance value of the second matching capacitance before adjustment, the adjustment amount of the second adjusting unit before adjustment, the single adjustment amount of the second adjusting unit, the capacitance change value of the second matching capacitance and a second capacitance value range; in the working state, the first adjusting unit is used for adjusting the capacitance value of the first matching capacitor in a first adjusting quantity range, the second adjusting unit is used for adjusting the capacitance value of the second matching capacitor in a second adjusting quantity range, and the first matching capacitor is matched with the second matching capacitor so that the radio frequency power supply is matched with the load impedance.

In one possible implementation manner, the first adjusting unit and the second adjusting unit are both stepper motors, the output shaft of the first adjusting unit is correspondingly connected with one of the plates of the first matching capacitor, the output shaft of the second adjusting unit is correspondingly connected with one of the plates of the second matching capacitor, the first adjusting unit and the second adjusting unit are used for receiving pulse signals, and the output shaft of the first adjusting unit and the output shaft of the second adjusting unit correspondingly rotate a first angle and a second angle according to the received pulse signals respectively so as to correspondingly change the positions of the plates in the connected first matching capacitor and second matching capacitor, and change the distance between the two plates of the first matching capacitor and the distance between the two plates of the second matching capacitor, thereby correspondingly adjusting the capacitance values of the first matching capacitor and the second matching capacitor; the single-rotation angle of the first adjusting unit and the second adjusting unit is the single-rotation adjustment amount of the first adjusting unit and the second adjusting unit, and the rotatable first angle range of the first adjusting unit and the rotatable second angle range of the second adjusting unit are the first adjustment amount range of the first adjusting unit and the second adjustment amount range of the second adjusting unit respectively.

In a possible implementation manner, the impedance matching circuit further includes a control unit and a switch unit, where the switch unit is at least used to connect or disconnect the connection between the detection node and the radio frequency power supply, and connect or disconnect the connection between the other end of the detection capacitor module and the detection node, and connect or disconnect the connection between the first matching capacitor or the second matching capacitor and the detection node, and the control unit is at least used to control the switch unit to connect or disconnect the connection between the detection node and the radio frequency power supply, and control the switch unit to connect or disconnect the connection between the other end of the detection capacitor module and the detection node, and control the switch unit to connect or disconnect the connection between the first matching capacitor or the second matching capacitor and the detection node; when the self-checking state is adopted, the control unit controls the switch unit to disconnect the connection between the detection node and the radio frequency power supply, and to conduct the connection between the other end of the detection capacitor module and the detection node, and to conduct the connection between the first matching capacitor or the second matching capacitor and the detection node, and to control the detection power supply to output detection voltage, and to receive the voltage value of the detection node output by the voltage value acquisition unit, so as to calculate the capacitance value of the first matching capacitor or the second matching capacitor according to the capacitance value of the detection capacitor module, the detection voltage value of the detection power supply and the voltage value of the detection node, and then to control the switch unit to conduct the connection between the second matching capacitor or the first matching capacitor and the detection node, and to control the detection power supply to output detection voltage, and to receive the voltage value of the detection node output by the voltage value acquisition unit, so as to calculate the capacitance value of the first matching capacitor or the second matching capacitor according to the capacitance value of the detection capacitor module, the detection voltage value of the detection power supply and the voltage value of the detection node; in the working state, the control unit controls the switch unit to conduct connection between the detection node and the radio frequency power supply, disconnect connection between the other end of the detection capacitor module and the detection node, conduct connection between the first matching capacitor and the second matching capacitor and the detection node, and conduct impedance matching on the radio frequency power supply and the load through the first matching capacitor and the second matching capacitor of the impedance matching unit.

In one possible implementation manner, one of the first matching capacitor and the second matching capacitor is connected between the radio frequency power supply and the detection node, the other of the first matching capacitor and the second matching capacitor is connected between the detection node and the ground, the switch unit comprises a first switch, a second switch, a third switch and a fourth switch, the impedance matching circuit further comprises a shielding node, and the shielding node is arranged between the radio frequency power supply and the first matching capacitor; the first switch is connected between the radio frequency power supply and the shielding node, and is connected or disconnected so that the shielding node is connected or disconnected with the radio frequency power supply; the second switch is connected between the shielding node and the ground, connected with a first matching capacitor or a second matching capacitor between the radio frequency power supply and the detection node and connected with the ground through the second switch, and the second switch is turned on or turned off so that the first matching capacitor or the second matching capacitor is connected with the ground or disconnected; the third switch is connected between the other end of the detection capacitor module and the detection node, and is turned on or turned off so that the other end of the detection capacitor module is connected with or disconnected from the detection node; the fourth switch is connected in series between the detection node and the ground with the first matching capacitor or the second matching capacitor connected between the detection node and the ground, and the fourth switch is turned on or turned off so that the first matching capacitor or the second matching capacitor is connected or disconnected with the detection node; in the self-checking state, the first switch and the fourth switch are disconnected, the second switch and the third switch are connected, the first matching capacitor or the second matching capacitor is connected with the detection capacitor module in parallel to calculate the capacitance value of the first matching capacitor or the second matching capacitor, then the second switch is disconnected, the fourth switch is connected, and the second matching capacitor or the first matching capacitor is connected with the detection capacitor module in parallel to calculate the capacitance value of the second matching capacitor or the first matching capacitor; or in the self-checking state, the first switch and the second switch are turned off, the third switch and the fourth switch are turned on, the second matching capacitor or the first matching capacitor is connected with the detection capacitor module in parallel to calculate the capacitance value of the second matching capacitor or the first matching capacitor, then the fourth switch is turned off, the second switch is turned on, and the first matching capacitor or the second matching capacitor is connected with the detection capacitor module in parallel to calculate the capacitance value of the first matching capacitor or the second matching capacitor; in the working state, the second switch and the third switch are disconnected, the first switch and the fourth switch are connected, and the first matching capacitor and the second matching capacitor are matched to perform impedance matching on the radio frequency power supply and the load.

In a possible implementation manner, the detected voltage output by the detected power supply is an ac voltage, the frequency of the ac voltage output by the detected power supply is the same as the working frequency of the radio frequency power supply, the voltage value acquisition unit includes a first acquisition module and a second acquisition module, the first acquisition module is used for acquiring an average detected voltage of the ac voltage output by the detected power supply, and the second acquisition module is used for acquiring an average voltage value of the detection node; in the self-checking state, the capacitance value of the detection capacitor module, the average detection voltage of the detection power supply and the average voltage value of the detection node are used for calculating and obtaining the capacitance value of the first matching capacitor.

In a second aspect, there is also provided a radio frequency power supply device, the radio frequency power supply device including an impedance matching circuit, a radio frequency power supply, and a radio frequency output terminal, the impedance matching circuit being connected between the radio frequency power supply and the radio frequency output terminal, the radio frequency output terminal being used for connecting a load. The impedance matching circuit is used for carrying out impedance matching on the radio frequency power supply and the load, the impedance matching circuit is provided with a detection node, and the impedance matching circuit further comprises an impedance matching unit, a capacitance value detection unit and a voltage value acquisition unit; the impedance matching unit at least comprises a first matching capacitor, and the first matching capacitor is connected with the detection node; the capacitance value detection unit comprises a detection capacitance module and a detection power supply, wherein the detection capacitance module is provided with a capacitance value, the detection power supply comprises an output end for outputting a detection voltage, one end of the detection capacitance module is connected with the output end of the detection power supply, and the other end of the detection capacitance module is selectively connected with the detection node; the voltage value acquisition unit is at least used for acquiring the voltage value of the detection node; wherein the detection node is selectively connected with the radio frequency power supply; the impedance matching circuit is provided with a self-checking state, the detection node is disconnected with the radio frequency power supply in the self-checking state, the detection capacitor module is connected with the detection node to form a detection loop comprising the detection power supply, the detection capacitor module and the first matching capacitor, the detection power supply outputs detection voltage and transmits the detection voltage to the detection node through the detection capacitor module, and the voltage value acquisition unit acquires the voltage value of the detection node, wherein the capacitance value of the detection capacitor module, the detection voltage of the detection power supply and the voltage value of the detection node are used for calculating and obtaining the capacitance value of the first matching capacitor.

According to the impedance matching circuit and the radio frequency power supply equipment, the capacitance value detection unit comprising the detection capacitor module and the detection power supply and the voltage value acquisition unit are arranged, the other end of the detection capacitor module is configured to be selectively connected with the detection node, the detection node is selectively connected with the radio frequency power supply, the detection node is disconnected with the radio frequency power supply when the impedance matching circuit is in a self-checking state, the detection capacitor module is connected with the detection node to form a detection loop comprising the detection power supply, the detection capacitor module and the first matching capacitor, the detection power supply outputs detection voltage, the voltage value acquisition unit acquires the voltage value of the detection node, and the capacitance value of the first matching capacitor can be calculated according to the capacitance value of the detection capacitor module, the detection voltage of the detection power supply and the voltage value of the detection node, so that the requirement of the capacitance value of the first matching capacitor in the impedance matching circuit is met.

Drawings

In order to more clearly describe the embodiments of the present application or the technical solutions in the background art, the following description will describe the drawings that are required to be used in the embodiments of the present application or the background art.

Fig. 1 is a schematic circuit diagram of an impedance matching circuit according to an embodiment of the application.

Fig. 2 is a circuit diagram of an impedance matching circuit according to another embodiment of the present application.

Fig. 3 is a schematic circuit diagram of an impedance matching circuit according to an embodiment of the application, which further includes a control unit and a switch unit.

Fig. 4 is a schematic circuit diagram of an impedance matching circuit according to another embodiment of the present application, which further includes a control unit and a switch unit.

Fig. 5 is a circuit diagram of an impedance matching circuit according to another embodiment of the present application.

Fig. 6 is a schematic circuit diagram of an impedance matching circuit according to another embodiment of the present application, which further includes a control unit and a switch unit.

Fig. 7 is a schematic block diagram of a voltage value acquisition unit in an embodiment of the application.

Fig. 8 is a schematic block diagram of a radio frequency power supply device in an embodiment of the application.

Fig. 9 is a schematic circuit diagram of a rf power supply device according to an embodiment of the application.

Reference numerals illustrate: 1. the radio frequency power supply device comprises a radio frequency power supply device 10, an impedance matching circuit, A, a detection node, B, a shielding node, 100, an impedance matching unit, C1, a first matching capacitor, C2, a second matching capacitor, L1, a matching inductor, M1, a first adjusting unit, 110, an output shaft of the first adjusting unit, M2, a second adjusting unit, 120, an output shaft of the second adjusting unit, 200, a capacitance value detection unit, 210, a detection capacitor module, C3, a detection capacitor, 211, one end of the detection capacitor module, 212, the other end of the detection capacitor module, 220, a detection power supply, 221, an output end of the detection power supply, 300, a voltage value acquisition unit, 310, a first acquisition module, 320, a second acquisition module, 400, a control unit, 500, a switch unit, S1, a first switch, S2, a second switch, S3, a third switch, S4, a fourth switch, 20, a radio frequency power supply, 21, a radio frequency output end, 30, a load, GND and ground.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without any inventive effort, are intended to be within the scope of the application.

In the description of the embodiments of the present application, it should be noted that the directions or positional relationships indicated by the terms "front", "rear", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present application and simplifying the description, and do not imply or indicate that the apparatus or element to be referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

In describing embodiments of the present application, it should be noted that, unless explicitly stated and limited otherwise, the terms "coupled," "coupled," and "connected" should be construed broadly, and may be either fixedly coupled, detachably coupled, or integrally coupled, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

In the following, the terms "first", "second", "third", "fourth" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", "a third" and a fourth "may explicitly or implicitly include one or more such feature. In the description of the embodiments of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more.

Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or server that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed or inherent to such process, method, article, or apparatus, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Referring to fig. 1 and fig. 2 together, fig. 1 is a circuit diagram of an impedance matching circuit according to an embodiment of the application, and fig. 2 is a circuit diagram of an impedance matching circuit according to another embodiment of the application. As shown in fig. 1 and 2, the present application provides an impedance matching circuit 10, where the impedance matching circuit 10 is configured to perform impedance matching on a radio frequency power supply 20 and a load 30, the impedance matching circuit 10 has a detection node a, and the impedance matching circuit 10 further includes an impedance matching unit 100, a capacitance value detection unit 200, and a voltage value acquisition unit 300; the impedance matching unit 100 at least comprises a first matching capacitor C1, and the first matching capacitor C1 is connected with the detection node a; the capacitance value detecting unit 200 includes a detecting capacitor module 210 and a detecting power supply 220, the detecting capacitor module 210 has a capacitance value, the detecting power supply 220 includes an output end for outputting a detecting voltage, one end 211 of the detecting capacitor module is connected to an output end 221 of the detecting power supply, and the other end 212 of the detecting capacitor module is selectively connected to the detecting node a; the voltage value obtaining unit 300 is at least configured to obtain a voltage value of the detection node a; wherein the detection node a is selectively connected to the rf power source 20; the impedance matching circuit 10 has a self-checking state, in which the detection node a is disconnected from the rf power supply 20, the detection capacitor module 210 is connected to the detection node a to form a detection loop including the detection power supply 220, the detection capacitor module 210, and the first matching capacitor C1, the detection power supply 220 outputs a detection voltage and transmits the detection voltage to the detection node a through the detection capacitor module 210, and the voltage value obtaining unit 300 obtains a voltage value of the detection node a, where the capacitance value of the detection capacitor module 210, the detection voltage of the detection power supply 220, and the voltage value of the detection node a are used to calculate the capacitance value of the first matching capacitor C1.

Thus, in the impedance matching circuit 10 of the present application, by providing the capacitance value detecting unit 200 and the voltage value acquiring unit 300 including the detecting capacitor module 210 and the detecting power supply 220, and configuring the other end 212 of the detecting capacitor module to be selectively connected to the detecting node a, the detecting node a is selectively connected to the radio frequency power supply 20, so that the detecting node a is disconnected from the radio frequency power supply 20 in the self-checking state of the impedance matching circuit 10, the detecting capacitor module 210 is connected to the detecting node a, and a detecting loop including the detecting power supply 220, the detecting capacitor module 210 and the first matching capacitor C1 is formed, the detecting power supply 220 outputs a detecting voltage, and the voltage value acquiring unit 300 acquires the voltage value of the detecting node a, and can calculate the capacitance value of the first matching capacitor C1 according to the capacitance value of the detecting capacitor module 210, the detecting voltage of the detecting power supply 220 and the voltage value of the detecting node a, so as to meet the requirement of the capacitance value of the first matching capacitor C1 in the detecting impedance matching circuit 10.

Specifically, when the detection node a is disconnected from the rf power source 20 and the detection capacitor module 210 is connected to the detection node a, a detection loop including the detection power source 220, the detection capacitor module 210, and the first matching capacitor C1 is formed, and the detection capacitor module 210 is connected in parallel to the first matching capacitor C1. According to the capacitance parallel voltage division formula, the charge amount of the parallel detection capacitor module 210 is equal to the charge amount of the first matching capacitor C1, and the charge amount is the product of the capacitance value and the voltage value, so that the capacitance value of the first matching capacitor C1 also satisfies the following relational expression:

Vs×cm1/(cm1+cs) =v0, where Cs is the capacitance value of the detection capacitor module 210, vs is the detection voltage of the detection power supply 220, V0 is the voltage value of the detection node a, and Cm1 is the capacitance value of the first matching capacitor C1.

In particular, as shown in fig. 1 and 2, the disconnection or connection of the detection node a and the rf power supply 20 means that the detection node a is disconnected or connected to the positive electrode of the rf power supply 20, and the negative electrode of the rf power supply 20 is grounded GND.

Thus, the capacitance value of the first matching capacitor C1 can be calculated according to the capacitance value of the detection capacitor module 210, the detection voltage of the detection power supply 220, the voltage value of the detection node a, and the above-mentioned relational expression.

In one or more embodiments, the first matching capacitor C1 may be a fixed capacitor or an adjustable capacitor, which is not limited in this disclosure, and may be selected according to specific needs.

Specifically, when the first matching capacitor C1 is a fixed capacitor, the fixed capacitance of the first matching capacitor C1 can be calculated according to the capacitance value of the detection capacitor module 210, the detection voltage of the detection power supply 220, and the voltage value of the detection node a, and according to the fixed capacitance value of the first matching capacitor C1, an appropriate impedance matching circuit 10 including the first matching capacitor C1 is selected to perform impedance matching on the radio frequency power supply 20 and the load 30, that is, the fixed capacitance value of the first matching capacitor C1 can perform relatively accurate impedance matching on the radio frequency power supply 20 and the load 30, thereby reducing occurrence of reflected power and obtaining a better output effect. When the first matching capacitor C1 is an adjustable capacitor, only the first capacitance range of the first matching capacitor C1 can be known, but the current capacitance value of the first matching capacitor C1 cannot be determined, and according to the capacitance value of the detection capacitor module 210, the detection voltage of the detection power supply 220 and the voltage value of the detection node a, the current capacitance value of the first matching capacitor C1 can be calculated, and according to the current capacitance value of the first matching capacitor C1, the capacitance value of the first matching capacitor C1 is adjusted within the first capacitance value range, so that the impedance matching circuit 10 including the first matching capacitor C1 performs impedance matching on the radio frequency power supply 20 and the load 30, and not only can the radio frequency power supply 20 and the load 30 be subjected to relatively accurate impedance matching, thereby reducing the occurrence of reflected power, obtaining a better output effect, but also avoiding damage to the first matching capacitor C1 when the first matching capacitor C1 is optionally adjusted under the condition that the current capacitance value of the first matching capacitor C1 is unknown.

In one or more embodiments, the impedance matching unit 100 may further include other resistive devices such as inductors, capacitors, and the like, and resistive devices such as resistors, to better match the impedance of the rf power source 20 to the load 30.

In one or more embodiments, the detection capacitance module 210 may include at least one detection capacitance C3, one end of each detection capacitance C3 being connected to the output 221 of the detection power source, and the other end of each detection capacitance C3 being selectively in communication with the detection node a. For example, when the detection capacitor module 210 includes one detection capacitor C3 as shown in fig. 1 and 2, the capacitance value of the detection capacitor C3 may be set according to specific needs, and the capacitance value of the detection capacitor C3 is the capacitance value of the detection capacitor module 210. When the detection capacitor module 210 includes a plurality of detection capacitors C3, each detection capacitor C3 is connected in series or in parallel, the capacitance value of each detection capacitor C3 pair may be the same, the capacitance value of each detection capacitor C3 pair may also be different, and the capacitance value of the detection capacitor module 210 is the total capacitance value of the connected detection capacitors C3.

In one or more embodiments, the detection voltage output by the detection power supply 220 may be a direct current voltage or an alternating current voltage, and the magnitude of the detection voltage may be set according to specific needs.

In one or more embodiments, the voltage value obtaining unit 300 may be a voltmeter, other voltage detection devices such as a voltage sensor, or a voltage detection circuit composed of elements such as a resistor, a capacitor, and a diode, which is not limited to this, so long as the voltage value of the detection node a can be obtained.

It should be noted that the voltage value acquisition unit 300 may be connected to only the detection node a to acquire the voltage value of the detection node a. When no other device is provided between the detection node a and the load 30, the voltage value in the transmission path from the detection node a to the load 30 can be equal to the voltage value of the detection node a, that is, the voltage value obtaining unit 300 may be electrically connected to any point of the transmission path between the detection node a and the load 30, and obtain the voltage value of the detection node a by obtaining the voltage value in the transmission path from the detection node a to the load 30.

In one or more embodiments, the impedance matching circuit 10 further has an operating state in which the detection node a is connected to the rf power source 20, the detection capacitor module 210 is disconnected from the detection node a, and the impedance matching circuit 10 performs impedance matching on the rf power source 20 and the load 30 through at least the first matching capacitor C1 of the impedance matching unit 100.

Therefore, in the impedance matching circuit 10 of the present application, when the impedance matching circuit 10 is in the operating state, the detection node a is connected to the radio frequency power supply 20, the detection capacitor module 210 is disconnected from the detection node a, and the impedance matching circuit 10 can perform impedance matching on the radio frequency power supply 20 and the load 30 at least through the first matching capacitor C1 of the impedance matching unit 100, so that after the capacitance value of the first matching capacitor C1 is obtained by calculation, the radio frequency power supply 20 and the load 30 can be relatively accurately impedance-matched, thereby reducing the occurrence of reflected power and obtaining better output effect.

As shown in fig. 1 and 2, the first matching capacitor C1 is an adjustable capacitor having a first capacitance value range, and the impedance matching circuit 10 further includes a first adjusting unit M1, where the first adjusting unit M1 is matched with the first matching capacitor C1, and is used for adjusting the capacitance value of the first matching capacitor C1; in the self-checking state, the first adjusting unit M1 adjusts the first matching capacitor C1 at least once, and the calculated capacitance value of the first matching capacitor C1 includes the capacitance value of the first matching capacitor C1 before adjustment and the capacitance value of the first matching capacitor C1 after each adjustment; after the first adjusting unit M1 adjusts the first matching capacitor C1 at least once, when the capacitance value of the first matching capacitor C1 obtained by current calculation is equal to the maximum value and the minimum value of the first capacitance value range, the adjustment amount of the first adjusting unit M1 before adjustment, the cumulative adjustment amount of the first adjusting unit M1 respectively adjusted to the maximum value and the minimum value of the first capacitance value range, are used for correspondingly obtaining the first adjustment amount range of the first adjusting unit M1; or after the first adjusting unit M1 adjusts the first matching capacitor C1 at least once, calculating to obtain a capacitance change value of the first matching capacitor C1 before and after adjustment, so as to calculate a first adjustment amount range of the first adjusting unit M1 by the capacitance value of the first matching capacitor C1 before adjustment, the adjustment amount of the first adjusting unit M1 before adjustment, the single adjustment amount of the first adjusting unit M1, the capacitance change value of the first matching capacitor C1 and the first capacitance value range; in the operating state, the first adjusting unit M1 adjusts the capacitance value of the first matching capacitor C1 within the first adjustment amount range so that the radio frequency power supply 20 is impedance-matched with the load 30.

Therefore, in the impedance matching circuit 10 of the present application, when the first matching capacitor C1 is an adjustable capacitor having a first capacitance value range, by setting the first adjusting unit M1 to adjust the capacitance value of the first matching capacitor C1, the first adjusting unit M1 can adjust the first matching capacitor C1 at least once in the self-checking state of the impedance matching circuit 10, and when the capacitance value of the first matching capacitor C1 obtained by current calculation is equal to the maximum value and the minimum value of the first capacitance value range, the adjustment amount of the first adjusting unit M1 before adjustment and the cumulative adjustment amount of the first adjusting unit M1 respectively adjusted to the maximum value and the minimum value of the first capacitance value range are used to obtain the first adjustment amount range of the first adjusting unit M1 correspondingly; or after the first adjusting unit M1 adjusts the first matching capacitor C1 at least once, calculating to obtain a capacitance change value of the first matching capacitor C1 after and before adjustment, and according to the capacitance value of the first matching capacitor C1 before adjustment, the adjustment amount of the first adjusting unit M1 before adjustment, the single adjustment amount of the first adjusting unit M1, the capacitance change value of the first matching capacitor C1 and the first capacitance value range, calculating to obtain a first adjustment amount range of the first adjusting unit M1; in addition, when the impedance matching circuit 10 is in a working state, the first adjusting unit M1 is configured to adjust the capacitance value of the first matching capacitor C1 within the first adjusting range, so as to avoid damage to the first matching capacitor C1, and simultaneously, the radio frequency power supply 20 and the load 30 are impedance matched, thereby reducing the occurrence of reflected power and obtaining better output effect.

It should be noted that, when the first matching capacitor C1 is an adjustable capacitor having a first capacitance value range, when impedance matching is performed on the rf power supply 20 and the load 30, it is often necessary to correspondingly set the first adjusting unit M1 to adjust the capacitance value of the first matching capacitor C1, so that impedance matching is performed on the rf power supply 20 and the load 30, however, when the capacitance value of the first matching capacitor C1 before adjustment and the capacitance value of the first matching capacitor C1 after each adjustment cannot be determined, the capacitance value of the first matching capacitor C1 is adjusted, so that the first matching capacitor C1 is easily adjusted to be out of the first capacitance value range of the first matching capacitor C1, and further damage to the first matching capacitor C1 is caused, the first adjustment range of the first adjusting unit M1 is obtained by calculation, and the capacitance value of the first matching capacitor C1 is adjusted in the first adjustment range, so that damage to the first matching capacitor C1 is avoided, and the service life of the impedance matching circuit 10 including the first matching capacitor C1 is prolonged.

Specifically, for the embodiment in which the adjustment amount of the first adjustment unit M1 before adjustment, the integrated adjustment amount of the first adjustment unit M1 adjusted to the maximum value and the minimum value of the first capacitance value range, respectively, are used to correspondingly obtain the first adjustment amount range of the first adjustment unit M1, the adjustment amount of the first adjustment unit M1 before adjustment, the integrated adjustment amount of the first adjustment unit M1 adjusted to the maximum value and the minimum value of the first capacitance value range, respectively, and the first adjustment amount range of the first adjustment unit M1 satisfy the following relational expression:

D1+e1=h1, D1-f1=g1, where D1 is the adjustment amount of the first adjustment unit M1 before adjustment, E1, F1 are the cumulative adjustment amounts of the first adjustment unit M1 adjusted to the maximum value and the minimum value of the first capacitance value range, respectively, the first adjustment amount range of the first adjustment unit M1 is G1 to H1, G1 is the minimum adjustment amount of the first adjustment amount range, and H1 is the maximum adjustment amount of the first adjustment amount range.

In particular, when the capacitance value of the first matching capacitor C1 before the adjustment is the maximum value or the minimum value of the first capacitance value range, the adjustment amount of the first adjustment unit M1 before the adjustment is the minimum adjustment amount of the first adjustment amount range of the first adjustment unit M1, and the sum of the integrated adjustment amount of the first adjustment unit M1 adjusted to the minimum value or the maximum value of the first capacitance value range and the adjustment amount of the first adjustment unit M1 before the adjustment is the maximum adjustment amount of the first adjustment amount range of the first adjustment unit M1.

For example, the adjustment amount of the first adjustment unit M1 before adjustment is 1 cm, the cumulative adjustment amounts of the first adjustment unit M1 adjusted to the maximum value and the minimum value of the first capacitance value range are 4 cm and 1 cm, respectively, and the first adjustment amount range of the first adjustment unit M1 is 0 to 5 cm.

Therefore, according to the adjustment amount of the first adjustment unit M1 before adjustment, the cumulative adjustment amount of the first adjustment unit M1 adjusted to the maximum value and the minimum value of the first capacitance value range, and the above-mentioned relational expression, the first adjustment amount range of the first adjustment unit M1 can be calculated, and the calculation is relatively simple.

Specifically, for the embodiment in which the first adjustment amount range of the first adjustment unit M1 is calculated by the capacitance value of the first matching capacitance C1 before adjustment, the adjustment amount of the first adjustment unit M1 before adjustment, the single adjustment amount of the first adjustment unit M1, the capacitance variation value of the first matching capacitance C1, and the first capacitance value range, the capacitance value of the first matching capacitance C1 before adjustment, the adjustment amount of the first adjustment unit M1 before adjustment, the single adjustment amount of the first adjustment unit M1, the capacitance variation value of the first matching capacitance C1, the first capacitance value range of the first matching capacitance C1, and the first adjustment amount range of the first adjustment unit M1 satisfy the following relational expression:

D1+x1× (J1-Cb 1)/cc1=h1, d1+x1× (Cb 1-I1)/cc1=g1, wherein the capacitance value of the first matching capacitance C1 before adjustment is Cb1, D1 is the adjustment amount of the first adjustment unit M1 before adjustment, X1 is the single adjustment amount of the first adjustment unit M1, cc1 is the capacitance variation value of the first matching capacitance C1, the first capacitance value range of the first matching capacitance C1 is I1 to J1, I1 is the minimum value of the first capacitance value range, J1 is the maximum value of the first capacitance value range, the first adjustment amount range of the first adjustment unit M1 is G1 to H1, G1 is the minimum adjustment amount of the first adjustment amount range, and H1 is the maximum adjustment amount of the first adjustment amount range.

For example, the capacitance value of the first matching capacitor C1 before the adjustment is 3 picofarads (Picofarad, pF), the adjustment amount of the first adjustment unit M1 before the adjustment is 3 cm, the single adjustment amount of the first adjustment unit M1 is 1 cm, the capacitance variation value of the first matching capacitor C1 is 1pF, the first capacitance value range of the first matching capacitor C1 is 0 to 10pF, and the first adjustment amount range of the first adjustment unit M1 is 0 to 10 cm.

Thus, according to the capacitance value of the first matching capacitance C1 before adjustment, the adjustment amount of the first adjustment unit M1 before adjustment, the single adjustment amount of the first adjustment unit M1, the capacitance change value of the first matching capacitance C1, the first capacitance value range, and the above-described relational expression, the first adjustment amount range of the first adjustment unit M1 can be calculated, and only the capacitance value of the first matching capacitance C1 needs to be adjusted once.

Specifically, when the single adjustment amount of the first adjustment unit M1 is a fixed value, and the maximum adjustment amount and/or the minimum adjustment amount of the first adjustment amount range of the first adjustment unit M1 are calculated according to the above-mentioned relational expression, that is, when the capacitance value of the first matching capacitor C1 is adjusted once, the calculated capacitance value of the first matching capacitor C1 exceeds the first capacitance value range, the adjustable times of the first adjustment unit M1 to the maximum adjustment amount and the minimum adjustment amount respectively need to be calculated first, and then the first adjustment amount range of the first adjustment unit M1 is calculated according to the adjustment amount of the first adjustment unit M1 and the adjustable times of the first adjustment unit M1 to the maximum adjustment amount and the minimum adjustment amount respectively before adjustment, so that damage to the first matching capacitor C1 caused by exceeding the first capacitance value range of the first matching capacitor C1 can be further avoided.

For example, the capacitance value of the first matching capacitor C1 before the adjustment is 3.2pF, the adjustment amount of the first adjustment unit M1 before the adjustment is 3cm, the single adjustment amount of the first adjustment unit M1 is fixed to 1 cm, the capacitance change value of the first matching capacitor C1 is fixed to 1pF, the first capacitance value range of the first matching capacitor C1 is 0 to 10pF, the adjustable number of times of the first adjustment unit M1 is adjusted to the minimum adjustment amount is 3 times, the adjustable number of times of the first adjustment unit M1 is adjusted to the maximum adjustment amount is 6 times, and the first adjustment amount range of the first adjustment unit M1 is 0.2 to 9.2 cm instead of the calculated 0 to 10 cm.

Referring to fig. 3 and fig. 4 together, fig. 3 is a circuit schematic diagram of an impedance matching circuit according to an embodiment of the application, wherein the impedance matching circuit further includes a control unit and a switch unit, and fig. 4 is a circuit schematic diagram of the impedance matching circuit according to another embodiment of the application. As shown in fig. 3 and 4, the impedance matching circuit 10 further includes a control unit 400 and a switch unit 500, where the switch unit 500 is at least used to connect or disconnect the connection between the detection node a and the radio frequency power supply 20, and connect or disconnect the connection between the other end 212 of the detection capacitor module and the detection node a, and the control unit 400 is at least used to control the switch unit 500 to connect or disconnect the connection between the detection node a and the radio frequency power supply 20, and control the switch unit 500 to connect or disconnect the connection between the other end 212 of the detection capacitor module and the detection node a; in the self-checking state, the control unit 400 controls the switch unit 500 to disconnect the connection between the detection node a and the radio frequency power supply 20, and to connect the other end 212 of the detection capacitor module to the detection node a, and controls the detection power supply 220 to output a detection voltage, and receives the voltage value of the detection node a output by the voltage value obtaining unit 300, so as to calculate the capacitance value of the first matching capacitor C1 according to the capacitance value of the detection capacitor module 210, the detection voltage value of the detection power supply 220, and the voltage value of the detection node a; in the operating state, the control unit 400 controls the switching unit 500 to conduct the connection between the detection node a and the radio frequency power supply 20, and disconnect the connection between the other end 212 of the detection capacitor module and the detection node a, and perform impedance matching on the radio frequency power supply 20 and the load 30 at least through the first matching capacitor C1 of the impedance matching unit 100.

Thus, by providing the control unit 400 and the switch unit 500, the control unit 400 can be configured to control the switch unit 500 to disconnect the connection between the detection node a and the radio frequency power supply 20 and to connect the other end 212 of the detection capacitor module to the detection node a, and control the detection power supply 220 to output the detection voltage, and receive the voltage value of the detection node a output by the voltage value obtaining unit 300, so as to calculate the capacitance value of the first matching capacitor C1 according to the capacitance value of the detection capacitor module 210, the detection voltage value of the detection power supply 220, and the voltage value of the detection node a, and can control the switch unit 500 to connect the detection node a to the radio frequency power supply 20 and disconnect the connection between the other end 212 of the detection capacitor module and the detection node a in the operation state of the impedance matching circuit 10, so as to perform impedance matching on the radio frequency power supply 20 and the load 30 at least through the first matching capacitor C1 of the impedance matching unit 100.

In one or more embodiments, the control unit 400 calculates the capacitance value of the first matching capacitor C1 according to the capacitance value of the detection capacitor module 210, the detection voltage of the detection power supply 220, the voltage value of the detection node a, and the relational expression vs×cm1/(cm1+cs) =v0.

In one or more embodiments, the control unit 400 may be further configured to control the first adjusting unit M1 to adjust the capacitance value of the first matching capacitor C1, where after the first adjusting unit M1 adjusts the first matching capacitor C1 at least once, when the currently calculated capacitance value of the first matching capacitor C1 is equal to the maximum value and the minimum value of the first capacitance value range, the control unit 400 may be further configured to obtain the adjustment amount of the first adjusting unit M1 before the adjustment, and the cumulative adjustment amount of the first adjusting unit M1 adjusted to the maximum value and the minimum value of the first capacitance value range, respectively, so as to obtain the first adjustment amount range of the first adjusting unit M1 correspondingly; or after the first adjusting unit M1 adjusts the first matching capacitor C1 at least once, the control unit 400 may be further configured to calculate a capacitance change value of the first matching capacitor C1 after and before adjustment, and obtain a capacitance value of the first matching capacitor C1 before adjustment, an adjustment amount of the first adjusting unit M1 before adjustment, a single adjustment amount of the first adjusting unit M1, a capacitance change value of the first matching capacitor C1, and a first capacitance value range, so as to calculate a first adjustment amount range of the first adjusting unit M1; in the operating state, the control unit 400 is further configured to control the first adjusting unit M1 to adjust the capacitance value of the first matching capacitor C1 within the first adjustment range, so that the rf power source 20 is impedance-matched with the load 30.

Specifically, the control unit 400 may calculate the first adjustment amount range of the first adjustment unit M1 according to the adjustment amount of the first adjustment unit M1 before adjustment, the cumulative adjustment amounts of the first adjustment unit M1 adjusted to the maximum value and the minimum value of the first capacitance value range, and the relational expressions d1+e1=h1 and D1-f1=g1, where D1 is the adjustment amount of the first adjustment unit M1 before adjustment, E1 and F1 are the cumulative adjustment amounts of the first adjustment unit M1 adjusted to the maximum value and the minimum value of the first capacitance value range, respectively, the first adjustment amount range of the first adjustment unit M1 is G1 to H1, G1 is the minimum adjustment amount of the first adjustment amount range, and H1 is the maximum adjustment amount of the first adjustment amount range. The control unit 400 may calculate a first adjustment amount range of the first adjustment unit M1 according to a capacitance value of the first matching capacitance C1 before adjustment, an adjustment amount of the first adjustment unit M1 before adjustment, a single adjustment amount of the first adjustment unit M1, a capacitance variation value of the first matching capacitance C1, a first capacitance value range, and relational expressions d1+x1× (J1-Cb 1)/cc1=h1 and d1+x1× (Cb 1-I1)/cc1=g1, wherein the capacitance value of the first matching capacitance C1 before adjustment is Cb1, D1 is an adjustment amount of the first adjustment unit M1 before adjustment, X1 is a single adjustment amount of the first adjustment unit M1, cc1 is a capacitance variation value of the first matching capacitance C1, the first capacitance value range of the first matching capacitance C1 is a minimum value of the first capacitance value range, J1 is a maximum value of the first capacitance value range, the first adjustment unit M1 is a first adjustment amount range H1 to a maximum adjustment amount H1, and the first adjustment amount is a maximum adjustment amount H1.

In one or more embodiments, the switching unit 500 may include one or more switching devices, which is not limited by the present application, so long as the connection between the detection node a and the rf power source 20 and the connection between the other end 212 of the detection capacitor module and the detection node a can be turned on or off.

Please refer to fig. 1 and 3 again. As shown in fig. 1 and 3, in one or more embodiments, the first matching capacitor C1 is connected between the detection node a and the ground GND, and the switch unit 500 includes a first switch S1 and a second switch S2; the first switch S1 is connected between the rf power source 20 and the detection node a, and the first switch S1 is turned on or turned off, so that the detection node a is connected or disconnected with the rf power source 20; the second switch S2 is connected between the other end 212 of the detection capacitor module and the detection node a, and the second switch S2 is turned on or turned off, so that the other end 212 of the detection capacitor module is connected or disconnected with the detection node a; in the self-checking state, the first switch S1 is turned off, the second switch S2 is turned on, and the first matching capacitor C1 is connected in parallel with the detection capacitor module 210, so as to calculate and obtain a capacitance value of the first matching capacitor C1; in the operating state, the second switch S2 is turned off, the first switch S1 is turned on, and the first matching capacitor C1 performs impedance matching on the rf power supply 20 and the load 30.

Thus, in one or more embodiments, the first matching capacitor C1 may also be connected between the detection node a and the ground GND, and when the first matching capacitor C1 is connected between the detection node a and the ground GND, by providing the switching unit 500 including the first switch S1 connected between the rf power source 20 and the detection node a and the second switch S2 connected between the other end 212 of the detection capacitor module and the detection node a, only two switching devices can simply turn on or off the connection between the detection node a and the rf power source 20 and the connection between the other end 212 of the detection capacitor module and the detection node a.

In particular, the second switch S2 may be connected between the one end 211 of the detection capacitor module and the output end 221 of the detection power supply, and the second switch S2 may be turned on or turned off, so that the other end 212 of the detection capacitor module may be connected or disconnected with the detection node a.

Please refer to fig. 2 and fig. 4 again. As shown in fig. 2 and 4, in one or more embodiments, the first matching capacitor C1 is connected between the rf power supply 20 and the detection node a, the switch unit 500 includes a first switch S1, a second switch S2, and a third switch S3, and the impedance matching circuit 10 further includes a shielding node B, where the shielding node B is disposed between the rf power supply 20 and the first matching capacitor C1; the first switch S1 is connected between the rf power source 20 and the shielding node B, and the first switch S1 is turned on or turned off, so that the shielding node B is connected or disconnected with the rf power source 20, and the connection node a is connected or disconnected with the rf power source 20; the second switch S2 is connected between the shielding node B and the ground GND, the first matching capacitor C1 is connected to the ground GND through the second switch S2, and the second switch S2 is turned on or turned off, so that the first matching capacitor C1 is connected to or disconnected from the ground GND; the third switch S3 is connected between the other end 212 of the detection capacitor module and the detection node a, and the third switch S3 is turned on or turned off, so that the other end 212 of the detection capacitor module is connected or disconnected with the detection node a; in the self-checking state, the first switch S1 is turned off, the second switch S2 and the third switch S3 are turned on, and the first matching capacitor C1 is connected in parallel with the detection capacitor module 210, so as to calculate and obtain a capacitance value of the first matching capacitor C1; in the operating state, the second switch S2 and the third switch S3 are turned off, the first switch S1 is turned on, and the first matching capacitor C1 performs impedance matching on the rf power supply 20 and the load 30.

Thus, in one or more embodiments, the first matching capacitor C1 may also be connected between the rf power source 20 and the detection node a, when the first matching capacitor C1 is connected between the rf power source 20 and the detection node a, by providing the shielding node B, the influence of the rf power source 20 and other devices on the first matching capacitor C1 is avoided, and the switching unit 500 includes a first switch S1 connected between the rf power source 20 and the detection node a, a second switch S2 connected between the shielding node B and the ground GND, and a third switch S3 connected between the other end 212 of the detection capacitor module and the detection node a, three switching devices are required to be able to simply turn on or off the connection between the detection node a and the rf power source 20 and the connection between the other end 212 of the detection capacitor module and the detection node a.

In particular, the third switch S3 may be connected between the one end 211 of the detection capacitor module and the output end 221 of the detection power supply, and the third switch S3 may be turned on or turned off, so that the other end 212 of the detection capacitor module may be connected or disconnected with the detection node a.

In one or more embodiments, when the third switch S3 is connected between the one end 211 of the detection capacitor module and the output terminal 221 of the detection power source, the switch unit 500 may further include a detection switch connected between the one end 211 of the detection capacitor module and the ground GND, and the detection switch is turned on or off so that the one end 211 of the detection capacitor module is connected or disconnected from the ground GND; in the self-checking state, the detection switch is disconnected, so that the influence on the calculation of the capacitance value of the first matching capacitor C1 is avoided; in the working state, the detection switch can be turned on, and when the detection switch is turned on, the detection capacitor module 210 and the first matching capacitor C1 cooperate to perform impedance matching on the radio frequency power supply 20 and the load 30.

Referring to fig. 5, fig. 5 is a circuit diagram of an impedance matching circuit according to another embodiment of the application. As shown in fig. 5, the first matching capacitor C1 is selectively connected to the detection node a, and the impedance matching unit 100 further includes a second matching capacitor C2, where the second matching capacitor C2 is selectively connected to the detection node a; before the capacitance value of the first matching capacitor C1 is calculated or after the first adjustment amount range of the first adjustment unit M1 is calculated in the self-checking state, the first matching capacitor C1 is disconnected from the detection node a, the second matching capacitor C2 is connected with the detection node a, the detection node a is disconnected from the radio frequency power supply 20, the detection capacitor module 210 is connected with the detection node a, a detection loop including the detection power supply 220, the detection capacitor module 210 and the second matching capacitor C2 is formed, the detection power supply 220 outputs a detection voltage, and the voltage value of the detection node a is obtained through the voltage value obtaining unit 300, wherein the capacitance value of the detection capacitor module 210, the detection voltage of the detection power supply 220 and the voltage value of the detection node a are used for calculating to obtain the capacitance value of the second matching capacitor C2; in the working state, the first matching capacitor C1 and the second matching capacitor C2 are used for matching impedance matching of the rf power supply 20 and the load 30.

Therefore, for the case that the impedance matching unit 100 has the first matching capacitor C1 and the second matching capacitor C2 with the two different connection manners, by setting the first matching capacitor C1 to be selectively connected with the detection node a, the second matching capacitor C2 to be selectively connected with the detection node a, before the capacitance value of the first matching capacitor C1 is calculated or after the first adjustment range of the first adjustment unit M1 is calculated in the self-checking state of the impedance matching circuit 10, the first matching capacitor C1 is disconnected with the detection node a, and the second matching capacitor C2 is connected with the detection node a, so as to form a detection loop including the detection power supply 220, the detection capacitor module 210 and the second matching capacitor C2, and according to the capacitance value of the detection capacitor module 210, the detection voltage of the detection power supply 220 and the voltage value of the detection node a, the capacitance value of the second matching capacitor C2 can be calculated, and the radio frequency power supply 20 and the load 30 can be matched by the first matching capacitor C1 and the second matching capacitor C2 in the working state of the impedance matching circuit 10.

It should be noted that the first switch S1 is turned on or off, and the second switch S2 is turned on or off, so that the first matching capacitor C1 is connected or disconnected from the ground GND, so that the first matching capacitor C1 is selectively connected to the detection node a. Specifically, the first switch S1 is turned off, and the second switch S2 is turned on, so that the first matching capacitor C1 is connected to the ground GND, so that the first matching capacitor C1 is connected to the detection node a; the first switch S1 is turned off, and the second switch S2 is turned off, so that the first matching capacitor C1 is turned off from the ground GND, and thus the first matching capacitor C1 is turned off from the detection node a, that is, a path from the first matching capacitor C1 to the detection node a is short-circuited at this time.

It will be appreciated that in one or more embodiments, the first matching capacitor C1 includes two different connection manners, and the impedance matching circuit 10 may have various structures to achieve corresponding functions, and the connection manner, the corresponding structure and the achievable functions of the second matching capacitor C2 of the impedance matching circuit 10 may be described with reference to the first matching capacitor C1 in one or more embodiments, and may also be applied to the impedance matching circuit 10 including the second matching capacitor C2, which will not be described in detail herein.

As shown in fig. 5, the second matching capacitor C2 is an adjustable capacitor having a second capacitance value range, and the impedance matching circuit 10 further includes a second adjusting unit M2, where the second adjusting unit M2 is matched with the second matching capacitor C2, and is used for adjusting the capacitance value of the second matching capacitor C2; in the self-checking state, the second adjusting unit M2 adjusts the second matching capacitor C2 at least once, and the calculated capacitance value of the second matching capacitor C2 includes the capacitance value of the second matching capacitor C2 before adjustment and the capacitance value of the second matching capacitor C2 after each adjustment; after the second adjusting unit M2 adjusts the second matching capacitor C2 at least once, when the capacitance value of the second matching capacitor C2 obtained by current calculation is equal to the maximum value and the minimum value of the second capacitance value range, the adjustment amount of the second adjusting unit M2 before adjustment, the cumulative adjustment amount of the second adjusting unit M2 respectively adjusted to the maximum value and the minimum value of the first capacitance value range, are used for correspondingly obtaining the second adjustment amount range of the second adjusting unit M2; or after the second adjusting unit M2 adjusts the second matching capacitor C2 at least once, calculating to obtain a capacitance change value of the second matching capacitor C2 after adjustment and before adjustment, so as to calculate a second adjustment amount range of the second adjusting unit M2 by the capacitance value of the second matching capacitor C2 before adjustment, the adjustment amount of the second adjusting unit M2 before adjustment, the single adjustment amount of the second adjusting unit M2, the capacitance change value of the second matching capacitor C2 and the second capacitance value range; in the working state, the first adjusting unit M1 is configured to adjust the capacitance value of the first matching capacitor C1 in the first adjustment range, the second adjusting unit M2 is configured to adjust the capacitance value of the second matching capacitor C2 in the second adjustment range, and the first matching capacitor C1 is matched with the second matching capacitor C2, so that the radio frequency power supply 20 is impedance matched with the load 30.

Therefore, in the impedance matching circuit 10 of the present application, when the second matching capacitor C2 is an adjustable capacitor having a second capacitance value range, the second adjustment unit M2 is configured to adjust the capacitance value of the second matching capacitor C2, so that a second adjustment amount range of the second adjustment unit M2 can be calculated; in addition, when the impedance matching circuit 10 is in the working state, the second adjusting unit M2 is configured to adjust the capacitance value of the second matching capacitor C2 within the second adjusting range, so as to avoid the damage of the second matching capacitor C2, and simultaneously, the rf power supply 20 and the load 30 are impedance-matched, so that the occurrence of reflected power is reduced.

Specifically, for the embodiment in which the adjustment amount of the second adjustment unit M2 before adjustment, the integrated adjustment amount of the second adjustment unit M2 adjusted to the maximum value and the minimum value of the second capacitance value range, respectively, are used to correspondingly obtain the second adjustment amount range of the second adjustment unit M2, the adjustment amount of the second adjustment unit M2 before adjustment, the integrated adjustment amount of the second adjustment unit M2 adjusted to the maximum value and the minimum value of the second capacitance value range, respectively, and the second adjustment amount range of the second adjustment unit M2 satisfy the following relational expression:

D2+e2=h2, D2-f2=g2, where D2 is the adjustment amount of the second adjustment unit M2 before adjustment, E2, F2 second adjustment unit M2 are the cumulative adjustment amounts of the maximum value and the minimum value of the second capacitance value range, respectively, the second adjustment amount range of the second adjustment unit M2 is G2 to H2, G2 is the minimum adjustment amount of the second adjustment amount range, and H2 is the maximum adjustment amount of the second adjustment amount range.

Specifically, for the embodiment in which the second adjustment amount range of the second adjustment unit M2 is calculated by the capacitance value of the second matching capacitor C2 before adjustment, the adjustment amount of the second adjustment unit M2 before adjustment, the single adjustment amount of the second adjustment unit M2, the capacitance change value of the second matching capacitor C2, and the second capacitance value range, the capacitance value of the second matching capacitor C2 before adjustment, the adjustment amount of the second adjustment unit M2 before adjustment, the single adjustment amount of the second adjustment unit M2, the capacitance change value of the second matching capacitor C2, the second capacitance value range of the second matching capacitor C2, and the second adjustment amount range of the second adjustment unit M2 satisfy the following relational expression:

D2+x2× (J2-Cb 2)/cc2=h2, d2+x2× (Cb 2-I2)/cc2=g2, wherein the capacitance value of the second matching capacitance C2 before adjustment is Cb2, D2 is the adjustment amount of the second adjustment unit M2 before adjustment, X2 is the single adjustment amount of the second adjustment unit M2, cc2 is the capacitance variation value of the second matching capacitance C2, the second capacitance value range of the second matching capacitance C2 is I2 to J2, I2 is the minimum value of the second capacitance value range, J2 is the maximum value of the second capacitance value range, the second adjustment amount range of the second adjustment unit M2 is G2 to H2, G2 is the minimum adjustment amount of the second adjustment amount range, and H2 is the maximum adjustment amount of the second adjustment amount range.

As shown in fig. 5, the first adjusting unit M1 and the second adjusting unit M2 are stepper motors, the output shaft 110 of the first adjusting unit is correspondingly connected with one of the plates of the first matching capacitor C1, the output shaft 120 of the second adjusting unit is correspondingly connected with one of the plates of the second matching capacitor C2, the first adjusting unit M1 and the second adjusting unit M2 are used for receiving pulse signals, and the output shaft 110 of the first adjusting unit and the output shaft 120 of the second adjusting unit correspondingly rotate a first angle and a second angle according to the received pulse signals respectively, so as to correspondingly change the positions of the plates in the connected first matching capacitor C1 and second matching capacitor C2, and further change the distance between the two plates of the first matching capacitor C1 and the distance between the two plates of the second matching capacitor C2, and correspondingly adjust the capacitance values of the first matching capacitor C1 and the second matching capacitor C2; the single rotation angle of the first adjusting unit M1 and the second adjusting unit M2 is a single adjustment amount of the first adjusting unit M1 and the second adjusting unit M2, and the rotatable first angle range of the first adjusting unit M1 and the rotatable second angle range of the second adjusting unit M2 are a first adjustment amount range of the first adjusting unit M1 and a second adjustment amount range of the second adjusting unit M2, respectively.

Therefore, through the fact that the first adjusting unit M1 and the second adjusting unit M2 are both stepper motors, the output shaft 110 of the first adjusting unit is correspondingly connected with one of the polar plates of the first matching capacitor C1, and the output shaft 120 of the second adjusting unit is correspondingly connected with one of the polar plates of the second matching capacitor C2, the capacitance values of the first matching capacitor C1 and the second matching capacitor C2 can be correspondingly adjusted by changing the distance between the two polar plates of the first matching capacitor C1 and the distance between the two polar plates of the second matching capacitor C2.

Specifically, the first capacitance value range of the first matching capacitor C1 and the second capacitance value range of the second matching capacitor C2 are the distance range between the two plates of the first matching capacitor C1 and the distance range between the two plates of the second matching capacitor C2, and the distance between the two plates of the first matching capacitor C1 and the distance between the two plates of the second matching capacitor C2 are easily adjusted to be out of the distance range between the two plates of the first matching capacitor C1 and the distance range between the two plates of the second matching capacitor C2, so that the first matching capacitor C1 and the second matching capacitor C2 are damaged, and the damage to the first matching capacitor C1 and the second matching capacitor C2 is avoided, and the service life of the impedance matching circuit 10 including the first matching capacitor C1, the second matching capacitor C2 and the first matching capacitor C2 is prolonged.

It can be understood that the output shaft 110 of the first adjusting unit and the output shaft 120 of the second adjusting unit may be indirectly connected with one of the plates of the first matching capacitor C1 and the second matching capacitor C2 through a screw rod, so as to drive the first angle and the second angle of rotation of the output shaft 110 of the first adjusting unit and the output shaft 120 of the second adjusting unit to the positions of the plates of the connected first matching capacitor C1 and second matching capacitor C2, thereby changing the distance between the two plates of the first matching capacitor C1 and the distance between the two plates of the second matching capacitor C2, and correspondingly adjusting the capacitance values of the first matching capacitor C1 and the second matching capacitor C2.

Referring to fig. 6, fig. 6 is a schematic circuit diagram of an impedance matching circuit according to another embodiment of the application, which further includes a control unit and a switch unit. As shown in fig. 6, the impedance matching circuit 10 further includes a control unit 400 and a switch unit 500, where the switch unit 500 is at least used to connect or disconnect the connection between the detection node a and the radio frequency power supply 20, and connect or disconnect the connection between the other end 212 of the detection capacitor module and the detection node a, and connect or disconnect the connection between the first matching capacitor C1 or the second matching capacitor C2 and the detection node a, and the control unit 400 is at least used to control the switch unit 500 to connect or disconnect the connection between the detection node a and the radio frequency power supply 20, and control the switch unit 500 to connect or disconnect the connection between the other end 212 of the detection capacitor module and the detection node a, and control the switch unit 500 to connect or disconnect the connection between the first matching capacitor C1 or the second matching capacitor C2 and the detection node a; in the self-checking state, the control unit 400 controls the switch unit 500 to disconnect the connection between the detection node a and the radio frequency power supply 20, and to connect the other end 212 of the detection capacitor module with the detection node a, and to connect the first matching capacitor C1 or the second matching capacitor C2 with the detection node a, and to control the detection power supply 220 to output a detection voltage, and to receive the voltage value of the detection node a output by the voltage value acquisition unit 300, so as to calculate the capacitance value of the first matching capacitor C1 or the second matching capacitor C2 according to the capacitance value of the detection capacitor module 210, the detection voltage value of the detection power supply 220, and the voltage value of the detection node a, and then controls the switch unit 500 to connect the second matching capacitor C2 or the connection between the first matching capacitor C1 and the detection node a, and to control the detection power supply 220 to output a detection voltage, and to receive the voltage value of the detection node a output by the voltage value acquisition unit 300, so as to calculate the capacitance value of the second matching capacitor C2 or the first matching capacitor C1 according to the capacitance value of the detection capacitor module 210, the detection voltage value of the detection power supply 220, and the voltage value of the detection node a. In the operating state, the control unit 400 controls the switch unit 500 to conduct the connection between the detection node a and the radio frequency power supply 20, disconnect the connection between the other end 212 of the detection capacitor module and the detection node a, conduct the connection between the first matching capacitor C1 and the second matching capacitor C2 and the detection node a, and perform impedance matching on the radio frequency power supply 20 and the load 30 through the first matching capacitor C1 and the second matching capacitor C2 of the impedance matching unit 100.

Accordingly, by providing the control unit 400 and the switching unit 500, the capacitance values of the first matching capacitor C1 and the second matching capacitor C2 can be calculated in the self-test state of the impedance matching circuit 10, and the radio frequency power source 20 and the load 30 can be impedance-matched by the first matching capacitor C1 and the second matching capacitor C2 of the impedance matching unit 100 in the operation state of the impedance matching circuit 10.

In one or more embodiments, the control unit 400 may be further configured to control the second adjusting unit M2 to adjust the capacitance value of the second matching capacitor C2, where after the second adjusting unit M2 adjusts the second matching capacitor C2 at least once, when the currently calculated capacitance value of the second matching capacitor C2 is equal to the maximum value and the minimum value of the second capacitance value range, the control unit 400 may be further configured to obtain the adjustment amount of the second adjusting unit M2 before the adjustment, and the cumulative adjustment amount of the second adjusting unit M2 adjusted to the maximum value and the minimum value of the second capacitance value range, respectively, so as to obtain the second adjustment amount range of the second adjusting unit M2 correspondingly; or after the second adjusting unit M2 adjusts the second matching capacitor C2 at least once, the control unit 400 may be further configured to calculate a capacitance change value of the second matching capacitor C2 after and before adjustment, and obtain a capacitance value of the second matching capacitor C2 before adjustment, an adjustment amount of the second adjusting unit M2 before adjustment, a single adjustment amount of the second adjusting unit M2, a capacitance change value of the second matching capacitor C2, and a second capacitance value range, so as to calculate a second adjustment amount range of the second adjusting unit M2; in the operating state, the control unit 400 is further configured to control the second adjusting unit M2 to adjust the capacitance value of the second matching capacitor C2 within the second adjustment range, so that the rf power source 20 is impedance-matched with the load 30.

In one or more embodiments, when the first adjusting unit M1 and the second adjusting unit M2 are both stepper motors, the control unit 400 may be further configured to output pulse signals to control the output shaft 110 of the first adjusting unit and the output shaft 120 of the second adjusting unit to rotate by a first angle and a second angle respectively, and to control the output shaft 110 of the first adjusting unit and the output shaft 120 of the second adjusting unit to rotate within a first rotatable angle range of the first adjusting unit M1 and a second rotatable angle range of the second adjusting unit M2 respectively.

In one or more embodiments, the control unit 400 may be a general-purpose Processor such as a central processing unit (Central Processing Unit, CPU), a digital signal Processor (DIGITAL SIGNAL Processor, DSP), an Application SPECIFIC INTEGRATED Circuit (ASIC), a Field-Programmable gate array (Field-Programmable GATE ARRAY, FPGA), or other logic control device such as a Programmable logic device, a discrete gate logic device, or a transistor logic device, or may be a microprocessor such as a control unit (Micro Control Unit, MCU).

In one or more embodiments, the voltage value acquisition unit 300 may be a voltmeter as shown in fig. 5 and 6.

Please refer to fig. 5 and 6 again. As shown in fig. 5 and 6, one of the first matching capacitor C1 and the second matching capacitor C2 is connected between the radio frequency power supply 20 and the detection node a, the other of the first matching capacitor C1 and the second matching capacitor C2 is connected between the detection node a and the ground GND, the switch unit 500 includes a first switch S1, a second switch S2, a third switch S3 and a fourth switch S4, the impedance matching circuit 10 further has a shielding node B, and the shielding node B is disposed between the radio frequency power supply 20 and the first matching capacitor C1; the first switch S1 is connected between the rf power source 20 and the shielding node B, and the first switch S1 is turned on or turned off, so that the shielding node B is connected or disconnected with the rf power source 20, and the connection node a is connected or disconnected with the rf power source 20; the second switch S2 is connected between the shielding node B and the ground GND, and is connected to the first matching capacitor C1 or the second matching capacitor C2 between the radio frequency power supply 20 and the detection node a and is connected to the ground GND through the second switch S2, where the second switch S2 is turned on or turned off, so that the first matching capacitor C1 or the second matching capacitor C2 is connected to or disconnected from the ground GND; the third switch S3 is connected between the other end 212 of the detection capacitor module and the detection node a, and the third switch S3 is turned on or turned off, so that the other end 212 of the detection capacitor module is connected or disconnected with the detection node a; the fourth switch S4 is connected in series between the detection node a and the ground GND with the first matching capacitor C1 or the second matching capacitor C2 connected between the detection node a and the ground GND, and the fourth switch S4 is turned on or turned off, so that the first matching capacitor C1 or the second matching capacitor C2 is connected or disconnected with the detection node a; in the self-checking state, the first switch S1 and the fourth switch S4 are turned off, the second switch S2 and the third switch S3 are turned on, the first matching capacitor C1 or the second matching capacitor C2 is connected in parallel with the detection capacitor module 210 to calculate a capacitance value of the first matching capacitor C1 or the second matching capacitor C2, then the second switch S2 is turned off, the fourth switch S4 is turned on, and the second matching capacitor C2 or the first matching capacitor C1 is connected in parallel with the detection capacitor module 210 to calculate a capacitance value of the second matching capacitor C2 or the first matching capacitor C1; or in the self-checking state, the first switch S1 and the second switch S2 are turned off, the third switch S3 and the fourth switch S4 are turned on, the second matching capacitor C2 or the first matching capacitor C1 is connected in parallel with the detection capacitor module 210 to calculate the capacitance value of the second matching capacitor C2 or the first matching capacitor C1, and then the fourth switch S4 is turned off, the second switch S2 is turned on, and the first matching capacitor C1 or the second matching capacitor C2 is connected in parallel with the detection capacitor module 210 to calculate the capacitance value of the first matching capacitor C1 or the second matching capacitor C2; in the working state, the second switch S2 and the third switch S3 are turned off, the first switch S1 and the fourth switch S4 are turned on, and the first matching capacitor C1 and the second matching capacitor C2 cooperate to perform impedance matching on the radio frequency power supply 20 and the load 30.

Thus, when one of the first matching capacitor C1 and the second matching capacitor C2 is connected between the radio frequency power supply 20 and the detection node a, and the other of the first matching capacitor C1 and the second matching capacitor C2 is connected between the detection node a and the ground GND, the capacitance value detection of the first matching capacitor C1 and the second matching capacitor C2 can be achieved by providing the switching unit 500 including the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4.

In fig. 5 and 6, a first matching capacitor C1 is specifically illustrated as being connected between the rf power source 20 and the detection node a, and a second matching capacitor C2 is illustrated as being connected between the detection node a and the ground GND.

In one or more embodiments, the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4 may be a power field effect transistor (Metal Oxide Semiconductor FET, MOSFET), an insulated gate bipolar transistor (Insulate-Gate Bipolar Transistor, IGBT), or other controllable switching devices, which are not limited in this disclosure, so long as the on and off functions of the switches can be implemented.

In one or more embodiments, the impedance matching unit 100 further includes a matching inductance L1, where the matching inductance L1 is connected between the rf power supply 20 and the shielding node B, so that impedance matching between the rf power supply 20 and the load 30 is more conveniently completed, and the capacitance value of the first matching capacitance C1 connected between the shielding node B and the detection node a is not affected by the matching inductance L1 due to the shielding node B.

Referring to fig. 1-6 again, fig. 7 is a schematic block diagram of a voltage value obtaining unit according to an embodiment of the application. As shown in fig. 1 to fig. 7, the detected voltage output by the detected power supply 220 is an ac voltage, the frequency of the ac voltage output by the detected power supply 220 is the same as the operating frequency of the radio frequency power supply 20, the voltage value obtaining unit 300 includes a first obtaining module 310 and a second obtaining module 320, the first obtaining module 310 is configured to obtain an average detected voltage of the ac voltage output by the detected power supply 220, and the second obtaining module 320 is configured to obtain an average voltage value of the detection node a; in the self-checking state, the capacitance value of the detection capacitor module 210, the average detection voltage of the detection power supply 220, and the average voltage value of the detection node a are used to calculate the capacitance value of the first matching capacitor C1.

Therefore, by setting the detection voltage output by the detection power supply 220 as an ac voltage, the frequency of the ac voltage output by the detection power supply 220 is the same as the working frequency of the rf power supply 20, so that the accuracy of calculating the capacitance value of the first matching capacitor C1 can be improved, the detection voltage of the dc voltage or other frequency voltage is avoided, and the calculation of the capacitance value is affected by the dispersion parameter of the capacitor device, so that the impedance matching of the rf power supply 20 and the load 30 is affected.

In one or more embodiments, the first obtaining module 310 and the second obtaining module 320 may obtain the average detected voltage of the ac voltage output by the detecting power supply 220 and the average voltage value of the detecting node a through a diode or the like, which is not limited by the present application, as long as the average detected voltage of the ac voltage and the average voltage value of the detecting node a can be obtained.

According to the impedance matching circuit 10 disclosed by the application, through the structure, the capacitance values of the first matching capacitor C1 and the second matching capacitor C2 can be accurately calculated, the requirement of detecting the capacitance values of the first matching capacitor C1 and the second matching capacitor C2 in the impedance matching circuit 10 is met, the first adjustment range of the first adjustment unit M1 and the second adjustment range of the second adjustment unit M2 can be obtained in various modes, the first adjustment unit M1 is configured to adjust the capacitance value of the first matching capacitor C1 in the first adjustment range and the second adjustment unit M2 is configured to adjust the capacitance value of the second matching capacitor C2 in the second adjustment range, the damage of the first matching capacitor C1 and the second matching capacitor C2 is avoided, the radio frequency power supply 20 and the load 30 are further subjected to relatively accurate impedance matching, the occurrence of reflected power is reduced, and a better output effect is obtained.

Referring to fig. 8 and 9, fig. 8 is a schematic block diagram of a radio frequency power supply device according to an embodiment of the application, and fig. 9 is a circuit schematic diagram of the radio frequency power supply device according to an embodiment of the application. As shown in fig. 8 and 9, the present application further provides a radio frequency power supply device 1, where the radio frequency power supply device 1 includes the impedance matching circuit 10, the radio frequency power supply 20, and the radio frequency output terminal 21 in any of the foregoing embodiments, the impedance matching circuit 10 is connected between the radio frequency power supply 20 and the radio frequency output terminal 21, and the radio frequency output terminal 21 is used for connecting the load 30.

Please refer to fig. 1 and fig. 2 again. As shown in fig. 1 and 2, the impedance matching circuit 10 is configured to perform impedance matching on the rf power supply 20 and the load 30, the impedance matching circuit 10 has a detection node a, and the impedance matching circuit 10 further includes an impedance matching unit 100, a capacitance value detection unit 200, and a voltage value acquisition unit 300; the impedance matching unit 100 at least comprises a first matching capacitor C1, and the first matching capacitor C1 is connected with the detection node a; the capacitance value detecting unit 200 includes a detecting capacitor module 210 and a detecting power supply 220, the detecting capacitor module 210 has a capacitance value, the detecting power supply 220 includes an output end for outputting a detecting voltage, one end 211 of the detecting capacitor module is connected to an output end 221 of the detecting power supply, and the other end 212 of the detecting capacitor module is selectively connected to the detecting node a; the voltage value obtaining unit 300 is at least configured to obtain a voltage value of the detection node a; wherein the detection node a is selectively connected to the rf power source 20; the impedance matching circuit 10 has a self-checking state, in which the detection node a is disconnected from the rf power supply 20, the detection capacitor module 210 is connected to the detection node a to form a detection loop including the detection power supply 220, the detection capacitor module 210, and the first matching capacitor C1, the detection power supply 220 outputs a detection voltage and transmits the detection voltage to the detection node a through the detection capacitor module 210, and the voltage value obtaining unit 300 obtains a voltage value of the detection node a, where the capacitance value of the detection capacitor module 210, the detection voltage of the detection power supply 220, and the voltage value of the detection node a are used to calculate the capacitance value of the first matching capacitor C1.

The more specific structure of the impedance matching circuit 10 can be seen in any of the above embodiments, and the details of the impedance matching circuit 10 are not described herein.

According to the impedance matching circuit 10 and the radio frequency power supply device 1, through the structure, the capacitance values of the first matching capacitor C1 and the second matching capacitor C2 can be accurately calculated, the requirement of detecting the capacitance values of the first matching capacitor C1 and the second matching capacitor C2 in the impedance matching circuit 10 is met, the first adjustment range of the first adjustment unit M1 and the second adjustment range of the second adjustment unit M2 can be obtained in various modes, the first adjustment unit M1 is configured to adjust the capacitance value of the first matching capacitor C1 in the first adjustment range and the second adjustment unit M2 is configured to adjust the capacitance value of the second matching capacitor C2 in the second adjustment range, damage to the first matching capacitor C1 and the second matching capacitor C2 is avoided, further, the radio frequency power supply 20 and the load 30 can be subjected to relatively accurate impedance matching, the occurrence of reflected power is reduced, and a better output effect is obtained.

The foregoing description is merely illustrative of the present application, and the scope of the present application is not limited thereto, and any person skilled in the art can easily think about variations or substitutions within the technical scope of the present application, and should be covered by the scope of the present application; embodiments of the application and features of the embodiments may be combined with each other without conflict. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims (11)

1. An impedance matching circuit for impedance matching a radio frequency power supply to a load, the impedance matching circuit having a detection node, the impedance matching circuit further comprising:

The impedance matching unit at least comprises a first matching capacitor, and the first matching capacitor is connected with the detection node;

The capacitance value detection unit comprises a detection capacitance module and a detection power supply, wherein the detection capacitance module is provided with a capacitance value, the detection power supply comprises an output end for outputting a detection voltage, one end of the detection capacitance module is connected with the output end of the detection power supply, and the other end of the detection capacitance module is selectively connected with the detection node;

A voltage value obtaining unit, at least for obtaining the voltage value of the detection node;

Wherein the detection node is selectively connected with the radio frequency power supply; the impedance matching circuit is provided with a self-checking state, in the self-checking state, the detection node is disconnected from the radio frequency power supply, the detection capacitor module is connected with the detection node to form a detection loop comprising the detection power supply, the detection capacitor module and the first matching capacitor, the detection power supply outputs detection voltage and transmits the detection voltage to the detection node through the detection capacitor module, and the voltage value acquisition unit acquires the voltage value of the detection node, wherein the capacitance value of the detection capacitor module, the detection voltage of the detection power supply and the voltage value of the detection node are used for calculating and obtaining the capacitance value of the first matching capacitor;

The impedance matching circuit is also provided with a working state, in the working state, the detection node is connected with the radio frequency power supply, the detection capacitor module is disconnected with the detection node, and the impedance matching circuit performs impedance matching on the radio frequency power supply and the load at least through the first matching capacitor of the impedance matching unit;

the impedance matching circuit further comprises a first adjusting unit, wherein the first adjusting unit is matched with the first matching capacitor and used for adjusting the capacitance value of the first matching capacitor;

In the self-checking state, the first adjusting unit adjusts the first matching capacitor at least once, and the calculated capacitance value of the first matching capacitor comprises the capacitance value of the first matching capacitor before adjustment and the capacitance value of the first matching capacitor after each adjustment; after the first adjusting unit adjusts the first matching capacitor at least once, when the capacitance value of the first matching capacitor obtained by current calculation is equal to the maximum value and the minimum value of a first capacitance value range, the adjustment amount of the first adjusting unit before adjustment, and the accumulated adjustment amount of the first adjusting unit respectively adjusted to the maximum value and the minimum value of the first capacitance value range are used for correspondingly obtaining a first adjustment amount range of the first adjusting unit; or after the first adjusting unit adjusts the first matching capacitor at least once, calculating to obtain a capacitance change value of the first matching capacitor before and after adjustment, so as to calculate a first adjustment amount range of the first adjusting unit through the capacitance value of the first matching capacitor before adjustment, the adjustment amount of the first adjusting unit before adjustment, the single adjustment amount of the first adjusting unit, the capacitance change value of the first matching capacitor and a first capacitance value range; in the working state, the first adjusting unit adjusts the capacitance value of the first matching capacitor in a first adjusting quantity range so as to match the radio frequency power supply with the load impedance.

2. The impedance matching circuit according to claim 1, further comprising a control unit and a switching unit, the switching unit being at least for switching on or off a connection between the detection node and the radio frequency power supply and for switching on or off a connection between the other end of the detection capacitance module and the detection node, the control unit being at least for controlling the switching unit to switch on or off a connection between the detection node and the radio frequency power supply and for controlling the switching unit to switch on or off a connection between the other end of the detection capacitance module and the detection node;

When the self-checking state is adopted, the control unit controls the switch unit to disconnect the connection between the detection node and the radio frequency power supply, and to conduct the connection between the other end of the detection capacitor module and the detection node, and controls the detection power supply to output detection voltage, and receives the voltage value of the detection node output by the voltage value acquisition unit, so that the capacitance value of the first matching capacitor is calculated according to the capacitance value of the detection capacitor module, the detection voltage value of the detection power supply and the voltage value of the detection node; in the working state, the control unit controls the switch unit to conduct connection between the detection node and the radio frequency power supply, and disconnect connection between the other end of the detection capacitor module and the detection node, and impedance matching is performed on the radio frequency power supply and the load at least through the first matching capacitor of the impedance matching unit.

3. The impedance matching circuit of claim 2, wherein the first matching capacitor is connected between the detection node and ground, the switching unit comprising a first switch and a second switch;

The first switch is connected between the radio frequency power supply and the detection node, and is connected or disconnected so that the detection node is connected or disconnected with the radio frequency power supply;

the second switch is connected between the other end of the detection capacitor module and the detection node, and is turned on or turned off so that the other end of the detection capacitor module is connected with or disconnected from the detection node;

In the self-checking state, the first switch is disconnected, the second switch is connected, and the first matching capacitor is connected with the detection capacitor module in parallel so as to calculate and obtain the capacitance value of the first matching capacitor; in the working state, the second switch is disconnected, the first switch is connected, and the first matching capacitor performs impedance matching on the radio frequency power supply and the load.

4. The impedance matching circuit of claim 2, wherein the first matching capacitor is connected between the radio frequency power supply and the detection node, the switching unit comprises a first switch, a second switch, and a third switch, the impedance matching circuit further has a shielding node disposed between the radio frequency power supply and the first matching capacitor;

The first switch is connected between the radio frequency power supply and the shielding node, and is connected or disconnected so that the shielding node is connected or disconnected with the radio frequency power supply;

The second switch is connected between the shielding node and the ground, the first matching capacitor is connected with the ground through the second switch, and the second switch is turned on or off so that the first matching capacitor is connected with the ground or disconnected;

The third switch is connected between the other end of the detection capacitor module and the detection node, and is turned on or turned off so that the other end of the detection capacitor module is connected with or disconnected from the detection node;

In the self-checking state, the first switch is disconnected, the second switch and the third switch are connected, and the first matching capacitor is connected with the detection capacitor module in parallel so as to calculate and obtain the capacitance value of the first matching capacitor; in the working state, the second switch and the third switch are disconnected, the first switch is connected, and the first matching capacitor performs impedance matching on the radio frequency power supply and the load.

5. The impedance matching circuit of claim 1, wherein said first matching capacitor is selectively connectable to said detection node, said impedance matching unit further comprising a second matching capacitor, said second matching capacitor being selectively connectable to said detection node;

Before the capacitance value of the first matching capacitor is calculated or after the first adjustment amount range of the first adjustment unit is calculated in the self-checking state, the first matching capacitor is disconnected from the detection node, the second matching capacitor is connected with the detection node, the detection node is disconnected from the radio frequency power supply, the detection capacitor module is connected with the detection node to form a detection loop comprising the detection power supply, the detection capacitor module and the second matching capacitor, the detection power supply outputs detection voltage, and the voltage value of the detection node is obtained through the voltage value obtaining unit, wherein the capacitance value of the detection capacitor module, the detection voltage of the detection power supply and the voltage value of the detection node are used for calculating the capacitance value of the second matching capacitor; in the working state, the first matching capacitor and the second matching capacitor are used for matching to carry out impedance matching on the radio frequency power supply and the load.

6. The impedance matching circuit of claim 5, wherein the second matching capacitance is an adjustable capacitance having a second range of capacitance values, the impedance matching circuit further comprising a second adjustment unit cooperating with the second matching capacitance for adjusting the capacitance value of the second matching capacitance;

In the self-checking state, the second adjusting unit adjusts the second matching capacitor at least once, and the calculated capacitance value of the second matching capacitor comprises the capacitance value of the second matching capacitor before adjustment and the capacitance value of the second matching capacitor after each adjustment; after the second adjusting unit adjusts the second matching capacitor at least once, when the capacitance value of the second matching capacitor obtained by current calculation is equal to the maximum value and the minimum value of the second capacitance value range, the adjustment amount of the second adjusting unit before adjustment, and the accumulated adjustment amount of the second adjusting unit respectively adjusted to the maximum value and the minimum value of the first capacitance value range are used for correspondingly obtaining the second adjustment amount range of the second adjusting unit; or after the second adjusting unit adjusts the second matching capacitance at least once, calculating to obtain a capacitance change value of the second matching capacitance after adjustment and before adjustment, so as to calculate a second adjustment amount range of the second adjusting unit through the capacitance value of the second matching capacitance before adjustment, the adjustment amount of the second adjusting unit before adjustment, the single adjustment amount of the second adjusting unit, the capacitance change value of the second matching capacitance and a second capacitance value range; in the working state, the first adjusting unit is used for adjusting the capacitance value of the first matching capacitor in a first adjusting quantity range, the second adjusting unit is used for adjusting the capacitance value of the second matching capacitor in a second adjusting quantity range, and the first matching capacitor is matched with the second matching capacitor so that the radio frequency power supply is matched with the load impedance.

7. The impedance matching circuit according to claim 6, wherein the first adjusting unit and the second adjusting unit are each a stepping motor, an output shaft of the first adjusting unit is correspondingly connected to one of the plates of the first matching capacitor, an output shaft of the second adjusting unit is correspondingly connected to one of the plates of the second matching capacitor, the first adjusting unit and the second adjusting unit are configured to receive pulse signals, and the output shafts of the first adjusting unit and the second adjusting unit correspondingly rotate a first angle and a second angle according to the received pulse signals, so as to correspondingly change positions of the plates of the first matching capacitor and the second matching capacitor, and change distances between the two plates of the first matching capacitor and between the two plates of the second matching capacitor, thereby correspondingly adjusting capacitance values of the first matching capacitor and the second matching capacitor;

The single-rotation angle of the first adjusting unit and the second adjusting unit is the single-rotation adjustment amount of the first adjusting unit and the second adjusting unit, and the rotatable first angle range of the first adjusting unit and the rotatable second angle range of the second adjusting unit are the first adjustment amount range of the first adjusting unit and the second adjustment amount range of the second adjusting unit respectively.

8. The impedance matching circuit according to claim 5, further comprising a control unit and a switching unit, the switching unit being at least for switching on or off a connection between the detection node and the radio frequency power supply, and switching on or off a connection between the other end of the detection capacitance module and the detection node, and switching on or off a connection between the first matching capacitance or the second matching capacitance and the detection node, the control unit being at least for controlling the switching unit to switching on or off a connection between the detection node and the radio frequency power supply, and switching on or off a connection between the other end of the detection capacitance module and the detection node, and switching on or off a connection between the first matching capacitance or the second matching capacitance and the detection node;

When the self-checking state is adopted, the control unit controls the switch unit to disconnect the connection between the detection node and the radio frequency power supply, and to conduct the connection between the other end of the detection capacitor module and the detection node, and to conduct the connection between the first matching capacitor or the second matching capacitor and the detection node, and to control the detection power supply to output detection voltage, and to receive the voltage value of the detection node output by the voltage value acquisition unit, so as to calculate the capacitance value of the first matching capacitor or the second matching capacitor according to the capacitance value of the detection capacitor module, the detection voltage value of the detection power supply and the voltage value of the detection node, and then to control the switch unit to conduct the connection between the second matching capacitor or the first matching capacitor and the detection node, and to control the detection power supply to output detection voltage, and to receive the voltage value of the detection node output by the voltage value acquisition unit, so as to calculate the capacitance value of the first matching capacitor or the second matching capacitor according to the capacitance value of the detection capacitor module, the detection voltage value of the detection power supply and the voltage value of the detection node; in the working state, the control unit controls the switch unit to conduct connection between the detection node and the radio frequency power supply, disconnect connection between the other end of the detection capacitor module and the detection node, conduct connection between the first matching capacitor and the second matching capacitor and the detection node, and conduct impedance matching on the radio frequency power supply and the load through the first matching capacitor and the second matching capacitor of the impedance matching unit.

9. The impedance matching circuit of claim 8, wherein one of the first matching capacitor and the second matching capacitor is connected between the radio frequency power source and the detection node, the other of the first matching capacitor and the second matching capacitor is connected between the detection node and ground, the switching unit comprises a first switch, a second switch, a third switch, and a fourth switch, the impedance matching circuit further has a shielding node, the shielding node is disposed between the radio frequency power source and the first matching capacitor;

The first switch is connected between the radio frequency power supply and the shielding node, and is connected or disconnected so that the shielding node is connected or disconnected with the radio frequency power supply;

the second switch is connected between the shielding node and the ground, connected with a first matching capacitor or a second matching capacitor between the radio frequency power supply and the detection node and connected with the ground through the second switch, and the second switch is turned on or turned off so that the first matching capacitor or the second matching capacitor is connected with the ground or disconnected;

The third switch is connected between the other end of the detection capacitor module and the detection node, and is turned on or turned off so that the other end of the detection capacitor module is connected with or disconnected from the detection node;

the fourth switch is connected in series between the detection node and the ground with the first matching capacitor or the second matching capacitor connected between the detection node and the ground, and the fourth switch is turned on or turned off so that the first matching capacitor or the second matching capacitor is connected or disconnected with the detection node;

In the self-checking state, the first switch and the fourth switch are disconnected, the second switch and the third switch are connected, the first matching capacitor or the second matching capacitor is connected with the detection capacitor module in parallel to calculate the capacitance value of the first matching capacitor or the second matching capacitor, then the second switch is disconnected, the fourth switch is connected, and the second matching capacitor or the first matching capacitor is connected with the detection capacitor module in parallel to calculate the capacitance value of the second matching capacitor or the first matching capacitor; or in the self-checking state, the first switch and the second switch are turned off, the third switch and the fourth switch are turned on, the second matching capacitor or the first matching capacitor is connected with the detection capacitor module in parallel to calculate the capacitance value of the second matching capacitor or the first matching capacitor, then the fourth switch is turned off, the second switch is turned on, and the first matching capacitor or the second matching capacitor is connected with the detection capacitor module in parallel to calculate the capacitance value of the first matching capacitor or the second matching capacitor; in the working state, the second switch and the third switch are disconnected, the first switch and the fourth switch are connected, and the first matching capacitor and the second matching capacitor are matched to perform impedance matching on the radio frequency power supply and the load.

10. The impedance matching circuit according to claim 1, wherein the detection voltage output by the detection power supply is an ac voltage, the frequency of the ac voltage output by the detection power supply is the same as the operating frequency of the radio frequency power supply, the voltage value acquisition unit includes a first acquisition module for acquiring an average detection voltage of the ac voltage output by the detection power supply and a second acquisition module for acquiring an average voltage value of the detection node;

in the self-checking state, the capacitance value of the detection capacitor module, the average detection voltage of the detection power supply and the average voltage value of the detection node are used for calculating and obtaining the capacitance value of the first matching capacitor.

11. A radio frequency power supply device, characterized by comprising the impedance matching circuit of any one of claims 1-10, a radio frequency power supply and a radio frequency output, the impedance matching circuit being connected between the radio frequency power supply and the radio frequency output, the radio frequency output being for connecting a load.