A frequency-division controlled solid-state impedance matching circuit for RF power supplies and its method

Abstract

This invention discloses a frequency-division controlled solid-state impedance matching device for radio frequency power supplies and its method, aiming to solve the problems of slow response, low adjustment accuracy, and difficulty in adapting to dynamic loads of traditional mechanical impedance matching devices. The system employs an all-solid-state impedance matching device, with a matching network composed of adjustable inductor modules and switched capacitor modules to achieve dynamic impedance adjustment. A closed-loop control is constructed by combining an radio frequency signal detection module and a digital signal processor, employing a frequency-division control strategy: coarse adjustment is mainly performed using the adjustable inductor module in the low-frequency band; and fine adjustment is achieved using both the adjustable inductor module and the switched capacitor module in the high-frequency band, thus achieving high-precision matching. The device has advantages such as fast response speed and wide frequency band coverage, and is particularly suitable for industrial plasma applications with significant dynamic impedance characteristics.

Description

Technical Field

[0001] This invention relates to the field of radio frequency power supply control and impedance matching technology, and in particular to a frequency division controlled solid-state impedance matching device and method for radio frequency power supplies. It is suitable for radio frequency systems with high requirements for impedance stability and matching response speed, especially in high-frequency dynamic load scenarios such as plasma discharge and radio frequency heating, enabling rapid and stable adaptive impedance adjustment. Background Technology

[0002] With the widespread application of radio frequency (RF) power technology in fields such as plasma processing, semiconductor manufacturing, and RF heating, impedance matching devices are core components for efficient transmission between RF power supplies and loads, and their performance directly affects system stability. Existing impedance matching methods mostly rely on mechanically adjustable structures, which suffer from slow response speed, large size, and low reliability, making it difficult to meet the dynamic matching requirements of RF power supply loads that change rapidly.

[0003] Therefore, how to provide a solution to the above problems is a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] This invention provides a frequency division control RF power supply solid-state impedance matching device and method, aiming to solve the problems of traditional impedance matching devices, such as complex structure, slow matching response, weak frequency band adaptability, and insufficient matching accuracy under high frequency conditions.

[0005] A frequency division controlled solid-state impedance matching device for radio frequency power supply includes: a radio frequency power supply, a power control unit, a communication interface module, a digital signal processor, a matching control module, a matching network, a switched capacitor controller and an adjustable inductor controller, a plasma load, and a radio frequency signal detection module.

[0006] The radio frequency power supply generates a high-frequency AC signal to provide a radio frequency power source with a fixed output impedance for the matching system;

[0007] The power control unit dynamically adjusts the output power of the RF power supply, and adjusts the output power in real time according to the load status and the adjustment results of the matching network;

[0008] The communication interface module enables the transmission of commands and status between the RF power supply and the digital signal processor;

[0009] The digital signal processor receives feedback data from the radio frequency signal detection module, executes the impedance matching algorithm, and outputs control commands.

[0010] The matching control module controls the adjustable inductor controller and the switched capacitor controller respectively according to the control instructions of the digital signal processor, so as to realize the dynamic adjustment of the impedance in the matching network;

[0011] The matching network is located between the RF power supply and the plasma load, and includes an adjustable inductor module and a switched capacitor module to realize the impedance transformation of the system.

[0012] An adjustable inductor controller is used to drive an adjustable inductor, and a switched capacitor controller is used to drive a switched capacitor array, thereby realizing the dynamic adjustment of inductor and capacitor parameters, respectively.

[0013] The plasma load ensures stable RF power output through real-time impedance matching.

[0014] The radio frequency signal detection module acquires forward power, reflected power, voltage, current and phase information in real time, and feeds the detection results back to the digital signal processor.

[0015] The adjustable inductor module includes a magnetic core structure. The magnetic core uses high-frequency NiZn ferrite, and its permeability is controlled by a bias current source, making the inductance adjustable.

[0016] The switched capacitor module consists of multiple sets of capacitor units and GaN device switches. By controlling the conduction state of the GaN device, the capacitance can be adjusted.

[0017] The matching control module uses frequency data collected by the radio frequency signal detection module to divide the operating frequency into low-frequency and high-frequency bands. Based on the frequency band identification results, it switches the matching network, including:

[0018] In the low-frequency band, the matching control module uses an active magnetically controlled inductor, combined with a fuzzy PID control algorithm to adjust the bias current source, control the permeability, and achieve coarse matching of the impedance network.

[0019] In the high-frequency band, the matching control module adopts a control strategy of coarse inductor adjustment and fine capacitor adjustment: coarse adjustment is achieved by active magnetically controlled inductor to achieve initial impedance positioning, and fine adjustment is achieved by switched capacitor module. Combined with table lookup algorithm and fast switching mechanism, the impedance network is accurately matched.

[0020] A control method for a frequency-division controlled solid-state impedance matching circuit for an RF power supply includes the following steps:

[0021] Step 1: The RF signal detection module collects the voltage, current, reflected power and phase information of the load in real time. The sampled data is transmitted to the digital signal processor after amplitude and phase detection.

[0022] Step 2: The digital signal processor determines the current operating frequency using a frequency band identification algorithm;

[0023] Step 3: If a low frequency band is detected, the matching control module drives the adjustable inductor controller to adjust the bias current source to change the magnetic core permeability, thereby achieving adjustable inductance and completing coarse matching.

[0024] Step 4: If a high-frequency band is detected, first perform coarse adjustment through the adjustable inductor module, and then drive the switched capacitor controller to control the conduction state of the GaN device, so that the capacitor is adjustable and precise matching is achieved.

[0025] Step 5: The adjusted data is sampled by the radio frequency signal detection module and fed back to the digital signal processor to form a closed-loop control.

[0026] The beneficial effects of this invention are as follows: The RF power supply solid-state impedance matching device and its control method of this invention have advantages such as fast dynamic response speed and high matching accuracy. Based on a frequency division control strategy, combined with an adjustable inductor module and a switched capacitor module, it achieves wide-band impedance matching coverage and fast dynamic response capability, making it suitable for industrial plasma application scenarios with significant dynamic impedance characteristics. Attached Figure Description

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a structural principle block diagram of a frequency division controlled solid-state impedance matching circuit for radio frequency power supplies according to the present invention.

[0029] Figure 2 This is a control flowchart of a frequency division controlled solid-state impedance matching circuit for radio frequency power supplies according to the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0032] It should be noted that when one element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediary element. Furthermore, in the following embodiments, "connection" should be understood as "electrical connection," "communication connection," etc., if there is transmission of electrical signals or data between the connected objects.

[0033] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0034] To make the technical solution of the present invention clearer, the following is combined with... Figure 1 and Figure 2 The embodiments of the present invention will be described in detail.

[0035] like Figure 1 As shown, the present invention provides a frequency division controlled solid-state impedance matching device for radio frequency power supply. Its system structure mainly includes: radio frequency power supply, power control unit, communication interface module, digital signal processor, matching control module, matching network, switched capacitor controller and adjustable inductor controller, plasma load, radio frequency signal detection module and other components.

[0036] First, the RF power supply provides a high-frequency AC signal to the system, which is connected to the plasma load through a matching network. To ensure maximum power transmission, the system needs to achieve dynamic matching between the RF power supply output impedance and the load impedance. After processing by the power control unit and the RF signal detection module, the RF signal detection module collects forward power, reflected power, voltage, current, and phase information in real time, and feeds the detection results back to the digital signal processor.

[0037] like Figure 2 As shown, the signal sampling unit includes voltage sampling and current sampling modules, which respectively acquire the voltage across the load terminals. u (t) and current i (t). After pre-conditioning, the signal is sent to amplitude and phase detection to achieve control over the input impedance Z. L Real-time analysis is performed. Finally, the data is sent to the feedback controller for subsequent frequency band identification and matching control strategies. This invention employs a frequency division impedance matching control strategy:

[0038] The matching control module uses frequency data collected by the radio frequency signal detection module to divide the operating frequency into low-frequency and high-frequency bands. Based on the frequency band identification results, it switches the matching network, including:

[0039] In the low-frequency band, the matching control module uses an active magnetically controlled inductor, combined with a fuzzy PID control algorithm to adjust the bias current source and control the permeability to achieve coarse impedance matching.

[0040] In the high-frequency band, the matching control module adopts a control strategy of coarse inductor adjustment and fine capacitor adjustment: coarse adjustment is achieved by active magnetically controlled inductor to initially locate the impedance, and fine adjustment is achieved by the switched capacitor module. Combined with a lookup table algorithm and a fast switching mechanism, accurate matching in the high-frequency band is achieved.

[0041] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A frequency-division controlled solid-state impedance matching circuit for radio frequency power supplies, characterized in that, include: RF power supply, power control unit, communication interface module, digital signal processor, matching control module, matching network, switched capacitor controller and adjustable inductor controller, plasma load, RF signal detection module; The radio frequency power supply generates a high-frequency AC signal to provide a radio frequency power source with a fixed output impedance for the matching system; The power control unit dynamically adjusts the output power of the RF power supply, and adjusts the output power in real time according to the load status and the adjustment results of the matching network; The communication interface module enables the transmission of instructions and status between the radio frequency power supply and the digital signal processor. The digital signal processor receives feedback data from the radio frequency signal detection module, executes an impedance matching algorithm, and outputs control commands. The matching control module controls the adjustable inductor controller and the switched capacitor controller respectively according to the control instructions of the digital signal processor, so as to realize the dynamic adjustment of the impedance in the matching network. The matching network is located between the RF power supply and the plasma load, and includes an adjustable inductor module and a switched capacitor module to realize the impedance transformation of the system. The adjustable inductor controller is used to drive the adjustable inductor, and the switched capacitor controller is used to drive the switched capacitor array, so as to realize the dynamic adjustment of the inductor and capacitor parameters respectively. The plasma load ensures stable RF power output through real-time impedance matching. The radio frequency signal detection module collects forward power, reflected power, voltage, current and phase information in real time, and feeds the detection results back to the digital signal processor; The matching control module divides the operating frequency into low-frequency and high-frequency bands based on the frequency data collected by the radio frequency signal detection module, and switches the matching network according to the frequency band identification results, including: In the low-frequency band, the matching control module uses an active magnetically controlled inductor, combined with a fuzzy PID control algorithm to adjust the bias current source, control the permeability, and achieve coarse matching of the impedance network. In the high-frequency band, the matching control module adopts a control strategy of coarse inductor adjustment and fine capacitor adjustment: coarse adjustment is achieved by active magnetically controlled inductor to achieve initial impedance positioning, and fine adjustment is achieved by switched capacitor module. Combined with table lookup algorithm and fast switching mechanism, the impedance network is accurately matched.

2. The RF power supply solid-state impedance matching device according to claim 1, characterized in that, The adjustable inductor module includes a magnetic core structure. The magnetic core is made of high-frequency NiZn ferrite, and its permeability is controlled by a bias current source, making the inductance adjustable.

3. The RF power supply solid-state impedance matching device according to claim 1, characterized in that, The switched capacitor module consists of multiple sets of capacitor units and GaN device switches. By controlling the conduction state of the GaN device, the capacitance can be adjusted.

4. A control method for a frequency division controlled solid-state impedance matching circuit for a radio frequency power supply as described in claim 1, characterized in that, Includes the following steps: Step 1: The RF signal detection module collects the voltage, current, reflected power and phase information of the load in real time. The sampled data is transmitted to the digital signal processor after amplitude and phase detection. Step 2: The digital signal processor determines the current operating frequency using a frequency band identification algorithm; Step 3: If a low frequency band is detected, the matching control module drives the adjustable inductor controller to adjust the bias current source to change the magnetic core permeability, thereby achieving adjustable inductance and completing coarse matching. Step 4: If a high-frequency band is detected, first perform coarse adjustment through the adjustable inductor module, and then drive the switched capacitor controller to control the conduction state of the GaN device, so that the capacitor is adjustable and precise matching is achieved. Step 5: The adjusted data is sampled by the radio frequency signal detection module and fed back to the digital signal processor to form a closed-loop control.

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