Extreme value search control device and method with online parameter adjustment

Abstract

The power supply system includes: an RF power supply configured to generate an output signal at an output frequency; a signal source configured to generate a disturbance signal; an extremum search frequency controller configured to generate a frequency control signal based on the disturbance signal; and a frequency selector configured to select a perturbation frequency of the perturbation signal, the perturbation frequency being isolated from at least one frequency tone associated with the power supply system. The frequency control signal varies an output frequency of the RF power supply. Other example power supply systems, methods for controlling an RF generator, and control systems for controlling an RF generator are also disclosed.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 17 / 940,047, filed on September 8, 2022. The entire disclosure of the above application is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to RF generator systems and control of RF generators. Background Art

[0004] Plasma processing is often used in semiconductor manufacturing. In plasma processing, ions are accelerated by an electric field to etch material from or deposit material onto the surface of a substrate. In a basic embodiment, the electric field is generated based on an RF or DC power signal generated by a corresponding radio frequency (RF) or direct current (DC) generator of a power delivery system. The power signal generated by the generator must be precisely controlled to effectively perform plasma etching.

[0005] The background description provided here is for the purpose of generally presenting the context of the present disclosure. To the extent that the work of the presently named inventors is described in this background section and aspects of the description that may not constitute prior art at the time of filing are neither explicitly nor implicitly admitted to be prior art against the present disclosure. Summary of the invention

[0006] A system of one or more computers may be configured to perform specific operations or actions by installing software, firmware, hardware, or a combination thereof on the system, which software, firmware, hardware, or a combination thereof causes the system to perform actions in operation. One or more computer programs may be configured to perform specific operations or actions by including instructions that cause the device to perform actions when the instructions are executed by a data processing device. According to one aspect of the present disclosure, a power supply system for powering a load is disclosed. The power supply system includes: an RF power supply configured to generate an output signal at an output frequency; a signal source configured to generate a disturbance signal; an extreme value search frequency controller configured to generate a frequency control signal based on the disturbance signal; and a frequency selector configured to select a disturbance frequency of the disturbance signal, which is isolated from at least one frequency tone associated with the power supply system. The frequency control signal changes the output frequency of the RF power supply. Other embodiments of this aspect include corresponding computer systems, devices, and computer programs recorded on one or more computer storage devices, each of which is configured to perform the actions of the method.

[0007] Implementations may include one or more of the following features. A power system may include: a power controller coupled to an RF power source, wherein the power controller is configured to generate pulses to modulate an output signal of the RF power source, and wherein the pulses include a first state and a second state. A frequency selector may be configured to select a first perturbation frequency for the first state of the pulse and a second perturbation frequency for the second state, wherein the first perturbation frequency and the second perturbation frequency are different. The frequency selector may be configured to select a perturbation frequency for the first state and the second state of the pulse. A power system may include: a power controller coupled to an RF power source, wherein the power controller is configured to generate at least two pulses to modulate an output signal of the RF power source, wherein each pulse includes a first state and a second state, wherein the frequency selector is configured to select a first perturbation frequency for the first state of each of the at least two pulses and select a second perturbation frequency for the second state of each of the at least two pulses, and wherein the first perturbation frequency and the second perturbation frequency are different. The power system may include: a power controller coupled to an RF power source, wherein the power controller is configured to generate pulses to modulate an output signal of the RF power source, and wherein a frequency selector is configured to select a disturbance frequency based on a bandwidth of the power controller. The frequency selector may be configured to determine a first increment between a minimum value of the bandwidth and at least one frequency tone and a second increment between at least one frequency tone and a maximum value of the bandwidth, and select the disturbance frequency to be equal to a frequency value within the larger of the first increment and the second increment. The frequency value may be a midpoint of the larger of the first increment and the second increment. The frequency selector may be configured to analyze data indicating an operating parameter of the power system according to the selected disturbance frequency, and if the operating parameter is below a defined threshold, adjust the disturbance frequency within the larger of the first increment and the second increment. The frequency selector may be configured to analyze data indicating an operating parameter of the power system according to the adjusted disturbance frequency, and if the operating parameter is below a defined threshold, adjust the disturbance frequency again within the larger of the first increment and the second increment. The frequency selector may be configured to determine at least one frequency tone, wherein the at least one frequency tone may include an apparent frequency associated with a state of the pulse. The apparent frequency may be determined based on a duty cycle of the state, a repetition rate of the pulses, and a delay time associated with the state. The at least one frequency tone may include a first apparent frequency associated with a first state of the pulses and a second apparent frequency associated with a second state of the pulses, and the frequency selector may be configured to select a disturbance frequency isolated from the first apparent frequency and the second apparent frequency for the first state and the second state. The frequency selector may be configured to perform a transformation to analyze data of one or more feedback signals and determine at least one frequency tone based on the analyzed data. The frequency selector may be configured to adjust the disturbance frequency based on the analyzed data.The frequency selector may be configured to perform a transformation to analyze data of one or more feedback signals based on an output response according to a disturbance frequency. The frequency selector may be configured to adjust the disturbance frequency based on the analyzed data. The data may indicate an operating parameter of the power supply system, and the frequency selector may be configured to adjust the disturbance frequency if the operating parameter is below a defined threshold. The frequency selector may be configured to analyze data indicating the operating parameter of the power supply system based on the adjusted disturbance frequency, and if the operating parameter is below a defined threshold, adjust the disturbance frequency again. Implementations of the described technology may include hardware, methods or processes, or computer software on a computer accessible medium.

[0008] According to another aspect of the present disclosure, a method for controlling an RF generator of a power system includes: selecting a disturbance frequency of a disturbance signal, the disturbance frequency being isolated from at least one frequency tone associated with the power system; generating a disturbance signal having the selected disturbance frequency; and generating a frequency control signal based on the disturbance signal, wherein the frequency control signal changes the output frequency of the RF power supply. Other embodiments of this aspect include corresponding computer systems, apparatuses, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the method.

[0009] Implementations may include one or more of the following features. The method may include generating a pulse to modulate an output signal of an RF power supply, wherein the pulse includes a first state and a second state, and wherein selecting a perturbation frequency includes selecting a perturbation frequency for the first state and the second state of the pulse, or selecting a first perturbation frequency for the first state of the pulse and selecting a second perturbation frequency different from the first perturbation frequency for the second state. The method may include generating at least two pulses to modulate an output signal of an RF power supply, wherein each of the pulses includes a first state and a second state, and wherein selecting a perturbation frequency includes selecting a first perturbation frequency for the first state of each of the at least two pulses, and selecting a second perturbation frequency different from the first perturbation frequency for the second state of each of the at least two pulses. The method may include generating pulses to modulate an output signal of an RF power supply with a power controller, wherein selecting a perturbation frequency includes selecting a perturbation frequency based on a bandwidth of the power controller. The method may include determining a first increment between a minimum value of the bandwidth and at least one frequency tone and a second increment between at least one frequency tone and a maximum value of the bandwidth; and selecting the perturbation frequency to be equal to a frequency value within the larger of the first increment and the second increment. The frequency value may be a midpoint of the larger of the first increment and the second increment. The method may include analyzing data indicating an operating parameter of the power system according to the selected disturbance frequency, and if the operating parameter is below a defined threshold, adjusting the disturbance frequency within the larger of the first increment and the second increment. The method may include analyzing data indicating an operating parameter of the power system according to the adjusted disturbance frequency, and if the operating parameter is below a defined threshold, adjusting the disturbance frequency again within the larger of the first increment and the second increment. The method may include determining at least one frequency tone, wherein the at least one frequency tone may include an apparent frequency associated with a state of the pulse, and wherein determining at least one frequency tone includes determining the apparent frequency associated with the state of the pulse based on a duty cycle of the state, a repetition rate of the pulse, and a delay time associated with the state. The method may include selecting a disturbance frequency for the first state and the second state of the pulse, the disturbance frequency being isolated from a first apparent frequency associated with the first state of the pulse and a second apparent frequency associated with the second state of the pulse. The method may include performing a transformation to analyze data of one or more feedback signals, and determining at least one frequency tone based on the analyzed data. The method may include selecting a disturbance frequency based on the analyzed data. The method may include performing a transformation to analyze data of one or more feedback signals based on an output response according to a disturbance frequency. The method may include adjusting the disturbance frequency based on the analyzed data. The data may indicate an operating parameter of the power system, and the method may further include adjusting the disturbance frequency if the operating parameter is below a defined threshold.The method may include analyzing data indicative of an operating parameter of the power system based on the adjusted disturbance frequency, and if the operating parameter is below a defined threshold, adjusting the disturbance frequency again. Implementations of the described technology may include hardware, methods or processes, or computer software on a computer accessible medium.

[0010] According to another aspect of the present disclosure, a non-transitory computer-readable medium storing processor-executable instructions for controlling an RF generator of a power supply system is disclosed. The RF generator includes an RF power supply. The instructions include: selecting a disturbance frequency of a disturbance signal, the disturbance frequency being isolated from at least one frequency tone associated with the power supply system; generating a disturbance signal having the selected disturbance frequency; and generating a frequency control signal based on the disturbance signal, wherein the frequency control signal changes the output frequency of the RF power supply. Other embodiments of this aspect include corresponding computer systems, apparatuses, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the method.

[0011] Implementations may include one or more of the following features. The instructions may include: generating pulses with a power controller to modulate the output signal of the RF power supply, wherein selecting the disturbance frequency of the disturbance signal includes: selecting the disturbance frequency based on the bandwidth of the power controller. The instructions may include: determining a first increment between a minimum value of the bandwidth and at least one frequency tone and a second increment between at least one frequency tone and a maximum value of the bandwidth, wherein selecting the disturbance frequency of the disturbance signal includes: selecting the disturbance frequency to be equal to a frequency value within the larger of the first increment and the second increment. The frequency value may be the midpoint of the larger of the first increment and the second increment. The instructions may include: analyzing data indicating an operating parameter of the power system according to the selected disturbance frequency, and if the operating parameter is below a defined threshold, adjusting the disturbance frequency within the larger of the first increment and the second increment. The instructions may include: analyzing data indicating an operating parameter of the power system according to the adjusted disturbance frequency, and if the operating parameter is below a defined threshold, adjusting the disturbance frequency again within the larger of the first increment and the second increment. The instructions may include determining at least one frequency tone, wherein the at least one frequency tone includes an apparent frequency associated with a state of the pulse, and wherein determining at least one frequency tone includes determining the apparent frequency associated with the state of the pulse based on a duty cycle of the state, a repetition rate of the pulse, and a delay time associated with the state. The instructions may include determining at least one frequency tone, wherein the at least one frequency tone includes a first apparent frequency associated with a first state of the pulse and a second apparent frequency associated with a second state of the pulse, and wherein selecting a disturbance frequency of the disturbance signal includes selecting a disturbance frequency isolated from the first apparent frequency and the second apparent frequency for the first state and the second state. The instructions may include performing a transformation to analyze data of one or more feedback signals based on an output response according to the disturbance frequency, wherein the data indicates an operating parameter of the power system. The instructions may include adjusting the disturbance frequency if the operating parameter is below a defined threshold. The instructions may include analyzing data indicating an operating parameter of the power system according to the adjusted disturbance frequency, and adjusting the disturbance frequency again if the operating parameter is below the defined threshold. Implementations of the described technology may include hardware, methods or processes, or computer software on a computer-accessible medium.

[0012] According to another aspect of the present disclosure, a control system for controlling an RF generator of a power supply system includes: a signal source configured to generate a disturbance signal; an extreme value search frequency controller configured to generate a frequency control signal based on the disturbance signal; and a frequency selector configured to select a disturbance frequency of the disturbance signal, the disturbance frequency being isolated from at least one frequency tone associated with the power supply system. The frequency control signal changes the output frequency of the RF power supply. Other embodiments of this aspect include corresponding computer systems, apparatuses, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the method.

[0013] Implementations may include one or more of the following features. The control system may include: a power controller configured to generate pulses to modulate an output signal of an RF power supply, wherein the pulses include a first state and a second state, wherein the perturbation frequency is a first perturbation frequency, wherein the frequency selector may be configured to select the first perturbation frequency for the first state of the pulses and the second perturbation frequency for the second state, and wherein the first perturbation frequency and the second perturbation frequency are different. The control system may include: a power controller configured to generate pulses to modulate an output signal of an RF power supply, wherein the pulses include a first state and a second state, and wherein the frequency selector may be configured to select the perturbation frequency for the first state and the second state of the pulses. The control system may include: a power controller configured to generate at least two pulses to modulate an output signal of an RF power supply, wherein each of the at least two pulses includes a first state and a second state, wherein the perturbation frequency is a first perturbation frequency, wherein the frequency selector may be configured to select the first perturbation frequency for the first state of each of the at least two pulses, and select the second perturbation frequency different from the first perturbation frequency for the second state of each of the at least two pulses. The control system may include: a power controller configured to generate pulses to modulate an output signal of an RF power supply, wherein a frequency selector may be configured to select a disturbance frequency based on a bandwidth of the power controller. The frequency selector may be configured to determine a first increment between a minimum value of the bandwidth and at least one frequency tone and a second increment between at least one frequency tone and a maximum value of the bandwidth, and select the disturbance frequency to be equal to a frequency value within the larger of the first increment and the second increment. The frequency selector may be configured to determine at least one frequency tone. The frequency selector may be configured to perform a transformation to analyze data of one or more feedback signals, determine at least one frequency tone based on the analyzed data, and select the disturbance frequency based on the at least one frequency tone. The frequency selector may be configured to perform a transformation to analyze data of one or more feedback signals based on an output response according to the disturbance frequency, and adjust the disturbance frequency based on the analyzed data. The data may indicate an operating parameter of the power system, and the frequency selector may be configured to adjust the disturbance frequency if the operating parameter is below a defined threshold. Implementations of the described technology may include hardware, methods or processes, or computer software on a computer-accessible medium.

[0014] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims and drawings.The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present disclosure will be more fully understood from the detailed description and accompanying drawings.

[0016] Figure 1 is a schematic block diagram of a power delivery system having multiple power sources arranged in accordance with various configurations of the present disclosure;

[0017] Figure 2 The waveform of an RF signal and the waveform of a pulse modulating the RF signal are shown to describe a pulsed mode of operation;

[0018] FIG. 3A to FIG. 3B A schematic diagram showing a cost function as a function of cost and actuator frequency;

[0019] Figure 4 A block diagram of an RF power delivery system implementing an extremum seeking control (ESC) based method is shown;

[0020] FIG. 5A to FIG. 5B A diagram showing the apparent pulse frequency as a function of the pulse repetition rate and the duty cycle;

[0021] Figure 6 Schematic diagrams showing various waveforms associated with implemented sinusoidal frequency modulated signals;

[0022] Figure 7 shows a block diagram of an RF power delivery system arranged according to the principles of the present disclosure;

[0023] FIG. 8A to FIG. 8B An exemplary method of selecting a disturbance frequency based on the bandwidth of a power control loop, arranged according to the principles of the present disclosure, is shown;

[0024] Figure 9 to Figure 1 0 shows an exemplary method of selecting a perturbation frequency arranged according to the principles of the present disclosure;

[0025] FIG. 11A to FIG. 11B An exemplary method of selecting a disturbance frequency based on analyzed feedback data, arranged according to the principles of the present disclosure, is shown;

[0026] Fig.12 functional block diagrams showing example control modules arranged according to various configurations; and

[0027] Figures 13 to 16 A flow chart illustrating the operation of a control system for disturbance frequency selection, arranged according to the principles of the present disclosure.

[0028] In the drawings, reference numerals may be repeated to identify similar and / or identical elements. DETAILED DESCRIPTION

[0029] The power system may include a DC or RF power generator or a DC or RF generator, a matching network and a load (such as a processing chamber, a plasma chamber or a reactor with a fixed or variable impedance). The power generator generates a DC or RF power signal received by a matching network or an impedance optimization controller or circuit. The matching network or impedance optimization controller or circuit matches the input impedance of the matching network with the characteristic impedance of the transmission line between the power generator and the matching network. Impedance matching helps to maximize the amount of power forwarded to the matching network ("forward power") and minimize the amount of power reflected back from the matching network to the power generator ("reverse power" or "reflected power"). When the input impedance of the matching network matches the characteristic impedance of the transmission line and the generator, the delivered power to the load can be maximized by minimizing the reflected power.

[0030] In the field of power supplies or power supplies, there are generally two methods of applying a power signal to a load. The first, more traditional method, is to apply a continuous power signal to the load. In continuous mode or continuous wave mode, the continuous power signal is typically a constant DC or sinusoidal RF power signal that is continuously output by the power supply to the load. In the continuous mode method, the power signal exhibits a constant DC or sinusoidal output, and the amplitude and / or frequency (of the RF power signal) of the power signal can be varied in order to vary the output power applied to the load.

[0031] A second method of applying a power signal to a load involves pulsing the RF signal rather than applying a continuous RF signal to the load. In a pulsed or pulse modulated mode of operation, the RF signal is modulated by a modulating signal so as to define the envelope of the modulated power signal. The RF signal may be, for example, a sinusoidal RF signal or other time varying signal. The power delivered to the load is typically varied by varying the modulating signal.

[0032] In a typical power supply configuration, the output power applied to the load is determined by using sensors that measure the forward power and reflected power or the voltage and current of the RF signal applied to the load. Either set of these signals is analyzed in a control loop. This analysis typically determines the power value used to adjust the output of the power supply in order to change the power applied to the load. In a power delivery system where the load is a process chamber or other nonlinear or time-varying load, since the applied power is partly a function of the impedance of the load, the changing impedance of the load causes a corresponding change in the power applied to the load.

[0033] In systems where the manufacture of various devices relies on the introduction of power into a load to control the manufacturing process, power is typically delivered in one of two configurations. In the first configuration, power is capacitively coupled to the load. Such a system is referred to as a capacitively coupled plasma (CCP) system. In the second configuration, power is inductively coupled to the load. Such a system is typically referred to as an inductively coupled plasma (ICP) system. Power coupling to the plasma can also be achieved via wave coupling at microwave frequencies. This approach typically uses electron cyclotron resonance (ECR) or a microwave source. A helicon source is another form of wave coupling source and typically operates at an RF frequency similar to that of conventional ICP and CCP systems. The power delivery system may include at least one bias power and / or source power applied to one or more electrodes of the load. The source power typically generates plasma and controls plasma density, and the bias power modulates ions in the composition of the sheath. Depending on various design considerations, the bias and source may share the same electrode or separate electrodes may be used.

[0034] When the power delivery system drives a time-varying or nonlinear load (such as a processing chamber or a plasma chamber), the power absorbed by the bulk plasma and the plasma sheath results in an ion density with a certain ion energy range. A characteristic measure of ion energy is the ion energy distribution function (IEDF). The IEDF can be controlled using bias power. One way to control the IEDF of a system in which multiple RF power signals are applied to a load is to change multiple RF signals associated by amplitude, frequency, and phase. The relative amplitude, frequency, and phase of multiple RF power signals can also be associated by Fourier series and correlation coefficients. The frequencies between multiple RF power signals can be locked, and the relative phases between multiple RF signals can also be locked. Examples of such systems can be found with reference to U.S. Patent Nos. 7,602,127, 8,110,991, and 8,395,322, all of which have been assigned to the assignee of the present application and incorporated by reference into the present application.

[0035] Time-varying or nonlinear loads may be present in a variety of applications. In one application, a plasma processing system may also include components for plasma generation and control. One such component is a nonlinear load implemented as a processing chamber, such as a plasma chamber or reactor. A typical plasma chamber or reactor used in a plasma processing system such as, for example, for thin film manufacturing may use a dual power system. A power generator (source) controls the generation of plasma, and a power generator (bias) controls the ion energy. Examples of dual power systems include the systems described in U.S. Patent Nos. 7,602,127, 8,110,991, and 8,395,322 cited above. The dual power systems described in the patents cited above employ a closed-loop control system to adapt the power supply operation to achieve the purpose of controlling ion density and its corresponding ion energy distribution function (IEDF).

[0036] There are a variety of methods for controlling a processing chamber such as may be used to generate a plasma. For example, in an RF power delivery system, the phase and frequency of multiple drive RF signals operating at the same or nearly the same frequency may be used to control plasma generation. For RF driven plasma sources, the periodic waveforms and corresponding ion energies that affect the plasma sheath dynamics are generally known and controlled by the frequency and associated phase interactions of the periodic waveforms. Another method in an RF power delivery system involves dual frequency control. That is, two RF frequency sources operating at different frequencies are used to power a plasma chamber to provide substantially independent control of ion density and electron density.

[0037] Another approach utilizes broadband RF power to drive the plasma chamber. The broadband approach presents certain challenges. One challenge is coupling the power to the electrodes. A second challenge is that the transfer function of the generated waveform to the actual sheath voltage for the desired IEDF must be formulated for a wide process space to support material surface interactions. In a responsive approach in an inductively coupled plasma system, controlling the power applied to the source electrode controls the plasma density, while controlling the power applied to the bias electrode modulates the ions to control the IEDF, thereby providing etch rate control. By using source electrode control and bias electrode control, the etch rate is controlled via ion density and energy.

[0038] With the continuous development of integrated circuit and device manufacturing, the power requirements for controlling manufacturing processes are also constantly developing. For example, with the manufacture of memory devices, the demand for bias power continues to increase. The increased power produces higher energy ions to speed up surface interactions, thereby increasing the etching rate and directionality of the ions. In RF systems, increased bias power is sometimes accompanied by lower bias frequency requirements and an increase in the number of bias power supplies coupled to the plasma sheath generated in the plasma chamber. The increased power and the increased number of bias power supplies at lower bias frequencies result in intermodulation distortion (IMD) emissions from sheath modulation. IMD emissions can significantly reduce the power delivered by the source where plasma is generated. U.S. Patent No. 10,821,542, entitled "Pulse Synchronization by Monitoring Power in Another Frequency Band" issued on November 3, 2020, which has been assigned to the assignee of the present application and incorporated herein by reference, describes a method for pulse synchronization by monitoring power in another frequency band. In the cited US patent application, the pulses of the second RF generator are controlled based on the detection of the pulses of the first RF generator at the second RF generator, thereby synchronizing the pulses between the two RF generators.

[0039] Figure 1 An RF generator or power supply system 10 is depicted. The power supply system 10 includes a pair of radio frequency (RF) generators or power supplies 12a, 12b, matching networks 18a, 18b, and a load 32, such as a non-linear load, which may be a plasma chamber, a plasma reactor, a processing chamber, or the like. In various configurations, the RF generator 12a is referred to as a source RF generator or power supply, and the matching network 18a is referred to as a source matching network. Additionally, in various configurations, the RF generator 12b is referred to as a bias RF generator or power supply, and the matching network 18b is referred to as a bias matching network. It will be understood that reference numerals with and without letters, subscripts, or apostrophes may be used to refer to components individually or collectively.

[0040] In various configurations, the source RF generator 12a receives a control signal 30 from the matching network 18b and / or a control signal 30' from the bias RF generator 12b. The control signal 30 or 30' represents an input signal to the source RF generator 12a that indicates one or more operating characteristics or parameters of the bias RF generator 12b. In various configurations, a synchronization bias detector 34 senses the RF signal output from the matching network 18b to the load 32 and outputs a synchronization or trigger signal 30 to the source RF generator 12a. In various configurations, the synchronization or trigger signal 30' may be output from the bias RF generator 12b to the source RF generator 12a instead of the trigger signal 30. The difference between the trigger or synchronization signals 30, 30' may be caused by the effect of the matching network 18b, which may adjust the phase between the input signal to the matching network and the output signal from the matching network. Signals 30, 30' include information about the operation of biased RF generator 12b in various configurations to enable predictive responsiveness to account for periodic fluctuations in the impedance of load 32 caused by biased RF generator 12b. In the absence of control signals 30 or 30', RF generators 12a, 12b operate autonomously.

[0041] The RF generators 12a, 12b include respective RF power supplies or amplifiers 14a, 14b, sensors 16a, 16b, and processors, controllers, or control modules 20a, 20b. The RF power supplies 14a, 14b generate respective RF power signals 22a, 22b that are output to the respective sensors 16a, 16b. The RF power signals 22a, 22b pass through the sensors 16a, 16b and are provided to matching networks 18a, 18b as respective RF power signals f1 and f2. Although the sensors 16a, 16b are shown as being within the respective RF generators 12a, 12b, the sensors 16a, 16b may be located outside the RF power generators 12a, 12b. Such external sensing may occur at the output of the RF generator, at the input of an impedance matching device located between the RF generator and the load, or between the output of the impedance matching device (included within the impedance matching device) and the load.

[0042] The sensors 16a, 16b detect various operating parameters and output signals X and Y. The sensors 16a, 16b may include voltage sensors, current sensors and / or directional coupler sensors. The sensors 16a, 16b may detect (i) voltage V and current I and / or (ii) forward power P outputted from the corresponding power amplifiers 14a, 14b and / or RF generators 12a, 12b. FWD and the reverse power or reflected power P received from the corresponding matching network 18a, 18b or the load 32 connected to the corresponding sensor 16a, 16b REV . Voltage V, current I, forward power PFWD and reverse power P REV The signals X and Y may be scaled versions, filtered versions, or scaled and filtered versions of the actual voltage, current, forward power, and reverse power associated with the respective power sources 14a, 14b. The sensors 16a, 16b may be analog sensors or digital sensors or a combination thereof. In a digital implementation, the sensors 16a, 16b may include an analog-to-digital (A / D) converter and a signal sampling component with a corresponding sampling rate. The signals X and Y may represent the voltage V and the current I or the forward (or source) power P FWD , reverse (or reflected) power P REV Any one of .

[0043] The sensors 16a, 16b generate sensor signals X, Y that are received by respective controllers or power control modules 20a, 20b. The power control modules 20a, 20b process respective X, Y signals 24a, 26a and 24b, 26b and generate one or more feedforward or feedback control signals 28a, 28b to respective power supplies 14a, 14b. The power supplies 14a, 14b regulate the RF power signals 22a, 22b based on the received one or more feedback or feedforward control signals. In various configurations, the control modules 20a, 20b may control the matching networks 18a, 18b based on, for example, the X, Y signals 24a, 26a and 24b, 26b and via respective control signals 29a, 29b. In some configurations, the control signals 29a, 29b may be the same, similar, or different from the control signals 28a, 28b. The control modules 20a, 20b may include at least a proportional-integral (PI) controller, a proportional-integral-derivative (PID) controller, a linear-quadratic regulator (LQR), or a subset thereof and / or a direct digital synthesis (DDS) component and / or any of the various components described below in conjunction with the modules.

[0044] In various configurations, the control modules 20a, 20b may include functions, processes, processors or submodules. The control signals 28a, 28b may be control or drive signals that may transmit DC offset or mains voltage, voltage or current amplitude, frequency and phase components, etc. In various configurations, feedback control signals 28a, 28b may be used as inputs to one or more control loops. In various configurations, multiple control loops may include control loops for RF drive and for mains voltage. In various configurations, control signals 28a, 28b may be used in single-input single-output (SISO) or multiple-input multiple-output (MIMO) control schemes. An example of a MIMO control scheme may be found in U.S. Patent No. 10,546,724, entitled “Pulsed Bidirectional Radio Frequency Source / Load”, issued on January 28, 2020, which has been assigned to the assignee of the present application and is incorporated herein by reference. In other configurations, the signals 28a, 28b may provide feed-forward control as described in US Pat. No. 10,049,857, assigned to the assignee of the present application and incorporated herein by reference.

[0045] In various configurations, the power supply system 10 may include a controller 20'. The controller 20' may be disposed outside one or both of the RF generators 12a, 12b and may be referred to as an external or common controller 20'. In various configurations, the controller 20' may implement one or more functions, processes, or algorithms described herein with respect to one or both of the controllers 20a, 20b. Accordingly, the controller 20' communicates with the corresponding RF generators 12a, 12b via a pair of corresponding links 36, 38, which enable appropriate exchange of data and control signals between the controller 20' and the RF generators 12a, 12b. For various configurations, the controllers 20a, 20b, 20' may provide analysis and control in a distributed and collaborative manner with the RF generators 12a, 12b. In various other configurations, the controller 20' may provide control of the RF generators 12a, 12b, eliminating the need for corresponding local controllers 20a, 20b.

[0046] In various configurations, the RF power supply 14a, the sensor 16a, the controller 20a, and the matching network 18a may be referred to as the source RF power supply 14a, the source sensor 16a, the source controller 20a, and the source matching network 18a. Similarly, in various configurations, the RF power supply 14b, the sensor 16b, the controller 20b, and the matching network 18b may be referred to as the bias RF power supply 14b, the bias sensor 16b, the bias controller 20b, and the bias matching network 18b. In various configurations and as described above, the term "source" refers to an RF generator that generates a plasma, and the term "bias" refers to an RF generator that tunes the ion potential or IEDF of the plasma. In various configurations, the source RF power supply and the bias RF power supply operate at different frequencies. In various configurations, the source RF power supply operates at a higher frequency than the bias RF power supply. In various other configurations, the source RF power supply and the bias RF power supply operate at the same frequency or substantially the same frequency.

[0047] According to various configurations, the source RF generator 12a and the bias RF generator 12b include multiple ports for external communication. The source RF generator 12a includes a pulse synchronization output port 40, a digital communication port 42, and an RF output port 44 and a control signal port 60. The bias RF generator 12b includes an RF input port 48, a digital communication port 50, and a pulse synchronization input port 52. The pulse synchronization output port 40 outputs a pulse synchronization signal 56 to the pulse synchronization input port 52 of the bias RF generator 12b. The digital communication port 42 of the source RF generator 12a and the digital communication port 50 of the bias RF generator 12b communicate via a digital communication link 57. The control signal port 60 of the source RF generator 12a receives the control signal 30 and / or 30'. The RF output port 44 generates an RF control signal 58 input to the RF input port 48. In various configurations, the RF control signal 58 is substantially the same as the RF control signal that controls the source RF generator 12a. In various other configurations, the RF control signal 58 is the same as the RF control signal controlling the source RF generator 12 a, but is phase shifted within the source RF generator 12 a according to the requested phase shift generated by the bias RF generator 12 b. Thus, in various configurations, the source RF generator 12 a and the bias RF generator 12 b are driven by substantially the same RF control signal or by substantially the same RF control signal that is phase shifted by a predetermined amount.

[0048] Figure 2 A voltage versus time diagram is depicted to describe the voltage applied to a load such as Figure 1 The pulse or pulse modulation mode of operation of delivering power to the load 32). More specifically, Figure 2 Two multi-state pulses P1, P2 of the pulse signal 70 are depicted, each with multiple states S1 to S4 and S1 to S3. Figure 2 In the embodiment, the RF signal 80 is modulated by pulses P1 and P2. As shown at state S1 of P1 and state S1 of P2, when the pulse is on, the RF generator 12 outputs the RF signal 80, and the RF signal 80 has an amplitude defined by the pulse amplitude in each state. In contrast, during state S4 of P1 and state S3 of P2, the pulse is off and the RF generator 12 does not output the RF signal 80. The pulses P1, P2 can be repeated with a constant duty cycle or a variable duty cycle, and the states S1 to S4, S1 to S3 of each pulse P1, P2 can have the same or varying amplitudes and widths. In addition, the pulse signal 70 does not need to be as Figure 2 As shown in FIG. 7 , the pulse 70 may be a square wave. As non-limiting examples, the pulse 70 may be trapezoidal, triangular, Gaussian, or other shapes. Furthermore, the pulses P1, P2 may have a plurality of states S1, ..., Sn of varying amplitude, duration, and shape. The states S1, ..., Sn may be repeated in a fixed or variable period. In addition, Figure 2 As shown in , the RF signal 80 operates at a frequency that varies between states or within states.

[0049] In a typical RF power delivery system, the matching network (e.g. Figure 1 The matching network 18a) is used to achieve maximum power delivery to the load through the tunable mechanical components. The maximum power delivery indicates the minimum reflected power. Since the response time of the electromechanical tuning elements in the matching network is relatively slow, the adjustment of the matching network may take a relatively long time to complete the power adjustment. In order to improve the impedance matching, the impedance of the load by the power amplifier (e.g., Figure 1 The RF frequency of the power amplifier 14a) output is set to the frequency based tuning. Frequency based tuning improves performance and provides responsiveness that is several orders of magnitude faster than adjustment of the electromechanical components of the matching network.

[0050] When frequency-based impedance matching is employed, it is desirable to find the optimal frequency that provides the minimum reflected power. The minimum reflected power can be indicated by the minimum magnitude |Γ| of the measured complex reflection coefficient gamma. There are many existing methods for adjusting the RF frequency.

[0051] For example, automated frequency tuning is a standard method for high-speed impedance matching. By adjusting the RF carrier frequency, the RF generator steers to lower reflected power and compensates for transients in the load, even at pulse state change boundaries. Examples of automated frequency tuning methods include extreme value search control (ESC) methods and methods based on closed-form models (e.g., transfer functions). Examples of ECS-based methods for performing automatic or automated frequency tuning can be found in reference to U.S. Patent No. 10,741,363, which has been assigned to the assignee of the present application and is incorporated herein by reference.

[0052] The ESC method minimizes reflected power without requiring extensive process knowledge. The ESC method implements a dynamic adjustment mechanism to automatically tune the frequency along the gradient direction of a cost function without requiring an explicit model of the system or process. The cost function can generally be referred to as a functional equation that maps a set of points to a single scalar value. The scalar value obtained after evaluating the cost function can be referred to as the cost. For frequency tuning applications, the cost is sometimes related to the gamma squared or gamma magnitude squared (|Γ| 2 ) or the magnitude of an output response (e.g., delivered power). It is often desirable to minimize or maximize cost.

[0053] For example, Figure 3A Plotted as a function of the cost function J (or the square of the gamma magnitude (|Γ| 2 )) and actuator frequency U of the quadratic cost function 302 schematic diagram 300A. As shown, schematic diagram 300A includes a maximum value 304 and positions 306, 308 along the cost function 302, each position 306, 308 is on a different side of the maximum value 304. Accordingly, all points to the left of the maximum value 304 have a positive slope (or gradient), and all points to the right of the maximum value 304 have a negative slope. If it is desired to maximize the cost J, and the actuator frequency is at position 306, the actuator frequency can be increased, resulting in an increase in the cost J (or output response value). In other embodiments, if it is desired to maximize the cost J, and the actuator frequency is at position 308, the actuator frequency can be reduced, resulting in an increase in the cost J.

[0054] A similar relationship exists in association with the quadratic cost function having a minimum. For example, Figure 3B Plotted as a function of the cost function J (or the square of the gamma magnitude (|Γ| 2 )) and actuator frequency U of the quadratic cost function 310 schematic diagram 300B. As shown, schematic diagram 300B includes a minimum 312 and positions 314, 316 along the cost function 310, each position 314, 316 is on a different side of the minimum 312. Therefore, in this example, all points to the left of the minimum 312 have a negative slope, and all points to the right of the minimum 312 have a positive slope. If it is desired to minimize the cost J, and the actuator frequency is at position 314, the actuator frequency can be increased, resulting in a reduction in the cost J (or output response value). In other embodiments, if it is desired to minimize the cost J, and the actuator frequency is at position 316, the actuator frequency can be reduced, resulting in a reduction in the cost J.

[0055] In order to FIG. 3A to FIG. 3BIn order to maximize or minimize the cost J in the cost function, it is desirable to understand the directionality of the actuator frequency U required to move the cost function toward the minimum or maximum value. In some ESC methods, this can be achieved by injecting a sinusoidal disturbance signal over multiple cycles on the actuator to detect the response of the system to the changed actuator frequency (e.g., the change in the cost function). For example, based on the sinusoidal disturbance signal, the output response value changes, and its amplitude and direction depend on its current position (e.g., FIG. 3A to FIG. 3B The output response values ​​may be processed to estimate the local slope (or gradient) of the cost function (e.g., cost function 302, 310), which in turn indicates the direction of the actuator frequency adjustment required to move toward the minimum or maximum point. An example of an ESC method using a sinusoidal disturbance signal may be found in U.S. Pat. No. 10,741,363.

[0056] Figure 4 An example of a power delivery system 400 including an RF generator 410 implementing an ESC-based approach is depicted. As shown, the power delivery system 410 provides an output to a matching network 412, which in turn provides an output to a load 414 (such as a nonlinear load or a plasma chamber). The RF generator 410 includes a power controller 416, a power amplifier 418, and a sensor 420. The sensor 420 can be implemented as one of a voltage / current sensor (VI sensor) or a directional coupler, as described above. The power controller 416 outputs an actuation signal that is input to the power amplifier 418. Signal represents the power control signal in response to the feedback signal. The power amplifier 418 is The sensor 420 outputs the RF signal to the matching network 412 to supply the load 414. The sensor 420 outputs the feedback signal X, Y to the block 422. In various embodiments, the block 422 can be a scaling or calibration module that scales X and Y to output predetermined electrical parameters. The block 422 outputs the positive power value to the adder 424. Summer 424 also receives a power set point input and determines the power set point input and the forward power value The difference between fb ). Error e fb is input to the power controller 416. The error signal e input to the power controller 416 fb Determine the power amplifier 418 to be operated by the power controller 416 expectation adjustment.

[0057] Block 422 also outputs the magnitude of the reflection coefficient |Γ|. The magnitude of the reflection coefficient |Γ| is input to block 426, which implements a transfer function D filt (z) is high-pass filtered to remove any DC offset. The filtered amplitude of |Γ| is input to mixer 423. Mixer 423 also receives a disturbance signal generated by signal source 429 As shown in the figure, the disturbance signal It is represented as a sinusoidal signal sin(ω pert t), and has a sinusoidal or perturbation frequency ω pert The mixer 423 will disturb the signal The output of mixer 423 represents the disturbance signal The output from mixer 423 is input to integrator D esc (z) 425, integrator 425 generates a frequency control or frequency feedback signal which is input to a signal combiner or adder 427 Therefore, the feedback signal With disturbance signal Combined to generate a feedback component or frequency control signal Feedback component or frequency control signal It can be described in the following equation (1):

[0058]

[0059] in:

[0060] is the frequency tuning signal component used to adjust the frequency to achieve automatic frequency tuning of the power transmission system, and

[0061] is the disturbance signal component serving as the disturbance signal.

[0062] u t esc The signal can be a complete frequency control signal (center frequency and AFT offset), or just an automated frequency tuning (AFT) offset from the center frequency. In various non-limiting embodiments, if the center frequency of the system is 13.56 MHz, then u t esc The signal may represent an offset from 13.56 MHz to enable automated frequency tuning, or may be the desired output frequency, such as 13.58 MHz.

[0063] In various other embodiments, adder 427 may output a matching control signal u generated in a manner similar to equation (1) above: t’esc , used to control the operation of the matching network 412. In various other embodiments, the signal u t’ esc One of the impedance tuning actuators, such as a reactive component embodied as a capacitor or an inductor, may be controlled to vary the reactance of the matching network 412 .

[0064] In various embodiments, the signals generated in system 400 may be corrupted by various signals or noise sources having the same or similar frequencies. For example, signals used to generate frequency control or frequency feedback signals The disturbance signal may be similar in frequency (and in some cases identical) to various other signals or noise sources in the system. This in turn may disrupt the ability of the system to measure or otherwise use the output response (or the gamma magnitude squared of the output) and / or other signals of interest. Therefore, it is desirable to select a frequency of the disturbance signal that is within the spectrum without other strong signal content (e.g., other frequency tones). This allows the final signal of interest to be isolated so that the local gradient of the cost function can be reliably and accurately measured.

[0065] One source of interference can come from the pulse train itself. For example, frequency tuners are typically static because each tuner is receiving data related to one state of the pulse(s). Therefore, an "apparent" pulse frequency can be generated that moves around based on the pulse settings. For example, the apparent pulse frequency associated with each state can be calculated based on the duty cycle of the state, the repetition rate of the pulse, and the delay time associated with the state, as shown below in equation (2):

[0066]

[0067] in:

[0068] T Pulse is the pulse period, and throughout the pulse repetition rate is equal to 1,

[0069] Duty Cycle is the percentage of the state width throughout the entire pulse, and

[0070] Holdoff_Time is the period of time that the tuner remains idle while transitioning between pulse states.

[0071] For example, for a pulse repetition rate of 2kHz, with a delay time of 50 microseconds and a 20% duty cycle in one of the pulse states, the tuner will see an effective frequency content (apparent frequency) of 20kHz from the pulse train itself. If the duty cycle is changed from 20% to 15%, the apparent pulse frequency moves to 40kHz.

[0072] For example, FIG. 5A to FIG. 5BDepicted are schematic diagrams 500A, 500B showing the apparent pulse frequency (Y-axis) as a function of the pulse repetition rate (X-axis), duty cycle, and delay time calculated according to equation (2) above. FIG. 5A to FIG. 5B In the example above, the delay time is constant. Figure 5A The delay time in Figure 5B The delay time in and the pulse repetition rate range between values ​​x1 and x2. In addition, Figure 5A The apparent pulse frequency in ranges between value y1 (e.g., 0 Hz) and value y2, and Figure 5B The apparent pulse frequency in ranges between value y1 and value y3. In this example, Figure 5B The value of y3 is greater than Figure 5A The value of y2. FIG. 5A to FIG. 5B Each line 502, 504, 506, 508, 510, 512, 514, 516 of represents the apparent pulse frequency relative to the change in pulse repetition rate while achieving a different duty cycle. For example, lines 502, 510 represent the apparent pulse frequency as a function of the pulse repetition rate and a first duty cycle, lines 504, 512 represent the apparent pulse frequency as a function of the pulse repetition rate and a second duty cycle, lines 506, 514 represent the apparent pulse frequency as a function of the pulse repetition rate and a third duty cycle, and lines 508, 516 represent the apparent pulse frequency as a function of the pulse repetition rate and a fourth duty cycle.

[0073] As in FIG. 5A to FIG. 5B As can be seen in , for many combinations of repetition rate and duty cycle, these data indicate that a high perturbation frequency may be acceptable. However, if the repetition rate is moved, for example, to a higher rate, the perturbation frequency may be too close to the apparent pulse frequency and cause the desired gradient measurement to be corrupted. In fact, in various embodiments, the apparent pulse frequency may fall exactly at the perturbation frequency. Therefore, although FIG. 5A to FIG. 5B The data in can show that choosing a relatively high perturbation frequency can provide some assurance against the effects of the pulse repetition rate, but small changes in the settings can significantly affect the final apparent pulse frequency. Therefore, only small changes to, for example, the delay time, duty cycle and / or repetition rate can greatly affect the final apparent pulse frequency and cause interference with the perturbation frequency.

[0074] Furthermore, in some embodiments, choosing a high disturbance frequency can lead to other problems in the control system. For example, a frequency tuner constantly modulates the load impedance with its sinusoidal disturbance signal, and Figure 4The power controller 416 of the power controller may control the power amplifier in dependence on the sensed parameters from the load. If the power controller (more specifically, the power control loop) does not have sufficient bandwidth, such disturbances will penetrate and affect the delivered power to the load. Therefore, in many cases, a higher disturbance frequency to the frequency tuning loop may result in a lower ability of the power control loop to suppress such disturbances. This can be Figure 6 It can be seen in.

[0075] For example, Figure 6 Various waveforms 602, 604, 606, 608, 610, 612 are depicted, representing forward power, measured delivered power, actual power set point, gamma magnitude squared, power drive signal, and sinusoidal frequency modulated signal. Figure 6 As can be seen in the graph of FIG604 , the effect of the 40 kHz sinusoidal frequency modulation (waveform 612) is clearly visible in the measured delivered power (waveform 604). For example, it is desirable to deliver constant power to a load. However, the 40 kHz sinusoidal frequency modulation results in a delivered power variation (e.g., swing or ripple) of + / - 5% of the delivered power. This is because the power control loop does not have sufficient bandwidth to handle the 40 kHz sinusoidal frequency modulation. However, if the disturbance frequency is within the bandwidth of the controller, the controller is able to compensate for the impedance fluctuations caused by the frequency tuning loop and maintain constant delivered power.

[0076] In view of the above, and as recognized by the inventors, it is desirable to select a disturbance frequency of the disturbance signal that satisfies various design constraints. For example, and as further explained herein, the disturbance frequency is in a window that avoids other signal content (frequencies) that would interfere with the gradient measurement. In other words, the selected disturbance frequency is isolated from other frequency tones in the system (e.g., frequency tones associated with the RF generator utilizing the disturbance signal, other RF generators in the system, load components such as plasma chamber components, controllers in the system, etc.). In addition, the disturbance frequency is small enough (e.g., less than the bandwidth limit) to avoid interference with the power control loop and / or large enough to avoid low-frequency content that is not associated with the disturbance signal.

[0077] The present disclosure provides various solutions for selecting and / or adjusting the disturbance frequency of the disturbance signal that satisfies one or more of these various design constraints. For example, the disturbance frequency can be dynamically selected, adjusted, etc., so that it is below the bandwidth limit of the power control loop while being sufficiently isolated from other frequency tones in the system (e.g., apparent pulse frequency, harmonics, etc.). This can occur while the system is being used (e.g., online) rather than in the design phase, and can be based on current operating conditions. By doing so, the tuning performance of the ESC-based automated frequency tuning system is improved because the signal of interest can be reliable and available (e.g., not corrupted).

[0078] In addition, and as further explained herein, the perturbation frequency can be selected for various situations. For example, based on the operating conditions, a single perturbation frequency can be selected for each state of a pulse, a single perturbation frequency can be selected for the entire pulse, a single perturbation frequency can be selected for each corresponding state of multiple pulses (e.g., one perturbation frequency for state S1 of each pulse, another perturbation frequency for state S2 of each pulse, etc.).

[0079] Figure 7 An example of a power delivery system 700 including an RF generator 710 implementing an ESC-based approach is depicted, wherein the disturbance frequency may be ideally selected according to the teachings herein. As shown, the power delivery system 700 includes Figure 4 The RF generator 710 includes a matching network 412 and a load 414 and an RF generator 710 for providing an output to the load 414. The RF generator 710 includes Figure 4 The RF generator 710 includes a power controller 416, a power amplifier 418, a sensor 420, a control block 422 (e.g., including a scaling or calibration module), a mixer 423, an adder 424, a control block 425 (e.g., including an integrator), a control block 426 (e.g., including a high-pass filter), a signal combiner or adder 427, and a disturbance signal source 429. These components function and interact in a similar manner to that explained above. In addition, the RF generator 710 includes a frequency selector control block (or module) 702 for selecting the disturbance signal generated by the signal source 429. The expected disturbance frequency.

[0080] According to various embodiments, the various parts of the RF generator 710 can be considered to cooperate with each other to define a frequency controller such as an extremum search frequency controller. For example, in various embodiments, the frequency controller can include all or part of the mixer 423, the control block 425, the adder 427, the disturbance signal source 429, and / or the frequency selector block 702. In other embodiments, the frequency controller can include, for example, the control block 425 and receive a signal based on the disturbance signal from the signal source 429. In addition, according to various embodiments, Figure 7 Individual parts or all control elements can be used such as Figure 1 For example, in Figure 7 In the embodiment, part or all of the power controller 416, the control block 422, the mixer 423, the adder 424, the control block 425, the control block 426, the adder 427, the disturbance signal source 429 and / or the frequency selector control block 702 may be implemented as Figure 1 Controllers 20a, 20b, 20'.

[0081] In various embodiments, the frequency selector block 702 can determine one or more frequency tones associated with the RF generator 710 and / or other RF generators in the system 700, and then select a perturbation frequency that is isolated from the frequency tone(s). For example, the frequency selector block 702 can extract or otherwise receive various known operating parameters, and then select a desired perturbation frequency based on these operating parameters. For example, the operating parameters can include harmonic aliasing, a pulse repetition rate associated with the RF generator 710, a state duty cycle and / or delay time, an operating frequency associated with the RF generator 710 and / or one or more other RF generators in the system 700, and the like. In various embodiments, the operating frequency of the RF generator can produce a beat frequency tone (e.g., a difference between the operating frequencies of the RF generators). Based on this data or a portion thereof, the frequency selector block 702 can calculate the apparent frequency (e.g., frequency tone) associated with a particular state of the pulse as explained above, and then select an appropriate perturbation frequency to avoid the apparent frequency, any related frequencies (e.g., harmonics of the apparent frequency), and other frequency tones (e.g., beat frequency tones). In other words, the perturbation frequency can be selected to ensure robust separation from the apparent frequency, its related frequencies, and / or other known frequency tones.

[0082] The operating parameters may include information for a single state for a pulse, multiple states for a single pulse, multiple states for multiple pulses, etc. Thus, the frequency selector block 702 may calculate or otherwise determine an apparent frequency associated with a single state in a pulse and / or an apparent frequency associated with multiple states in a pulse (or multiple pulses) based on the provided operating parameters. In some examples, the apparent frequency for one state may be the same as or different from the apparent frequency for another state.

[0083] Once the apparent frequency for a single state or the apparent frequencies for multiple states are determined, the frequency selector block 702 can select an appropriate disturbance frequency. For example, the frequency selector block 702 can select a single disturbance frequency for each different state in the pulse. For example, this may be necessary if the apparent frequencies of the multiple states determined are such that no suitable frequency can be used to avoid each apparent frequency. In other examples, based on operating parameters, the same disturbance frequency can be selected and used for multiple states of the pulse (if applicable), multiple corresponding states of multiple pulses (if applicable). For example, the frequency selector block 702 can determine that multiple states in one or more pulses have sufficiently similar apparent frequencies to allow selection of a single disturbance frequency that can avoid each of the apparent frequencies.

[0084] In other embodiments, and as further explained below, the frequency selector block 702 can determine one or more frequency tones associated with the RF generator 710 based on measured feedback and analysis of the feedback. For example, the frequency selector block 702 can perform a transform (e.g., a fast Fourier transform (FFT)) to analyze data of one or more feedback signals (e.g., gamma magnitude squared, reflected power, etc.) and determine one or more frequency tones based on the analyzed data. Once the frequency tones are determined, the frequency selector block 702 can select an appropriate perturbation frequency to avoid the frequency tones.

[0085] Additionally, when selecting the perturbation frequency, the frequency selector block 702 may consider the bandwidth limitations of the power controller 416. For example, the frequency selector block 702 may select a frequency that is below a known control bandwidth limit while also avoiding frequency tones (e.g., the apparent pulse frequency of each state).

[0086] FIG. 8A to FIG. 8B An example method of such selection is depicted. For example, and as FIG. 8A to FIG. 8B , the frequency selector block 702 can receive or otherwise determine a bandwidth limit 804 of a control loop, such as a power control loop associated with the power controller 416. After determining a frequency tone, such as an apparent frequency, the frequency selector block 702 can select an optimal disturbance frequency to avoid both the frequency tone and the bandwidth limit 804.

[0087] For example, in Fig. 8A , the apparent frequency 806 is determined to be closer to the bandwidth limit 804 than the DC value (0 Hz) 802 of the bandwidth. In other words, the delta 1 between the DC value 802 and the apparent frequency 806 is greater than the delta 2 between the apparent frequency 806 and the bandwidth limit 804. In such an example, the frequency selector block 702 selects the disturbance frequency 808 to fall within the delta 1 ( Fig. 8A In other words, the disturbance frequency 808 is set equal to the frequency value or point within increment 1.

[0088] However, in Figure 8B , the apparent frequency 816 is determined to be closer to the DC value 802 than the bandwidth limit 804. Thus, the delta 2 between the apparent frequency 816 and the bandwidth limit 804 is greater than the delta 1 between the DC value 802 and the apparent frequency 816. Therefore, in this example, the frequency selector block 702 selects the disturbance frequency 818 to fall within the delta 2 ( Figure 8B In other words, the disturbance frequency 818 is set equal to the frequency value or point within increment 2.

[0089] In various embodiments, the frequency selector block 702 selects the perturbation frequency so that it falls at the midpoint of the larger increment. Fig. 8A In , the disturbance frequency 808 is selected so that it falls at the midpoint of increment 1, while in Figure 8B , the disturbance frequency 818 is selected so that it falls at the midpoint of increment 2. This can ensure that the disturbance frequency is sufficiently far from the bandwidth limit 804, the DC value 802, and the apparent frequency 816. Therefore, this can ensure that the disturbance frequency is small enough (e.g., less than the bandwidth limit) to avoid disturbances to the power control loop, large enough to avoid low-frequency content that is not related to the disturbance signal, and isolated from the apparent frequency 816. Otherwise, if the disturbance frequency is too close to the apparent frequency 816, the frequency controller may not be able to tune to the minimum or maximum value of the cost function (or the squared gamma magnitude), and instead, tune to another less desirable value.

[0090] In other embodiments, the frequency selector block 702 may select another perturbation frequency that is not necessarily at the midpoint of the largest increment while still maintaining a sufficient distance from the bandwidth limit 804, the DC value 802, and the apparent frequency 816. For example, the frequency selector block 702 may select the smallest possible perturbation frequency in any increment (larger or smaller) that is at least a minimum distance from the apparent pulse frequency 816 (e.g., + / - 2.5 kHz, + / - 5 kHz, etc.) while also maintaining a defined distance from the DC value 802 or the bandwidth limit 804 (e.g., 5 kHz, 10 kHz, etc., depending on other frequency tones in the system, the value of the bandwidth limit, etc.).

[0091] In various embodiments, the frequency selector block 702 may select an initial disturbance frequency so that it falls at a specific point or frequency value (e.g., midpoint, not at midpoint, etc.) within one of increment 1 and increment 2, and then adjust the disturbance frequency to another point or frequency value in the increment. For example, once the frequency selector block 702 determines the initial disturbance frequency, data from the feedback signal (e.g., gamma amplitude squared or another signal) may be observed and analyzed. If the feedback signal indicates that the operating parameters of the system 700 and / or the RF generator 710 meet a threshold (e.g., the swing of the delivered power is below a defined threshold, etc.), the frequency selector block 702 may adjust the disturbance frequency to another point further away from, for example, the apparent pulse frequency 816. The adjustment of the disturbance frequency may be repeated until the feedback signal indicates that the threshold is not met (e.g., the swing of the delivered power is at a defined threshold). Therefore, in such an example, the distance from the apparent pulse frequency 816 may be increased while still maintaining a sufficient distance from the bandwidth limit 804 and the DC value 802.

[0092] In some embodiments, it may be desirable to use the same perturbation frequency for multiple pulse states. This may allow some common elements (e.g., a high pass filter in a feedback loop) to be reused across multiple pulse states. As a result, in some implementations such as FPGA implementations that utilize at least some common elements, improved resource usage efficiency may be achieved. In these embodiments, a single perturbation frequency would then need to be selected.

[0093] For example, known pulse settings and pulse state delays can be analyzed to calculate the apparent pulse frequencies that the tuner will see for each state. Using this information, desired exclusion bands (e.g., frequency bands around each apparent pulse frequency) can be identified as operating regions that should be avoided.

[0094] Figure 9 to Figure 1 0 depicts an example method for such selection. For example, in Fig. 9, a schematic diagram 900 is depicted showing an apparent pulse frequency curve for a pulse configuration for a defined delay time and four different values ​​of pulse state duty cycle. As shown, exclusion band 902 is centered on the apparent pulse frequency curve at a first duty cycle value, exclusion band 904 is centered on the apparent pulse frequency curve at a second duty cycle value, exclusion band 906 is centered on the apparent pulse frequency curve at a third duty cycle value, and exclusion band 908 is centered on the apparent pulse frequency curve at a fourth duty cycle value. In this embodiment, each exclusion band 902, 904, 906, 908 represents a region of 5 kHz on each side of its corresponding apparent frequency curve.

[0095] Once the exclusion band is identified, the frequency selector block 702 can select a single perturbation frequency for multiple pulse states based on, for example, the pulse repetition rate. Fig. 9 The exclusion bands or zones can be superimposed with a specific pulse repetition rate to identify possible perturbation frequencies, thereby avoiding each of the exclusion bands or zones.

[0096] For example, Fig. 10A Depicted Fig. 9 1000A is a schematic diagram of the final superposition of the exclusion band or region of the first pulse repetition rate. As shown, line 1002 has a value of 0 from frequency value x0 (e.g., 0 Hz (DC)) to frequency value x1, which indicates that the perturbation frequency is not appropriate in this region. This represents the first pulse repetition rate. Fig. 9 Then, line 1002 has a value of 1 from frequency value x1 to frequency value x2, which indicates that the perturbation frequency is appropriate in this second zone. This represents Fig. 9 The exclusion bands 904, 902. Line 1002 has a value of 0 again from frequency value x2 to frequency value x3, which indicates that the perturbation frequency is not appropriate in this region. This represents Fig. 9 Then, line 1002 has a value of 1 again from frequency value x3 to frequency value x4, which indicates that the perturbation frequency may be suitable in this region. This represents Fig. 9 The region between the exclusion band 902 of the power control loop and the bandwidth limit of the power control loop. In such an example, the frequency selector block 702 can identify the largest suitable region (e.g., between frequency values ​​x1 and x2) and select the perturbation frequency in the region (e.g., at the midpoint between frequency values ​​x1 and x2) for a plurality of pulse states having a first pulse repetition rate.

[0097] Fig. 10B Depicted is a schematic diagram 1000B similar to schematic diagram 100A, but having Fig. 9The exclusion band or region is relative to the final superposition of a second pulse repetition rate greater than the first pulse repetition rate. As shown, line 1004 has a value of 0 from frequency value x0 (e.g., 0 Hz (DC)) to frequency value x5 (representing the second pulse repetition rate). Fig. 9 The frequency selector block 702 may further include a frequency value x5 having a value of 1 (representing a region between the exclusion bands 906, 904) from the frequency value x5 to the frequency value x6 (representing a region between the exclusion bands 906, 904), a value of 0 (representing the exclusion band 904) from the frequency value x6 to the frequency value x7, and a value of 1 (representing a region between the exclusion band 904 and the bandwidth limit of the power control loop) from the frequency value x7 to the frequency value x8. In such an example, the frequency selector block 702 may again identify the largest suitable region (between the frequency values ​​x7 and x8) and select a perturbation frequency in the region (e.g., at a midpoint between the frequency values ​​x7 and x8) for a plurality of pulse states having a second pulse repetition rate.

[0098] In various embodiments, the frequency selector block 702 may consider the entire set of pulse conditions in order to select the most appropriate single perturbation frequency for multiple pulses. FIG. 10A to FIG. 10B The logical AND of the two contour lines shown in will indicate that a particular operating disturbance frequency is most appropriate.

[0099] In various embodiments, the acceptable operating region (or conversely, the undesirable exclusion band) can vary with the pulse repetition rate and duty cycle. For example, Fig. 10C Depicted Fig. 9 1000C shows the resulting superposition of the exclusion band or region of the four pulse states with respect to three different repetition rates (represented by lines 1006, 1008, 1010) and four different duty cycles. Using the data from the schematic 1000C, the frequency selector block 702 can calculate Fig. 10C The logical AND of the three contour lines shown in , to generate Fig. 10D Schematic diagram 1000D. As shown, schematic diagram 1000D includes line 1012, line 1012 has a value of 0 from frequency value x0 (e.g., 0 Hz (DC)) to frequency value x9, which indicates an unsuitable zone for the disturbance frequency, and has a value of 1 from frequency value x9 to frequency value x10, which indicates a suitable zone for the disturbance frequency. In such an example, frequency selector block 702 can select the disturbance frequency in the suitable zone (e.g., at the midpoint between frequency values ​​x9 and x10) for multiple pulses having any one of three different pulse repetition rates.

[0100] In some cases, the overlap constraint may not produce a single perturbation frequency across the entire pulse set. Therefore, in such an example, the frequency selector block 702 may iteratively identify a minimum set of suitable operable perturbation frequencies. In such a scenario, instead of calculating Fig. 10C The frequency selector block 702 can calculate the sum of the contour lines by logically ANDing the three contour lines shown in . The frequency that produces the largest sum indicates the frequency that satisfies the most overlapping pulse constraints. By selecting the frequency with the largest sum, the frequency selector block 702 can then exclude these pulse conditions and recalculate the sum under the remaining (not included) pulse conditions. In this way, by selecting the frequency with the largest sum, the frequency selector block 702 can iteratively identify the minimum set of perturbation frequencies required to satisfy all pulse conditions in a given method.

[0101] In various embodiments, the frequency selector block 702 may also consider other frequency tones that may be present in the system (e.g., in addition to the apparent pulse frequency) when selecting the disturbance frequency. In other words, the frequency selector block 702 may determine other frequency tones that should be avoided. For example, the frequency selector block 702 may consider known harmonic aliasing for one of the RF frequencies (e.g., harmonics of the apparent pulse frequency), beat frequencies occurring between two RF carrier frequencies, and / or disturbance frequencies associated with another RF generator (e.g., when the RF generators generate pulses in harmony). These additional frequency tones may appear in the form of a single frequency or an exclusion band (a set of frequencies to be avoided) as explained above. For example, using the frequency selection method described above, the frequency selector block 702 may select a suitable disturbance frequency that is isolated (e.g., avoided) from such frequency tones or constraints by selecting the disturbance frequency via an overlapping constraint.

[0102] In some embodiments, potential interfering signal content including apparent pulse frequency and other frequency tones can be determined by online frequency analysis. This can identify potential unexpected signal content (e.g., strong harmonics) that may disrupt gradient measurements. For example, the frequency selector block 702 can collect a set of feedback data (gamma amplitude squared, reflected power, etc.) under a given operating pulse, state in a pulse, etc., and perform a transform (e.g., a fast Fourier transform (FFT)) to analyze the data. Based on the transform analysis, the frequency selector block 702 can determine possible interfering signal content (e.g., interfering frequency tones).

[0103] For example, Fig.11A A schematic diagram 1100A is depicted, which shows a data spectrum (amplitude and frequency) for an operating condition based on feedback data analyzed using FFT. As shown, the schematic diagram 1100A includes multiple potential interfering frequency tones 1102, 1104, 1106A to 1106I. Specifically, in Fig.11A , frequency tone 1102 represents the identified apparent pulse frequency, frequency tone 1104 represents harmonics of the identified apparent pulse frequency 1102, and frequency tones 1106A to 1106I represent other potential interfering signals (which cannot be identified). Once the potential interfering signal content is determined, the frequency selector block 702 can identify one or more suitable regions (e.g., the largest region) between the frequency tones 1102, 1104, 1106A to 1106I, and then select a disturbance frequency for each state, multiple states in a pulse, or multiple corresponding states in multiple pulses in one of these regions. For example, based on the determined signal content, the frequency selector block 702 may select the disturbance frequency so that it falls within the region between frequency tones 1106C to 1106D (e.g., at the midpoint between frequency tones 1106C to 1106D) or within the region between frequency tones 1106E to 1106F (e.g., at the midpoint between frequency tones 1106E to 1106F).

[0104] Furthermore, in some embodiments, a disturbance frequency may be initially selected (e.g., by frequency selector block 702), and frequency selector block 702 may collect and analyze (by performing, e.g., FFT) a set of feedback data based on the output response to the disturbance frequency, across a given operating pulse, state in a pulse, etc. In doing so, frequency selector block 702 may determine potential interfering signal content near the disturbance frequency.

[0105] For example, Fig. 11B Depicted with Fig.11A Schematic 1100A is similar to schematic 1100B, but shows the data spectrum (amplitude and frequency) of the output response based on the selected disturbance frequency. Specifically, schematic 1100B includes Fig.11A 1104, 1106A to 1106I and disturbance frequency 1108. Based on the data in schematic 1100B, it can be seen that disturbance frequency 1108 is located near multiple frequency tones (e.g., tones 1104, 1106D, 1106E). Therefore, in this example, frequency selector block 702 can select another disturbance frequency or adjust disturbance frequency 1108 based on the output response. For example, and similar to Fig.11A , the frequency selector block 702 may select another disturbance frequency or adjust the disturbance frequency 1108 to fall within the region between frequency tones 1106C to 1106D or within the region between frequency tones 1106E to 1106F. In various embodiments, a data spectrum (amplitude and frequency) based on the output response of the newly selected disturbance frequency may be created to ensure that the new frequency does not strongly overlap with another signal source.

[0106] In various embodiments, the desired disturbance frequency can be determined during the online learning / training phase. For example, during the online learning / training phase, the disturbance frequency value can be determined, selected, etc. for different settings (e.g., different pulse conditions, etc.). In some examples, the disturbance frequency value can be selected based on the data provided by the transformation, as explained herein. In this way, one or more specific disturbance frequency values ​​can be applied each time a specific setting is implemented in the future. In addition, when a new setting with different operating conditions is developed, one or more disturbance frequency values ​​can be selected for each new setting.

[0107] In various embodiments, the systems and methods herein can implement various control processes after selecting a disturbance frequency. For example, after selecting a disturbance frequency, the systems and methods herein can implement any of the control processes / systems described in reference to Figures 17 to 22 in U.S. Patent No. 10,741,363.

[0108] Fig.12 A control module 1200 is shown. The control module 1200 includes Figure 1 , Figure 4 and Figure 7 The control module 1200 may include an amplitude control module 1202, a frequency control module 1204, a matching network control module 1206, a perturbation module 1208, a frequency tuning module 1210, and a cost determination module 1212. As shown, the perturbation module 1208 includes a frequency selector module 1214. In various embodiments, the control module 1200 includes one or more processors that execute code associated with the modules 1202, 1204, 1206, 1208, 1210, 1212, and 1214. Figures 13 to 16 The method of using one or more of the modules 1202, 1204, 1206, 1208, 1210, 1212, and 1214 is described. In addition, in various embodiments, the method of using one or more of the modules 1202, 1204, 1206, 1208, 1210, 1212, and 1214 is described with reference to Figures 17 to 22 in U.S. Patent No. 10,741,363.

[0109] about Figure 1 Controllers 20a, 20b and 20' and / or Figure 4 and Figure 7 For further definition of the various control elements, see the following Figures 13 to 16 17 to 22 of U.S. Pat. No. 10,741,363, and the definition of the term "module" provided below. A variety of methods, examples, and various control system methods (some of which are described in Figures 13 to 16) to operate the system disclosed in this article. Although the following operation mainly refers to Figure 1 , Figure 4 and Figure 7 The following operations are described with reference to the embodiments of the present disclosure, but these operations can be easily modified to apply them to other embodiments of the present disclosure. These operations can be performed iteratively. Although the following operations are shown and described as being performed primarily in sequence, one or more of the following operations can be performed while performing one or more of the other operations.

[0110] Fig.13 It is shown that the Figure 7 13. A flow chart of a control process 1300 for performing disturbance frequency selection in an RF generator of the RF generator 710 of the embodiment of the present invention. Control begins at block 1302 where initialization is performed. Control proceeds to block 1304.

[0111] At block 1304, control receives operating parameters associated with the RF generator. In various embodiments, the operating parameters may include a duty cycle of a state of a pulse, a repetition rate of a pulse, and a delay time associated with a state. In other embodiments, the operating parameters may include, for example, a duty cycle of multiple states of a pulse, a repetition rate of a pulse, and a delay time associated with a state of a pulse, and / or, a duty cycle of multiple states of multiple pulses, a repetition rate of a pulse, and a delay time associated with a state of multiple pulses. Control then proceeds to block 1306.

[0112] At block 1306, control determines or otherwise identifies one or more potentially interfering frequency tones. For example, potentially interfering frequency tones may be determined in any of the manners described herein, such as by determining one or more apparent pulse frequencies, determining one or more exclusion bands associated with the apparent pulse frequencies, etc. Once the potentially interfering frequency tones are determined, control proceeds to block 1308.

[0113] At block 1308, control selects one or more disturbance frequencies that are suitable and away from the determined frequency tone. In other words, control selects a suitable disturbance frequency that is sufficiently isolated from the frequency tone. This selection of one or more disturbance frequencies can be implemented in accordance with any of the methods described herein. For example, control can select a disturbance frequency that falls within a zone (e.g., at the midpoint of the zone) between frequency tones, between exclusion bands, between frequency tones and bandwidth limits, between a DC value and a frequency tone, etc. Once control selects one or more disturbance frequencies at block 1308, control can proceed to block 1310, thereby terminating process 1300 (e.g., Fig.13 ), or return to block 1304 if necessary.

[0114] Fig.14 It is shown that the Figure 7 14. A flow chart of another example control process 1400 for selecting a disturbance frequency in an RF generator of an RF generator 710 of an embodiment of the present invention. Control begins at block 1402, where initialization is performed. Control proceeds to block 1404. At block 1404, control receives one or more feedback signals associated with the RF generator. Feedback data associated with, for example, gamma amplitude squared, reflected power, and / or other data of interest may be provided by or derived from the feedback signal. Subsequently, control proceeds to block 1406.

[0115] At block 1406, control performs a transform to analyze the data in the feedback signal or data derived from the feedback signal. For example, control may perform an FFT or another suitable transform to analyze such data. Then, control proceeds to block 1408.

[0116] At block 1408, control determines or otherwise identifies one or more potentially interfering frequency tones. For example, potentially interfering frequency tones may be determined in any of the ways described herein, such as by determining frequency tones across the spectrum under operating conditions based on the analyzed feedback data. Subsequently, control proceeds to block 1410.

[0117] At block 1410, control selects a suitable disturbance frequency or frequencies away from the determined frequency tone. Fig.13 This selection is implemented in a similar manner as in block 1308 of FIG. Once control selects one or more disturbance frequencies at block 1410, control may proceed to block 1412, thereby ending process 1400 (eg, Fig.14 ), or return to block 1404 if necessary.

[0118] Fig.15 It is shown that the Figure 7 15. A flow chart of another example control process 1500 for performing disturbance frequency selection in an RF generator of an RF generator 710 of FIG. 15. Control begins at block 1502 where initialization is performed. Control proceeds to block 1504. At block 1504, control receives or otherwise determines a power controller (e.g., Figure 7 The control proceeds to block 1506.

[0119] At block 1506, control determines or otherwise identifies one or more potentially interfering frequency tones. Such determination of potentially interfering frequency tones may be performed in a manner similar to Figure 13 to Figure 14 The control proceeds to block 1508.

[0120] At block 1508, control determines the delta between the lower bandwidth limit or minimum value (e.g., DC or 0 Hz) and one of the frequency tones and between the same or different frequency tone and the upper bandwidth limit or maximum value. This can be accomplished, for example, by taking the difference between the lower bandwidth limit and the frequency tone and the difference between the upper bandwidth limit and the frequency tone. Control then proceeds to block 1510 where the maximum delta is identified. Control then proceeds to block 1512.

[0121] At block 1512, control selects a disturbance frequency at the midpoint of the maximum increment. For example, after determining the maximum increment, control may divide the value of the increment by 2 and then select a disturbance frequency to be placed at the divided value. Alternatively, as explained herein, control may select a disturbance frequency at another suitable point (e.g., frequency value) within the maximum increment. Control then proceeds to block 1514, where control generates a disturbance signal based on the selected disturbance frequency (e.g., at the midpoint of the maximum increment or another frequency value). Control then proceeds to blocks 1516, 1518.

[0122] At block 1516, control analyzes the feedback response data associated with the selected disturbance frequency, as explained herein. At block 1518, control determines whether the data indicates that a defined threshold is met (e.g., the swing in delivered power is below a defined threshold). If not, control proceeds to block 1520. If yes, control may proceed to block 1522, thereby ending process 1500 (e.g., Fig.15 ), or return to block 1504 if necessary.

[0123] At block 1520 , control adjusts the selected disturbance frequency or selects another disturbance frequency at another point (eg, frequency value) in the maximum increment. Control then returns to block 1514 .

[0124] Fig.16 It is shown that the Figure 7 1600 for performing disturbance frequency selection in an RF generator of an RF generator 710 of FIG. 1610. Control begins at block 1602, where initialization is performed. Control proceeds to block 1604. At block 1604, control receives one or more feedback signals associated with the RF generator, from which feedback data associated with, for example, gamma amplitude squared, reflected power, and / or other data of interest may be provided or derived. Subsequently, control proceeds to blocks 1606, 1608, and 1610. At block 1606, control performs, for example, a control signal associated with the RF generator 710 of FIG. 1610. Fig.14 In a similar manner as described at block 1406 of FIG. 1 , a transformation is performed to analyze data in or derived from the feedback signal. At block 1608, control is performed, for example, in the same manner as described at Fig.14 In a similar manner as described at block 1408 of , one or more potentially interfering frequency tones are determined or otherwise identified. At block 1610, control is performed, for example, in a manner similar to that described at Fig.14 In a similar manner as described at block 1410 of , a suitable disturbance frequency or frequencies away from the determined frequency tone are selected. Subsequently, control proceeds to blocks 1612, 1614, 1616.

[0125] At block 1612, control generates a disturbance signal based on the selected disturbance frequency. At block 1614, control analyzes the feedback response data associated with the selected disturbance frequency, and at block 1616, control generates a disturbance signal based on the selected disturbance frequency, for example, in a manner similar to that in the Fig.15 In a similar manner as described at blocks 1516 and 1518 of FIG. 16 , it is determined whether the data indicates that a defined threshold is met. At block 1616, if the threshold is not met, control passes to block 1618. Otherwise, control may pass to block 1620, thereby terminating process 1600 (eg, Fig.16 ), or return to block 1604 if necessary.

[0126] At block 1618 , control adjusts the selected disturbance frequency or selects another disturbance frequency at another point (eg, frequency value) away from the determined frequency pitch. Control then returns to block 1612 .

[0127] The systems and methods described herein can provide one or more of the following advantages in various configurations. For example, the systems and methods described herein can enable dynamic optimization of disturbance frequencies for use in ESC-based frequency tuning control. As a result, the robustness of disturbance-based signal extraction (e.g., gradient measurements) can be improved, thereby improving ESC-based frequency tuning control relative to known pulse artifacts and other signal content occurring in the system. In addition, the systems and methods described herein can enable optimization under single pulse conditions or under a complete pulse approach. In this way, the number of changes in disturbance frequency required in the system can be minimized. In addition, the systems and methods described herein can improve efficiency by adjusting the disturbance frequency online based on current or previous operating conditions, settings, etc., as explained herein.

[0128] The foregoing description is merely illustrative in nature and is in no way intended to limit the present disclosure, its application or use. The broad teachings of the present disclosure can be implemented in various forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be so limited, because after studying the drawings, the specification and the appended claims, other modifications will become apparent. In the written description and the claims, one or more steps within the method can be performed in a different order (or simultaneously) without changing the principles of the present disclosure. Similarly, one or more instructions stored in a non-transitory computer-readable medium can be executed in a different order (or simultaneously) without changing the principles of the present disclosure. Unless otherwise specified, numbering or other marking of instructions or method steps is for ease of reference, rather than indicating a fixed order.

[0129] Further, although each embodiment is described above as having certain features, any one or more of those features described with respect to any embodiment of the present disclosure may be implemented in and / or combined with the features of any other embodiment, even if the combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and the permutation of one or more embodiments with each other is still within the scope of the present disclosure.

[0130] Various terms including "connected," "engaged," "coupled," "adjacent," "proximate," "on," "above," "below," and "disposed" are used to describe spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.). Unless explicitly described as "directly," when describing a relationship between a first element and a second element in the above disclosure, the relationship may be a direct relationship in which no other intervening elements exist between the first element and the second element, but may also be an indirect relationship in which one or more intervening elements exist between the first element and the second element (spatially or functionally).

[0131] The phrase "at least one of A, B, and C" should be interpreted to mean a logical (A or B or C), using a non-exclusive logical OR, and should not be interpreted to mean "at least one of A, at least one of B, and at least one of C". The term "set" does not necessarily exclude the empty set, in other words, in some cases, a "set" can have zero elements. The term "non-empty set" may be used to indicate the exclusion of the empty set, in other words, a non-empty set will always have one or more elements. The term "subset" does not necessarily require a proper subset. In other words, a "subset" of a first set may be contiguous with (equal to) the first set. Further, the term "subset" does not necessarily exclude the empty set - in some cases, a "subset" may have zero elements.

[0132] In the drawings, the direction of the arrows, as indicated by the arrows, generally demonstrates the flow of information (such as data or instructions) of interest in the diagram. For example, when component A and component B exchange various information but the information transmitted from component A to component B is relevant to the diagram, the arrow may point from component A to component B. This unidirectional arrow does not mean that no other information is transmitted from component B to component A. Further, for information sent from component A to component B, component B may send a request for the information or a confirmation of receipt of the information to component A.

[0133] In this application, including the following definitions, the term "module" may be replaced with the term "controller" or the term "circuit". In this application, the term "controller" may be replaced with the term "module". The term "module" may refer to, be part of, or include an application specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); processor hardware (shared, dedicated, or group) that executes code; memory hardware (shared, dedicated, or group) that stores code executed by the processor hardware; other suitable hardware components that provide the described functionality; or a combination of some or all of the above components such as in a system on a chip.

[0134] The module may include one or more interface circuits. In some examples, the interface circuit may implement a wired or wireless interface connected to a local area network (LAN) or a wireless personal area network (WPAN). Examples of LANs are the Institute of Electrical and Electronics Engineers (IEEE) standard 802.11-2020 (also known as the WIFI wireless networking standard) and the IEEE standard 802.3-2018 (also known as the Ethernet wired networking standard). Examples of WPANs are IEEE standard 802.15.4 (including the ZIGBEE standard from the ZigBee Alliance) and the Bluetooth wireless networking standard from the Bluetooth Special Interest Group (SIG) (including core specification versions 3.0, 4.0, 4.1, 4.2, 5.0, and 5.1 from the Bluetooth SIG).

[0135] Modules can communicate with other modules using interface circuits. Although modules may be depicted in the present disclosure as being in logical communication directly with other modules, in various embodiments, modules may actually communicate via a communication system. The communication system includes physical and / or virtual networking devices, such as hubs, switches, routers, and gateways. In some embodiments, the communication system is connected to or traverses a wide area network (WAN) such as the Internet. For example, the communication system may include multiple LANs connected to each other via the Internet or point-to-point leased lines using technologies including multi-protocol label switching (MPLS) and virtual private networks (VPNs).

[0136] In various embodiments, the functionality of a module can be distributed among multiple modules connected via a communication system. For example, multiple modules can implement the same function distributed by a load balancing system. In a further example, the functionality of a module can be split between a server (also referred to as a remote or cloud) module and a client (or user) module. For example, a client module can include a local application or a network application that executes on a client device and performs network communication with a server module.

[0137] Some or all of the hardware features of a module may be defined using a hardware description language such as IEEE Standard 1364-2005 (commonly referred to as "Verilog") and IEEE Standard 1076-2008 (commonly referred to as "VHDL"). Hardware description languages ​​may be used to manufacture and / or program hardware circuits. In some embodiments, some or all of the features of a module may be defined by a language such as IEEE 1666-2005 (commonly referred to as "SystemC") that includes both code and hardware descriptions as described below.

[0138] As used above, the term "code" may include software, firmware, and / or microcode, and may refer to programs, routines, functions, classes, data structures, and / or objects. Shared processor hardware includes a single microprocessor that executes some or all of the code from multiple modules. Group processor hardware includes a microprocessor that executes some or all of the code from one or more modules in conjunction with an additional microprocessor. References to multiple microprocessors include multiple microprocessors on discrete dies, multiple microprocessors on a single die, multiple cores of a single microprocessor, multiple threads of a single microprocessor, or a combination of the above.

[0139] Memory hardware may also store data together with or separately from the code. Shared memory hardware includes a single memory device that stores some or all of the code from multiple modules. An example of shared memory hardware may be a level 1 cache on or near a microprocessor die that can store code from multiple modules. Another example of shared memory hardware may be a persistent storage such as a solid state drive (SSD) that can store code from multiple modules. Group memory hardware includes a memory device that stores some or all of the code from one or more modules in combination with other memory devices. An example of group memory hardware is a storage area network (SAN) that can store code for a particular module across multiple physical devices. Another example of group memory hardware is a random access memory that stores code for a particular module in combination for each server in a group of servers.

[0140] The term "memory hardware" is a subset of the term "computer-readable medium". The term "computer-readable medium" as used herein does not include transient electrical or electromagnetic signals propagated through a medium (such as on a carrier wave); the term "computer-readable medium" is therefore considered to be tangible and non-transitory. Non-limiting examples of non-transitory computer-readable media are non-volatile memory devices (such as flash memory devices, erasable programmable read-only memory devices, or mask read-only memory devices), volatile memory devices (such as static random access memory devices or dynamic random access memory devices), magnetic storage media (such as analog or digital magnetic tape or hard drives), and optical storage media (such as CDs, DVDs, or Blu-ray discs).

[0141] The apparatus and methods described in this application may be implemented in part or in whole by a special-purpose computer created by configuring a general-purpose computer to perform one or more specific functions contained in a computer program. Such apparatus and methods may be described as computerized apparatus and computerized methods. The functional blocks and flow chart elements described above serve as software specifications that can be converted into computer programs by the routine work of a skilled technician or programmer.

[0142] The computer program includes processor executable instructions stored on at least one non-transitory computer readable medium. The computer program may also include or rely on stored data. The computer program may include a basic input / output system (BIOS) that interacts with the hardware of the special-purpose computer, device drivers that interact with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0143] A computer program may include: (i) descriptive text to be parsed, such as HTML (Hypertext Markup Language), XML (Extensible Markup Language), or JSON (JavaScript Object Notation); (ii) assembly code; (iii) object code generated by a compiler from source code; (iv) source code for execution by an interpreter; (v) source code for compilation and execution by a just-in-time compiler, etc. By way of example only, source code may be written using syntax from languages ​​including: C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Fortran, Perl, Pascal, Curl, OCaml, HTML5 (Hypertext Markup Language Version 5), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Visual Lua, MATLAB, SIMULINK, and

Claims

1. A power supply system for supplying power to a load, the power supply system comprising: A radio frequency (RF) power supply configured to generate an output signal at an output frequency; a signal source configured to generate a disturbance signal; an extremum-searching frequency controller configured to generate a frequency control signal based on the disturbance signal, the frequency control signal changing the output frequency of the RF power supply; as well as A frequency selector is configured to select a disturbance frequency of the disturbance signal that is isolated from at least one frequency tone associated with the power system.

2. The power supply system according to claim 1, further comprising: A power controller is coupled to the RF power supply, the power controller being configured to generate a pulse to modulate the output signal of the RF power supply, the pulse comprising a first state and a second state.

3. The power supply system according to claim 2, wherein: The disturbance frequency is a first disturbance frequency; The frequency selector is configured to select the first perturbation frequency for the first state of the pulse and to select a second perturbation frequency for the second state; and The first disturbance frequency and the second disturbance frequency are different.

4. The power supply system according to claim 2, wherein: The frequency selector is configured to select the perturbation frequency for the first state and the second state of the pulse.

5. The power supply system according to claim 1, further comprising: a power controller coupled to the RF power supply, the power controller configured to generate at least two pulses to modulate the output signal of the RF power supply, each of the at least two pulses comprising a first state and a second state, wherein The disturbance frequency is a first disturbance frequency; The frequency selector is configured to select the first perturbation frequency for the first state of the each of the at least two pulses, and to select a second perturbation frequency for the second state of the each of the at least two pulses; and The first disturbance frequency and the second disturbance frequency are different.

6. The power supply system according to claim 1, further comprising: A power controller is coupled to the RF power supply, the power controller being configured to generate pulses to modulate the output signal of the RF power supply, wherein the frequency selector is configured to select the perturbation frequency based on a bandwidth of the power controller.

7. The power supply system according to claim 6, wherein: The frequency selector is configured as: determining a first delta between a minimum value of the bandwidth and the at least one frequency tone and a second delta between the at least one frequency tone and a maximum value of the bandwidth; and The perturbation frequency is selected to be equal to a frequency value within the larger of the first increment and the second increment.

8. The power supply system according to claim 7, wherein: The frequency value is the midpoint of the larger of the first increment and the second increment.

9. The power supply system according to claim 7, wherein: The frequency selector is configured to analyze data indicative of an operating parameter of the electrical power system in accordance with the selected disturbance frequency and to adjust the disturbance frequency within the greater of the first increment and the second increment if the operating parameter is below a defined threshold.

10. The power supply system according to claim 9, wherein: The frequency selector is configured to analyze data indicative of the operating parameter of the power system based on the adjusted disturbance frequency and to adjust the disturbance frequency again within the larger of the first increment and the second increment if the operating parameter is below the defined threshold.

11. The power supply system according to claim 1, wherein: The frequency selector is configured to determine the at least one frequency tone.

12. The power supply system according to claim 11, further comprising: A power controller is coupled to the RF power supply, the power controller being configured to generate pulses to modulate the output signal of the RF power supply, wherein the at least one frequency tone comprises an apparent frequency associated with a state of the pulses.

13. The power supply system according to claim 12, wherein: The apparent frequency is determined based on a duty cycle of the state, a repetition rate of the pulses, and a delay time associated with the state.

14. The power supply system according to claim 12, wherein the state of the pulse is a first state, and the apparent frequency is a first apparent frequency associated with the first state; The at least one frequency tone comprises a second apparent frequency associated with a second state of the pulse; and The frequency selector is configured to select the perturbation frequency for the first state and the second state, the perturbation frequency being isolated from the first apparent frequency and the second apparent frequency.

15. The power supply system according to claim 1, wherein: The frequency selector is configured to perform a transform to analyze data of one or more feedback signals and determine the at least one frequency tone based on the analyzed data.

16. The power supply system according to claim 15, wherein: The frequency selector is configured to select the perturbation frequency based on the analyzed data.

17. The power supply system according to claim 1, wherein: The frequency selector is configured to perform a transformation to analyze data of one or more feedback signals based on an output response as a function of the disturbance frequency.

18. The power supply system according to claim 17, wherein: The frequency selector is configured to adjust the perturbation frequency based on the analyzed data.

19. The power supply system according to claim 17, wherein: The data is indicative of an operating parameter of the electrical power system, and the frequency selector is configured to adjust the disturbance frequency if the operating parameter is below a defined threshold.

20. The power supply system according to claim 19, wherein: The frequency selector is configured to analyze data indicative of the operating parameter of the power supply system according to the adjusted disturbance frequency and to adjust the disturbance frequency again if the operating parameter is below the defined threshold.

21. A method for controlling a radio frequency (RF) generator of a power system, the RF generator comprising an RF power supply, the method comprising: selecting a disturbance frequency of a disturbance signal that is isolated from at least one frequency tone associated with the power system; generating said disturbance signal having a selected disturbance frequency; as well as A frequency control signal is generated based on the disturbance signal, the frequency control signal changing an output frequency of the RF power supply.

22. The method according to claim 21, further comprising: A pulse is generated to modulate an output signal of the RF power supply, the pulse comprising a first state and a second state, wherein selecting the disturbance frequency of the disturbance signal comprises: selecting a first disturbance frequency for the first state of the pulse and selecting a second disturbance frequency different from the first disturbance frequency for the second state.

23. The method according to claim 21, further comprising: A pulse is generated to modulate an output signal of the RF power supply, the pulse comprising a first state and a second state, wherein selecting the perturbation frequency of the perturbation signal comprises selecting the perturbation frequency for the first state and the second state of the pulse.

24. The method of claim 21, further comprising: At least two pulses are generated to modulate the output signal of the RF power supply, each of the at least two pulses comprising a first state and a second state, wherein selecting the disturbance frequency of the disturbance signal comprises: selecting a first disturbance frequency for the first state of each of the at least two pulses, and selecting a second disturbance frequency different from the first disturbance frequency for the second state of each of the at least two pulses.

25. The method of claim 21, further comprising: A power controller is used to generate pulses to modulate an output signal of the RF power supply, wherein selecting the perturbation frequency of the perturbation signal includes selecting the perturbation frequency based on a bandwidth of the power controller.

26. The method according to claim 25, further comprising: Determining a first increment between a minimum value of the bandwidth and the at least one frequency tone and a second increment between the at least one frequency tone and a maximum value of the bandwidth, wherein selecting the disturbance frequency of the disturbance signal comprises selecting the disturbance frequency to be equal to a frequency value within the larger of the first increment and the second increment.

27. The method according to claim 26, wherein: The frequency value is the midpoint of the larger of the first increment and the second increment.

28. The method of claim 26, further comprising: Data indicative of an operating parameter of the electrical power system is analyzed according to the selected disturbance frequency, and if the operating parameter is below a defined threshold, the disturbance frequency is adjusted within the greater of the first increment and the second increment.

29. The method according to claim 28, further comprising: Data indicative of the operating parameter of the electrical power system is analyzed based on the adjusted disturbance frequency, and if the operating parameter is below the defined threshold, the disturbance frequency is again adjusted within the greater of the first increment and the second increment.

30. The method of claim 21, further comprising: The at least one frequency tone is determined.

31. The method according to claim 30, wherein: The at least one frequency tone comprises an apparent frequency associated with a state of the pulse.

32. The method according to claim 31, wherein: Determining the at least one frequency tone includes determining the apparent frequency associated with the state of the pulse based on a duty cycle of the state, a repetition rate of the pulse, and a delay time associated with the state.

33. The method according to claim 31, wherein: the state of the pulse is a first state, and the apparent frequency is a first apparent frequency associated with the first state; the at least one frequency tone comprising a second apparent frequency associated with a second state of the pulse; and Selecting the disturbance frequency of the disturbance signal includes selecting the disturbance frequency for the first state and the second state, the disturbance frequency being isolated from the first apparent frequency and the second apparent frequency.

34. The method of claim 21, further comprising: A transform is performed to analyze data of the one or more feedback signals and to determine the at least one frequency tone based on the analyzed data.

35. The method of claim 34, wherein: Selecting the disturbance frequency of the disturbance signal includes selecting the disturbance frequency based on the analyzed data.

36. The method of claim 21, further comprising: A transform is performed to analyze data of one or more feedback signals based on an output response as a function of the disturbance frequency.

37. The method of claim 36, further comprising: The perturbation frequency is adjusted based on the analyzed data.

38. The method of claim 36, wherein: The data indicates an operating parameter of the power system; and The method further comprises adjusting the disturbance frequency if the operating parameter is below a defined threshold.

39. The method of claim 38, further comprising: Data indicative of the operating parameter of the power supply system are analyzed based on the adjusted disturbance frequency, and if the operating parameter is below the defined threshold, the disturbance frequency is adjusted again.

40. A non-transitory computer readable medium storing processor executable instructions for controlling a radio frequency (RF) generator of a power system, the RF generator comprising an RF power supply, the instructions comprising: selecting a disturbance frequency of a disturbance signal that is isolated from at least one frequency tone associated with the power system; generating said disturbance signal having a selected disturbance frequency; as well as A frequency control signal is generated based on the disturbance signal, the frequency control signal changing an output frequency of the RF power supply.

41. The non-transitory computer readable medium storing processor executable instructions of claim 40, the instructions further comprising: A power controller is used to generate pulses to modulate an output signal of the RF power supply, wherein selecting the perturbation frequency of the perturbation signal includes selecting the perturbation frequency based on a bandwidth of the power controller.

42. The non-transitory computer readable medium storing processor executable instructions of claim 41, the instructions further comprising: Determining a first increment between a minimum value of the bandwidth and the at least one frequency tone and a second increment between the at least one frequency tone and a maximum value of the bandwidth, wherein selecting the disturbance frequency of the disturbance signal comprises selecting the disturbance frequency to be equal to a frequency value within the larger of the first increment and the second increment.

43. The non-transitory computer readable medium storing processor executable instructions of claim 42, wherein: The frequency value is the midpoint of the larger of the first increment and the second increment.

44. The non-transitory computer readable medium storing processor executable instructions of claim 42, the instructions further comprising: Data indicative of an operating parameter of the electrical power system is analyzed according to the selected disturbance frequency, and if the operating parameter is below a defined threshold, the disturbance frequency is adjusted within the greater of the first increment and the second increment.

45. The non-transitory computer readable medium storing processor executable instructions of claim 44, the instructions further comprising: Data indicative of the operating parameter of the electrical power system is analyzed based on the adjusted disturbance frequency, and if the operating parameter is below the defined threshold, the disturbance frequency is again adjusted within the greater of the first increment and the second increment.

46. ​​The non-transitory computer readable medium storing processor executable instructions of claim 40, the instructions further comprising: The at least one frequency tone is determined.

47. The non-transitory computer readable medium storing processor executable instructions of claim 46, wherein: The at least one frequency tone comprises an apparent frequency associated with a state of the pulse; and Determining the at least one frequency tone includes determining the apparent frequency associated with the state of the pulse based on a duty cycle of the state, a repetition rate of the pulse, and a delay time associated with the state.

48. The non-transitory computer readable medium storing processor executable instructions of claim 46, wherein: The at least one frequency tone includes a first apparent frequency associated with a first state of a pulse and a second apparent frequency associated with a second state of the pulse; and Selecting the disturbance frequency of the disturbance signal includes selecting the disturbance frequency for the first state and the second state, the disturbance frequency being isolated from the first apparent frequency and the second apparent frequency.

49. The non-transitory computer readable medium storing processor executable instructions of claim 40, the instructions further comprising: A transformation is performed to analyze data of one or more feedback signals indicative of operating parameters of the power system based on an output response according to the disturbance frequency, and to adjust the disturbance frequency if the operating parameter is below a defined threshold.

50. The non-transitory computer readable medium storing processor executable instructions of claim 49, the instructions further comprising: Data indicative of the operating parameter of the power supply system are analyzed based on the adjusted disturbance frequency, and if the operating parameter is below the defined threshold, the disturbance frequency is adjusted again.

51. A control system for controlling a radio frequency (RF) generator of a power system, the RF generator comprising an RF power supply, the RF power supply being configured to generate an output signal at an output frequency, the control system comprising: a signal source configured to generate a disturbance signal; an extremum-searching frequency controller configured to generate a frequency control signal based on the disturbance signal, the frequency control signal changing the output frequency of the RF power supply; as well as A frequency selector is configured to select a disturbance frequency of the disturbance signal that is isolated from at least one frequency tone associated with the power system.

52. The control system of claim 51 further comprising: a power controller configured to generate a pulse to modulate the output signal of the RF power supply, the pulse comprising a first state and a second state, wherein, The disturbance frequency is a first disturbance frequency; The frequency selector is configured to select the first perturbation frequency for the first state of the pulse and to select a second perturbation frequency for the second state; and The first disturbance frequency and the second disturbance frequency are different.

53. The control system of claim 51 further comprising: A power controller is configured to generate a pulse to modulate the output signal of the RF power supply, the pulse comprising a first state and a second state, wherein the frequency selector is configured to select the perturbation frequency for the first state and the second state of the pulse.

54. The control system of claim 51 further comprising: a power controller configured to generate at least two pulses to modulate the output signal of the RF power supply, each of the at least two pulses comprising a first state and a second state, wherein The disturbance frequency is a first disturbance frequency; The frequency selector is configured to select the first perturbation frequency for the first state of the each of the at least two pulses, and to select a second perturbation frequency for the second state of the each of the at least two pulses; and The first disturbance frequency and the second disturbance frequency are different.

55. The control system of claim 51 further comprising: A power controller is configured to generate pulses to modulate the output signal of the RF power supply, wherein the frequency selector is configured to select the perturbation frequency based on a bandwidth of the power controller.

56. A control system according to claim 55, wherein: The frequency selector is configured as: determining a first delta between a minimum value of the bandwidth and the at least one frequency tone and a second delta between the at least one frequency tone and a maximum value of the bandwidth; and The perturbation frequency is selected to be equal to a frequency value within the larger of the first increment and the second increment.

57. The control system of claim 51, wherein: The frequency selector is configured to determine the at least one frequency tone.

58. The control system of claim 57, wherein: The frequency selector is configured to perform a transform to analyze data of one or more feedback signals, determine the at least one frequency tone based on the analyzed data, and select the disturbance frequency based on the at least one frequency tone.

59. The control system of claim 51, wherein: The frequency selector is configured to perform a transformation to analyze data of one or more feedback signals based on an output response as a function of the disturbance frequency.

60. The control system of claim 59, wherein The data indicates an operating parameter of the power system; and The frequency selector is configured to adjust the disturbance frequency if the operating parameter is below a defined threshold.

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