A binary turn ratio transformer based megahertz radio frequency transducer and method of application

Abstract

This invention relates to the field of radio frequency (RF) converter technology, and more particularly to a megahertz RF converter and its application method based on a binary turns ratio transformer. The RF converter includes m power units, where m ≥ 2. Each m power unit comprises one out-of-phase modulation unit and m-1 resonant conversion units. Each out-of-phase modulation unit includes two inverters and one transformer. Each resonant conversion unit includes one inverter and one transformer. Both the transformers of the out-of-phase modulation units and the resonant conversion units are binary turns ratio transformers. The input terminals of the inverters in the power units are connected in parallel and connected to the DC bus voltage. The output terminals of the inverters in the power units are connected to the primary winding of the transformers in the power units. The secondary windings of the transformers in the power units are connected in series and connected to the RF load through an impedance matching network. This RF converter can simultaneously achieve wide-range power coverage, continuous seamless adjustment, and high-frequency soft-switching operation.

Description

Technical Field

[0001] This invention relates to the field of radio frequency converter technology, and in particular to a megahertz radio frequency converter and its application method based on a binary turns ratio transformer. Background Technology

[0002] With the increasing demands for higher output power, efficiency, and adjustment flexibility from industries such as semiconductor manufacturing and plasma processing, radio frequency (RF) power converters are developing towards higher power, higher frequency, and higher efficiency. In particular, RF converters operating in the megahertz band can significantly reduce system size and improve plasma uniformity and stability, making them of significant engineering application value.

[0003] However, existing RF converters have the following shortcomings: First, modular RF power structures mostly employ homogeneous modules and parallel AC outputs, typically relying on DC bus regulation or unified module switching, making it difficult to achieve wide-range and continuous power regulation under fixed DC bus conditions. Second, while existing LLC resonant structures offer advantages in high efficiency and soft switching, they are primarily geared towards voltage conversion scenarios and lack modular designs suitable for continuous RF power regulation. Therefore, existing RF converters, under fixed main circuit parameters and a fixed DC bus, struggle to simultaneously achieve wide-range power coverage, continuous seamless regulation, and high-frequency soft-switching operation. Summary of the Invention

[0004] This application provides a megahertz radio frequency converter and application method based on a binary turns ratio transformer. It solves the technical problem that existing radio frequency converters, under fixed main circuit parameters and fixed DC bus conditions, are difficult to achieve wide-range power coverage, continuous seamless adjustment, and high-frequency soft-switching operation at the same time. It achieves seamless output of wide-range power, adapts to the needs of different operating conditions, avoids power supply replacement, improves equipment versatility, and the continuously adjustable output power can also adapt to load changes within a certain range, improving process stability and energy utilization.

[0005] In a first aspect, embodiments of the present invention provide a megahertz radio frequency converter based on a binary turns ratio transformer, comprising: m power units, m≥2, wherein the m power units include: one out-of-phase modulation unit and m-1 resonant conversion units; the out-of-phase modulation unit includes: two inverters and one transformer; each of the resonant conversion units includes: one inverter and one transformer; both the transformer of the out-of-phase modulation unit and the transformer of the resonant conversion unit are binary turns ratio transformers; The input terminals of each power unit are connected in parallel to the DC bus voltage, and the output terminals of each power unit are connected in series to form a series branch. The series branch is connected to the RF load through an impedance matching network. The input terminals of the two inverters of the out-of-phase modulation unit are connected in parallel to form the input terminal of the out-of-phase modulation unit. Each output terminal of the first inverter of the out-of-phase modulation unit is connected to the first terminal of the primary side of the transformer of the out-of-phase modulation unit through a series resonant circuit. Each output terminal of the second inverter of the out-of-phase modulation unit is connected to the second terminal of the primary side of the transformer of the out-of-phase modulation unit through a series resonant circuit. The secondary side of the transformer of the out-of-phase modulation unit is the output terminal of the out-of-phase modulation unit. In each of the resonant converter units, the input terminal of the inverter of the resonant converter unit is the input terminal of the resonant converter unit, the output terminal of the inverter of the resonant converter unit is connected to the primary side of the transformer of the resonant converter unit through a series resonant capacitor, and the secondary side of the transformer of the resonant converter unit is the output terminal of the resonant converter unit; the first resonant inductance of the resonant converter unit is provided by the leakage inductance of the primary side of the transformer of the resonant converter unit, and the second resonant inductance of the resonant converter unit is provided by the magnetizing inductance of the transformer of the resonant converter unit; The turns ratio N of the transformer of the out-of-phase modulation unit is determined by the step difference of the transmission power of the resonant conversion unit, and the turns ratio of the transformer of the m and the turns of the resonant conversion unit is determined by the output power of the radio frequency converter and the rated transmission power of the inverter of the resonant conversion unit.

[0006] Preferably, the turns ratio of the transformer in the out-of-phase modulation unit is N, and the turns ratios of the transformers in the m-1 resonant conversion units are N1, 2N1, ... ... m-1 N1.

[0007] Preferably, the resonant reactance of the series resonant circuit for: ; in, The inductance value of the series resonant circuit is given. Let be the capacitance value of the series resonant circuit. The resonant angular frequency of the radio frequency converter is denoted as ω.

[0008] Preferably, the secondary equivalent impedance of the transformer in the power unit for: ; in, The capacitance value in the impedance matching network. The resistance value of the radio frequency load. The inductance value in the impedance matching network is... Let be the equivalent leakage inductance of the secondary side of the i-th transformer; By setting the equivalent impedance of the secondary side The imaginary part is zero, therefore we get and The relationship is: .

[0009] Preferably, based on the impedance matching network, the secondary equivalent resistance of the transformer in the power unit is... for: .

[0010] Preferably, based on the equivalent resistance of the secondary side of the transformer of the power unit. The primary-side equivalent resistance of the transformer of the power unit is obtained. : .

[0011] Preferably, the power regulation method of the radio frequency converter is as follows: the discrete and stepped power is output through the resonant conversion unit, and the stepped power is compensated through the out-of-phase modulation unit to obtain the output power of the radio frequency converter; The output power of the radio frequency converter for: ; Wherein, k represents the equivalent turns ratio weighting coefficient corresponding to the switching combination of the resonant transformer unit. V L V is the output voltage corresponding to the radio frequency load. bus Let θ be the DC bus voltage, θ be the phase difference of the out-of-phase modulation unit, R1 be the primary-side equivalent resistance of the transformer of the out-of-phase modulation unit, and A = [x1, x2, ..., xi, ..., x] be the switching combination set of the resonant converter unit. m When the i-th resonant transformer unit is in the on state, x i =1, when the i-th resonant transformation unit is in the off state, x i =0.

[0012] Preferably, the step power output through the resonant converter unit, which is discrete and stepped, includes: Based on the target power of the RF converter and the rated power of the first resonant converter, the normalized residual power ratio of the first resonant converter is obtained, wherein the target power is consistent with the output power of the RF converter; Starting from the normalized residual power ratio of the first resonant transformer unit, the switching combination of the resonant transformer units is obtained through iteration; The stepped power is obtained by switching the resonant transformer unit.

[0013] Preferably, the step of compensating the stepped power through the out-of-phase modulation unit to obtain the output power of the RF converter includes: The phase difference of the out-of-phase modulation unit is obtained based on the residual power ratio corresponding to the last resonant transformation unit in the switching combination of the resonant transformation units; The output power of the RF converter is obtained by compensating the stepped power through the phase difference of the out-of-phase modulation unit.

[0014] Based on the same inventive concept, in a second aspect, the present invention also provides an application method for determining the megahertz radio frequency converter based on the binary turns ratio transformer described in the first aspect, the application method comprising: Obtain the specifications of the radio frequency converter, including: target power, DC bus voltage and operating frequency; The number m of power units of the RF converter and the turns ratio of the transformer of each power unit are initially set according to the power control method of the RF converter. Based on the operating frequency and the RF load of the RF converter, the parameters of the resonant circuit of each power unit are determined. The parameters of the resonant circuit include: resonant inductance, resonant capacitance, and equivalent impedance. The parameter values ​​of the first resonant inductor and series resonant capacitor of the resonant converter in the power unit are selected to ensure that the RF converter achieves resonant operation and has ZVS characteristics at the operating frequency. Based on the parameters of the series resonant network of the resonant converter unit and the radio frequency load, the circuit parameter configuration of the resonant converter unit is obtained, and based on the parameters of the series resonant network of the out-of-phase modulation unit in the power unit and the radio frequency load, the circuit parameter configuration of the out-of-phase modulation unit is obtained. By selecting the inverter of the power unit, the initial architecture of the radio frequency converter is obtained; According to the power control method of the RF converter, the phase difference between the outputs of the power units is obtained, and the initial architecture is subjected to cyclic performance evaluation and cyclic update processing based on the phase difference until the updated architecture of the RF converter reaches the target condition. The updated architecture of the RF converter is then determined as the target RF converter. The target condition is that the output power of the updated architecture of the RF converter reaches the target power or the RF power amplifier efficiency of the updated architecture of the RF converter is not less than the RF power amplifier efficiency threshold.

[0015] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages: The RF converter of this invention includes m power units. Each m power unit comprises one out-of-phase modulation unit and m-1 resonant converter units. The out-of-phase modulation unit includes two inverters and one transformer. Both the transformers of the out-of-phase modulation unit and the resonant converter units are binary turns ratio transformers. The input terminals of the inverters in the power units are connected in parallel and connected to the DC bus voltage. The output terminals of the inverters in the power units are connected to the primary winding of the transformers in the power units. The secondary windings of the transformers in the power units are connected in series and connected to the RF load through an impedance matching network. The resonant converter units output discrete, stepped power, which is used to construct a wide range of discrete stepped power through a binary turns ratio array. Simultaneously, the out-of-phase modulation unit compensates for the stepped power to obtain the output power of the RF converter. Thus, the RF converter of this invention achieves excellent performance such as wide-range power coverage, continuous seamless adjustment, and high-frequency soft-switching operation under fixed main circuit parameters such as the fixed DC bus voltage. The RF converter in this embodiment of the invention can also adapt to different operating conditions based on seamless output of wide power range, avoid power supply replacement, improve equipment versatility, and adapt to load changes within a certain range based on continuously adjustable output power, thereby improving process stability and energy utilization. Attached Figure Description

[0016] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic diagram of the circuit structure of a megahertz radio frequency converter based on a binary turns ratio transformer in an embodiment of the present invention is shown; Figure 2 The equivalent circuit diagram of a megahertz radio frequency converter based on a binary turns ratio transformer in an embodiment of the present invention is shown. Figure 3 A flowchart illustrating the steps of the application method in an embodiment of the present invention is shown. Detailed Implementation

[0017] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0018] Example 1 The first embodiment of the present invention provides a megahertz radio frequency converter based on a binary turns ratio transformer, such as... Figure 1 As shown, it includes: m power units, where m ≥ 2. Each power unit includes: one inverter unit and one transformer. The m power units include: one out-of-phase modulation unit and m-1 resonant converter units. The out-of-phase modulation unit includes: two inverters and one transformer. The two inverters of the out-of-phase modulation unit are... Figure 1 Inverter unit 1, i.e., the first inverter unit, is located in the middle. The transformer for the out-of-phase modulation unit is #1 BTRT-LR, i.e., the first transformer. Each resonant converter unit includes: one inverter and one transformer. Figure 1 In the m-1 resonant converter units shown, the inverter of the first resonant converter unit is inverter unit 2, i.e., the second inverter unit; the inverter of the second resonant converter unit is inverter unit 3, i.e., the third inverter unit; and so on, with the inverter of the (m-1)th resonant converter unit being inverter unit m, i.e., the mth inverter unit. The transformer of the first resonant converter unit is #2 BTRT-LR, i.e., the second transformer; the transformer of the second resonant converter unit is #3 BTRT-LR, i.e., the third transformer; and so on, with the transformer of the (m-1)th resonant converter unit being #m BTRT-LR, i.e., the mth transformer. The inverter can be configured with appropriate parameters according to actual needs; in this embodiment, a full-bridge inverter is preferred.

[0019] In this design, both the transformers in the out-of-phase modulation unit and the transformers in the resonant converter unit are binary turns-ratio transformers (BTRT-LR), meaning that each power unit's transformer is a binary turns-ratio transformer. m-1 resonant converter units are used to generate binary-weighted discrete power codes, i.e., to generate discrete, step-like stepped power. The out-of-phase modulation unit is used to compensate for the stepped power, converting it into continuous power to obtain the output power of the RF converter.

[0020] The input terminals of each power unit are connected in parallel to the DC bus voltage, and the output terminals of each power unit are connected in series to form a series branch. This series branch is connected to the RF load through an impedance matching network. Figure 1 In the series branch, one end is connected to the inductor L of the impedance matching network. s One end is connected to the capacitor C of the impedance matching network, and the other end is connected to the capacitor C. s One end of the impedance matching network is connected to the other end of the RF load. The inductance L of the impedance matching network... s The other end is connected to the capacitor C of the impedance matching network. s The other end and the other end of the RF load.

[0021] The input terminals of the two inverters in the out-of-phase modulation unit are connected in parallel, forming the input terminal of the out-of-phase modulation unit. Each output terminal of the first inverter in the out-of-phase modulation unit is connected to the first terminal of the primary winding of the transformer in the out-of-phase modulation unit via a series resonant circuit. Each output terminal of the second inverter in the out-of-phase modulation unit is connected to the second terminal of the primary winding of the transformer in the out-of-phase modulation unit via a series resonant circuit. The secondary winding of the transformer in the out-of-phase modulation unit forms the output terminal. The series resonant circuit is a resonant circuit in which the capacitor and inductor are connected in series. Figure 1 In the middle, the first terminal of the output of the first inverter of the out-of-phase modulation unit is connected in sequence through the capacitor C of the series resonant circuit. a The inductance L of the series resonant circuit a The first terminal of the primary winding of the transformer in the out-of-phase modulation unit is connected to the second terminal of the output of the first inverter in the out-of-phase modulation unit. The second terminal is connected in sequence to the capacitor C of the series resonant circuit. b The inductance L of the series resonant circuit b The first terminal of the primary winding of the transformer in the out-of-phase modulation unit is connected to the second inverter of the out-of-phase modulation unit. The first terminal of the output of the second inverter in the out-of-phase modulation unit is connected in sequence to capacitor C of a series resonant circuit. c The inductance L of the series resonant circuit c The second terminal of the primary winding of the transformer in the out-of-phase modulation unit is connected to the second terminal of the output of the second inverter in the out-of-phase modulation unit. The second terminal of the output of the second inverter in the out-of-phase modulation unit is connected in sequence to the capacitor C of the series resonant circuit. d The inductance L of the series resonant circuit d The second end of the primary side of the transformer connected to the out-of-phase modulation unit.

[0022] In each resonant converter unit, the input terminal of the inverter is the input terminal of the resonant converter unit, and the output terminal of the inverter is connected to the primary winding of the transformer of the resonant converter unit through a series resonant capacitor. The secondary winding of the transformer of the resonant converter unit is the output terminal of the resonant converter unit. The series resonant capacitor is a capacitor connected in series at the output terminal of the inverter of the resonant converter unit, and this capacitor, together with the primary winding of the corresponding transformer, forms a resonant circuit. For example... Figure 1 As shown, the series resonant capacitance of the first resonant transformer unit is C. f2 The output of the inverter of the first resonant converter unit (i.e., inverter unit 2) is connected in series with a resonant capacitor C. f2 Connect the primary side of the transformer (i.e., #2 BTRT-LR) to the first resonant transformer unit. And so on, the series resonant capacitance of the (m-1)th resonant transformer unit is C. fm The output of the inverter of the (m-1)th resonant converter unit (i.e., inverter unit m) is connected in series with a resonant capacitor C. fmThe primary winding of the transformer (i.e., #mBTRT-LR) connected to the (m-1)th resonant transformer unit. The first resonant inductor L of the resonant transformer unit. fi The leakage inductance L of the transformer in the resonant converter unit is provided by the primary leakage inductance of the transformer. pi The second resonant inductor L of the resonant transformer unit mi Provided by the magnetizing inductance of the transformer in the resonant converter unit, representing the multiplexed magnetizing inductance of the transformer in the resonant converter unit.

[0023] The turns ratio N of the transformer in the out-of-phase modulation unit is determined by the step difference of the transmission power of the resonant converter unit, and the turns ratio m of the transformer in the resonant converter unit is determined by the output power of the RF converter and the rated transmission power of the inverter in the resonant converter unit.

[0024] It should also be noted that the operating frequency range of the RF converter in this embodiment is 1MHz and above, for example, the operating frequency of the RF converter is 1.6MHz.

[0025] The RF converter in this embodiment includes m power units. Each power unit comprises one out-of-phase modulation unit and m-1 resonant converter units. The out-of-phase modulation unit includes two inverters and one transformer. Both the transformer in the out-of-phase modulation unit and the transformer in the resonant converter unit are binary turns ratio transformers. The input terminals of the inverters in the power units are connected in parallel and connected to the DC bus voltage. The output terminals of the inverters in the power units are connected to the primary winding of the transformer in the power units. The secondary windings of the transformer in the power units are connected in series and connected to the RF load through an impedance matching network. The resonant converter units output discrete, stepped power, which is used to construct a wide range of discrete stepped power through a binary turns ratio array. Simultaneously, the out-of-phase modulation units compensate for the stepped power to obtain the output power of the RF converter. Thus, the RF converter in this embodiment achieves excellent performance such as wide-range power coverage, continuous seamless adjustment, and high-frequency soft-switching operation under fixed main circuit parameters such as the fixed DC bus voltage. The RF converter in this embodiment can also adapt to different operating conditions based on seamless output with a wide power range, avoiding the need to replace the power supply and improving the versatility of the equipment. Furthermore, based on continuously adjustable output power, it can also adapt to load changes within a certain range, improving process stability and energy utilization.

[0026] Below, in conjunction with Figure 1 This embodiment will provide a detailed explanation of the architecture and principle of the megahertz radio frequency converter based on a binary turns ratio transformer. exist Figure 1 In the above, the turns ratio of the transformer in the out-of-phase modulation unit is N, and the turns ratios of the transformers in the m-1 resonant converter units are N1, 2N1, ... ... m-1N1. The turns ratios of the transformers in the m-1 resonant converter units constitute discrete coded power, i.e., stepped power, also known as the transmission power of the resonant converter units, according to a binary relationship, and this transmission power is stepped. The turns ratio N of the transformer in the out-of-phase modulation unit is determined by the step difference of the transmission power of the resonant converter units; that is, N is selected to match the power difference between adjacent stepped power. The turns ratios of the transformers in the m and resonant converter units are determined by the output power of the RF converter and the rated transmission power of the inverter in the resonant converter units; that is, N1 is used to determine the reference granularity of the stepped power. In this way, by jointly configuring N and N1, while satisfying the maximum power transmission capability of the RF converter, a continuously compensable adjustment range between adjacent stepped power is guaranteed.

[0027] Figure 2 for Figure 1 The equivalent circuit diagram of the RF converter architecture is shown. Figure 2 In this context, the output voltage of the first inverter in the out-of-phase modulation unit is equivalent to a voltage source v. 1a , The capacitor C of the series resonant circuit at the first terminal of the output of the first inverter of the out-of-phase modulation unit flows through the first terminal. a The inductance L of the series resonant circuit a The current, The capacitor C is the capacitor of the series resonant circuit at the second terminal of the output of the first inverter of the out-of-phase modulation unit. b The inductance L of the series resonant circuit b The current. and The current flows to the first terminal of the primary winding of transformer #1 BTRT-LR (i.e., the first transformer) of the out-of-phase modulation unit. The output voltage of the second inverter of the out-of-phase modulation unit is equivalent to a voltage source v. 1b , The capacitor C is the capacitor of the series resonant circuit at the first terminal of the output of the second inverter of the out-of-phase modulation unit. c The inductance L of the series resonant circuit c The current, The capacitor C is the capacitor of the series resonant circuit at the second terminal of the output of the second inverter of the out-of-phase modulation unit. d The inductance L of the series resonant circuit d The current. and The current flows to the second terminal of the primary winding of transformer #1 BTRT-LR (i.e., the first transformer) in the out-of-phase modulation unit. It should be noted that the resonant circuit in the out-of-phase modulation unit is a series resonant circuit. m1 R is the magnetizing inductance of the first transformer, also known as the second resonant inductance of the first transformer. pR represents the internal resistance of the primary side of each transformer. s This indicates the internal resistance of the secondary side of the transformer.

[0028] exist Figure 2 In this context, the output voltage of the inverter in each resonant converter unit is equivalent to a voltage source, namely voltage sources v2, v3, ..., v... m The voltage source of each resonant converter unit is connected to the primary side of the transformer of the resonant converter unit through a resonant circuit formed based on a series resonant capacitor. For example, the resonant circuit of the first resonant converter unit is a series resonant capacitor C. f2 The first resonant inductance L of the second transformer f2 (i.e., the primary leakage inductance L of the second transformer) p2 ) and the magnetizing inductance L of the second transformer m2 (That is, the second resonant inductance of the second transformer). Similarly, the resonant circuit of the (m-1)th resonant transformer unit is a series resonant capacitor C. fm The first resonant inductance L of the second transformer fm (i.e., the primary leakage inductance L of the second transformer) pm ) and the magnetizing inductance L of the second transformer mm (That is, the second resonant inductance of the second transformer). This represents the secondary current. R1, R2, ..., R m These represent the primary-side equivalent resistances of the first, second, ..., m transformers, respectively.

[0029] The secondary side of the transformer in each power unit is connected in series and connected to the RF load through an impedance matching network.

[0030] Regarding the out-of-phase modulation unit, in order to simplify the circuit, improve reliability and reduce cost, each segment of the inverter output terminal of the out-of-phase modulation unit is connected by the same series resonant circuit, as shown in formula (1).

[0031] (1); in, The inductance value of the series resonant circuit. This represents the capacitance value of the series resonant circuit.

[0032] Resonant reactance of a series resonant circuit for: (2), This is the resonant angular frequency of the radio frequency converter.

[0033] Regarding the resonant transformer unit, the first resonant inductor L fi The primary leakage inductance L of the transformer of the resonant transformer unit pi Provided, second resonant inductor L miThe magnetizing inductance is provided by the transformer in the resonant converter unit. Full utilization of the transformer leakage inductance in the resonant converter unit significantly reduces the number of components and the size of the RF converter system.

[0034] The equivalent impedance of the secondary side of the transformer in the power unit for: (3); in, This refers to the capacitance value in the impedance matching network. This represents the resistance value of the RF load. The inductance value in the impedance matching network. Let be the equivalent leakage inductance of the secondary side of the i-th transformer.

[0035] By setting the equivalent impedance of the secondary side The imaginary part is zero, therefore we get and The relationship is: (4).

[0036] Based on impedance matching networks, the equivalent resistance of the secondary side of the transformer in a power unit. (i.e., the equivalent resistance of the RF load) is: (5).

[0037] The equivalent resistance of the secondary side is equivalent to that of the primary side, that is, based on the equivalent resistance of the secondary side of the transformer in the power unit. The primary-side equivalent resistance of the transformer in the power unit is obtained. : (6).

[0038] Based on the architecture of the RF converter in this embodiment, a power regulation method is implemented. This power regulation method combines the start-stop control strategy of the resonant converter unit with out-of-phase modulation to achieve coordinated control of discrete and continuous power regulation under the same operating mode. The power modulation method includes two types of regulation strategies: one is to achieve discrete power regulation by controlling the switching combination state of the resonant converter unit, and the other is to achieve continuous power regulation by adjusting the output phase difference of the out-of-phase modulation unit.

[0039] The start-stop control strategy is used to control the on / off states of m-1 resonant converter units. Since the transformer turns ratios of each resonant converter unit are configured according to a binary relationship, different resonant converter unit configurations correspond to different base output power levels (referred to as base power), thus forming a discrete stepped power distribution covering a wide range. The out-of-phase modulation unit is used to adjust the phase difference between the output voltages of the bridge arms of the two inverters within the out-of-phase modulation unit, achieving continuous power compensation within the current base power step while maintaining the resonant converter unit configuration (i.e., the same switching combination).

[0040] Therefore, the power regulation method divides the power adjustment process into two levels from a control mechanism perspective: the start-stop control strategy of the resonant converter unit achieves coarse adjustment to expand the power coverage range; the out-of-phase modulation of the out-of-phase modulation unit achieves fine adjustment to complete continuous compensation within the power step. The two work together to enable the entire system to achieve wide-range and seamless power regulation without changing the main circuit parameters.

[0041] Based on the power regulation method, a discrete, stepped power is output through a resonant converter unit, and the stepped power is compensated by a phase modulation unit to obtain the output power of the RF converter. The output power of the RF converter can be expressed as a function of the start-stop control strategy variable and the phase angle. By performing equivalent modeling of the RF converter, the expression for the output power can be obtained as follows: (7); Where k represents the equivalent turns ratio weighting coefficient corresponding to the switching combination of the resonant transformer unit, as shown in formula (8): (8); V L V is the output voltage corresponding to the RF load. bus Let θ be the DC bus voltage, θ be the phase difference of the out-of-phase modulation unit, R1 be the primary equivalent resistance of the transformer of the out-of-phase modulation unit, and A be the set of switching combinations of the resonant transformer unit, where A = [x1, x2, ..., xi, ..., x...]. m When the i-th resonant transformer unit is in the on state, x i =1, when the i-th resonant transformer unit is in the off state, x i =0.

[0042] To achieve the target power P under the above power regulation method ref Real-time adjustment, detailing the process of power regulation. This process is used to adjust the power based on the target power P. refThe specific control process of the power regulation method is executed by real-time calculation of the switching combination of the resonant transformer units and the phase angle of the out-of-phase modulation units. This process is divided into two stages: coarse adjustment allocation and fine adjustment compensation. First, the target power is discretized using the binary rated power relationship of m-1 resonant transformer units to determine the switching combination of the resonant transformer units, thereby forming a basic power step that does not exceed the target power. Then, based on the residual error between the basic power and the target power, continuous compensation is achieved by adjusting the phase difference of the out-of-phase modulation units, so that the output power accurately approximates the target power within this step.

[0043] During the coarse adjustment phase, the output discrete and stepped power is specifically generated through the resonant transformation unit as follows: First, based on the target power of the RF converter and the rated power of the first resonant converter unit... The normalized residual power ratio of the first resonant transformer unit is obtained. As shown in formula (9). Wherein, the target power is consistent with the output power of the RF converter.

[0044] (9).

[0045] Secondly, starting with the normalized residual power ratio of the first resonant transformer unit, the switching combination of the resonant transformer units is obtained through iteration. Specifically, in the q-th iteration, based on the current residual ratio... Determine the binary index: (10); This leads to the number of the resonant transformer unit that should be used in this operation: (11); Simultaneously update the residual power ratio to: (12).

[0046] Then, based on the switching combination of the resonant transformer units, the stepped power is obtained. Specifically, through an iterative process, the switching combination A of the resonant transformer units corresponding to the target power is obtained, and thus the basic power step of the switching combination A is obtained.

[0047] After coarse adjustment, the remaining power error between the target power and the base power step is compensated by the out-of-phase modulation unit. By adjusting the phase difference θ between the output voltages of the bridge arms in the out-of-phase modulation unit, the output power is made to change continuously within the current base power step.

[0048] During the fine-tuning and compensation stage, the out-of-phase modulation unit compensates for the stepped power to obtain the output power of the RF converter, specifically as follows: Based on the residual power ratio corresponding to the last resonant transformer unit in the switching combination of resonant transformer units, the phase difference of the out-of-phase modulation unit is obtained, as shown in formula (13).

[0049] (13); in, P1 represents the residual power ratio of the last resonant transformer unit in the switching combination of resonant transformer units, and P2 represents the rated power of the first resonant transformer unit.

[0050] The output power of the RF converter is obtained by compensating the stepped power through the phase difference of the out-of-phase modulation unit.

[0051] The power regulation method can be summarized as follows: first, a basic power step is determined through binary power allocation, and then continuous adjustment within the step is achieved through phase compensation. This power regulation method enables the system to achieve wide-range, high-resolution power control under fixed main circuit parameters.

[0052] Thus, this embodiment addresses the technical problem of "achieving wide-range continuous power regulation under fixed main circuit parameters and fixed bus conditions." Through heterogeneous unit structure, binary turns ratio configuration, power synthesis method of primary side parallel and secondary side series, and a two-layer regulation mechanism of start-stop control of resonant converter unit and out-of-phase modulation, it achieves wide-range, seamless and high-efficiency power output in megahertz radio frequency scenarios.

[0053] In addition, such as Figure 2 As shown in Figure 2, the equivalent circuit diagram of the RF converter is illustrated. This figure shows the equivalent model of the transformer, an architecture that fully utilizes the transformer's leakage inductance. The primary side of the transformer in the out-of-phase modulation unit does not require an additional resonant inductor in series; the transformer's leakage inductance is completely equivalent to the secondary side. m-1 resonant converter units achieve the goal of equivalently inducting a portion of the transformer's leakage inductance (i.e., the required inductance on the primary side) to the primary side as a resonant inductor, and the remainder to the secondary side as a filter inductor. The RF converter in this embodiment supports the following two adjustment strategies: Resonant converter start-stop control strategy: By switching different resonant converter unit combinations, the total equivalent turns ratio is controlled, thereby achieving a large-step power adjustment range. Each combination corresponds to a fixed output power point, and the power coverage range is determined by the number of units m and the base turns ratio N1. Out-of-phase modulation strategy: Under a fixed resonant converter unit configuration, the phase difference θ between the arms within the out-of-phase modulation unit is adjusted to achieve fine-grained power adjustment.

[0054] The design process (i.e., application method) of the RF converter in this embodiment is as follows: The first step is to determine the specifications of the RF converter system based on the actual application requirements. These specifications include the operating frequency, DC bus voltage, and target power.

[0055] The second step involves initially determining the number of power units, *m*, and their corresponding transformer turns ratios based on the power regulation method, thus forming a binary turns ratio combination relationship that satisfies the power coverage range. The turns ratios of the transformers in the resonant converter unit are set to N1, 2N1, ..., 2... m-2 N1, the specific value of which can be matched according to the system's rated power and the unit's load-bearing capacity.

[0056] The third step is to determine the operating frequency f and the RF load R. L Calculate the parameters of the resonant circuit for each power unit. The parameters of the resonant circuit include: resonant inductance, resonant capacitance, and equivalent impedance. The resonant circuit of the out-of-phase modulation unit is a series resonant circuit. The resonant inductance of the out-of-phase modulation unit's resonant circuit is the same as the inductance in the series resonant circuit, and the resonant capacitance of the out-of-phase modulation unit's resonant circuit is the same as the capacitance in the series resonant circuit. For example, the first series resonant circuit in the out-of-phase modulation unit's resonant circuit is a series-connected capacitor C. a and inductor L a The resulting resonant circuit. The resonant circuit of the resonant transformer unit is a resonant circuit formed based on a series resonant capacitor and the primary side of the corresponding transformer. For example, the resonant circuit of the first resonant transformer unit is a series resonant capacitor C. f2 The first resonant inductance L of the second transformer f2 (i.e., the primary leakage inductance L of the second transformer) p2 ) and the magnetizing inductance L of the second transformer m2 The resonant circuit is formed by the second resonant inductance of the second transformer.

[0057] The fourth step is to select the first resonant inductor L of the resonant transformer unit. f With series resonant capacitor C f The parameter values ​​are determined to ensure that the system achieves resonant operation at the target frequency and possesses ZVS characteristics.

[0058] The fifth step involves optimizing the resonant parameter matching for different unit structures and load conditions, thus completing the circuit parameter configuration for the resonant converter unit and the out-of-phase modulation unit. Specifically, the circuit parameter configuration for the resonant converter unit is obtained based on the parameters of its series resonant network and the RF load, and the circuit parameter configuration for the out-of-phase modulation unit is obtained based on the parameters of its series resonant network and the RF load.

[0059] The sixth step is to select MOSFET devices with fast switching capability and low on-resistance to implement the full-bridge Class D high-frequency inverter unit.

[0060] Step 7: Based on the power control method of the RF converter, the phase difference between the outputs of the power units is obtained. The initial architecture is then subjected to cyclic performance evaluation and cyclic update processing based on this phase difference until the updated architecture of the RF converter meets the target conditions. The updated architecture is then identified as the target RF converter. The target condition is that the output power of the updated architecture reaches the target power or... Specifically, based on the power control method of the RF converter, the initial phase difference between the outputs of the power units is obtained. This initial phase difference is then substituted into the initial architecture to perform a performance evaluation, obtaining the corresponding output power or RF power amplifier efficiency. If the output power corresponding to the initial architecture reaches the target power, or the RF power amplifier efficiency corresponding to the initial architecture is not less than the RF power amplifier efficiency threshold, the initial architecture meets the standard, and is thus confirmed as the target architecture for the device converter. If the output power corresponding to the initial architecture does not reach the target power, or the RF power amplifier efficiency corresponding to the initial architecture is less than the RF power amplifier efficiency threshold, it means that the initial architecture does not meet the standard. Then, return to step two, that is, re-execute steps two to seven to obtain the updated architecture. Then, perform a performance evaluation on the updated architecture until the updated architecture meets the target conditions. Finally, determine the updated architecture of the RF converter as the target RF converter.

[0061] Through the above design process, the coordinated optimization of unit configuration state structure, transformer turns ratio configuration, resonant network design and power regulation strategy can be achieved, and a high-efficiency RF conversion system with wide range, continuous output regulation capability and soft-switching operation can be constructed, which is suitable for plasma excitation and power regulation scenarios required by semiconductor processes.

[0062] In summary, this RF converter system can achieve wide-range and high-efficiency RF power output at a megahertz operating frequency. It also achieves a combination of soft switching and continuous regulation through unit configuration states and out-of-phase modulation, making it suitable for RF energy supply under complex and variable process conditions such as semiconductor manufacturing, plasma etching, and thin film deposition.

[0063] Example 2 Based on the same inventive concept, the second embodiment of the present invention also provides an application method, such as... Figure 3 As shown, the method for determining the megahertz radio frequency converter based on a binary turns ratio transformer in Embodiment 1 includes: S201, Obtain the specifications of the radio frequency converter, including: target power, DC bus voltage and operating frequency; S202, the number m of power units of the RF converter and the turns ratio of the transformer of each power unit are initially set according to the power control method of the RF converter; S203, Based on the operating frequency and the RF load of the RF converter, determine the parameters of the resonant circuit of each power unit, wherein the parameters of the resonant circuit include: resonant inductance, resonant capacitance and equivalent impedance; S204, Select the parameter values ​​of the first resonant inductor and series resonant capacitor of the resonant converter unit in the power unit to ensure that the RF converter achieves resonant operation and has ZVS characteristics at the operating frequency; S205, based on the parameters of the series resonant network of the resonant converter unit and the radio frequency load, the circuit parameter configuration of the resonant converter unit is obtained, and based on the parameters of the series resonant network of the out-of-phase modulation unit in the power unit and the radio frequency load, the circuit parameter configuration of the out-of-phase modulation unit is obtained. S206, Select the inverter of the power unit to obtain the initial architecture of the radio frequency converter; S207, according to the power control method of the RF converter, the phase difference between the outputs of the power units is obtained, and the initial architecture is subjected to cyclic performance evaluation and cyclic update processing based on the phase difference until the updated architecture of the RF converter reaches the target condition. The updated architecture of the RF converter is then determined as the target RF converter. The target condition is that the output power of the updated architecture of the RF converter reaches the target power or the RF power amplifier efficiency of the updated architecture of the RF converter is not less than the RF power amplifier efficiency threshold.

[0064] Those skilled in the art will understand that although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0065] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A megahertz radio frequency converter based on a binary turns ratio transformer, characterized in that, include: There are m power units, where m ≥ 2, and the m power units include: one out-of-phase modulation unit and m-1 resonant converter units; each out-of-phase modulation unit includes: two inverters and one transformer; each resonant converter unit includes: one inverter and one transformer; the transformers of the out-of-phase modulation unit and the transformers of the resonant converter units are both binary turns ratio transformers; The input terminals of each power unit are connected in parallel to the DC bus voltage, and the output terminals of each power unit are connected in series to form a series branch. The series branch is connected to the RF load through an impedance matching network. The input terminals of the two inverters of the out-of-phase modulation unit are connected in parallel to form the input terminal of the out-of-phase modulation unit. Each output terminal of the first inverter of the out-of-phase modulation unit is connected to the first terminal of the primary side of the transformer of the out-of-phase modulation unit through a series resonant circuit. Each output terminal of the second inverter of the out-of-phase modulation unit is connected to the second terminal of the primary side of the transformer of the out-of-phase modulation unit through a series resonant circuit. The secondary side of the transformer of the out-of-phase modulation unit is the output terminal of the out-of-phase modulation unit. In each of the resonant converter units, the input terminal of the inverter of the resonant converter unit is the input terminal of the resonant converter unit, the output terminal of the inverter of the resonant converter unit is connected to the primary side of the transformer of the resonant converter unit through a series resonant capacitor, and the secondary side of the transformer of the resonant converter unit is the output terminal of the resonant converter unit; the first resonant inductance of the resonant converter unit is provided by the leakage inductance of the primary side of the transformer of the resonant converter unit, and the second resonant inductance of the resonant converter unit is provided by the magnetizing inductance of the transformer of the resonant converter unit; The turns ratio N of the transformer of the out-of-phase modulation unit is determined by the step difference of the transmission power of the resonant conversion unit, and the turns ratio of the transformer of the m and the turns of the resonant conversion unit is determined by the output power of the radio frequency converter and the rated transmission power of the inverter of the resonant conversion unit.

2. The megahertz radio frequency converter based on a binary turns ratio transformer as described in claim 1, characterized in that, The turns ratio of the transformer in the out-of-phase modulation unit is N, and the turns ratios of the transformers in the m-1 resonant conversion units are N1, 2N1, ... ... m-1 N1.

3. The megahertz radio frequency converter based on a binary turns ratio transformer as described in claim 2, characterized in that, The resonant reactance of the series resonant circuit for: ; in, The inductance value of the series resonant circuit is given. Let be the capacitance value of the series resonant circuit. The resonant angular frequency of the radio frequency converter is denoted as ω.

4. The megahertz radio frequency converter based on a binary turns ratio transformer as described in claim 3, characterized in that, The equivalent impedance of the secondary side of the transformer in the power unit for: ; in, The capacitance value in the impedance matching network. The resistance value of the radio frequency load. The inductance value in the impedance matching network is... Let be the equivalent leakage inductance of the secondary side of the i-th transformer; By setting the equivalent impedance of the secondary side The imaginary part is zero, therefore we get and The relationship is: 。 5. The megahertz radio frequency converter based on a binary turns ratio transformer as described in claim 4, characterized in that, Based on the impedance matching network, the equivalent resistance of the secondary side of the transformer in the power unit is... for: .

6. The megahertz radio frequency converter based on a binary turns ratio transformer as described in claim 5, characterized in that, Based on the equivalent resistance of the secondary side of the transformer in the power unit The primary-side equivalent resistance of the transformer of the power unit is obtained. : 。 7. The megahertz radio frequency converter based on a binary turns ratio transformer as described in claim 6, characterized in that, The power regulation method of the radio frequency converter is as follows: the discrete and stepped power is output through the resonant conversion unit, and the stepped power is compensated through the out-of-phase modulation unit to obtain the output power of the radio frequency converter. The output power of the radio frequency converter for: ; Wherein, k represents the equivalent turns ratio weighting coefficient corresponding to the switching combination of the resonant transformer unit. V L V is the output voltage corresponding to the radio frequency load. bus Let θ be the DC bus voltage, θ be the phase difference of the out-of-phase modulation unit, R1 be the primary-side equivalent resistance of the transformer of the out-of-phase modulation unit, and A = [x1, x2, ..., xi, ..., x] be the switching combination set of the resonant converter unit. m When the i-th resonant transformer unit is in the on state, x i =1, when the i-th resonant transformation unit is in the off state, x i =0.

8. The megahertz radio frequency converter based on a binary turns ratio transformer as described in claim 7, characterized in that, The step power output, which is discrete and stepped, through the resonant conversion unit includes: Based on the target power of the RF converter and the rated power of the first resonant converter, the normalized residual power ratio of the first resonant converter is obtained, wherein the target power is consistent with the output power of the RF converter; Starting from the normalized residual power ratio of the first resonant transformer unit, the switching combination of the resonant transformer units is obtained through iteration; The stepped power is obtained by switching the resonant transformer unit.

9. The megahertz radio frequency converter based on a binary turns ratio transformer as described in claim 8, characterized in that, The step-wise compensation of the stepped power by the out-of-phase modulation unit to obtain the output power of the RF converter includes: The phase difference of the out-of-phase modulation unit is obtained based on the residual power ratio corresponding to the last resonant transformation unit in the switching combination of the resonant transformation units; The output power of the RF converter is obtained by compensating the stepped power through the phase difference of the out-of-phase modulation unit.

10. An application method, characterized in that, The method for identifying a megahertz radio frequency converter based on a binary turns ratio transformer as described in any one of claims 1-9 includes: Obtain the specifications of the radio frequency converter, including: target power, DC bus voltage and operating frequency; The number m of power units of the RF converter and the turns ratio of the transformer of each power unit are initially set according to the power control method of the RF converter. Based on the operating frequency and the RF load of the RF converter, the parameters of the resonant circuit of each power unit are determined. The parameters of the resonant circuit include: resonant inductance, resonant capacitance, and equivalent impedance. The parameter values ​​of the first resonant inductor and series resonant capacitor of the resonant converter in the power unit are selected to ensure that the RF converter achieves resonant operation and has ZVS characteristics at the operating frequency. Based on the parameters of the series resonant network of the resonant converter unit and the radio frequency load, the circuit parameter configuration of the resonant converter unit is obtained, and based on the parameters of the series resonant network of the out-of-phase modulation unit in the power unit and the radio frequency load, the circuit parameter configuration of the out-of-phase modulation unit is obtained. By selecting the inverter of the power unit, the initial architecture of the radio frequency converter is obtained; According to the power control method of the RF converter, the phase difference between the outputs of the power units is obtained, and the initial architecture is subjected to cyclic performance evaluation and cyclic update processing based on the phase difference until the updated architecture of the RF converter reaches the target condition. The updated architecture of the RF converter is then determined as the target RF converter. The target condition is that the output power of the updated architecture of the RF converter reaches the target power or the RF power amplifier efficiency of the updated architecture of the RF converter is not less than the RF power amplifier efficiency threshold.

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