Parallel radio frequency power supply and power control method
By using a parallel RF power supply structure and power control method, the problem of narrow operating range of switch-mode power amplifiers is solved, and efficient power control and high-efficiency output of RF power supply are achieved over a wide power range.
Patent Information
- Application Number
- CN202411501803.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-25
- Publication Date
- 2026-04-28
AI Technical Summary
Existing RF power supplies have extremely narrow operating ranges for their switch-mode power amplifiers, resulting in limited effective operating power ranges and low overall efficiency and power density.
A parallel RF power supply structure is adopted, which uses multiple power amplification modules connected in parallel. Combined with a turn-on module, power combining network and controller, it realizes hierarchical power control and fine phase adjustment, and uses the phase difference between the turn-on signal and the drive signal to adjust the output power.
It achieves efficient power control over a wide power range, improving the overall efficiency and power density of the RF power supply.
Smart Images
Figure CN121939946A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an radio frequency power supply and a power control method, belonging to the field of radio frequency power supply technology. Background Technology
[0002] Plasma etching systems control plasma distribution via radio frequency (RF) power supplies. As the number of stacked layers and etching steps increases with the number of 3D NAND and other devices, RF power supplies need to provide higher and more precise RF power to improve the collimation of hole etching. Existing RF power supplies typically use a combination of linear power amplifier modules and RF power coupling mechanisms to control power. The disadvantage of this approach is that both the linear amplifier module and the coupling mechanism have high losses, resulting in low overall system efficiency and power density. Some new RF power supplies use switch-mode power amplifiers, which regulate power using the input DC voltage to improve overall efficiency at rated power. The disadvantage of this approach is that the switch-mode power amplifier has an extremely narrow operating range, limiting the effective power range of the system. Summary of the Invention
[0003] To address the problem that the operating range of the switch-mode power amplifier in existing RF power supplies is extremely narrow and the effective operating power range of the system is limited, this invention proposes a parallel RF power supply and power control method.
[0004] The technical solution adopted by the present invention to solve the above problems is as follows: The parallel radio frequency power supply of the present invention includes multiple power amplification modules, a turn-on module, a power combining network, a power meter and a controller;
[0005] Multiple power amplifier modules are connected in parallel. The power amplifier modules are connected to the activation module, the activation module is connected to the power combining network, the power combining network is connected to the load through the power meter, and the power amplifier modules, activation modules, power combining network and power meter are all connected to the controller.
[0006] Furthermore, the turn-on module consists of a thyristor and an isolation drive circuit;
[0007] One end of the isolation drive circuit is connected to the controller and receives the turn-on signal, while the other end is connected to the gate and cathode of the thyristor.
[0008] Furthermore, the power combining network is composed of passive components such as inductors, capacitors, and transmission lines. It isolates the parallel voltage sources through passive components and achieves the superposition of power between branches through the parallel combination of passive components.
[0009] Furthermore, the power meter is composed of an RF power meter, which is responsible for detecting the output positive power signal.
[0010] Furthermore, the controller is composed of a microcontroller or a single-chip microcomputer, which is responsible for calculating and distributing the turn-on signals and drive signals of each branch based on the desired power and the forward power detection signal, so as to accurately control the output power.
[0011] The present invention discloses a parallel radio frequency power control method, which adjusts the turn-on signal and the drive signal according to the desired power and the detected positive power signal to achieve precise control of the parallel radio frequency power.
[0012] Furthermore, adjusting the turn-on signal specifically involves using a turn-on signal allocation algorithm to determine the power level of the desired power. When the desired power is greater than the output power of the i power amplifier modules but less than the output power of the (i+1) power amplifier modules, the turn-on signal of the (i+1) power amplifier modules is made valid to control the (i+1) power amplifier modules to be turned on, while the remaining power amplifier modules are turned off.
[0013] Furthermore, the relationship between the number of activated modules and power is as follows:
[0014]
[0015] In formula (1), P represents the desired power, P im This represents the maximum output power of a single module when the phase shift angle of the drive signal i is 0.
[0016] Furthermore, adjusting the drive signal specifically includes using a phase-shifting signal allocation algorithm to adjust the drive signal of each branch according to the difference between the desired power and the forward power.
[0017] Furthermore, the formula for calculating the power difference in the phase-shifting signal allocation algorithm is as follows:
[0018] Power difference = desired power - forward power. When the power difference > 0, the phase difference of the drive signal between the power amplifier module with even number and the power amplifier module with odd number decreases to increase the output power. When the power difference < 0, the phase difference of the drive signal between the power amplifier module with even number and the power amplifier module with odd number increases to decrease the output power.
[0019] The beneficial effects of this invention are as follows: This invention proposes a parallel RF power supply structure and power control method based on a switching module. It achieves graded power control by connecting and disconnecting power amplifier modules, and further refines the power through the phase adjustment of the output voltage of the power amplifier modules. This invention ensures that the power amplifier modules operate within the ideal load range through power gradation, thereby guaranteeing the overall efficiency of the RF power supply under wide power modulation. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of a parallel radio frequency power supply.
[0021] Figure 2 This is a structural diagram of the activation module;
[0022] Figure 3 It is a flowchart of the control algorithm;
[0023] Figure 4 This is a schematic diagram of a power amplifier module;
[0024] Figure 5 This is a schematic diagram of a power combining network;
[0025] Figure 6 This is a schematic diagram of the RF power supply output power;
[0026] Figure 7 This is a schematic diagram of RF power supply efficiency. Detailed Implementation
[0027] like Figure 1 As shown, a parallel radio frequency power supply includes multiple power amplification modules, a turn-on module, a power combining network, a power meter, and a controller;
[0028] Multiple power amplifier modules are connected in parallel. The power amplifier modules are connected to the activation module, the activation module is connected to the power combining network, the power combining network is connected to the load through the power meter, and the power amplifier modules, activation modules, power combining network and power meter are all connected to the controller.
[0029] The activation module controls the number of power amplifier modules activated based on the desired power. The output power of the power amplifier modules connected to the system is combined via a power combining network and then transmitted to the load. The controller allocates activation signals according to the desired power to control the drive signals of the activation modules. It initially controls the output power using the number of power amplifier modules connected to the subsequent stage and allocates drive signals i with the same duty cycle but different phase shift angles to the power amplifier modules to adjust the voltage phase of each power amplifier module, thereby further refining the output power. When i is odd, the phase shift angle of drive signal i is 0; when i is even, the phase shift angle of drive signal i is related to the desired power. It should be understood that other methods of adjusting the phase difference between the drive signals of power amplifier modules with even numbers and those with odd numbers are also within the scope of this invention.
[0030] Furthermore, the power amplifier module is used to convert DC voltage into a fixed-frequency radio frequency voltage output. The amplitude of the radio frequency voltage is kept in a fixed ratio with the input voltage and the duty cycle of the controller drive signal, and the phase is determined by the phase shift angle of the controller drive signal. The radio frequency voltage is an AC voltage.
[0031] The activation module includes multiple activation units, which are respectively connected to the output terminals of multiple power amplifier modules. Each activation unit includes a power switching device and an isolation drive circuit, which are used to turn on or off the power amplifier module connected to it to adjust the output power level.
[0032] A power combining network is composed of passive components such as inductors and capacitors. It is used to combine and transfer output power to the load. Inductors, capacitors and other components have the functions of isolating voltage and distributing power among branches.
[0033] A power meter is used to detect the positive power output of a power combining network to output a positive power detection signal. It should be understood that the power mentioned in this article refers to active power.
[0034] The controller, composed of a microcontroller or single-chip microcomputer, is responsible for calculating and distributing the turn-on and drive signals to each branch based on the desired power and forward power detection signals. Turn-on signals 1 to n are distributed to the n power switching devices in the turn-on module to control the output power level. Drive signals 1 to n are distributed to the n power amplification modules to precisely control the output power. The flowchart of its control algorithm is shown below. Figure 3 As shown.
[0035] The power amplifier module can be composed of linear power amplifiers such as Class A, Class AB, and Class C, or switching-mode power amplifiers such as Class D and Class E. These power amplifiers typically include a power amplifier circuit composed of active components, passive inductors, and capacitors, and a driver circuit composed of a driver chip and passive components. The driver circuit drives the active components to operate at a fixed frequency and duty cycle according to the drive signal provided by the controller, causing the power amplifier module to output a radio frequency voltage with a fixed amplitude and a phase proportional to the phase shift angle of the drive signal.
[0036] Figure 2 A schematic diagram of the activation module is provided. The activation module includes multiple activation units, each connected to the output terminals of multiple power amplifier modules. Each activation unit includes a power switch and an isolation drive circuit. The first terminal of the power switch is connected to the output terminal of the corresponding power amplifier module to receive the radio frequency voltage i, and the second terminal generates a parallel radio frequency voltage i that is transmitted to the power combining network. The control terminal receives the control signal generated by the isolation drive circuit. In this embodiment, a thyristor is used as an example of the power switch.
[0037] Each isolated drive circuit has its input connected to the controller and receives a corresponding turn-on signal i (i is 1 to n). Its output is connected to the gate and cathode of the thyristor to provide a control signal between the gate and cathode to control the thyristor's turn-on and turn-off. It should be understood that when the thyristor is turned on, it indicates that the corresponding power amplifier module branch is connected; otherwise, it is not connected.
[0038] Specifically, when the controller outputs a valid turn-on signal (e.g., high level), the voltage value of the control signal provided by the isolation drive circuit is higher than the thyristor threshold voltage to control the thyristor to turn on. When the controller outputs an invalid turn-on signal (e.g., low level), the voltage value of the control signal provided by the isolation drive circuit is lower than the thyristor threshold voltage, thus the thyristor will turn off. The power supply voltage of the isolation drive circuit is provided by the control bus. The turn-on module can convert the n sets of turn-on signals output by the controller into the access states of 1 to n power amplifier module branches. When the output power of the power amplifier module in the i-th branch is Pi and the turn-on signal is Si (Si=1 for valid, Si=0 for invalid), the final output power of the power amplifier module in that branch is S. i P i When the activation signal of the corresponding branch is valid, the power amplifier module of that branch outputs power to the load; when the activation signal of the corresponding branch is invalid, the power amplifier module of that branch cannot output power to the load.
[0039] Figure 4 A schematic diagram of a power amplifier module is provided. The example uses a Class D power amplifier module; however, it should be understood that in other embodiments, the power amplifier module may have other structures. In this embodiment, the power amplifier module includes switching transistors S1 and S2 (active components), connected in series between the DC bus and reference ground, forming a half-bridge structure. A capacitor Cs1 is connected in parallel across the two ends of switching transistor S1, and a capacitor Cs2 is connected in parallel across the two ends of switching transistor S2. An input capacitor C is connected between the first end of switching transistor S1 and reference ground. IN The power amplifier module also includes an inductor L. F and capacitor C F A series connection is established between the common node of switches S1 and S2 and the output terminal. The output terminal outputs a radio frequency voltage i (i is 1 to n) with a fixed amplitude and a phase proportional to the phase shift angle of the drive signal. Furthermore, the power amplifier module also includes a half-bridge driver, whose power supply voltage comes from the control bus and receives the drive signal i. This driver provides a voltage signal to switch S1 with the same timing as the drive signal i, and provides a voltage signal to switch S2 that lags behind the drive signal i by half a cycle, ensuring that the phase of the radio frequency voltage i is consistent with the phase shift angle of the drive signal i.
[0040] Figure 5 A schematic diagram of a power combining network is given. The power combining network includes an impedance network composed of inductors and capacitors. It isolates the parallel voltage sources through passive components and achieves the superposition of power between branches through the parallel combination of passive components.
[0041] In some embodiments, the power combining network can be constructed using lossless combining networks such as Doherty and Chireix. It should be understood that in other embodiments, the power combining network has other structures, and different network structures and parameters correspond to different branch power allocation relationships. In this embodiment, the power combining network includes multiple power combining branches, each connected to a corresponding multiple turn-on unit, receiving a parallel RF voltage i. Specifically, each power combining branch includes an impedance network composed of capacitors C1 and C2 and inductor L1. Capacitors C1 and C2 are connected in series between the input and output terminals of the power combining branch, and inductor L1 is connected between the common node of capacitors C1 and C2 and the reference ground. The output terminals of each power combining branch are connected together to generate an output voltage. It should be understood that the output terminals of the power amplification modules are connected in parallel via the power combining branches, thereby achieving the superposition of the output power of each power amplification module. The output power of the power combining network is...
[0042] Figure 6 This is a schematic diagram of the RF power supply output power. The horizontal axis represents the phase shift angle of the driving signal i (where i is an even number), and the vertical axis represents the RF power supply output power. Figure 6 The curves illustrate that the output power of the RF power supply is inversely correlated with the phase shift angle of the drive signal i and positively correlated with the number N of power amplifier modules turned on, proving that the proposed method can control the power through the combined phase control of the turn-on signal and the drive signal. When the desired power transitions from the highest rated power to 1 / 7 of the highest rated power, the number N of power amplifier modules turned on gradually decreases from 8 to 4. It should be understood that in other embodiments, the number N of power amplifier modules turned on can be increased or decreased for other power ranges. Figure 7 This is a schematic diagram of RF voltage efficiency. The horizontal axis represents the phase shift angle of the driving signal i (where i is an even number), and the vertical axis represents the RF power supply efficiency. Figure 7 The curves show that the system RF power efficiency is always greater than 50% when the number of power amplifier modules N changes from 4 to 8 and the phase shift angle of the drive signal i changes from 0° to 80°, proving that the proposed method can improve the overall efficiency of the RF power supply over a wide power range.
[0043] This invention also discloses a parallel RF power supply power control method for driving signals. It generates an on-state signal and a driving signal based on the desired power and the forward power output from the power combining network, thereby achieving precise control of the parallel RF power supply power. The driving signal is generated based on the difference between the desired power and the forward power detection signal, and the phase difference between the driving signals of each power amplification module is adjusted to regulate the output power.
[0044] Specifically, the control method includes: calculating and allocating turn-on signals to the turn-on modules based on the desired power to control the number of power amplifier modules that are turned on. For example, when the desired power is greater than the output power of i power amplifier modules but less than the output power of i+1 power amplifier modules, the turn-on signals of i+1 power amplifier modules are made valid to control i+1 power amplifier modules to be turned on, while the remaining power amplifier modules are turned off.
[0045] Furthermore, the relationship between the number N of the connected power amplifier modules and the power is as follows:
[0046]
[0047] In formula (1), P represents the desired power, P im This indicates the maximum output power of a single power amplifier module when the phase shift angle of the drive signal i is 0.
[0048] The control method further includes adjusting the drive signal based on the power difference between the desired power and the forward power detection signal to adjust the phase difference between the drive signals of the even-numbered power amplifier modules and the odd-numbered power amplifier modules, thereby achieving the desired output power. Specifically, the phase shift angle of the drive signal for the odd-numbered power amplifier modules is zero, while the phase shift angle of the drive signal for the even-numbered power amplifier modules is adjusted within a certain range, such as 0°-80°.
[0049] Specifically, the power difference = desired power - forward power detection signal. When the power difference > 0, the phase difference of the drive signal between the power amplifier module with even number and the power amplifier module with odd number is reduced to increase the output power. When the power difference < 0, the phase difference of the drive signal between the power amplifier module with even number and the power amplifier module with odd number is increased to reduce the output power.
[0050] Alternatively, closed-loop control methods such as PID can be used to adjust the phase difference between drive signals based on the power difference.
[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.
Claims
1. A parallel radio frequency power supply, characterized in that, include: Multiple power amplifier modules, each configured to convert DC voltage into a fixed-frequency radio frequency voltage; The activation module is configured to connect or disconnect the power amplifier module connected to it; A power combining network is configured to combine the output power of the connected power amplifier modules and output it. as well as The controller is configured to control the plurality of power amplification modules and the turn-on module according to the desired power and the positive power output by the power combining network to adjust the output power.
2. The parallel radio frequency power supply according to claim 1, characterized in that, The plurality of power amplifier modules are controlled by the controller to output radio frequency voltages with the same amplitude, and each radio frequency voltage has a phase, wherein the phase is determined by the phase shift angle of the drive signal generated by the controller.
3. A parallel radio frequency power supply according to claim 2, characterized in that, The phase is determined by the phase difference between the drive signal corresponding to the power amplifier module with an even number and the drive signal corresponding to the power amplifier module with an odd number.
4. A parallel radio frequency power supply according to claim 1, characterized in that, The power amplifier module is a linear power amplifier or a switch-mode power amplifier.
5. A parallel radio frequency power supply according to claim 1, characterized in that, The activation module includes multiple activation units, which are respectively connected to the output terminals of multiple power amplifier modules. Each activation unit is controlled by an activation signal to turn on or off the power amplifier module connected to it.
6. A parallel radio frequency power supply according to claim 5, characterized in that, The activation unit includes a power switching device, the first end of which is connected to the output end of the corresponding power amplifier module, the second end of which generates a parallel radio frequency voltage and transmits it to the power combining network, and the control end receives a control signal.
7. A parallel radio frequency power supply according to claim 6, characterized in that, The power switching device is a thyristor.
8. A parallel radio frequency power supply according to claim 6, characterized in that, The turn-on unit further includes an isolation drive circuit, which receives the turn-on signal generated by the controller and generates the control signal according to the turn-on signal to control the on / off state of the power switching device.
9. A parallel radio frequency power supply according to claim 1, characterized in that, The power combining network includes multiple power combining branches, each of which includes an impedance network composed of inductors and capacitors. The input terminal of each power combining branch is connected to the turn-on module, and the output terminals of the multiple power combining branches are connected together to achieve the superposition of the output power of each power amplification module.
10. A parallel radio frequency power supply according to claim 9, characterized in that, The power combining branch includes a first capacitor, a second capacitor, and an inductor, wherein the first capacitor and the second capacitor are connected in series between the input and output terminals of the power combining branch, and the inductor is connected between the common node of the first capacitor and the second capacitor and a reference ground.
11. A parallel radio frequency power supply according to claim 1, characterized in that, Also includes: The power meter is responsible for detecting the positive power output by the power combining network to output a positive power detection signal.
12. A parallel radio frequency power supply according to claim 1, characterized in that, The controller is configured to calculate and assign each turn-on signal to the turn-on module based on the desired power to control the number of power amplifier modules turned on.
13. A parallel radio frequency power supply according to claim 12, characterized in that, The controller is also configured to generate a drive signal based on the difference between the desired power and the forward power detection signal, and to adjust the phase difference between the drive signals of the even-numbered power amplifier modules and the odd-numbered power amplifier modules, thereby adjusting the output power.
14. A parallel radio frequency power supply according to claim 13, characterized in that, The controller is also configured to adjust the phase shift angle of the drive signal of the even-numbered power amplifier module according to the difference between the desired power and the forward power detection signal, and to control the phase shift angle of the drive signal of the even-numbered power amplifier module to be zero.
15. A power control method for a parallel radio frequency power supply, characterized in that, The parallel RF power supply includes multiple power amplification modules; an activation module configured to connect or disconnect the connected power amplification modules; and a power combining network configured to combine the output power of the activated power amplification modules before outputting it. The power control method includes: An on-line signal is generated based on the desired power and the positive power output of the power combining network to control the number of power amplifier modules that are turned on, and a drive signal is generated and the phase difference between the drive signals of the multiple power amplifier modules is adjusted, thereby adjusting the output power of the parallel RF power supply.
16. The power control method according to claim 15, characterized in that, Also includes: When the desired power is greater than the output power of i power amplifier modules and less than the output power of i+1 power amplifier modules, the turn-on signal corresponding to i+1 power amplifier modules is made valid to control i+1 power amplifier modules to be turned on and the remaining power amplifier modules to be turned off, where i is a positive integer.
17. A parallel radio frequency power control method according to claim 15, characterized in that, Also includes: The phase difference between the drive signal corresponding to the power amplifier module with an even number and the drive signal corresponding to the power amplifier module with an odd number is adjusted according to the difference between the desired power and the positive power.
18. A parallel radio frequency power control method according to claim 17, characterized in that, Also includes: The phase shift angle of the drive signal corresponding to the power amplifier module with an even number is adjusted according to the difference between the desired power and the forward power, and the phase shift angle of the drive signal corresponding to the power amplifier module with an odd number is controlled to be zero.
19. A parallel radio frequency power control method according to claim 17, characterized in that, Also includes: When the desired power is greater than the positive power, the phase difference of the driving signal between the power amplifier module with even number and the power amplifier module with odd number is reduced to increase the output power. When the desired power is less than the positive power, the phase difference of the driving signal between the power amplifier module with even number and the power amplifier module with odd number is increased to reduce the output power.