High frequency power supply device and control method for high frequency power supply device

Abstract

In a high-frequency power supply with a wide frequency band from the VHF band to the UHF band, the occurrence of aliasing due to undersampling is suppressed even in a configuration using an ADC with a low Nyquist frequency. [Solution] Even when the frequency of the RF signal changes within a variable frequency range due to variable frequency control, the high-frequency power supply device of the present invention controls the local oscillation frequency fLo of the local oscillation signal Lo used for frequency conversion in the downconverter so that it has a certain correlation with the variable frequency fRF of the RF signal, thereby imposing a limit on the range of change in the local oscillation frequency fLo so that the frequency of the intermediate frequency signal is lower than the Nyquist frequency of the analog-to-digital converter (ADC).

Description

[Technical Field]

[0001] The present invention relates to a high frequency power supply device that can vary the frequency of an RF signal over a wide band from the VHF band to the UHF band, and a method for controlling a high frequency power supply device. [Background technology]

[0002] In a radio frequency power supply that outputs an RF signal used in a semiconductor film forming apparatus or the like, a configuration is known in which the RF output of a radio frequency amplifier is converted into a digital signal and fed back (Patent Document 1). Fig. 15 shows an outline of the radio frequency power supply 100 shown in Patent Document 1.

[0003] In the high frequency power supply 100, an oscillation signal generated by an oscillator 106 is converted into an analog signal by a DAC (Digital to Analog Converter) 101, the high frequency signal (RF signal) is then amplified by a high frequency amplifier 102, and the amplified RF signal is output to a load.

[0004] A portion of the RF signal amplified by the high-frequency amplifier 102 is branched by a directional coupler 103 and converted into a digital signal by an ADC (Analog to Digital Converter) 104. A digital processing unit 105 digitally processes the digital signal converted by the ADC 104, and then an oscillator 106 generates an oscillation signal. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-168231 Summary of the Invention [Problem to be solved by the invention]

[0006] In a high-frequency power supply for the LF / MF / HF (30kHz to 30MHz) frequency band, the RF signals of the traveling and reflected waves detected by the power detection section of the directional coupler are directly sampled by an ADC, and signal processing is performed using the digital signals obtained by digital conversion. In the LF / MF / HF (30kHz to 30MHz) frequency band, high-speed variable frequency operation is possible even when using a low-power ADC whose Nyquist frequency exceeds 30MHz.

[0007] However, in a high-frequency power supply that handles RF signals in a wide frequency band from the VHF band (30 MHz to 300 MHz) to the UHF band (300 MHz to 3 GHz), sampling an RF signal in the 30 MHz to 3 GHz range using an ADC with a low Nyquist frequency results in undersampling, which causes aliasing (folding noise), making it difficult to faithfully process the RF signal.

[0008] Furthermore, when an ADC with a high Nyquist frequency and a wide bandwidth is used instead of an ADC with a low Nyquist frequency, there is a problem that costs increase due to the high component prices of the ADC.

[0009] The present invention aims to solve the above-mentioned problems and to process RF signals without causing aliasing due to undersampling, even in a configuration using an ADC with a low Nyquist frequency, in a high-frequency power source with a wide frequency band from the VHF band (30 MHz to 300 MHz) to the UHF band (300 MHz to 3 GHz). [Means for solving the problem]

[0010] The present invention controls the local oscillation frequency fLo of the local oscillation signal Lo used for frequency conversion in the downconverter so that it has a certain correlation with the variable frequency fRF of the RF signal. This local oscillation frequency control imposes a limit on the range of change in the local oscillation frequency fLo so that the frequency of the intermediate frequency signal is lower than the Nyquist frequency of the analog-to-digital converter (ADC), even when the frequency of the RF signal changes within the variable frequency range due to variable frequency control, thereby suppressing undersampling.

[0011] A. High frequency power supply: The high frequency power supply device of the present invention is a high frequency power supply device that outputs high frequency power (RF power) of a variable frequency, (a) A wideband power amplifier that amplifies the power of a wideband RF signal (b) Power detector that detects the high-frequency output of the wideband power amplifier (c) A down converter that converts the high-frequency power signal of a wideband power amplifier into a low-frequency intermediate frequency signal. (d) Analog-to-digital converter (ADC) converts intermediate frequency signals into digital signals (e) A control unit that controls frequency Equipped with.

[0012] The control unit also performs the following control. (f) Variable frequency control for varying RF signals (g) Local oscillation control for controlling the local oscillation frequency fLo of the local oscillation signal Lo used for frequency conversion of the downconverter in a manner that has a certain correlation with the variable frequency of the RF signal by variable frequency control.

[0013] The wideband power amplifier amplifies the power of high-frequency signals over a wide band from the VHF band (30 MHz to 300 MHz) to the UHF band (300 MHz to 3 GHz), and power detection uses a directional coupler or the like to detect the forward wave power going from the wideband power amplifier to the load, and the reflected wave power returning from the load to the wideband power amplifier.

[0014] The downconverter is composed of a mixer that multiplies a high frequency signal of high frequency power detected by the power detector by a local oscillation signal, and outputs an intermediate frequency signal that is lower in frequency than the high frequency signal.

[0015] By using a class A amplifier as the amplifier for the forward wave and reflected wave detection signals and the intermediate frequency, and a double balanced mixer as the down-converter, the output level of the signal after frequency conversion by the down-converter can be given linearity characteristics proportional to the high-frequency signal of the high-frequency power, and output power control can be improved.

[0016] Furthermore, even if the frequency of the RF signal changes within the variable frequency range due to variable frequency control, by controlling the local oscillation frequency fLo of the local oscillation signal Lo used for frequency conversion in the downconverter so that it has a certain correlation with the variable frequency fRF of the RF signal, a limit is imposed on the frequency of the intermediate frequency signal so that the range of change in the local oscillation frequency fLo is lower than the Nyquist frequency of the analog-to-digital converter (ADC).

[0017] This prevents undersampling in the sampling process of the analog-to-digital converter (ADC), eliminating the occurrence of aliasing (folding noise), and enabling faithful processing of RF signals.

[0018] The control unit also includes multiple control modes. (1) First control mode The control unit of the first control mode is In variable frequency control, an RF signal frequency setting section sets the RF signal frequency within the variable frequency range of the RF signal. In local oscillation control, a local oscillation signal frequency setting section sets the local oscillation frequency fLo of the local oscillation signal Lo based on the RF signal frequency setting data. It has.

[0019] The variable frequency fRF of the RF signal and the local oscillation frequency fLo are related in such a way that the difference frequency between the two frequencies becomes the intermediate frequency of the down-converter.

[0020] The local oscillation signal frequency setting unit sets a local oscillation frequency fLo such that the intermediate frequency is lower than the Nyquist frequency of an ADC (analog-to-digital converter) for any variable frequency fRF of the RF signal within the variable frequency range of the RF signal.

[0021] According to the first control mode, the frequency of the local oscillation signal Lo is changed in conjunction with the change in frequency of the RF signal, thereby making the intermediate frequency of the constant and fixed intermediate frequency signal lower than the Nyquist frequency of the ADC (analog-to-digital converter).

[0022] Furthermore, even if the frequency of the RF signal changes due to variable frequency control, the intermediate frequency is linked to the frequency change of the RF signal, so the occurrence of aliasing (folding noise) due to undersampling is always suppressed.

[0023] (2) Second control mode The control unit of the second control mode is In variable frequency control, an RF signal frequency setting unit sets the variable frequency fRF of the RF signal that is variably controlled within the variable frequency range. A memory unit that stores a plurality of local oscillation frequencies fLo that are respectively determined for the divided frequency intervals obtained by dividing the variable frequency range of the RF signal into a plurality of intervals. A local oscillation signal frequency selection unit that selects, in local oscillation control, a local oscillation frequency fLo that is set within a frequency range that includes a variable frequency fRF of the set RF signal from among a plurality of local oscillation frequencies fLo stored in a storage unit. It has.

[0024] The variable frequency fRF of the RF signal and the local oscillation frequency fLo are related in such a way that the difference frequency between the variable frequency fRF of the RF signal and the defined local oscillation frequency fLo for the divided frequency range of the RF signal that includes this variable frequency fRF becomes the intermediate frequency of the downconverter.

[0025] The local oscillation signal frequency selection unit selects a determined local oscillation frequency fLo for a divided frequency range of the RF signal that includes the variable frequency fRF of the RF signal, thereby setting a local oscillation frequency fLo whose intermediate frequency is lower than the Nyquist frequency of the ADC (analog-to-digital converter) for any variable frequency fRF of the RF signal within the variable frequency range of the RF signal.

[0026] According to the second control mode, the local oscillation frequency fLo is determined for the divided frequency range of the RF signal, and the local oscillation frequency fLo determined for the divided frequency range that includes the RF signal frequency is selected in response to frequency changes in the RF signal, and the intermediate frequency of the intermediate frequency signal is set to a frequency lower than the Nyquist frequency of the ADC (analog-to-digital converter).

[0027] Furthermore, even if the frequency of the RF signal changes due to variable frequency control, the intermediate frequency is linked to the frequency change of the RF signal, so the occurrence of aliasing (folding noise) due to undersampling is always suppressed.

[0028] (3) The third control mode The control unit of the third control mode is In variable frequency control, an RF signal frequency setting unit sets the variable frequency fRF of the RF signal that is variably controlled within the variable frequency range. A memory unit that stores a plurality of local oscillation frequencies fLo that are respectively determined for each divided frequency interval obtained by dividing the variable frequency range of the RF signal into a plurality of intervals. a local oscillation signal frequency selection unit that selects a local oscillation frequency fLo determined in a divided frequency range including a high-frequency signal from among a plurality of local oscillation frequencies fLo stored in the storage unit based on a high-frequency feedback signal RFfb of the high-frequency power of the wideband power amplifier in local oscillation control; It has.

[0029] The control unit of the third control form is similar to the control unit of the second control form in that it includes an RF signal frequency setting unit, a memory unit, and a local oscillation signal frequency selector, but differs in the signal that selects the local oscillation frequency fLo in the local oscillation signal frequency selector.The local oscillation signal frequency selector of the third control form selects a local oscillation frequency fLo that is set in a frequency range that includes the high frequency signal from among multiple local oscillation frequencies fLo stored in the memory unit, based on a high frequency feedback signal RFfb of the high frequency power of the wideband power amplifier.

[0030] Since the frequency of the high-frequency signal of the high-frequency power that is the output of the wideband power amplifier matches the frequency of the RF signal that is the input of the wideband power amplifier, the control unit in the third control form selects the local oscillation frequency fLo based on the frequency of the high-frequency signal of the high-frequency power instead of the RF signal frequency setting data that sets the RF signal.

[0031] (4) Fourth control mode The control unit of the fourth control mode is In variable frequency control, an RF signal frequency setting unit sets the variable frequency fRF of the RF signal that is variably controlled within the variable frequency range. In local oscillation control, the local oscillation fixed frequency fLo is fixed. fix Local oscillation signal fixed frequency setting section that sets It has.

[0032] Local oscillation fixed frequency fLo fix does not change in conjunction with the change in the variable frequency fRF of the RF signal, but the variable frequency fRF of the RF signal and the local oscillation fixed frequency fLo fixThere is a frequency relationship between the two frequencies in that the difference frequency between the two frequencies is equal to or less than the upper limit of the intermediate frequency of the down-converter.

[0033] The local oscillation signal fixed frequency setting unit of the fourth control form sets the local oscillation frequency fLo such that the intermediate frequency with respect to the upper limit frequency of the variable frequency of the RF signal is lower than the Nyquist frequency of the ADC (analog-to-digital converter). fix Set as.

[0034] According to the fourth control mode, the variable frequency fRF of the RF signal and the fixed local oscillation frequency fLo fix By making the difference frequency between the input and output signals equal to or lower than the upper limit of the intermediate frequency of the down-converter, the intermediate frequency of the intermediate frequency signal is made lower than the Nyquist frequency of the ADC (analog-to-digital converter).

[0035] Furthermore, even if the frequency of the RF signal changes due to variable frequency control, the intermediate frequency is lower than the Nyquist frequency of the ADC (analog-to-digital converter), so the occurrence of aliasing (folding noise) due to undersampling is always suppressed.

[0036] The high frequency power supply device of the present invention detects the high frequency signal of the high frequency power of the wideband power amplifier using a traveling wave signal and / or a reflected wave signal, and information related to the high frequency signal obtained by an analog-to-digital converter (ADC) is applied to various controls of the high frequency power supply device.

[0037] B. Control method of high frequency power supply device The method for controlling a high frequency power supply device of the present invention comprises: (a) A wideband power amplifier that amplifies the power of a wideband RF signal (b) Power detector that detects the high-frequency output of the wideband power amplifier (c) A down converter that converts the high-frequency power signal of a wideband power amplifier into a low-frequency intermediate frequency signal. (d) Analog-to-digital converter (ADC) converts intermediate frequency signals into digital signals (e) A control unit that controls frequency The present invention relates to a method for controlling a high frequency power supply device that outputs high frequency power (RF power) of a variable frequency.

[0038] The control by the control unit includes the following. (f) Variable frequency control for varying RF signals (g) A local oscillation control that controls the local oscillation frequency fLo of the local oscillation signal Lo used for frequency conversion of the downconverter in a manner that has a certain relationship with the variable frequency of the RF signal by the variable frequency control.

[0039] The local oscillation frequency fLo of the local oscillation control is a frequency of the intermediate frequency signal that is lower than the Nyquist frequency of the ADC (analog-to-digital converter) within the variable frequency range of the RF signal by the variable frequency control.

[0040] The variable frequency fRF of the RF signal and the local oscillation frequency fLo have a relationship such that the difference frequency between the two frequencies becomes the intermediate frequency of the down-converter.

[0041] Furthermore, the local oscillation control sets a local oscillation frequency fLo such that the intermediate frequency is lower than the Nyquist frequency of the ADC (analog-to-digital converter) for any variable frequency fRF of the RF signal within the variable frequency range of the RF signal.

[0042] According to the control method for a high frequency power supply device of the present invention, the frequency of the local oscillation signal Lo is changed in conjunction with the change in frequency of the RF signal, thereby making the intermediate frequency of the intermediate frequency signal lower than the Nyquist frequency of the ADC (analog-to-digital converter).

[0043] Furthermore, even if the frequency of the RF signal changes due to variable frequency control, the intermediate frequency is linked to the frequency change of the RF signal, so the occurrence of aliasing (folding noise) due to undersampling is always suppressed. [Effects of the Invention]

[0044] According to the high frequency power supply device and the control method for the high frequency power supply device of the present invention, in a high frequency power supply with a wide frequency band from the VHF band (30 MHz to 300 MHz) to the UHF band (300 MHz to 3 GHz), RF signals can be processed without causing aliasing due to undersampling, even in a configuration using an ADC with a low Nyquist frequency. [Brief explanation of the drawings]

[0045] [Figure 1] 1 is a diagram for explaining a schematic configuration of a high-frequency power supply device according to the present invention; [Figure 2] 1 is a diagram for explaining a configuration example of a first control mode of a high frequency power supply device according to the present invention. [Figure 3] 4 is a flowchart illustrating an example of operation of a first control mode of the high frequency power supply device of the present invention. [Figure 4] FIG. 3 is a diagram for explaining the frequency relationship in the first control mode of the high frequency power supply device of the present invention. [Figure 5] FIG. 4 is a diagram for explaining a schematic configuration of a second control mode of the high frequency power supply device of the present invention. [Figure 6] FIG. 4 is a diagram for explaining a configuration example of a second control mode of the high frequency power supply device of the present invention. [Figure 7] 5 is a flowchart illustrating an example of operation of a second control mode of the high frequency power supply device of the present invention. [Figure 8] FIG. 4 is a diagram for explaining the frequency relationship in the second control mode of the high frequency power supply device of the present invention. [Figure 9] FIG. 10 is a diagram for explaining a schematic configuration of a third control mode of the high frequency power supply device of the present invention. [Figure 10] FIG. 10 is a diagram for explaining a configuration example of a third control mode of the high frequency power supply device of the present invention. [Figure 11] FIG. 10 is a diagram for explaining a schematic configuration of a fourth control mode of the high frequency power supply device of the present invention. [Figure 12] FIG. 10 is a diagram for explaining a configuration example of a fourth control mode of the high frequency power supply device of the present invention. [Figure 13] 10 is a flowchart illustrating an example of operation of a fourth control mode of the high frequency power supply device of the present invention. [Figure 14] FIG. 10 is a diagram for explaining the frequency relationship in the fourth control mode of the high frequency power supply device of the present invention. [Figure 15] FIG. 1 is a diagram illustrating an outline of a conventional high-frequency power supply 100. DETAILED DESCRIPTION OF THE INVENTION

[0046] Hereinafter, a high frequency power supply device and a method for controlling a high frequency power supply device according to the present invention will be described with reference to the drawings.

[0047] The radio frequency power supply device of the present invention is a radio frequency power supply device that outputs variable frequency radio frequency power (RF power), and varies the frequency of the radio frequency power through variable frequency control, and controls the local oscillation frequency fLo used for frequency conversion of a downconverter through local oscillation control. The local oscillation control controls the local oscillation frequency fLo so that it has a certain correlation with the variable frequency of the RF signal through variable frequency control. This prevents aliasing due to undersampling in a high-frequency, wide-band radio frequency power supply, even in a configuration using an ADC with a low Nyquist frequency.

[0048] (First control mode of the high frequency power supply device of the present invention) 1 is a diagram illustrating a schematic configuration of a first control mode of a high-frequency power supply device of the present invention. High-frequency power supply device 1 includes a wideband power amplifier 12 that power-amplifies a wideband RF signal, a power detection unit 13 that detects the high-frequency output of wideband power amplifier 12, a downconverter 14 that frequency-converts the high-frequency power signal of wideband power amplifier 12 into a low-frequency intermediate-frequency signal, an analog-to-digital converter (ADC) 15 that converts the intermediate-frequency signal into a digital signal, and a control unit 11 that performs frequency control.

[0049] The wideband power amplifier 12 amplifies the power of the RF signal at a set frequency based on the variable frequency control of the control unit 11 and outputs a high frequency output. The power used for power amplification by the wideband power amplifier 12 is supplied from a power supply (not shown). As the wideband power amplifier, an AB-class amplifier with good linearity characteristics and high efficiency can be used.

[0050] Downconverter 14 mixes the high-frequency signal of the high-frequency power detected by power detection unit 13 with the local oscillation signal generated by the local oscillator in a frequency mixer, and outputs the difference frequency between the high-frequency signal and local oscillation signal Lo as an intermediate frequency signal having an intermediate frequency. The intermediate frequency fIF of the intermediate frequency signal IF obtained by downconverter 14 is lower than the high-frequency signal of the high-frequency power, allowing sampling at an optimal sampling frequency in analog-to-digital converter (ADC) 15.

[0051] The control unit 11 performs variable frequency control to vary the frequency of the RF signal that sets the frequency of the high-frequency output, and controls the local oscillation frequency fLo of the local oscillation signal Lo used for frequency conversion of the downconverter so as to have a certain correlation with the variable frequency of the RF signal varied by the variable frequency control. The local oscillation control controls the local oscillation frequency fLo so as to suppress the intermediate frequency fIF of the intermediate frequency signal IF to a frequency lower than the Nyquist frequency of the analog-to-digital converter (ADC) with respect to the variable frequency of the RF signal within the variable frequency range varied by the variable frequency control.

[0052] 2 is a diagram illustrating a configuration example of a first control mode of the high frequency power supply device of the present invention. The control unit 11 includes an RF signal frequency setting unit 11a, an RF signal level control unit 11b, and a local oscillation signal frequency setting unit 11c.

[0053] The RF signal generating unit 21 receives the RF signal frequency setting data (RF setDATA). RF signal generation unit 21 can be configured with a DDS (Direct Digital Synthesizer). Wideband power amplifier 12 amplifies the power of the RF signal generated by RF signal generation unit 21 and outputs high frequency power.

[0054] A power detector 13 is provided between the wideband power amplifier 12 and the output terminal to detect the high frequency power signal. The power detector 13 splits the detection signal using a directional coupler and detects a forward wave detection signal FWD_RF and a reflected wave detection signal REF_RF of the high frequency power.

[0055] The detection signal of the high frequency power signal is converted to a low frequency by the down converter 14, and then sampled and converted into a digital signal by the analog-to-digital converter (ADC) 15. The digital signal is digitally processed by the digital processing unit 16, and then used for various controls by the control unit 11.

[0056] The downconverter 14 performs frequency conversion of the detection signals separately for the forward wave detection signal FWD_RF and the reflected wave detection signal REF_RF.

[0057] The traveling wave signal detection signal FWD_RF passes through a traveling wave detection signal bandpass filter 22a and is amplified by a traveling wave detection signal amplifier 23a, and then input to a traveling wave downconverter frequency converter 14a of the downconverter 14. On the other hand, the reflected wave signal detection signal REF_RF passes through a reflected wave detection signal bandpass filter 22b and is amplified by a reflected wave detection signal amplifier 23b, and then input to a reflected wave downconverter frequency converter 14b of the downconverter 14 as one of the input signals.

[0058] The local oscillation signal Lo generated by the local oscillator 14d of the downconverter 14 is distributed to each frequency converter by the distributor 14c and input to the traveling wave downconverter frequency converter 14a and the reflected wave downconverter frequency converter 14b as the other input signal.

[0059] Traveling-wave downconverter frequency converter 14a receives traveling-wave signal detection signal FWD_RF and local oscillation signal Lo, and frequency-mixes the frequency of the traveling-wave signal with local oscillation frequency fLo. The difference frequency obtained by frequency mixing is output as intermediate frequency fIF, amplified by traveling-wave intermediate frequency amplifier 24a, passed through traveling-wave intermediate frequency bandpass filter 25a, and then sampled by traveling-wave intermediate frequency analog-to-digital converter 15a to be converted into a digital signal.

[0060] The reflected wave downconverter frequency converter 14b receives the reflected wave signal detection signal REF_RF and the local oscillation signal Lo, and frequency-mixes the frequency of the traveling wave signal with the local oscillation frequency fLo. The difference frequency obtained by frequency mixing is output as an intermediate frequency fIF, amplified by a reflected wave intermediate frequency amplifier 24b, passed through a reflected wave intermediate frequency bandpass filter 25b, and then sampled by a reflected wave intermediate frequency analog-to-digital converter 15b to be converted into a digital signal.

[0061] The digital processing unit 16 digitally processes the digital signal of the traveling wave obtained by the traveling-wave intermediate frequency analog-digital converter 15a and the digital signal of the reflected wave obtained by the reflected-wave intermediate frequency analog-digital converter 15b, and uses the processed signals for various controls performed by the control unit 11. The digital processing unit 16 can be configured with an FPGA (Field Programmable Gate Array) or a DSP (Digital Signal Processor). The RF signal level control unit 11b generates an RF level control signal based on the output voltage of the high-frequency output obtained by the digital processing of the digital processing unit 16, and controls the level of the RF signal generated by the RF signal generation unit 21.

[0062] The local oscillation signal frequency setting unit 11c generates local oscillation signal setting data based on the RF signal frequency setting data set by the RF signal frequency setting unit 11a. The local oscillator 14d generates the local oscillation signal setting data (IF set DATA) to generate a local oscillation signal Lo.

[0063] Furthermore, local oscillation signal frequency setting unit 11c sets the local oscillation frequency fLo, which is set by the local oscillation signal setting data, so that the frequency difference between it and the variable frequency fRF of the RF signal, which is set by the RF signal frequency setting data, is a predetermined frequency. By setting the predetermined frequency value to intermediate frequency fIF, the frequency of the intermediate frequency signal obtained by downconverter 14 can be set to intermediate frequency fIF.

[0064] FIG. 3 is a flowchart for explaining an example of operation of the first control mode of the high frequency power supply device of the present invention.

[0065] (Step S1) Local oscillation signal frequency setting section 11c generates local oscillation signal setting data based on a frequency value obtained by subtracting a predetermined frequency from the RF signal frequency setting data set by RF signal frequency setting section 11a, and inputs the data to local oscillator 14d.

[0066] (Step S2) The local oscillator 14d generates a local oscillation signal Lo having a local oscillation frequency fLo based on the local oscillation signal setting data.

[0067] (Step S3) The distributor 14c distributes the local oscillation signal Lo generated by the local oscillator 14d to the traveling wave downconverter frequency converter 14a and the reflected wave downconverter frequency converter 14b.

[0068] (Step S4) The mixers (traveling wave downconverter frequency converter 14a and reflected wave downconverter frequency converter 14b) frequency mix the RF signal detection signals (traveling wave signal detection signal FWD_RF, reflected wave signal detection signal REF_RF) with the local oscillation signal Lo to generate intermediate frequency signals IF (traveling wave intermediate frequency signal FWD_IF, reflected wave intermediate frequency signal REF_IF).

[0069] (Step S5) The analog-to-digital converter 15 (traveling wave intermediate frequency analog-to-digital converter 15a, reflected wave intermediate frequency analog-to-digital converter 15b) acquires sampling data obtained by converting the intermediate frequency signals IF (traveling wave intermediate frequency signal FWD_IF, reflected wave intermediate frequency signal REF_IF) into digital signals.

[0070] (Step S6) The digital processing unit 16 digitally processes the sampling data and sends the processed data to the control unit 11 .

[0071] (Step S7) When the frequency of the RF signal is changed by variable frequency control, steps S1 to S6 are repeated based on the changed frequency.

[0072] FIG. 4 is a diagram for explaining the frequency relationship in the first control mode of the high frequency power supply device of the present invention, showing the relationship between the variable frequency fRF of the RF signal, the local oscillation frequency fLo, and the intermediate frequency fIF.

[0073] The variable frequency fRF of the RF signal varies within the variable frequency range [fRF·low, fRF·high] by variable frequency control. The local oscillation frequency fLo is set with a frequency difference of Δf with respect to a certain variable frequency fRF of the RF signal within the variable frequency range [fRF·low, fRF·high]. As a result, when the variable frequency fRF of the RF signal varies by variable frequency control, the local oscillation frequency fLo is set to a frequency within the local oscillation frequency range [fRF·low-Δf, fRF·high-Δf].

[0074] The intermediate frequency fIF of the intermediate frequency signal IF is the difference frequency (fRF - fLo) between the variable frequency fRF of the RF signal and the local oscillation frequency fLo. By setting the frequency difference Δf as the intermediate frequency fIF, the intermediate frequency is always fIF within the variable frequency range [fRF low, fRF high].

[0075] Within the variable frequency range of [(fRF·low-Δf), (fRF·high-Δf)], the frequency difference Δf is set to be equal to or lower than the Nyquist frequency fn of the analog-to-digital converter ADC so that the arbitrary intermediate frequency fIF is equal to or lower than the Nyquist frequency fn.

[0076] (Example of operation) An example of the operation of the first control mode of the high frequency power supply device of the present invention will be described below. High frequency power output frequency range: 500MHz±10MHz (490MHz~510MHz) Local oscillation frequency Lo: 460MHz~480MHz Intermediate frequency: 30MHz ADC maximum sampling frequency: 65MSPS ADC Nyquist frequency fn: 32.5MHz (half the maximum sampling frequency of the ADC, 65MSPS / 2)

[0077] In the UHF band high-frequency power supply used in the film deposition process, high-speed frequency change in the μs unit is required to match the impedance with the plasma equipment. Below, we will explain the operating sequence associated with frequency change from 500 MHz to 501 MHz.

[0078] The control unit 11 sends RF signal frequency setting data for a set frequency of 500 MHz to the RF signal generation unit 21, which generates a 500 MHz RF signal. The RF signal is power-amplified by the wideband power amplifier 12. The power detection unit 13 detects the RF signals of the forward wave detection signal FWD_RF and the reflection detection signal REF_RF.

[0079] A local oscillation signal with a frequency of 470 MHz is generated in synchronization with the set frequency of 500 MHz of the RF signal. The local oscillator generates a local oscillation signal with a frequency of 470 MHz based on the frequency setting data, and the divider divides the local oscillation signal with a frequency of 470 MHz into two and inputs them to the mixers (traveling wave downconverter frequency converter and reflected wave downconverter frequency converter).

[0080] The downconverter extracts the frequency component of (RF-Lo) = 30 MHz, which passes through an intermediate frequency amplifier (traveling wave intermediate frequency amplifier, reflected wave intermediate frequency amplifier) ​​and an intermediate frequency bandpass filter (traveling wave intermediate frequency bandpass filter, reflected wave intermediate frequency bandpass filter) before being input to an analog-to-digital converter (traveling wave intermediate frequency analog-to-digital converter, reflected wave intermediate frequency analog-to-digital converter) to be converted into a digital signal, which is then processed in the digital processing unit.

[0081] When the RF signal frequency changes instantaneously from 500 MHz to 501 MHz, the automatic frequency tuning function of the control unit generates 501 MHz RF signal frequency setting data and 471 MHz local oscillation signal frequency setting data. The intermediate frequency fIF remains fixed at 30 MHz while frequency conversion and sampling are performed.

[0082] The Nyquist frequency of the ADC is 32.5 MHz, half the sampling frequency (65 MSPS), which is higher than the intermediate frequency fIF of 30 MHz, so RF signals are optimally sensed.Even in a configuration using an inexpensive ADC with a low Nyquist frequency, high-speed sampling of high-frequency RF signals is possible.

[0083] The RF signal frequency setting data and the local oscillation signal frequency setting data are set in synchronization with the variation of the RF signal frequency, so the ADCs of the forward wave and reflected wave are sampled in phase and are always converted to a constant intermediate frequency.

[0084] (Second control mode of the high frequency power supply device of the present invention) The second control mode of the high frequency power supply device of the present invention will be described below. In the second control mode, in setting the local oscillation signal frequency, a local oscillation frequency fLo determined for a divided frequency range of the RF signal including the variable frequency fRF of the RF signal is selected, and the local oscillation frequency fLo is set so that the intermediate frequency is lower than the Nyquist frequency of the ADC (analog-to-digital converter) for any variable frequency fRF of the RF signal within the variable frequency range of the RF signal.

[0085] According to the second control mode, the local oscillation frequency fLo is determined for the divided frequency range of the RF signal, and the local oscillation frequency fLo determined for the divided frequency range that includes the RF signal frequency is selected in response to frequency changes in the RF signal, and the intermediate frequency of the intermediate frequency signal is set to a frequency lower than the Nyquist frequency of the ADC (analog-to-digital converter).

[0086] FIG. 5 is a diagram for explaining the schematic configuration of a second control mode of a high-frequency power supply device according to the present invention, and FIG. 6 is a diagram for explaining an example of the configuration of the second control mode of a high-frequency power supply device according to the present invention.

[0087] The second control mode differs from the first control mode in the configuration for setting the local oscillation frequency fLo, but shares other configurations. Below, we will mainly explain the configurations that differ from the first control mode, and will omit explanations of the common configurations.

[0088] The high frequency power supply device 1 includes a wideband power amplifier 12 that power-amplifies a wideband RF signal, a power detection unit 13 that detects the high frequency output of the wideband power amplifier 12, a downconverter 14 that frequency-converts the high frequency signal of the high frequency power of the wideband power amplifier 12 into a low frequency intermediate frequency signal, an analog-to-digital converter (ADC) 15 that converts the intermediate frequency signal into a digital signal, and a control unit 11 that performs frequency control. The control unit 11 also includes a local oscillation signal frequency selector 11d and a storage unit 11e.

[0089] The local oscillation frequency fLo of the local oscillation signal Lo used in the downconverter 14 is determined based on the local oscillation signal setting data of the local oscillation signal frequency selected by the local oscillation signal frequency selector 11d.

[0090] In FIG. 6, the control unit 11 includes an RF signal frequency setting unit 11a that sets the variable frequency fRF of the RF signal that is variably controlled within a variable frequency range in variable frequency control, and an RF signal level control unit 11b that controls the signal level of the RF signal, as well as a local oscillation signal frequency selection unit 11d and a memory unit 11e.

[0091] The storage unit 11e stores a plurality of local oscillation frequencies fLo, which are determined for respective divided frequency intervals obtained by dividing the variable frequency range of the RF signal into a plurality of intervals.

[0092] In local oscillation control, the local oscillation signal frequency selector 11d selects a local oscillation frequency fLo that is set in a divided frequency range that includes the variable frequency fRF of the set RF signal from among a plurality of local oscillation frequencies fLo stored in the memory unit 11e.

[0093] The local oscillator 14d outputs a local oscillation signal Lo based on the local oscillation frequency fLo selected by the local oscillation signal frequency selector 11d.

[0094] The local oscillation signal frequency selection unit 11d selects a local oscillation frequency fLo determined for a divided frequency range of the RF signal that includes the variable frequency fRF of the RF signal, thereby setting a local oscillation frequency fLo whose intermediate frequency is lower than the Nyquist frequency of the ADC (analog-to-digital converter) for any variable frequency fRF of the RF signal within the variable frequency range of the RF signal.

[0095] According to the second control mode, the local oscillation frequency fLo is determined for the divided frequency range of the RF signal, and the local oscillation frequency fLo determined for the divided frequency range that includes the RF signal frequency is selected in response to frequency changes in the RF signal, and the intermediate frequency of the intermediate frequency signal is set to a frequency lower than the Nyquist frequency of the ADC (analog-to-digital converter).

[0096] FIG. 7 is a flowchart for explaining an example of operation of the second control mode of the high frequency power supply device of the present invention.

[0097] (Step S11) Based on the RF signal frequency setting data set by RF signal frequency setting unit 11a, local oscillation signal frequency selection unit 11d reads out from storage unit 11e the set local oscillation frequencies corresponding to the divided frequency intervals in which the set variable frequency fRF of the RF signal exists, generates local oscillation signal setting data, and inputs it to local oscillator 14d.

[0098] (Step S12) The local oscillator 14d generates a local oscillation signal Lo having a local oscillation frequency fLo based on the local oscillation signal setting data.

[0099] (Step S13) The distributor 14c distributes the local oscillation signal Lo generated by the local oscillator 14d to the traveling wave downconverter frequency converter 14a and the reflected wave downconverter frequency converter 14b.

[0100] (Step S14) The mixers (traveling wave downconverter frequency converter 14a and reflected wave downconverter frequency converter 14b) frequency mix the RF signal detection signals (traveling wave signal detection signal FWD_RF, reflected wave signal detection signal REF_RF) with the local oscillation signal Lo to generate intermediate frequency signals IF (traveling wave intermediate frequency signal FWD_IF, reflected wave intermediate frequency signal REF_IF).

[0101] (Step S15) The analog-to-digital converter 15 (traveling wave intermediate frequency analog-to-digital converter 15a, reflected wave intermediate frequency analog-to-digital converter 15b) acquires sampling data obtained by converting the intermediate frequency signals IF (traveling wave intermediate frequency signal FWD_IF, reflected wave intermediate frequency signal REF_IF) into digital signals.

[0102] (Step S16) The digital processing unit 16 digitally processes the sampling data and sends the processed data to the control unit 11 .

[0103] (Step S17) When the frequency of the RF signal is changed by variable frequency control, steps S11 to S16 are repeated based on the changed frequency.

[0104] FIG. 8 is a diagram for explaining the frequency relationship in the second control mode of the high frequency power supply device of the present invention, showing the relationship between the variable frequency fRF of the RF signal, the divided frequency interval, the local oscillation frequency fLo, and the intermediate frequency fIF.

[0105] The variable frequency fRF of the RF signal is varied within the variable frequency range [fRF·low, fRF·high] by variable frequency control. This variable frequency range [fRF·low, fRF·high] is divided into multiple frequency intervals, and a local oscillation frequency fLo is set for each frequency interval.

[0106] As the variable frequency fRF of the RF signal changes due to variable frequency control, the divided frequency interval in which the changed variable frequency fRF exists also changes. Figure 8 shows an example in which the variable frequency range [fRF·low, fRF·high] of the variable frequency fRF of the RF signal is divided into n divided frequency intervals, divided frequency interval Se1 to divided frequency interval Sen, and local oscillation frequencies fLo1 to fLon are set for each divided frequency interval.

[0107] (a) of Figure 8 shows an example in which the variable frequency fRF of the RF signal exists in the divided frequency interval Se1, (b) of Figure 8 shows an example in which the variable frequency fRF of the RF signal exists in the divided frequency interval Se2, and (c) of Figure 8 shows an example in which the variable frequency fRF of the RF signal exists in the divided frequency interval Sen.

[0108] When the variable frequency fRF of the RF signal is changed by variable frequency control, the local oscillation frequency fLo set corresponding to the divided frequency interval Se in which the changed variable frequency fRF exists is selected from the divided frequency intervals Se1 to Sen.

[0109] The intermediate frequency fIF of the intermediate frequency signal IF is the difference frequency (fRF - fLo) between the variable frequency fRF of the RF signal and the local oscillation frequency fLo. As shown in (a) of Figure 8, when the variable frequency fRF of the RF signal exists in the divided frequency interval Se1, the intermediate frequency signal IF1 is expressed as the difference frequency (fRF - fLo1) between the variable frequency fRF of the RF signal and the local oscillation frequency fLo1, using the local oscillation frequency fLo1 set corresponding to this divided frequency interval Se1.

[0110] In the example shown in (b) of Figure 8, the variable frequency fRF of the RF signal exists in the divided frequency interval Se2, so the intermediate frequency signal IF2 is expressed as the differential frequency (fRF-fLo2) between the variable frequency fRF of the RF signal and the local oscillation frequency fLo2, using the local oscillation frequency fLo2 set corresponding to this divided frequency interval Se2.

[0111] In the example shown in (c) of Figure 8, the variable frequency fRF of the RF signal exists in the divided frequency interval Sen, so the intermediate frequency signal IFn is expressed as the differential frequency (fRF-fLon) between the variable frequency fRF of the RF signal and the local oscillation frequency fLon using the local oscillation frequency fLon set corresponding to this divided frequency interval Sen.

[0112] Therefore, for the variable frequency range [fRF·low, fRF·high], the frequency range of the intermediate frequency fIF is expressed as [(fRF·low-fLo1), (fRF·high-fLon)], and the intermediate frequency fIF falls within this frequency range.

[0113] In order to make any intermediate frequency fIF within the frequency range [(fRF·low-fLo1), (fRF·high-fLon)] equal to or less than the Nyquist frequency fn of the analog-to-digital converter ADC, fLon is set so that the upper limit frequency (fRF·high-fLon) of the frequency range [(fRF·low-fLo1), (fRF·high-fLon)] is equal to or less than the Nyquist frequency fn.

[0114] (Third Control Mode of the High Frequency Power Supply Device of the Present Invention) The third control mode of the high frequency power supply device of the present invention will be described below. The third control mode is similar to the second control mode in that it includes an RF signal frequency setting unit, a memory unit, and a local oscillation signal frequency selection unit, but differs in that the local oscillation signal frequency selection unit selects the local oscillation frequency fLo from among multiple local oscillation frequencies fLo stored in the memory unit, selecting a local oscillation frequency fLo that is set in a frequency range that includes the high frequency signal based on a high frequency feedback signal RFfb of the high frequency power of the wideband power amplifier.

[0115] The frequency of the high-frequency signal of the high-frequency power that is the output of the wideband power amplifier matches the frequency of the RF signal that is the input of the wideband power amplifier. In the third control mode, the control unit selects the local oscillation frequency fLo based on the frequency of the high-frequency signal of the high-frequency power, instead of the RF signal frequency setting data that sets the RF signal.

[0116] FIG. 9 is a diagram for explaining the schematic configuration of a third control mode of a high-frequency power supply device according to the present invention, and FIG. 10 is a diagram for explaining an example of the configuration of the third control mode of a high-frequency power supply device according to the present invention.

[0117] The third control mode differs from the second control mode in the configuration for setting the local oscillation frequency fLo, but shares other configurations. Below, we will mainly explain the configurations that differ from the second control mode, and will omit explanations of the common configurations.

[0118] The high frequency power supply device 1 includes a wideband power amplifier 12 that power-amplifies a wideband RF signal, a power detection unit 13 that detects the high frequency output of the wideband power amplifier 12, a downconverter 14 that frequency-converts the high frequency signal of the high frequency power of the wideband power amplifier 12 into a low frequency intermediate frequency signal, an analog-to-digital converter (ADC) 15 that converts the intermediate frequency signal into a digital signal, and a control unit 11 that performs frequency control. The control unit 11 also includes a local oscillation signal frequency selection unit 11d and a storage unit 11e.

[0119] The local oscillation frequency fLo of the local oscillation signal Lo used in downconverter 14 is determined based on the local oscillation signal setting data of the local oscillation signal frequency selected by local oscillation signal frequency selector 11d. The selection by local oscillation signal frequency selector 11d is based on the detection signal detected by power detector 13.

[0120] The frequency of the detection signal from the power detection unit 13 matches the high-frequency signal of the high-frequency power of the wideband power amplifier. Therefore, the selection of the local oscillation signal frequency based on the frequency of the detection signal is the same as the selection of the local oscillation signal frequency based on the RF signal frequency in the second control mode.

[0121] In FIG. 10, the control unit 11 includes an RF signal frequency setting unit 11a that sets a variable frequency fRF of an RF signal that is variably controlled within a variable frequency range in variable frequency control, and an RF signal level control unit 11b that controls the signal level of the RF signal, as well as a local oscillation signal frequency selection unit 11d and a storage unit 11e.

[0122] The storage unit 11e stores a plurality of local oscillation frequencies fLo, which are determined for respective divided frequency intervals obtained by dividing the variable frequency range of the RF signal into a plurality of intervals.

[0123] In local oscillation control, the local oscillation signal frequency selector 11d selects a local oscillation frequency fLo that is set in a divided frequency range that includes the variable frequency fRF of the RF signal, from among a plurality of local oscillation frequencies fLo stored in the memory unit 11e.

[0124] The local oscillator 14d outputs a local oscillation signal Lo based on the local oscillation frequency fLo selected by the local oscillation signal frequency selector 11d.

[0125] The local oscillation signal frequency selection unit 11d selects a local oscillation frequency fLo determined for a divided frequency range of the RF signal that includes the variable frequency fRF of the RF signal, thereby setting a local oscillation frequency fLo whose intermediate frequency is lower than the Nyquist frequency of the ADC (analog-to-digital converter) for any variable frequency fRF of the RF signal within the variable frequency range of the RF signal.

[0126] According to the third control mode, the local oscillation frequency fLo is determined for the divided frequency range of the RF signal, and by selecting the local oscillation frequency fLo determined for the divided frequency range that includes the RF signal frequency in response to frequency changes of the RF signal, the intermediate frequency of the intermediate frequency signal is made lower than the Nyquist frequency of the ADC (analog-to-digital converter).

[0127] (Fourth Control Mode of the High-Frequency Power Supply Device of the Present Invention) The fourth control mode of the high frequency power supply device of the present invention will be described below. In the fourth control mode, a local oscillation fixed frequency fLo is set to a fixed frequency in the local oscillation control. fix The ADC (analog-to-digital converter) outputs a local oscillation fixed frequency fLo fix An intermediate frequency signal is generated by frequency conversion using

[0128] Local oscillation fixed frequency fLo fix does not change in conjunction with the change in the variable frequency fRF of the RF signal, but the variable frequency fRF of the RF signal and the local oscillation fixed frequency fLo fix and have a frequency relationship such that the difference frequency between the two frequencies is equal to or less than the upper limit of the intermediate frequency of the down-converter.

[0129] The fourth control mode is the variable frequency fRF of the RF signal and the fixed local oscillation frequency fLo. fix By making the difference frequency between the input and output signals equal to or lower than the upper limit of the intermediate frequency of the down-converter, the intermediate frequency of the intermediate frequency signal is made lower than the Nyquist frequency of the ADC (analog-to-digital converter).

[0130] Even if the frequency of the RF signal changes due to variable frequency control, the intermediate frequency is lower than the Nyquist frequency of the ADC (analog-to-digital converter), so the occurrence of aliasing (folding noise) due to undersampling is always suppressed.

[0131] FIG. 11 is a diagram illustrating a schematic configuration of a fourth control mode of a high-frequency power supply device according to the present invention, and FIG. 12 is a diagram illustrating an example of the configuration of the fourth control mode of a high-frequency power supply device according to the present invention.

[0132] The fourth control mode differs from the first control mode in the configuration for setting the local oscillation frequency fLo, but shares other configurations. Below, we will mainly explain the configurations that differ from the first control mode, and will omit explanations of the common configurations.

[0133] The high frequency power supply device 1 includes a wideband power amplifier 12 that power-amplifies a wideband RF signal, a power detection unit 13 that detects the high frequency output of the wideband power amplifier 12, a downconverter 14 that frequency-converts the high frequency signal of the high frequency power of the wideband power amplifier 12 into a low frequency intermediate frequency signal, an analog-to-digital converter (ADC) 15 that converts the intermediate frequency signal into a digital signal, and a control unit 11 that performs frequency control. The control unit 11 also includes a local oscillation signal fixed frequency setting unit 11f.

[0134] The local oscillation frequency fLo of the local oscillation signal Lo used in downconverter 14 is set based on the local oscillation signal setting data of the local oscillation frequency set by local oscillation signal fixed frequency setting unit 11f. Local oscillation signal fixed frequency setting unit 11f sets a fixed frequency that is set independently of changes in the frequency of the RF signal due to frequency control.

[0135] In FIG. 12, the control unit 11 includes an RF signal frequency setting unit 11a that sets the variable frequency fRF of the RF signal that is variably controlled within a variable frequency range in variable frequency control, an RF signal level control unit 11b that controls the signal level of the RF signal, and a local oscillation signal fixed frequency setting unit 11f.

[0136] The local oscillation signal fixed frequency setting unit 11f sets a fixed frequency that is not dependent on frequency changes of the RF signal due to frequency control, and the local oscillator 14d outputs the local oscillation signal Lo based on the local oscillation frequency fLo set by the local oscillation signal fixed frequency setting unit 11f.

[0137] The local oscillation signal fixed frequency setting unit 11f sets a fixed local oscillation fixed frequency fLo in which the intermediate frequency is lower than the Nyquist frequency of the ADC (analog-to-digital converter) for an arbitrary variable frequency fRF of the RF signal within the variable frequency range of the RF signal. fix Set.

[0138] According to the fourth control mode, the local oscillation frequency fLo, which is a fixed frequency that is not dependent on the frequency change of the RF signal, is set to the local oscillation fixed frequency fLo fix The intermediate frequency of the intermediate frequency signal is set to a frequency lower than the Nyquist frequency of the ADC (analog-to-digital converter). Then, the variable frequency fRF of the RF signal and the local oscillation fixed frequency fLo are fix By making the difference frequency between the input and output signals equal to or lower than the upper limit of the intermediate frequency of the down-converter, the intermediate frequency of the intermediate frequency signal is made lower than the Nyquist frequency of the ADC (analog-to-digital converter).

[0139] FIG. 13 is a flowchart for explaining an example of operation of the fourth control mode of the high frequency power supply device of the present invention.

[0140] (Step S21) Local oscillation signal fixed frequency setting section 11f generates local oscillation signal setting data of a fixed frequency that is not dependent on frequency changes of the RF signal, and inputs the data to local oscillator 14d.

[0141] (Step S22) The local oscillator 14d generates a local oscillation fixed frequency fLo based on the local oscillation signal setting data. fix A local oscillation signal Lo is generated.

[0142] (Step S23) The distributor 14c distributes the local oscillation signal Lo generated by the local oscillator 14d to the traveling wave downconverter frequency converter 14a and the reflected wave downconverter frequency converter 14b.

[0143] (Step S24) The mixers (traveling wave downconverter frequency converter 14a and reflected wave downconverter frequency converter 14b) frequency mix the RF signal detection signals (traveling wave signal detection signal FWD_RF, reflected wave signal detection signal REF_RF) with the local oscillation signal Lo to generate intermediate frequency signals IF (traveling wave intermediate frequency signal FWD_IF, reflected wave intermediate frequency signal REF_IF).

[0144] (Step S25) The analog-to-digital converter 15 (traveling wave intermediate frequency analog-to-digital converter 15a, reflected wave intermediate frequency analog-to-digital converter 15b) acquires sampling data by converting the intermediate frequency signals IF (traveling wave intermediate frequency signal FWD_IF, reflected wave intermediate frequency signal REF_IF) into digital signals.

[0145] (Step S26) The digital processing unit 16 digitally processes the sampled data and sends the processed data to the control unit 11 .

[0146] FIG. 14 is a diagram for explaining the frequency relationship in the fourth control mode of the high frequency power supply device according to the present invention, showing the relationship between the variable frequency fRF of the RF signal, the local oscillation frequency fLo, and the intermediate frequency fIF.

[0147] The variable frequency fRF of the RF signal varies within the variable frequency range [fRF·low, fRF·high] by variable frequency control. The local oscillation frequency fLo remains fixed at the local oscillation fixed frequency fLo regardless of the frequency change of the variable frequency fRF of the RF signal. fix is set to

[0148] The intermediate frequency fIF of the intermediate frequency signal IF is the difference frequency (fRF-fLo) between the variable frequency fRF of the RF signal and the local oscillation frequency fLo. Therefore, for the variable frequency range [fRF·low, fRF·high], the frequency range of the intermediate frequency fIF is [(fRF·low-fLo fix ),(fRF·high-fLo fix )] and the intermediate frequency fIF falls within this frequency range.

[0149] Intermediate frequency fIF [(fRF·low-fLo fix ),(fRF·high-fLo fix )], to ensure that any intermediate frequency fIF is equal to or less than the Nyquist frequency fn of the analog-to-digital converter ADC, the frequency range [(fRF·low-fLo fix ),(fRF·high-fLo fix )] upper limit frequency (fRF high-fLo fix ) is less than the Nyquist frequency fn, the local oscillator fixed frequency fLo fix Set. [Industrial Applicability]

[0150] The high frequency signal generator of the present invention can be applied to a high frequency power source (RF generator) used in semiconductor manufacturing equipment, liquid crystal panel manufacturing equipment, and the like. [Explanation of symbols]

[0151] 1 High frequency power supply 11 Control section 11a RF signal frequency setting section 11b RF signal level control section 11c Local oscillation signal frequency setting section 11d Local oscillation signal frequency selection section 11e Storage section 11f Local oscillation signal fixed frequency setting section 12 Wideband Power Amplifier 13 Power detection section 14 Down Converter 14a Traveling Wave Down Converter Frequency Converter 14b Reflected Wave Down Converter Frequency Converter 14c distributor 14d Local Oscillator 15a Traveling Wave Intermediate Frequency Analog to Digital Converter 15b Reflected Wave Intermediate Frequency Analog-to-Digital Converter 16 Digital Processing Section 21 RF signal generation section 22a Traveling wave detection signal bandpass filter 22b Reflected wave detection signal bandpass filter 23a Traveling wave detection signal amplifier 23b Reflected wave detection signal amplifier 24a Traveling Wave Intermediate Frequency Amplifier 24b Reflected wave intermediate frequency amplifier 25a Traveling wave intermediate frequency bandpass filter 25b Reflected wave intermediate frequency bandpass filter 100 high frequency power supply 101 DAC 102 High frequency amplifier 103 Directional coupler 104 ADC 105 Digital Processing Unit 106 oscillators ADC Analog-to-Digital Converter FWD Traveling wave detection signal FWD_RF Traveling wave signal detection signal REF_RF Reflected wave signal detection signal FWD_IF Traveling wave intermediate frequency signal REF_IF Reflected intermediate frequency signal RFfb High frequency feedback signal IF intermediate frequency signal IF1, IF2, IFn intermediate frequency signals Lo local oscillator signal fIF intermediate frequency fLo, fLo1, fLo2, fLon Local oscillation frequency fLo fix Local Oscillator Fixed Frequency fRF variable frequency fn Nyquist frequency Se, Se1, Sen division frequency interval

Claims

1. A high frequency power supply device that outputs high frequency power of a variable frequency, a wideband power amplifier for power-amplifying a wideband RF signal; a power detection unit that detects a high frequency output of the wideband power amplifier; a down converter that converts a high-frequency signal of the high-frequency power of the wideband power amplifier into a low-frequency intermediate frequency signal; an analog-to-digital converter for converting the intermediate frequency signal into a digital signal; A control unit that controls frequency Equipped with the control unit performs variable frequency control for varying the RF signal, and local oscillation control for controlling a local oscillation frequency fLo of a local oscillation signal Lo used for frequency conversion by the downconverter in a manner that has a certain correlation with the variable frequency of the RF signal obtained by the variable frequency control; the local oscillation control controls a local oscillation frequency fLo so as to suppress the frequency of the intermediate frequency signal to a frequency lower than the Nyquist frequency of the analog-to-digital converter, with respect to the variable frequency of the RF signal within a variable frequency range that is varied by the variable frequency control; The control unit an RF signal frequency setting unit that sets a variable frequency fRF of an RF signal that is variably controlled within a variable frequency range in the variable frequency control; a storage unit that stores a plurality of local oscillation frequencies fLo that are respectively determined for divided frequency intervals obtained by dividing a variable frequency range of the RF signal into a plurality of intervals; a local oscillation signal frequency selection unit that selects, in the local oscillation control, a local oscillation frequency fLo that is determined within a frequency range that includes the set variable frequency fRF of the RF signal from among a plurality of local oscillation frequencies fLo stored in the storage unit; and the variable frequency fRF of the RF signal and the local oscillation frequency fLo have a relationship in which the difference frequency between the variable frequency fRF of the RF signal and the local oscillation frequency fLo determined for a divided frequency range of the RF signal that includes the variable frequency fRF is the intermediate frequency of the downconverter; The local oscillation signal frequency selection unit By selecting a local oscillation frequency fLo determined for a divided frequency range of an RF signal including the variable frequency fRF of the RF signal, a local oscillation frequency fLo is set such that the intermediate frequency is lower than the Nyquist frequency of the analog-to-digital converter for any variable frequency fRF of an RF signal within the variable frequency range of the RF signal. High frequency power supply.

2. A high frequency power supply device that outputs high frequency power of a variable frequency, a wideband power amplifier for power-amplifying a wideband RF signal; a power detection unit that detects a high frequency output of the wideband power amplifier; a down converter that converts a high-frequency signal of the high-frequency power of the wideband power amplifier into a low-frequency intermediate frequency signal; an analog-to-digital converter for converting the intermediate frequency signal into a digital signal; A control unit that controls frequency Equipped with the control unit performs variable frequency control for varying the RF signal, and local oscillation control for controlling a local oscillation frequency fLo of a local oscillation signal Lo used for frequency conversion by the downconverter in a manner that has a certain correlation with the variable frequency of the RF signal obtained by the variable frequency control; the local oscillation control controls a local oscillation frequency fLo so as to suppress the frequency of the intermediate frequency signal to a frequency lower than the Nyquist frequency of the analog-to-digital converter, with respect to the variable frequency of the RF signal within a variable frequency range that is varied by the variable frequency control; The control unit an RF signal frequency setting unit that sets a variable frequency fRF of an RF signal that is variably controlled within a variable frequency range in the variable frequency control; a storage unit that stores a plurality of local oscillation frequencies fLo that are respectively determined for each divided frequency interval obtained by dividing a variable frequency range of the RF signal into a plurality of intervals; a local oscillation signal frequency selection unit that selects, in the local oscillation control, a local oscillation frequency fLo that is determined within a frequency range that includes the high-frequency signal from among a plurality of local oscillation frequencies fLo stored in the storage unit, based on the high-frequency signal of the high-frequency power of the wideband power amplifier; and the variable frequency fRF of the RF signal and the local oscillation frequency fLo have a relationship in which the difference frequency between the variable frequency fRF of the RF signal and the local oscillation frequency fLo determined for a divided frequency range of the RF signal that includes the variable frequency fRF is the intermediate frequency of the downconverter; The local oscillation signal frequency selection unit By selecting a local oscillation frequency fLo determined for a divided frequency range of an RF signal including the variable frequency fRF of the RF signal, a local oscillation frequency fLo is set such that the intermediate frequency is lower than the Nyquist frequency of the analog-to-digital converter for any variable frequency fRF of an RF signal within the variable frequency range of the RF signal. High frequency power supply.

3. A high frequency power supply device that outputs high frequency power of a variable frequency, a wideband power amplifier for power-amplifying a wideband RF signal; a power detection unit that detects a high frequency output of the wideband power amplifier; a down converter that converts a high-frequency signal of the high-frequency power of the wideband power amplifier into a low-frequency intermediate frequency signal; an analog-to-digital converter for converting the intermediate frequency signal into a digital signal; A control unit that controls frequency Equipped with the control unit performs variable frequency control for varying the RF signal, and local oscillation control for controlling a local oscillation frequency fLo of a local oscillation signal Lo used for frequency conversion by the downconverter in a manner that has a certain correlation with the variable frequency of the RF signal obtained by the variable frequency control; the local oscillation control controls a local oscillation frequency fLo so as to suppress the frequency of the intermediate frequency signal to a frequency lower than the Nyquist frequency of the analog-to-digital converter, with respect to the variable frequency of the RF signal within a variable frequency range that is varied by the variable frequency control; The control unit an RF signal frequency setting unit that sets a variable frequency fRF of an RF signal that is variably controlled within a variable frequency range in the variable frequency control; In the local oscillation control, the frequency is fixed to a local oscillation fixed frequency fLo ｆｉｘ a local oscillation signal fixed frequency setting unit that outputs the and Variable frequency fRF of RF signal and fixed local oscillation frequency fLo ｆｉｘ The relationship is such that the difference frequency between the two frequencies is equal to or less than the upper limit of the intermediate frequency of the down-converter. The local oscillation signal fixed frequency setting unit The local oscillation frequency fLo, which is an intermediate frequency with respect to the upper limit frequency of the variable frequency of the RF signal, is lower than the Nyquist frequency of the analog-to-digital converter, and is defined as the local oscillation fixed frequency fLo. ｆｉｘ Set it as, High frequency power supply.

4. The high-frequency signal of the high-frequency power of the wideband power amplifier is a traveling wave signal and / or a reflected wave signal; 4. The high frequency power supply device according to claim 1.

5. A control method for a high frequency power supply device that outputs variable frequency high frequency power, the control method comprising: a wideband power amplifier that power-amplifies a wideband RF signal; a down-converter that frequency-converts the high frequency signal of the high frequency power of the wideband power amplifier into a low frequency intermediate frequency signal; an analog-to-digital converter that converts the intermediate frequency signal into a digital signal; and a control unit that performs frequency control, a variable frequency control that varies the RF signal, and a local oscillation control that controls a local oscillation frequency fLo of a local oscillation signal Lo used for frequency conversion by the downconverter so as to have a certain correlation with the variable frequency of the RF signal by the variable frequency control, the local oscillation control controls a local oscillation frequency fLo so as to suppress the frequency of the intermediate frequency signal to a frequency lower than the Nyquist frequency of the analog-to-digital converter, with respect to the variable frequency of the RF signal within a variable frequency range that is varied by the variable frequency control; storing a plurality of local oscillation frequencies fLo respectively determined for divided frequency intervals obtained by dividing the variable frequency range of the RF signal into a plurality of intervals; In the variable frequency control, a variable frequency fRF of an RF signal that is variably controlled within a variable frequency range is set; In the local oscillation control, a local oscillation frequency fLo is selected from a plurality of stored local oscillation frequencies fLo, the local oscillation frequency fLo being determined within a frequency range including the set variable frequency fRF of the RF signal; the variable frequency fRF of the RF signal and the local oscillation frequency fLo have a relationship in which the difference frequency between the variable frequency fRF of the RF signal and the local oscillation frequency fLo determined for a divided frequency range of the RF signal that includes the variable frequency fRF is the intermediate frequency of the downconverter; In selecting the local oscillation frequency, a local oscillation frequency fLo determined for a divided frequency range of an RF signal including the variable frequency fRF of the RF signal is selected, thereby setting a local oscillation frequency fLo such that the intermediate frequency is lower than the Nyquist frequency of the analog-to-digital converter for any variable frequency fRF of an RF signal within the variable frequency range of the RF signal. A method for controlling a high frequency power supply device.

6. A control method for a high frequency power supply device that outputs variable frequency high frequency power, the control method comprising: a wideband power amplifier that power-amplifies a wideband RF signal; a down-converter that frequency-converts the high frequency signal of the high frequency power of the wideband power amplifier into a low frequency intermediate frequency signal; an analog-to-digital converter that converts the intermediate frequency signal into a digital signal; and a control unit that performs frequency control, a variable frequency control that varies the RF signal, and a local oscillation control that controls a local oscillation frequency fLo of a local oscillation signal Lo used for frequency conversion by the downconverter so as to have a certain correlation with the variable frequency of the RF signal by the variable frequency control, the local oscillation control controls a local oscillation frequency fLo so as to suppress the frequency of the intermediate frequency signal to a frequency lower than the Nyquist frequency of the analog-to-digital converter, with respect to the variable frequency of the RF signal within a variable frequency range that is varied by the variable frequency control; storing a plurality of local oscillation frequencies fLo respectively determined for each divided frequency interval obtained by dividing the variable frequency range of the RF signal into a plurality of intervals; In the variable frequency control, a variable frequency fRF of an RF signal that is variably controlled within a variable frequency range is set; In the local oscillation control, a local oscillation frequency fLo is selected from a plurality of stored local oscillation frequencies fLo based on a high-frequency signal of the high-frequency power of the wideband power amplifier, the local oscillation frequency fLo being determined to be within a frequency range including the high-frequency signal; the variable frequency fRF of the RF signal and the local oscillation frequency fLo have a relationship in which the difference frequency between the variable frequency fRF of the RF signal and the local oscillation frequency fLo determined for a divided frequency range of the RF signal that includes the variable frequency fRF is the intermediate frequency of the downconverter; In selecting the local oscillation frequency, a local oscillation frequency fLo determined for a divided frequency range of an RF signal including the variable frequency fRF of the RF signal is selected, thereby setting a local oscillation frequency fLo such that the intermediate frequency is lower than the Nyquist frequency of the analog-to-digital converter for any variable frequency fRF of an RF signal within the variable frequency range of the RF signal. A method for controlling a high frequency power supply device.

7. A control method for a high frequency power supply device that outputs variable frequency high frequency power, the control method comprising: a wideband power amplifier that power-amplifies a wideband RF signal; a down-converter that frequency-converts the high frequency signal of the high frequency power of the wideband power amplifier into a low frequency intermediate frequency signal; an analog-to-digital converter that converts the intermediate frequency signal into a digital signal; and a control unit that performs frequency control, a variable frequency control that varies the RF signal, and a local oscillation control that controls a local oscillation frequency fLo of a local oscillation signal Lo used for frequency conversion by the downconverter so as to have a certain correlation with the variable frequency of the RF signal by the variable frequency control, the local oscillation control controls a local oscillation frequency fLo so as to suppress the frequency of the intermediate frequency signal to a frequency lower than the Nyquist frequency of the analog-to-digital converter, with respect to the variable frequency of the RF signal within a variable frequency range that is varied by the variable frequency control; In the variable frequency control, a variable frequency fRF of an RF signal that is variably controlled within a variable frequency range is set; In the local oscillation control, the frequency is fixed to a local oscillation fixed frequency fLo ｆｉｘ Set Variable frequency fRF of RF signal and fixed local oscillation frequency fLo ｆｉｘ The relationship is such that the difference frequency between the two frequencies is equal to or less than the upper limit of the intermediate frequency of the down-converter. In setting the local oscillation fixed frequency, the local oscillation frequency fLo is set so that the intermediate frequency with respect to the upper limit frequency of the variable frequency of the RF signal is lower than the Nyquist frequency of the analog-to-digital converter. ｆｉｘ Set it as, A method for controlling a high frequency power supply device.

Images