Radio frequency device, reflection coefficient determination method and communication equipment

Abstract

The invention provides a radio frequency device, a reflection coefficient determination method and communication equipment, relates to the technical field of radio frequency, and aims to determine a reflection coefficient under the condition of not influencing a plasma state and improve the anti-interference characteristic of the reflection coefficient determination method of the radio frequency device. The method is applied to a radio frequency device and comprises the steps that a transmitting channel outputs a transmitting signal according to a first signal and a detection sequence; the ratio of the power of the first signal to the power of the detection sequence is greater than or equal to a first threshold value; the feedback channel collects a forward feedback baseband signal and a reverse feedback baseband signal corresponding to the transmitted signal; the control circuit determines a forward channel parameter according to the detection sequence and the forward feedback baseband signal; the control circuit determines a reverse channel parameter according to the detection sequence and the reverse feedback baseband signal; and the control circuit determines the reflection coefficient of at least one frequency point in the working frequency band of the radio frequency device according to the forward channel parameter and the reverse channel parameter.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of radio frequency technology, and in particular to a radio frequency device, a method for determining a reflection coefficient, and a communication device. BACKGROUND

[0002] In a semiconductor manufacturing process, the process stability of plasma dry etching (ETCH) is directly related to the accuracy and yield of wafer pattern transfer. The core of the process is to excite and maintain high-density plasma by a radio frequency generator (RFG). In the process, the dynamic characteristics of the chamber impedance matching system have a decisive role in the transmission efficiency of radio frequency energy to the plasma. When the RFG output frequency and the chamber impedance are not matched, the radio frequency energy will be lost due to reflection, resulting in fluctuations in plasma density and deviation of ion bombardment energy from the design value. That is, the RFG works at the wrong frequency point, which will cause the process result to deviate. Therefore, the RFG usually needs to determine the reflection coefficient of the full frequency band, and then find the best matching frequency point based on the reflection coefficient of the full frequency band. However, the current method for determining the reflection coefficient usually uses a fixed step scanning method, which easily causes interference to the plasma, thereby affecting the wafer process effect. SUMMARY

[0003] The present application discloses a radio frequency device, a method for determining a reflection coefficient, and a communication device, which can determine the reflection coefficient without affecting the state of the plasma, and improve the anti-interference characteristics of the reflection coefficient determination method of the radio frequency device.

[0004] To achieve the above object, the embodiments of the present application adopt the following technical solutions:

[0005] In a first aspect, the present application provides a radio frequency device, which comprises a control circuit, a transmitting channel and a feedback channel, the control circuit being connected with the transmitting channel and the feedback channel, and the transmitting channel and the feedback channel being connected; the transmitting channel is used for outputting a transmitting signal according to a first signal and a probe sequence; the ratio between the power of the first signal and the power of the probe sequence is greater than or equal to a first threshold value; the feedback channel is used for collecting a forward feedback baseband signal and a reverse feedback baseband signal corresponding to the transmitting signal; the control circuit is used for determining a forward channel parameter according to the probe sequence and the forward feedback baseband signal; the control circuit is also used for determining a reverse channel parameter according to the probe sequence and the reverse feedback baseband signal; and the control circuit is also used for determining a reflection coefficient of at least one frequency point in the working frequency band of the radio frequency device according to the forward channel parameter and the reverse channel parameter.

[0006] Based on the technical solution, the reflection coefficient is determined by using the probe sequence. Since the ratio between the power of the first signal and the power of the probe sequence is limited, the power of the probe sequence is not too large compared with the first signal, so as to avoid changing the overall state of the plasma or causing significant interference due to the large power. Therefore, the technical solution can measure the reflection coefficient without interfering with the normal operation of the plasma, has high anti-interference characteristics, and is highly reliable. Moreover, the technical solution can use the probe sequence to detect the reflection coefficient in the full frequency band in real time, can realize synchronous calculation of the reflection coefficient at multiple frequency points, and has higher measurement efficiency.

[0007] In a possible implementation manner of the first aspect, the control circuit is configured to determine the forward channel parameter according to the probe sequence and the forward feedback baseband signal, and includes: the control circuit is specifically configured to: construct a first autocorrelation matrix of the probe sequence and a first cross-correlation vector between the probe sequence and the forward feedback baseband signal according to the probe sequence and the forward feedback baseband signal; and determine the forward channel parameter according to the first autocorrelation matrix and the first cross-correlation vector. Optionally, the control circuit is further configured to determine the reverse channel parameter according to the probe sequence and the reverse feedback baseband signal, and includes: the control circuit is specifically configured to: construct a second autocorrelation matrix of the probe sequence and a second cross-correlation vector between the probe sequence and the reverse feedback baseband signal according to the probe sequence and the reverse feedback baseband signal; and determine the reverse channel parameter according to the second autocorrelation matrix and the second cross-correlation vector. In the possible implementation manner, the channel parameter can be accurately decoupled through joint calculation of the autocorrelation matrix and the cross-correlation vector, thereby enhancing the anti-interference of the technical solution.

[0008] In a possible implementation manner of the first aspect, the radio frequency device includes a probe sequence generation module configured to inject the probe sequence into the transmission channel.

[0009] In a possible implementation manner of the first aspect, the probe sequence generation module comprises any one of a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), or a digital signal processor (DSP). In the possible implementation manner, multiple possible implementation manners of the probe sequence generation module are provided. The FPGA has high flexibility, high parallel processing capability, and reconfigurability, and can generate various complex probe sequences to adapt to different working environments and requirements of the radio frequency device. The ASIC has high performance, low power consumption, and small size, and can efficiently generate probe sequences with lower power consumption. The DSP has high multiplication-accumulation operation capability and rich instruction sets, is suitable for processing complex algorithms and large amounts of data, can implement a complex probe sequence generation algorithm, and improves real-time performance and accuracy of the probe sequence.

[0010] In a possible implementation manner of the first aspect, the transmitting channel is configured to output the transmitting signal according to the first signal and the probe sequence. In a case where the first signal is a continuous wave signal, the transmitting channel is specifically configured to output the transmitting signal according to the first signal and a plurality of same probe sequences. In the possible implementation manner, the plurality of same probe sequences are injected, and the forward feedback baseband signal and the reverse feedback baseband signal are continuously collected, so that the reflection coefficients of all frequency points in the full frequency band can be continuously monitored, and the stability of the radio frequency device is improved.

[0011] In a possible implementation manner of the first aspect, the transmitting channel is configured to output the transmitting signal according to the first signal and the probe sequence. In a case where the first signal is a pulse signal, the transmitting channel is specifically configured to output the transmitting signal according to the first signal and a probe sequence corresponding to a pulse level of the first signal. Different pulse levels of the first signal correspond to different probe sequences. In the possible implementation manner, in a pulse working scenario, different probe sequences can be selected according to different pulse levels, so that the gain fluctuation and the reflection coefficient can be more accurately estimated for different pulse levels, and the performance of the system under different pulse levels can be determined, so that targeted optimization and adjustment can be performed.

[0012] In a possible implementation manner of the first aspect, the probe sequence is generated based on the first signal. In the possible implementation manner, the specific sequence of the probe sequence can be determined according to information such as a frame structure and a power of the first signal, so that the adaptation degree between the probe sequence and the first signal can be improved.

[0013] In a possible implementation of the first aspect, the self-correlation of the probe sequence is higher than a second threshold. In the possible implementation, the self-correlation of the probe sequence is higher or better, and the self-correlation peak can be detected.

[0014] In a possible implementation of the first aspect, the transmitting channel is further configured to output a transmitting signal according to the second signal and a probe sequence corresponding to the second signal, and a cross-correlation between the probe sequence corresponding to the second signal and the probe sequence corresponding to the first signal is less than a third threshold. In the possible implementation, the cross-correlation between the probe sequences corresponding to different first signals is less than the third threshold, which can avoid interference between different signals and improve the determination accuracy of the reflection coefficient.

[0015] In the second aspect, the present application provides a method for determining a reflection coefficient, applied to a radio frequency device, the radio frequency device including a control circuit, a transmitting channel and a feedback channel. The method includes: the transmitting channel outputs a transmitting signal according to a first signal and a probe sequence; a ratio between the power of the first signal and the power of the probe sequence is greater than or equal to a first threshold; the feedback channel collects a forward feedback baseband signal and a reverse feedback baseband signal corresponding to the transmitting signal; the control circuit determines a forward channel parameter according to the probe sequence and the forward feedback baseband signal; the control circuit determines a reverse channel parameter according to the probe sequence and the reverse feedback baseband signal; and the control circuit determines a reflection coefficient of at least one frequency point in a working frequency band of the radio frequency device according to the forward channel parameter and the reverse channel parameter.

[0016] In a possible implementation of the second aspect, the control circuit determines the forward channel parameter according to the probe sequence and the forward feedback baseband signal, including: the control circuit constructs a first self-correlation matrix of the probe sequence and a first cross-correlation vector between the probe sequence and the forward feedback baseband signal according to the probe sequence and the forward feedback baseband signal; and the control circuit determines the forward channel parameter according to the first self-correlation matrix and the first cross-correlation vector.

[0017] In a possible implementation of the second aspect, the control circuit determines the reverse channel parameter according to the probe sequence and the reverse feedback baseband signal, including: the control circuit constructs a second self-correlation matrix of the probe sequence and a second cross-correlation vector between the probe sequence and the reverse feedback baseband signal according to the probe sequence and the reverse feedback baseband signal; and the control circuit determines the reverse channel parameter according to the second self-correlation matrix and the second cross-correlation vector.

[0018] In a possible implementation of the second aspect, the radio frequency device includes a probe sequence generation module, and the method further includes: the probe sequence generation module injects the probe sequence into the transmitting channel.

[0019] In a possible implementation manner of the second aspect, the probe sequence generation module comprises any one of an FPGA, an ASIC or a DSP.

[0020] In a possible implementation manner of the second aspect, the transmitting channel outputs the transmitting signal according to the first signal and the probe sequence, comprising: in a case where the first signal is a continuous wave signal, the transmitting channel outputs the transmitting signal according to the first signal and a plurality of same probe sequences.

[0021] In a possible implementation manner of the second aspect, the transmitting channel outputs the transmitting signal according to the first signal and the probe sequence, comprising: in a case where the first signal is a pulse signal, the transmitting channel outputs the transmitting signal according to the first signal and a probe sequence corresponding to a pulse level of the first signal; wherein different pulse levels of the first signal correspond to different probe sequences.

[0022] In a possible implementation manner of the second aspect, the probe sequence is generated based on the first signal. In the possible implementation manner, specific sequences of the probe sequence can be determined according to information such as frame structure and power of the first signal, so that the adaptation degree between the probe sequence and the first signal can be improved.

[0023] In a possible implementation manner of the second aspect, the probe sequence has a self-correlation higher than a second threshold.

[0024] In a possible implementation manner of the second aspect, the method further comprises: the transmitting channel outputs a transmitting signal according to a second signal and a probe sequence corresponding to the second signal; wherein a cross-correlation between the probe sequence corresponding to the second signal and the probe sequence corresponding to the first signal is less than a third threshold.

[0025] In a third aspect, a communication device is provided, which comprises a radio frequency device, and at least one of baseband circuitry and an antenna, the radio frequency device being provided in any one of possible implementation manners of the first aspect.

[0026] The detailed description of the second aspect to the third aspect and various implementation manners thereof in the present application can refer to the detailed description in the first aspect and various implementation manners thereof; and the beneficial effects of the second aspect or the third aspect and various implementation manners thereof can refer to the beneficial effect analysis in the first aspect and various implementation manners thereof, which will not be described herein. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

[0028] Figure 1 A schematic diagram of a reflection coefficient provided for an embodiment of the present application;

[0029] Figure 2 A structural schematic diagram of a radio frequency device provided for an embodiment of the present application;

[0030] Figure 3 A structural schematic diagram of another radio frequency device provided for an embodiment of the present application;

[0031] Figure 4 A structural schematic diagram of another radio frequency device provided for an embodiment of the present application;

[0032] Figure 5 A schematic diagram of a determination method of a reflection coefficient provided for an embodiment of the present application;

[0033] Figure 6 A schematic diagram of a detection sequence provided for an embodiment of the present application;

[0034] Figure 7 A schematic diagram of another detection sequence provided for an embodiment of the present application;

[0035] Figure 8 A schematic diagram of a channel simulation result provided for an embodiment of the present application;

[0036] Figure 9 A schematic diagram of a signal estimation error provided for an embodiment of the present application;

[0037] Figure 10 A flow schematic diagram of a determination method of a reflection coefficient provided for an embodiment of the present application. DETAILED DESCRIPTION

[0038] The making and using of various embodiments will now be discussed in detail below. It should be appreciated that numerous specific implementation details of the application will be set forth in the description that follows. However, it should be understood that the aspects of the application might be practiced without resorting to the details specifically set forth and that the scope of the application is capable of further additions and modifications, such as would be apparent to those skilled in the art, however, it should be noted that the application can be practiced without resorting to the details specifically set forth.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0040] Circuits or other components can be described as, or said to be, “configured to” perform a task or tasks. In such contexts, “configured to” is used to connote structure by indicating that a circuit / component includes structure (e.g., circuitry) that performs the task or tasks during operation. As such, the circuit / component can be said to be configured to perform the task or tasks even when the specified circuit / component is not currently operational (e.g., is not on). The circuits / components used with the “configured to” language can include, for example, a structural configuration, hardware, or a combination of both, designed to perform the task or tasks during operation.

[0041] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. In the present application, “at least one” means one or more, and “multiple” means two or more. “And / or” describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone, where A and B can be singular or plural. The character “ / ” generally represents an “or” relationship between the associated objects before and after it. “At least one of the following” or similar expressions means any combination of these items, including any combination of single item or multiple items. For example, at least one of a, b or c can represent a, b, c, a and b, a and c, b and c, or a, b and c, where a, b and c can be single or multiple.

[0042] The embodiments of the present application use “first” and “second” and the like to distinguish objects or functions or roles with similar names or functions or roles. Those skilled in the art can understand that “first” and “second” and the like do not limit the quantity and execution order. The word “coupled” is used to represent electrical connection, including direct connection through wires or connection terminals or indirect connection through other devices. Therefore, “coupled” should be regarded as a general electronic communication connection.

[0043] It should be noted that in the present application, the words “exemplary” or “for example” are used to mean serving as an example, instance, or illustration. Any embodiment or design solution described as “exemplary” or “for example” in the present application should not be interpreted as being more preferred or advantageous than other embodiments or design solutions. Rather, the use of the words “exemplary” or “for example” is intended to present relevant concepts in a specific way.

[0044] As a time-varying nonlinear medium, plasma's impedance changes with its operating frequency, leading to a significant "multiple solutions" problem for the chamber reflection coefficient across the entire frequency band. This means a single reflection coefficient may correspond to multiple frequency points, and the RFG operating at an incorrect frequency can cause deviations in process results. When the RFG uses a fixed-step frequency scanning method to determine the full-band reflection coefficient, its single-dimensional frequency sweep strategy struggles to resolve the multi-frequency mapping relationship of the reflection coefficient. Here, "full band" refers to all frequency points within the RFG's operating frequency range. Especially when plasma impedance changes rapidly, the process equipment may misjudge local extrema as the globally optimal matching frequency point, such as... Figure 1 As shown, the optimal frequency point could be Frequency0 = 61.116MHz (i.e., 61,116,000), corresponding to a reflection coefficient Gamma0 = 0.0293 and a forward channel signal characteristic value Forward0 = 619. However, there is another reflection coefficient peak point A to the right of this point. The system may misjudge the frequency point corresponding to peak point A as the globally optimal matching frequency point. This could cause the RFG to lock into a non-optimal operating frequency band, thus affecting the final process results.

[0045] In view of this, this application provides a radio frequency (RF) device, which includes a control circuit, a transmission channel, and a feedback channel. The control circuit is connected to the transmission channel and the feedback channel, and the transmission channel and the feedback channel are connected. The transmission channel is used to output a transmission signal according to a first signal and a detection sequence. The ratio between the power of the first signal and the power of the detection sequence is greater than or equal to a first threshold. The feedback channel is used to acquire a forward feedback baseband signal and a reverse feedback baseband signal corresponding to the transmission signal. The control circuit is used to determine forward channel parameters and reverse channel parameters according to the detection sequence, the forward feedback baseband signal, and the reverse feedback baseband signal, and to determine the reflection coefficients of multiple frequency points according to the forward channel parameters and the reverse channel parameters.

[0046] This method utilizes a detection sequence to determine the reflection coefficient. By limiting the ratio between the power of the first signal and the power of the detection sequence, the power of the detection sequence is prevented from being excessively high compared to the first signal. This avoids excessive power altering the overall state of the plasma or causing significant interference. Therefore, this technical solution can measure the reflection coefficient without interfering with the normal operation of the plasma, exhibiting high anti-interference characteristics and reliability. Furthermore, this technical solution can utilize the detection sequence for real-time detection of the reflection coefficient across the entire frequency band, enabling synchronous calculation of the reflection coefficient at multiple frequency points, resulting in higher measurement efficiency.

[0047] The radio frequency (RF) device in this application refers to a system used to generate, amplify, modulate, or process RF signals, whose core functions include signal generation, power amplification, and dynamic control. For example, an RF device can be an RF generator used to generate RF signals of specific frequency, power, and waveform. RF generators are primarily used in test circuits or antennas, in industrial applications such as high-frequency heating (e.g., plasma generation, semiconductor etching), and in medical devices (e.g., radio frequency ablation for tumor treatment). For instance, in the semiconductor manufacturing field, RF generators can be used for plasma generation and control, and are core equipment for key processes such as etching, deposition, and ion implantation. Another example is an RF transceiver used to transmit or receive RF signals. RF transceivers can be installed in wireless communication devices (e.g., mobile phones, wireless network cards, Bluetooth devices), and can be used in radio broadcasting, satellite communication, radar, and wireless communication technologies (Wi-Fi) / Bluetooth modules. Yet another example is an RF amplifier used to amplify the power or voltage of RF signals. RF amplifiers are primarily used in communication base stations, broadcast television towers, and RF heating systems. For example, the radio frequency device can also be a radio frequency filter, radio frequency mixer, radio frequency switch, radio frequency antenna, radio frequency test and measurement equipment, or it can also be other possible radio frequency integrated circuits. The specific form of the device is not limited in the embodiments of this application.

[0048] Figure 2 A schematic diagram of the structure of a radio frequency device provided in an embodiment of this application is shown. Figure 2 As shown, the radio frequency (RF) device includes a control circuit 201, a transmit channel 202, and a feedback channel 203. The transmit channel 202 and feedback channel 203 are connected. The control circuit 201 is typically used for estimating the forward and reverse channel signals and calculating the reflection coefficient within the operating frequency band. The transmit channel 202 is typically used to transmit the generated RF signal through an antenna or other transmitting device, and to receive control commands and generate corresponding RF signals based on those commands. The feedback channel 203 is typically used to acquire the feedback baseband signal corresponding to the transmitted signal output from the transmit channel, and to process the feedback baseband signal, such as through amplification, filtering, and digitization.

[0049] Transmit channel 202 is used to output a transmit signal based on the first signal and the detection sequence. Feedback channel 203 is used to acquire the forward feedback baseband signal and the reverse feedback baseband signal corresponding to the transmit signal. Control circuit 201 is used to determine the forward channel parameters and the reverse channel parameters based on the detection sequence, the forward feedback baseband signal, and the reverse feedback baseband signal, and to determine the reflection coefficients at multiple frequency points based on the forward channel parameters and the reverse channel parameters. The ratio between the power of the first signal and the power of the detection sequence is greater than or equal to a first threshold.

[0050] In the present application, no order is limited between the determination of the forward channel parameter by the control circuit and the determination of the reverse channel parameter by the control circuit. For example, the control circuit can first determine the forward channel parameter according to the probe sequence and the forward feedback baseband signal, and then determine the reverse channel parameter according to the probe sequence and the reverse feedback baseband signal. For another example, the control circuit can first determine the reverse channel parameter according to the probe sequence and the reverse feedback baseband signal, and then determine the forward channel parameter according to the probe sequence and the forward feedback baseband signal.

[0051] The first signal is an original signal generated in the radio frequency device, which can also be referred to as a main signal. For example, the signal generated by the first signal generation module 321 and the frequency shift module 322, or the signal generated by the first signal generation module 421. The first signal can contain information to be transmitted, and the frequency, amplitude, modulation mode and other related parameters thereof can be adjusted, for example, by the instruction issued by the control circuit 201. For example, the first signal can be a continuous wave signal, a pulse signal or other possible signals. The number of first signals can be one or more.

[0052] The first signal and the probe sequence provided in the present application are real signals. For example, the first signal can be expressed as a complex signal during the process of controlling, designing and the like of the first signal, so as to facilitate theoretical simplification analysis by means of the corresponding complex signal of the first signal. The real signal is a physical signal generated by a signal generator or the like, and the spectrum is symmetrical, and the value at each time in the time domain is a real number (such as the actual measured value of voltage or current). The complex signal is a representation of the real signal, which is convenient for signal processing.

[0053] The transmit signal is an output signal processed by the transmit channel, which can be radiated or transmitted to the target load through the antenna. The transmit signal herein can be understood as a signal determined based on the first signal and the probe sequence. For example, the transmit channel can superimpose the first signal and the probe sequence to obtain the transmit signal.

[0054] The probe sequence is a signal sequence used for determining the reflection coefficient. The number of probe sequences can be one or more.

[0055] In some embodiments, the ratio between the power of the first signal and the power of the probe sequence is greater than or equal to a first threshold.

[0056] The ratio between the power of the first signal and the power of the probe sequence refers to the power ratio between the first signal and the probe sequence. It can also be referred to as a probe ratio. The probe sequence can be regarded as a noise signal of the first signal, and therefore in some examples, the power ratio between the first signal and the probe sequence can also be referred to as the signal-to-noise ratio of the first signal.

[0057] The aforementioned first threshold is the lower limit of the ratio between the power of the constraint first signal and the power of the detection sequence. The first threshold can be determined based on relevant plasma parameters in the actual process environment to ensure that the detection sequence power is insufficient to change the plasma state. For example, when the plasma in the actual process environment has strong anti-interference capabilities, the value of the first threshold can be relatively small (in which case the detection sequence power is relatively high), such as 20dBc, 30dBc, or other possible values; conversely, when the plasma in the actual process environment has weak anti-interference capabilities, the value of the first threshold can be relatively large (in which case the detection sequence power is relatively low), such as 50dBc, 60dBc, or other possible values.

[0058] dBc refers to decibels (dB) relative to the carrier wave. Specifically, dBc is a general-purpose unit used to express the ratio or relative value between the power of one signal and the power of another signal. Based on this general-purpose unit, dBc = 10log 10 (P 信号1 / P 信号2 The power ratio between the first signal and the detection sequence is 10log. 10 (P 第一信号 / P 探测序列 P 第一信号 This refers to the power of the first signal, P. 探测序列 This refers to the power of the probe sequence.

[0059] For example, taking a first threshold of 50 dBc as an example, the ratio between the power of the first signal and the power of the detection sequence is greater than or equal to 50 dBc, that is, P 第一信号 / P 探测序列 ≥50dBc=10 (50 / 10) =10 5 P can be obtained. 探测序列 ≤P 第一信号 ×10 -5 That is, the power of the detection sequence is less than or equal to 1 / 100000 of the power of the first signal, thus making the power of the detection sequence much lower than that of the first signal.

[0060] Furthermore, in practical applications, when the ratio of the power of the first signal to the power of the probe sequence is equal to 50 dBc, it can usually be simply stated that the power of the probe sequence is 50 dB lower than the power of the main signal, for example, P 探测序列 =P 第一信号 -50dB. Based on the common unit dB = 10log 10 (Physical quantity 1 / Physical quantity 2) can be based on P 探测序列 =P 第一信号 -50dB results in -50 = 10log 10(P 探测序列 / P 第一信号 ), so that P 探测序列 / P 第一信号 = 10 (-50 / 10) = 10 -5 , so that P 探测序列 = P 第一信号 * 10 -5 , that is, the ratio between the power of the first signal and the power of the detection sequence is equal to 50 dBc.

[0061] It should be noted that the detection sequence as an auxiliary signal needs to avoid occupying too much transmission power to ensure the signal-to-noise ratio and transmission efficiency of the main signal (i.e., the first signal). The ratio between the power of the first signal and the power of the detection sequence is greater than or equal to the first threshold, which can ensure the high power ratio of the first signal and the detection sequence. Moreover, since the power of the detection sequence is much lower than that of the main signal (i.e., the first signal), it means that the influence of the detection sequence on the transmission channel and the plasma state will be very small, so that injecting the detection sequence into the transmission channel does not affect the transmission of the main signal and the overall state of the plasma.

[0062] In some embodiments, the detection sequence is generated based on the first signal.

[0063] For example, based on the frame structure, power, and other information of the first signal, the basic parameters such as the sequence length and period of the detection sequence can be determined. The type of the detection sequence can be a pre-set detection sequence type, such as a pseudo-noise (PN) sequence, or the transmission channel can also select a suitable type of detection sequence based on the related parameters of the radio frequency device, so that the adaptation between the detection sequence and the first signal can be improved. For example, the power of the detection sequence can be determined based on the power of the first signal.

[0064] The PN sequence is a periodic digital sequence with similar random noise statistical characteristics, which is different from a real random signal and can be repeatedly generated and processed, so it is called a pseudo-random noise sequence, which is usually generated through a linear feedback shift register (LFSR) or other mathematical algorithms.

[0065] In some embodiments, the detection sequence in the present application can also satisfy at least one of the following: the ratio between the power of the first signal and the power of the detection sequence is greater than or equal to a second threshold; the cross-correlation of the detection sequences corresponding to different first signals is less than a third threshold.

[0066] The autocorrelation refers to a similarity of a signal with itself at different time delays. The autocorrelation can be positive or negative. Optionally, the autocorrelation can be measured by an autocorrelation function (ACF). A value close to 1 can indicate a strong positive correlation.

[0067] For example, the second threshold is a preset threshold. For example, the radio device is preset based on the autocorrelation function of the detection sequence with a high autocorrelation. If the autocorrelation of the detection sequence is higher than the second threshold, it can be understood that the autocorrelation of the detection sequence is high or the autocorrelation is good, and the autocorrelation peak can be detected.

[0068] In an example, the detection sequence can use a maximum length sequence (m-sequence), which is a special form of a PN sequence. It can be understood as a pseudo-random sequence, a pseudo-noise code or a pseudo-random code, which is generated by a linear feedback shift register. Due to its wideband characteristics, the m-sequence is suitable for estimating time delay, small signal gain, channel flatness, etc. The generation of the m-sequence only requires a small number of registers, and the correlation operation can be realized by a fast algorithm (such as FFT acceleration), which can reduce power consumption and cost, and save computing resources.

[0069] It should be noted that the autocorrelation function of the PN sequence (such as the m-sequence) has a clear peak at zero time delay, that is, the autocorrelation of the PN sequence can be higher than the second threshold, and the autocorrelation of the PN sequence is high at this time. Therefore, the PN sequence is used as the detection sequence, and the feedback channel is acquired by collecting the forward feedback baseband signal and the reverse feedback baseband signal, and then the reflection coefficient is determined by combining the autocorrelation of the PN sequence and the cross-correlation between the PN sequence and the feedback signal. As shown in Figure 5 The reflection coefficient determination module of the radio device can acquire the collected detection sequence data, reverse feedback baseband signal data (such as reverse feedback baseband signal waveform, which can also be referred to as reverse feedback waveform), and forward feedback baseband signal data (such as forward feedback baseband signal waveform, which can also be referred to as forward feedback waveform), thereby performing channel estimation based on the autocorrelation of the PN sequence and the cross-correlation between the PN sequence and the forward feedback baseband signal, the cross-correlation between the PN sequence and the reverse feedback baseband signal, and calculating the reflection coefficient in the frequency band, for example, the reflection coefficient of each frequency point in the 57M-63M frequency band can be output. Figure 6 In addition, the PN sequence has strong anti-noise and anti-interference capabilities, and using the PN sequence can improve the accuracy of reflection coefficient determination. Furthermore, the PN sequence is easy to generate and synchronize, and has low complexity. The PN sequence also has a fixed period, and based on its periodicity, the PN cycle can be injected into the transmission channel, so that the PN sequence can be used to realize dynamic real-time reflection coefficient determination.

[0070] wherein the cross-correlation refers to the similarity of two different signals in time or phase. For example, the cross-correlation between two different signals can be reflected by calculating the similarity of the two different signals at different time delays. Alternatively, the cross-correlation can also be reflected by a cross-correlation function.

[0071] For example, the third threshold is a preset threshold, for example, a preset cross-correlation function of different probe sequences with smaller cross-correlation based on the radio frequency device. The cross-correlation of the probe sequences corresponding to different first signals is smaller than the third threshold, that is, for different first signals, a probe sequence with smaller cross-correlation can be assigned to it. When the cross-correlation is smaller, it means that the difference between them is larger, and the interference and influence between them will also be smaller, so as to avoid the interference between different signals and improve the accuracy of the determination of the channel reflection coefficient.

[0072] In some embodiments, as shown in FIG. 3, the radio frequency device can further include a probe sequence generation module 323, which is configured to inject a probe sequence into the transmitting channel 202. Figure 3

[0073] In this application, "injection" refers to signal injection, that is, adding an externally generated signal to a certain circuit or system. The injection can be completed by signal coupling or signal superposition, so that the signal of the probe sequence and the original first signal of the transmitting channel are combined to form a new signal.

[0074] wherein the probe sequence generation module 323 is a device or module capable of generating a specific sequence signal, which can also be called a probe sequence generator, and can provide a known signal source (probe sequence) for the radio frequency device to calibrate and test the performance of the transmitting channel 202.

[0075] Alternatively, the probe sequence generation module 323 can include any of FPGA, ASIC or DSP.

[0076] wherein FPGA is a semi-custom circuit, and the user can configure its internal logic structure and connection mode by programming, which has the advantages of high flexibility, high parallel processing capability and reconfigurability. Therefore, by using FPGA as the probe sequence generation module in the radio frequency device, various complex probe sequences can be generated to adapt to different working environments and requirements of the radio frequency device.

[0077] ASIC is a kind of integrated circuit customized for specific applications, which has the advantages of high performance, low power consumption and small size. Therefore, by using ASIC as the probe sequence generation module in the radio frequency device, efficient probe sequence generation with lower power consumption can be realized.

[0078] ​A DSP is a microprocessor specifically designed for digital signal processing. It features high-speed multiplication-accumulation capabilities and a rich instruction set, making it suitable for handling complex algorithms and large amounts of data. Therefore, using a DSP as a probe sequence generation module in an RF device allows for the implementation of complex probe sequence generation algorithms, improving the real-time performance and accuracy of the probe sequences.

[0079] Optional, such as Figure 3 As shown, the transmission channel 202 may also include a low-pass filter module 324 for the detection sequence and an adder 325, such as... Figure 3 As shown, the bandwidth limitation of the low-pass filter module 324 is the cutoff frequency (BW), which refers to the upper limit of the signal frequency allowed by the filter. It is used to filter out the high-frequency components of the obtained real signal (probe sequence) and retain the components below BW. The adder 325 is used to superimpose the probe sequence on the first signal to generate the transmit baseband signal. The second receiving end of the adder 325 can be connected to the probe sequence generation module 323 and the low-pass filter module 324 to obtain the probe sequence injected into the transmit channel 202 by the probe sequence generation module 323. The first receiving end of the adder 325 can be connected to the first signal generation module 321 and the frequency shift module 322 to receive the first signal, superimpose the probe sequence on the first signal to generate the transmit baseband signal, and output the transmit baseband signal from the output end of the adder 325.

[0080] Optional, such as Figure 3 As shown, the transmit channel 202 may further include a numerically controlled oscillator (NCO) 326, a multiplier 327, and a bandpass filter module 328. The NCO 326 generates digital quadrature carrier signals (e.g., sine and cosine waves), the multiplier 327 modulates (up-converts) the transmit baseband signal, and the bandpass filter module 328 filters for spurious frequencies in the transmit baseband signal. Thus, through the NCO 326, multiplier 327, and bandpass filter module 328, the low-frequency, raw transmit baseband signal can be converted into a high-frequency, modulated, and transmittable prototype transmit signal. This prototype is then output through modules such as the digital-to-analog converter (DAC) 329, power amplifier (PA) 330, and directional coupler 331 in the transmit channel 202, resulting in the final transmit signal. Among them, the transmitted baseband signal is the original electrical signal without modulation. After being processed by modulation, up-conversion and other methods, it becomes the signal used for actual transmission, which is the transmitted signal.

[0081] In some implementations, such as Figure 3As shown, the transmitting channel 202 can further include a first signal generation module 321, which works with the frequency shift module 322 to generate various forms of electrical signals, including signals of different frequencies, amplitudes, phases and waveforms, to meet the needs of different application scenarios. In this application, the first signal generation module 321 and the frequency shift module 322 together can be used to generate the above-mentioned first signal. As shown in the figure, Figure 3 As shown, the real signal (i.e. the first signal) generated by the first signal generation module 321 is shifted by f0 after passing through the frequency shift module 322.

[0082] The output end of the frequency shift module 322 can also be connected with the adder 325, which is used to add the first signal and the probe sequence to generate the corresponding radio frequency baseband signal. In addition, the receiving end of the first signal generation module 321 can also be connected with the control circuit 201 of the radio frequency device, which can receive instructions from the control circuit 201 for indicating the generation of the first signal or other possible indications.

[0083] The application also provides another structural diagram of a radio frequency device, as shown in the figure, Figure 4 As shown, the structural diagram combines the complex signal processing process related to the radio frequency device.

[0084] Among them, the first signal generation module 421 generates the first signal, and the complex signal corresponding to the first signal supports amplitude, frequency, phase modulation and other processing. The probe sequence generation module 422 generates the probe sequence, and the complex signal corresponding to the probe sequence can also be processed by amplitude, frequency, phase modulation and other processing, and the bandwidth of the probe sequence is BW, so that the probe sequence generation module 422 is used to inject the probe sequence (frequency range-BW / 2 to +BW / 2) to the transmitting channel 202. The adder 423 and the adder 424 are used to add the complex signal corresponding to the first signal and the complex signal corresponding to the probe sequence respectively, and output to the up-conversion module. The up-conversion module of the transmitting channel 202 is composed of the multiplier 425, the multiplier 426, the NCO 428 and the adder 427, which is used to move the added first signal complex signal and probe sequence complex signal to the working frequency band.

[0085] Optionally, the first signal generation module 421 can be connected with the power ramp (RAMP) module, which is used to control the gradual change of the signal power, so as to maintain the stability of the signal.

[0086] Optionally, as shown in the figure, Figure 4 As shown, the NCO 428 in the transmitting channel 202 can also be based on the cosine lookup table (COS lookuptable, COLT) to quickly calculate the cosine value, so as to realize the modulation and demodulation of the signal and other possible signal processing.

[0087] In some implementations, such as Figure 3 As shown, the transmit channel 202 also includes a PA330. The PA330 can be used to increase the power of the low-power signal (low-power transmit baseband signal) in the transmit channel 202 to meet the requirements of antenna radiation or load drive.

[0088] In one possible implementation, when the first signal is a continuous wave signal, the transmission channel 202 is specifically used to output a transmission signal based on the first signal and a series of identical detection sequences.

[0089] For example, when the first signal is a continuous wave (CW) signal, the probe sequence generation module can continuously inject multiple identical probe sequences into the digital domain of the transmission channel, so that the transmission channel can output a transmission signal based on the first signal and multiple consecutive identical probe sequences. Specifically, the probe sequence generation module can continuously inject multiple identical probe sequences into the transmission channel. For example... Figure 6 As shown, the power of the first signal is 1kW, and a detection sequence PN1 can be continuously injected into the digital domain of the transmission channel. For example, the detection sequence generation module can continuously generate multiple identical detection sequences with fixed parameters and repeatedly inject them into the transmission channel. At this time, the first signal generation module generates a continuous wave first signal. Then, the multiple identical detection sequences are superimposed on the first signal using an adder. During superposition, the level of the detection sequences must be ensured so that the power ratio between the first signal and the detection sequences is greater than or equal to a first threshold, and then the transmission signal is output through the transmission channel.

[0090] Optionally, the probe sequence generation module needs to select a reasonable probe sequence (e.g., m-sequence) level so that the signal-to-noise ratio of the first signal is greater than or equal to the first threshold, for example, the first threshold is 50dBc.

[0091] Optionally, the feedback channel can continuously acquire forward feedback baseband signals and reverse feedback baseband signals, allowing the control circuit 201 to determine the reflection coefficient. Thus, by injecting multiple identical detection sequences and continuously acquiring forward and reverse feedback baseband signals, the reflection coefficient at each frequency point across the entire frequency band can be continuously monitored, improving the stability of the RF device.

[0092] In another possible implementation, when the first signal is a pulse signal, the transmitting channel 202 is specifically used to output a transmitting signal according to the first signal and the detection sequence corresponding to the pulse level of the first signal.

[0093] Different pulse levels of the first signal correspond to different detection sequences.

[0094] For example, the first signal can be divided into different pulse levels according to the amplitudes / powers of the transmitting pulses of the first signal, and then different detection sequences can be selected for each pulse level, so that the gain fluctuation of different pulses can be estimated by using different detection sequences. For example Figure 7 As shown, the pulse width of the first signal is 5us, and the detection sequence PN1 or the detection sequence PN2 can be injected into the first signal of different pulse levels. For example, the detection sequence PN1 can correspond to a higher pulse level of the first signal, and the detection sequence PN2 can correspond to a lower pulse level of the first signal.

[0095] Optionally, the detection sequence generation module can adjust the level of the detection sequence according to the pulse level, so that the signal-to-noise ratio of each pulse level of the first signal is greater than or equal to the first threshold, for example, the first threshold is 50dBc.

[0096] In some embodiments, the reflection coefficients corresponding to the first signals with different level configuration parameters are different.

[0097] The level configuration parameters of the first signal can include the power, amplitude, etc. of the transmitting pulse of the first signal.

[0098] Optionally, the feedback channel can collect the feedback signals corresponding to the first signals with different level configuration parameters, so that the control circuit 201 determines the reflection coefficient based on the feedback signals corresponding to the first signals with different level configuration parameters and the detection sequences corresponding to different level configuration parameters. The reflection coefficients determined based on the feedback signals corresponding to different level configuration parameters and different pulse levels can be different.

[0099] It should be noted that based on this implementation, in the pulse working scenario, different detection sequences can be selected according to different pulse levels, so that the reflection coefficient can be more accurately estimated for different pulse levels.

[0100] Optionally, as shown in Figure 3 The transmitting channel 202 can further include a band-pass filter module 328 for extracting signals of a specific frequency channel. For example, the center frequency f c +W / 2 and the bandwidth BW of the band-pass filter module 328 can be set to realize frequency selection and filtering processing of the signal.

[0101] In some embodiments, between the adder and the power amplifier, the transmitting channel 202 can further include a DAC, such as the DAC 329 in Figure 3 or the DAC 429 in Figure 4 After the power amplifier, the transmitting channel can further include a directional coupler, such as the directional coupler 430 in Figure 3a directional coupler 331 or Figure 4 a directional coupler 431.

[0102] The DAC can convert a digital signal into an analog signal. The directional coupler is a device for separating or combining signal power, which can couple a part of the power of the input signal to the output port while keeping the main power of the input signal flowing to another output port. Optionally, the directional coupler 331 or the directional coupler 431 can also be used to extract the forward and reflected signal components from the transmitted signal of the transmitting channel 202 to determine the forward power and the reflected power.

[0103] In this application, the "forward" feedback signal can also be referred to as the "forward" feedback signal or other similar names, and the "forward" power can also be referred to as the "forward" power, which is not specifically limited. Similarly, the "reflected" feedback signal can also be referred to as the "reflected" feedback signal, "backward" feedback signal, etc., and the "reflected" power can also be referred to as the "reflected" power, "backward" power, etc., which is not specifically limited.

[0104] Optionally, as shown in Figure 3 The feedback channel 203 can include a down-conversion module for processing the feedback signal and down-converting the feedback signal to a baseband signal.

[0105] Optionally, the feedback channel 203 collects the forward feedback signal and the reflected feedback signal. The forward feedback signal refers to the sampling value of the transmitted signal from the transmitting channel 202 of the radio frequency device to the load (such as an antenna), which can also be referred to as a forward feedback baseband signal. The reflected feedback signal refers to the sampling value of the reflected signal from the load (such as an antenna) to the radio frequency device, which can also be referred to as a reflected feedback baseband signal.

[0106] Optionally, as shown in Figure 3 In the feedback channel 203, the down-conversion module and the directional coupler 331 can further include an analog-to-digital converter ADC 341 and an ADC 344 for converting an analog signal to a digital signal.

[0107] Optionally, as shown in Figure 3 The feedback channel 203 can further include a multiplier 342 and a low-pass filter module 343 for converting the frequency of the forward feedback baseband signal and down-converting the forward feedback baseband signal. A multiplier 345 and a low-pass filter module 346 are used to convert the frequency of the reflected feedback baseband signal and down-convert the reflected feedback baseband signal.

[0108] Optionally, as shown in Figure 3As shown, the feedback channel 203 can further include a fundamental wave filter, such as a low-pass filter module 343 and a low-pass filter module 346, for filtering out high-frequency harmonics and spurious signals, extracting and retaining the fundamental frequency component in the signal, and ensuring the purity and effectiveness of the feedback signal. In the case where the feedback signal in the feedback channel 203 includes a forward feedback baseband signal and a reverse feedback baseband signal, the low-pass filter module 343 can be used to filter out high-frequency harmonics and spurious signals in the forward feedback baseband signal, and the low-pass filter module 346 can be used to filter out high-frequency harmonics and spurious signals in the reverse feedback baseband signal.

[0109] Optionally, as shown, the feedback channel 203 can further include a time delay correction module 347 and a time delay correction module 348 for performing channel time delay correction on the transmission signal of the transmission channel. Figure 3

[0110] In some embodiments, the control circuit 201 can include a forward feedback signal estimation module 311 and a reverse feedback channel estimation module 312, and a reflection coefficient calculation module 313 for determining the forward channel parameters and the reverse channel parameters based on the probe sequence, the forward feedback baseband signal and the reverse feedback baseband signal, and for determining the reflection coefficient of a plurality of frequency points based on the forward channel parameters and the reverse channel parameters.

[0111] The feedback signal can refer to the signal collected at the output port of the transmission channel, and can be understood as the signal output after the first signal is processed by the transmission channel, i.e., the feedback signal includes the original information of the transmission signal, but can be distorted due to the non-ideal characteristics of the channel.

[0112] The feedback signal collected by the feedback channel can include a forward feedback baseband signal and a reverse feedback baseband signal. The forward feedback baseband signal refers to the sampling value of the transmission signal transmitted from the transmission channel of the radio frequency device to the load (such as an antenna), which can also be referred to as a forward feedback signal. The reverse feedback baseband signal refers to the sampling value of the reflected signal reflected from the load (such as an antenna) to the radio frequency device, which can also be referred to as a reverse feedback signal.

[0113] For example, the control circuit 201 can determine the forward channel parameters based on the probe sequence and the forward feedback baseband signal. The control circuit 201 can also determine the reverse channel parameters based on the probe sequence and the reverse feedback baseband signal.

[0114] The reflection coefficient is a parameter that describes the reflection of electromagnetic waves due to impedance matching in the transmission medium, and is equal to the amplitude ratio of the reflected wave to the incident wave.

[0115] Optionally, the reflection coefficient can be determined based on the forward channel parameters and the reverse channel parameters.

[0116] ​The forward channel parameter refers to a relevant parameter of a forward channel (such as a channel of a transmitted signal emitted to a load). The reverse channel parameter refers to a relevant parameter of a reverse channel (such as a channel of a reflected signal returned through a coupler).

[0117] Optionally, the forward feedback channel estimation module 311 is specifically configured to: construct a first autocorrelation matrix of the probe sequence and a first cross-correlation vector between the probe sequence and the forward feedback baseband signal according to the probe sequence and the forward feedback baseband signal; and determine the forward channel parameter according to the first autocorrelation matrix and the first cross-correlation vector. The reverse feedback channel estimation module 312 is specifically configured to: construct a second autocorrelation matrix of the probe sequence and a second cross-correlation vector between the probe sequence and the reverse feedback baseband signal according to the probe sequence and the reverse feedback baseband signal; and determine the reverse channel parameter according to the second autocorrelation matrix and the second cross-correlation vector.

[0118] For example, the forward channel parameter and / or the reverse channel parameter can be determined based on the following formula (1):

[0119]

[0120] wherein M represents a channel memory length, indicating a length of time during which a channel channel can affect a current time input signal, eq TX The forward channel parameter or the reverse channel parameter, i represents a tap index.

[0121] In addition, based on the acquired channel memory length, a system output signal y(n) aligned with the probe sequence pn(n) can be obtained, so that linear channel estimation can be performed in a manner of minimizing a mean square error of a predicted output and an actual output to solve optimal tap coefficients w TXi The forward channel parameter or the reverse channel parameter, i represents a tap index.

[0122]

[0123] Based on the formula (2), the following formula (3) can be derived:

[0124]

[0125] wherein Rx is an autocorrelation matrix of pn(n), and Ry is a cross-correlation vector between pn(n) and the output signal y(n).

[0126]

[0127] wherein, N in the above formula (2) - formula (5) is the number of sampling points, n represents the nth sampling point, n = 0, 1, …, N. M represents the channel memory length. Optionally, a large number of samples are accumulated by repeatedly sending the probe sequence (such as a PN sequence), so that N >> the length of the PN sequence, that is, the number of sampling points is much larger than the period of the PN sequence, to avoid the estimation bias caused by the periodicity of the PN sequence and to improve the estimation accuracy of the channel parameters.

[0128] In some embodiments, it can be assumed that the real transmission channel and / or the feedback channel is a linear filter, the tap coefficient is [0.001, 0.005, 0.03, 1, 0.03, 0.04, 0.001], and the system noise is -40 dB, at which time the simulation results can be as shown in Figure 8 Figure 8 (a) in FIG. 1 shows the impulse response (Cascade filter coeffs.) of the filter and the error (Cascade filter coeffs. error) of the filter, that is, the difference between the actual tap coefficient and the ideal tap coefficient. The impulse response of the filter has significant values at certain tap positions, such as (X11, Y1.07005e-05), and is close to zero at other positions, such as (X14, Y7.4203e-06). The performance of the filter at different tap positions can be obtained in combination with the impulse response and the error. Figure 8 (b) in FIG. 1 shows the amplitude distribution of the first signal at different frequencies or sample points after the noise is superimposed on the probe sequence, including the amplitude distribution before and after the equalizer (EQ) adjustment. It can be seen that the first signal can still be clearly detected in the presence of noise due to the low noise power, so that the response of the channel can still be estimated by the known signal (such as the probe sequence) in the presence of noise to obtain the channel parameters, such as the above-mentioned forward channel parameters and / or reverse channel parameters.

[0129] Thus, based on the assumption of a linear channel, the probe sequence (such as a PN sequence) can be used and the signal (such as the above-mentioned forward feedback baseband signal / reverse feedback baseband signal) transmitted through the channel can be received to determine the channel parameters.

[0130] It should be understood that the collected signal (such as the above-mentioned forward feedback baseband signal / reverse feedback baseband signal) includes the main signal (the first signal), that is, y(n) contains s(n). Since pn(n-i) and s(n) are not correlated, under the condition that N is large enough, in combination with the above-mentioned formula (5), the following formula (6) can be obtained:

[0131]

[0132] ​It can be seen that when N is large enough, the influence of the main signal (first signal) in the cross-correlation vector is small and can approach zero. Therefore, the number of sampling points N can be increased to perform correlation calculations to improve the equivalent signal-to-noise ratio and thus achieve accurate estimation of channel parameters.

[0133] For example, when N is large enough, such as Figure 9 As shown in (a), the tap error between the curves of the actual transmitted signal (TX) and the estimated transmitted signal (Est.TX) is small, and the value on the error curve approaches zero and is relatively stable. Furthermore, as... Figure 9 As shown in (b), the signal fitting error (Emor) between the actual transmitted signal (TX) and the estimated transmitted signal (TX est) is also small; for example, at point X 3748, the Emor is 0.0688088. Therefore, a sufficiently large N can be set to calculate the relevant channel parameters, thereby improving the accuracy of the channel parameter estimation.

[0134] For example, control circuit 201 can construct a first autocorrelation matrix of the probe sequence and a first cross-correlation vector between the probe sequence and the forward feedback baseband signal based on the probe sequence and the forward feedback baseband signal, combined with the above formulas (4)-(6), thereby determining the forward channel parameters based on the first autocorrelation matrix and the first cross-correlation vector. Control circuit 201 can also construct a second autocorrelation matrix of the probe sequence and a second cross-correlation vector between the probe sequence and the reverse feedback baseband signal based on the probe sequence and the reverse feedback baseband signal, combined with the above formulas (4)-(6), thereby determining the reverse channel parameters based on the second autocorrelation matrix and the second cross-correlation vector.

[0135] As can be seen, the control circuit 201 can process the forward feedback baseband signal and the reverse feedback baseband signal collected by the feedback channel to estimate the characteristics of the forward channel and the reverse channel respectively.

[0136] Optional, such as Figure 3 As shown, the control circuit 201 may also include a forward power statistics module for calculating forward power and a reverse power statistics module for calculating reverse power.

[0137] Optional, such as Figure 4As shown, the feedback channel 203 includes a down-conversion component, which may include multipliers 442 and 443, a delay module (also known as a local oscillator delay module) 444, a low-pass filter module 445, and a low-pass filter module 446, etc. The down-conversion component down-converts the received feedback signal to a baseband signal and filters out out-of-band spurious signals, providing a forward feedback baseband signal for the control circuit 201. The down-conversion component may also include multipliers 448 and 449, a delay module (also known as a local oscillator delay module) 450, a low-pass filter module 451, and a low-pass filter module 452, etc. The down-conversion component down-converts the received feedback signal to a baseband signal and filters out out-of-band spurious signals, providing a reverse feedback complex baseband signal for the control circuit 201.

[0138] Optional, such as Figure 4 As shown, the control circuit 201 comprises a forward feedback signal estimation module 411, a reverse feedback signal estimation module 412, and a reflection coefficient calculation module 413. It is used to determine the forward channel parameters and reverse channel parameters based on the detection sequence complex signal, the forward feedback complex baseband signal, and the reverse feedback complex baseband signal, and to determine the reflection coefficients of multiple frequency points based on the forward channel parameters and the reverse channel parameters.

[0139] That is, the control circuit 201 determines the reflection coefficients of multiple frequency points based on the forward channel parameters and the reverse channel parameters.

[0140] In some implementations, such as Figure 4 The control circuit 201, transmission channel 202, and feedback channel 203 can also achieve the same functionality as described above. Figure 3 Other similar features, Figure 4 Other modules can be found by referring to Figure 3 The relevant descriptions in [the original text] will not be repeated here. For example, PA430 can be referred to [the relevant documentation]. Figure 3 The PA330 and ADC441 mentioned can be referenced. Figure 3 ADC341, etc.

[0141] In some implementations, the control circuit 201 can determine the forward equalization coefficient based on the forward channel parameters and the reverse equalization coefficient based on the reverse channel parameters, thereby determining the reflection coefficient based on the forward equalization coefficient and the reverse equalization coefficient.

[0142] The forward equalization coefficient can be understood as a compensation parameter for linear distortion in the forward channel. It can be used to eliminate forward channel distortion and improve the accuracy of the transmitted signal reaching the load. The reverse equalization coefficient can be understood as a compensation parameter for linear distortion in the reverse channel. It can be used to eliminate reflection channel distortion and extract the true reflection characteristics of the load. The forward channel can be the channel through which the transmitted signal reaches the load; the reverse channel can be the channel through which the reflected signal returns via the coupler.

[0143] For example, the reflection coefficient can be determined based on the following formula (7):

[0144]

[0145] wherein, Γ is the reflection coefficient, eq ref is the forward equalization coefficient, eq fwd is the backward equalization coefficient, ω is the normalized digital angular frequency, f det is the actual frequency (Hz) to be detected, for example, the plasma operating frequency, f s is the signal sampling rate (Hz).

[0146] Optionally, the forward equalization coefficient can be expressed as The backward equalization coefficient can be expressed as

[0147]

[0148] Thus, the following formula (8) can be obtained:

[0149]

[0150] Thus, based on the collected forward feedback baseband signal and the backward feedback baseband signal, the reflection coefficient of the full frequency band is determined respectively in combination with the above formula (8).

[0151] Based on the technical solution provided in the present application, the reflection coefficient is determined by using the detection sequence. Since the ratio between the power of the first signal and the power of the detection sequence is limited, the power of the detection sequence is not too large compared to the first signal, which avoids changing the overall state of the plasma or causing significant interference due to too large power. Therefore, the technical solution can measure the reflection coefficient without interfering with the normal operation of the plasma, and has high anti-interference characteristics. Moreover, the technical solution can use the detection sequence to detect the reflection coefficient in the full frequency band in real time, and can realize synchronous calculation of the reflection coefficient of multiple frequency points, and has higher measurement efficiency.

[0152] And, the technical scheme can avoid errors and interference caused by changes in the plasma state, avoid the multiple solution problem of the reflection coefficient, and improve the reliability of the reflection coefficient determination method. The multiple solution problem of the reflection coefficient refers to the fact that when the operating frequency of the RFG changes, the reflection coefficient may correspond to multiple valid solutions at the same frequency. During the ETCH process, due to the nonlinear, time-varying characteristics of the impedance of the plasma and the fact that the impedance changes with the operating frequency, the impedance may correspond to multiple different stable states (i.e., multiple different impedance values) at a single operating frequency point. This multiple value of the impedance directly leads to multiple solutions of the calculated reflection coefficient when measuring at a single frequency, so that the real load state of the plasma cannot be uniquely determined. However, the technical scheme of the present application can more reliably uniquely determine the reflection coefficient corresponding to each frequency point by independently obtaining the complete parameters of the forward and reverse channels and combining the known probe sequence, effectively eliminating the ambiguity caused by the multiple solutions, thereby improving the reliability of the reflection coefficient determination method.

[0153] It should be noted that the above-provided drawings are only used for exemplary illustration, and the number of each device and the name of each device in the drawings are not limited, and in addition to the devices shown in the above drawings, other devices such as a reverse feedback baseband signal acquisition module can also be included. Optionally, the radio frequency device can also include a control circuit, which is usually used to perform the control and coordination of the whole radio frequency device, and can control the working state of the radio frequency device by receiving and processing information from the feedback channel and the transmission channel.

[0154] In several embodiments provided in the present application, it should be understood that the disclosed different circuits or units can be implemented in other manners. For example, the above-described device embodiments are only schematic; the division of the units is only a logical function division; there can be another division manner for the actual implementation, for example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0155] The units described as separate components can or can not be physically separate, and the components shown as units can be one physical unit or multiple physical units, that is, can be located in one place or distributed to multiple different places. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments.

[0156] In addition, each functional unit in each embodiment of the present application can be integrated into one processing unit, or each unit can exist physically, or two or more units can be integrated into one unit. The above integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0157] The method for determining the reflection coefficient is described in detail below with reference to the accompanying drawings of the specification.

[0158] As shown in Figure 10 The method for determining the reflection coefficient is described in detail below with reference to the accompanying drawings of the specification.

[0159] S101, the transmission channel outputs a transmission signal according to the first signal and the probe sequence.

[0160] In some embodiments, the radio frequency device includes a probe sequence generation module. Before the step S101, the probe sequence generation module can inject a probe sequence into the transmission channel. Thus, the transmission channel can obtain the injected probe sequence, and obtain the transmission signal according to the first signal and the probe sequence, and output the obtained transmission signal. For example, the transmission channel obtains the injected probe sequence, and superimposes the first signal and the probe sequence by using time division multiplexing, frequency division multiplexing, code division multiplexing or embedded superposition, so as to obtain the transmission signal.

[0161] Optionally, the probe sequence generation module can include any one of FPGA, ASIC or DSP.

[0162] S102, the feedback channel collects a forward feedback baseband signal and a reverse feedback baseband signal corresponding to the transmission signal.

[0163] S103, the control circuit determines a forward channel parameter and a reverse channel parameter according to the probe sequence, the forward feedback baseband signal and the reverse feedback baseband signal.

[0164] S104, the control circuit determines the reflection coefficient of at least one frequency point according to the forward channel parameter and the reverse channel parameter.

[0165] The details of steps S101-S104 can be referred to the related description of the above-mentioned embodiments of the radio frequency device, which will not be described here.

[0166] The various schemes in the above embodiments of the present application can be combined without contradiction.

[0167] The present application also provides a communication device, which includes the radio frequency device provided by any of the above embodiments, and at least one of a baseband circuit and an antenna.

[0168] The above control circuit can be realized by software, hardware or a combination of software and hardware. For example, the module for determining the reflection coefficient in the control circuit can be realized by a combination of a central processing unit (CPU) and an FPGA.

[0169] In the present application, "implemented by software" means that the processor reads and executes program instructions stored in the memory to implement the functions of the above-mentioned modules or units, wherein the processor refers to a processing circuit having a program instruction execution function, including but not limited to at least one of the following: CPU, microprocessor, digital signal processor (DSP), microcontroller unit (MCU), or artificial intelligence processor and other types of processing circuits capable of running program instructions. In other embodiments, the processor can also include other processing function circuits (such as hardware circuits for hardware acceleration, bus and interface circuits, etc.). The processor can be in the form of an integrated chip, for example, in the form of an integrated chip whose processing function only includes the function of executing software instructions, or it can also be in the form of a system on a chip (SoC), that is, on one chip, in addition to including processing circuits capable of running program instructions (usually referred to as "core"), it also includes other hardware circuits for implementing specific functions (of course, these hardware circuits can also be implemented based on ASIC, FPGA), accordingly, the processing function in addition to including the function of executing software instructions, it can also include various hardware acceleration functions (such as AI computing, coding and decoding, compression and decompression, etc.).

[0170] In the present application, "implemented by hardware" means that the functions of the above-mentioned modules or units are implemented by hardware processing circuits without program instruction processing function. The hardware processing circuit can be composed of discrete hardware components, or it can be an integrated circuit. In order to reduce power consumption and size, an integrated circuit is usually used to implement it. The hardware processing circuit can include ASIC, or programmable logic device (PLD); wherein the PLD can include FPGA, complex programmable logic device (CPLD) and the like. These hardware processing circuits can be a separately packaged semiconductor chip (such as an ASIC packaged into one); it can also be packaged into a semiconductor chip together with other circuits (such as CPU, DSP), for example, a variety of hardware circuits and CPU can be formed on a silicon base and packaged into a chip separately, such a chip is also called SoC, or the circuit for implementing FPGA function and CPU can be formed on a silicon base and packaged into a chip separately, such a chip is also called system on a programmable chip (SoPC).

[0171] It should be noted that the present application can use different software, hardware, and does not limit to use only one kind of software or hardware when it is implemented by software, hardware or combination of software and hardware. For example, one of the modules or units can be implemented by CPU, and another module or unit can be implemented by DSP. Similarly, when implemented by hardware, one of the modules or units can be implemented by ASIC, and another module or unit can be implemented by FPGA. Of course, it is not limited that part or all of the modules or units are implemented by the same kind of software (such as all by CPU) or the same kind of hardware (such as all by ASIC). In addition, for those skilled in the art, it is known that software is more flexible but less performant than hardware, and hardware is just the opposite, therefore, those skilled in the art can select software or hardware or combination of both to implement according to actual needs.

[0172] The above preferred embodiments further illustrate the purposes, technical solutions and advantages of the present application. It should be understood that the above are only preferred embodiments of the present application, and are not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the principles of the present application shall be included in the protection scope of the present application.

Claims

1. A radio frequency device, characterized by, The radio frequency device comprises a control circuit, a transmitting channel and a feedback channel, the control circuit is connected with the transmitting channel and the feedback channel, and the transmitting channel and the feedback channel are connected; The transmitting channel is configured to output a transmitting signal according to a first signal and a probe sequence; a ratio between a power of the first signal and a power of the probe sequence is greater than or equal to a first threshold value; The feedback channel is configured to collect a forward feedback baseband signal and a reverse feedback baseband signal corresponding to the transmitting signal; The control circuit is configured to determine a forward channel parameter according to the probe sequence and the forward feedback baseband signal; The control circuit is further configured to determine a reverse channel parameter according to the probe sequence and the reverse feedback baseband signal; And the control circuit is further configured to determine a reflection coefficient of at least one frequency point in a working frequency range of the radio frequency device according to the forward channel parameter and the reverse channel parameter.

2. The radio-frequency device according to claim 1, characterized in that The control circuit is configured to determine a forward channel parameter according to the probe sequence and the forward feedback baseband signal, including: The control circuit is specifically configured to: construct a first autocorrelation matrix of the probe sequence and a first cross-correlation vector between the probe sequence and the forward feedback baseband signal according to the probe sequence and the forward feedback baseband signal; determine the forward channel parameter according to the first autocorrelation matrix and the first cross-correlation vector.

3. The radio frequency device of claim 1 or 2, wherein, The control circuit is further configured to determine a reverse channel parameter according to the probe sequence and the reverse feedback baseband signal, including: The control circuit is specifically configured to: construct a second autocorrelation matrix of the probe sequence and a second cross-correlation vector between the probe sequence and the reverse feedback baseband signal according to the probe sequence and the reverse feedback baseband signal; determine the reverse channel parameter according to the second autocorrelation matrix and the second cross-correlation vector.

4. The radio frequency device of any of claims 1-3, wherein, The radio frequency device comprises a probe sequence generation module, and the probe sequence generation module is configured to inject the probe sequence into the transmitting channel.

5. The radio-frequency device according to claim 4, characterized in that The probe sequence generation module comprises any one of a field programmable gate array (FPGA), an application specific integrated circuit (ASIC) or a digital signal processor (DSP).

6. The radio-frequency device according to any one of claims 1-5, characterized in that, The transmitting channel is configured to output a transmitting signal according to a first signal and a probe sequence, including: In a case where the first signal is a continuous wave signal, the transmitting channel is specifically configured to output a transmitting signal according to the first signal and a plurality of same probe sequences in succession.

7. The radio-frequency device according to any one of claims 1-5, characterized in that, The transmitting channel is configured to output a transmitting signal according to a first signal and a probe sequence, including: In a case where the first signal is a pulse signal, the transmitting channel is specifically configured to output a transmitting signal according to the first signal and the probe sequence corresponding to a pulse level of the first signal; different pulse levels of the first signal correspond to different probe sequences.

8. The radio-frequency device according to any one of claims 1 to 7, characterized in that, The probe sequence is generated based on the first signal.

9. The radio-frequency device according to any one of claims 1-8, characterized in that, An autocorrelation of the probe sequence is higher than a second threshold value.

10. The radio frequency device of any one of claims 1-9, wherein, The transmitting channel is further configured to output a transmitting signal according to the second signal and a detection sequence corresponding to the second signal; and a cross-correlation between the detection sequence corresponding to the second signal and the detection sequence corresponding to the first signal is less than a third threshold.

11. A method of determining a reflection coefficient, characterized by, The method is applied to a radio frequency device, and the radio frequency device comprises a control circuit, a transmitting channel and a feedback channel; the method comprises: The transmitting channel outputs a transmitting signal according to a first signal and a detection sequence; and a ratio between a power of the first signal and a power of the detection sequence is greater than or equal to a first threshold; The feedback channel collects a forward feedback baseband signal and a reverse feedback baseband signal corresponding to the transmitting signal; The control circuit determines a forward channel parameter according to the detection sequence and the forward feedback baseband signal; The control circuit determines a reverse channel parameter according to the detection sequence and the reverse feedback baseband signal; and the control circuit determines a reflection coefficient of at least one frequency point in a working frequency band of the radio frequency device according to the forward channel parameter and the reverse channel parameter.

12. A communication device, characterized by The communication device comprises a radio frequency device, and at least one of a baseband circuit and an antenna, and the radio frequency device is the radio frequency device of any one of claims 1-10.

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