阅读说明：本技术 一种混沌振子电路和基于混沌理论的微弱信号检测系统 (Chaotic oscillator circuit and weak signal detection system based on chaos theory ) 是由 杨红权 李开成 于 2021-07-23 设计创作，主要内容包括：本发明公开一种混沌振子电路和基于混沌理论的微弱信号检测系统,属于微弱信号检测领域。包括：混沌振子电路输出端接参数调节测量模块；参数调节测量模块包括：标准信号源,用于产生6GHz的标准正弦信号,输出至分频器；分频器,用于将标准信号等分为1/2、1/4…频率的信号,输出至控制模块；控制模块,用于根据分频后信号生成扫频范围,对扫频范围内的每个频率：根据选中频率调节第一反馈系数可调放大器、第二反馈系数可调放大器的放大比例系数,使得混沌振子电路处于混沌临界状态；采样此时混沌振子电路输出信号,若其方差超过设定阈值,则待测信号包含当前选中频率信号。本发明通过混沌系统所处状态检测出是否含有周期信号,提高探测精度和可靠性。(The invention discloses a chaotic oscillator circuit and a weak signal detection system based on a chaos theory, and belongs to the field of weak signal detection. The method comprises the following steps: the output end of the chaotic oscillator circuit is connected with a parameter adjusting and measuring module; the parameter adjustment measurement module includes: the standard signal source is used for generating a standard sinusoidal signal of 6GHz and outputting the standard sinusoidal signal to the frequency divider; the frequency divider is used for equally dividing the standard signal into signals with frequencies of 1/2 and 1/4 … and outputting the signals to the control module; the control module is used for generating a frequency sweeping range according to the frequency-divided signals, and for each frequency in the frequency sweeping range: adjusting the amplification scale coefficients of the first feedback coefficient adjustable amplifier and the second feedback coefficient adjustable amplifier according to the selected frequency, so that the chaotic oscillator circuit is in a chaotic critical state; and sampling the output signal of the chaotic oscillator circuit at the moment, and if the variance of the output signal exceeds a set threshold value, determining that the signal to be detected comprises a current selected frequency signal. The invention detects whether the chaotic system contains periodic signals or not through the state of the chaotic system, thereby improving the detection precision and reliability.)

1. The chaotic oscillator circuit is characterized by comprising a summing integration circuit, a first feedback branch and a second feedback branch;

the summation and integration circuit is used for carrying out summation and integration on each path of input signals;

the first feedback branch comprises a first feedback coefficient adjustable amplifier which is used for amplifying an output signal of the summing integration circuit and feeding the output signal back to the input end of the summing integration circuit;

the second feedback branch comprises a cubic operational amplifier and a second feedback coefficient adjustable amplifier which are connected in series, and is used for cubic operation, amplifying the output signal of the summation integration circuit and feeding back the output signal to the summation integration circuit.

2. The circuit of claim 1, wherein the sum-integration circuit is constituted by a sum-operation unit and an integration-operation unit;

the summation operation unit is used for carrying out summation operation on the signal to be detected after filtering and amplification processing and output signals of the first feedback branch and the second feedback branch and outputting the summation operation to the integral operation unit;

and the integral operation unit is used for finishing integral operation.

3. A weak signal detection system based on chaos theory is characterized by comprising:

the filter is used for filtering clutter interference in the electric signal to be detected and outputting the electric signal to the amplifying circuit;

the amplifying circuit is used for amplifying the filtered signal to millivolt level and outputting the signal to the chaotic oscillator circuit according to claim 1 or 2, and the output end of the chaotic oscillator circuit is connected with the parameter adjusting and measuring module;

a parameter adjustment measurement module comprising: the device comprises a standard signal source, a frequency divider and a control module; the standard signal source is used for generating a standard sinusoidal signal of 6GHz and outputting the standard sinusoidal signal to the frequency divider; the frequency divider is used for equally dividing the standard signal into signals with frequencies of 1/2 and 1/4 … and outputting the signals to the control module; the control module is used for generating a frequency sweeping range according to the frequency-divided signals and processing each frequency in the frequency sweeping range as follows:

adjusting the amplification scale factors of the first feedback coefficient adjustable amplifier and the second feedback coefficient adjustable amplifier according to the selected frequency, so that the chaotic oscillator circuit is in a chaotic critical state; and sampling the output signal of the chaotic oscillator circuit at the moment, and if the variance of the output signal exceeds a set threshold, determining that the signal to be detected comprises a signal of the current selected frequency.

4. The system of claim 3, wherein the control module comprises: the device comprises a signal source, a frequency control module, a phase accumulator, a synchronous accumulation module, a coherent calculation module, a frequency control word determination module, a data control word first determination module, a data control word second determination module, a digital potentiometer I and a digital potentiometer II;

the signal source and the frequency control are used for generating an original reference signal with a set frequency and outputting the original reference signal to the phase accumulator;

the phase accumulator is used for acquiring phase information of a signal source waveform, accumulating the accumulated phase data output last time and the current stored data when a clock signal arrives, storing the acquired data, taking the data as the accumulated signal at the next moment, and outputting the accumulated signal to the coherent calculation module;

the digital-to-analog conversion is used for collecting output signals of the chaotic array sub-circuit and outputting the output signals to the synchronous accumulation;

the synchronous accumulation and coherence calculation module is used for calculating the coherence between the signal generated after the signal source passes through the frequency control and phase accumulator and the signal acquired by the system output end through digital-to-analog conversion and outputting the signal to the frequency control word determination module;

the frequency control word determining module is used for further judging the frequency range of the signal according to the correlation between the output signal of the frequency divider and the signal output by the coherent computing module and outputting the frequency range to the first data signal control determining module and the second data signal control determining module;

the data signal control first determining module and the data signal control second determining module are respectively used for generating a data signal control first and a data signal control second according to the frequency control word and sending the data signal control first and the data signal control second to the corresponding digital potentiometer;

and the first digital potentiometer and the second digital potentiometer are respectively controlled by the first data control word and the second data control word and are used for generating an amplification scale factor and outputting the amplification scale factor to the first feedback coefficient adjustable amplifier and the second feedback coefficient adjustable amplifier, so that the amplification factor of the feedback loop is adjusted.

5. The system of claim 4, wherein the output frequency of the frequency divider is freely swept in the range of 0-3GHz, the cross-correlation coefficient between the output signal of the system and the reference signal is the largest when the frequency sweep is a certain frequency, and the frequency of the current frequency sweep is the frequency of the detection signal.

6. The system of claim 4, wherein the parameters are adjusted to the applicable range by using the normalized scale change of the chaotic system steady state system model and the system barrier height:

frequency scale transformation formula:

formula of barrier height: h is a²/4b；

Where x and y represent the signals before and after frequency conversion, respectively, and a and b represent the first and second feedback coefficients, respectively.

7. The system according to any one of claims 3 to 6, wherein if the maximum Lyapunov characteristic exponent is greater than zero, it is determined that the chaotic oscillator circuit is in the chaotic critical state.

Technical Field

The invention belongs to the technical field of weak signal detection, and particularly relates to a chaotic oscillator circuit and a weak signal detection system based on a chaos theory.

Background

The weak signal detection mainly researches a method and a technology for extracting information from noise, and by using the technology, weak quantity which is considered to be incapable of being measured by a traditional measuring means, such as weak light, small displacement, micro vibration, micro voltage, micro current and the like, can be measured. In most cases, people often measure weak physical quantities by converting the weak measured quantities into electric signals through various sensors, so that the measurement of the weak electric signals plays an extremely important role in the measurement of all physical quantities, and the measurement of the weak electric signals has important value for the measurement and exploration in the field of unknown engineering.

The measurement of the physical parameters in the engineering field is basically realized by adopting sensors to acquire data, and no matter the sensors are electric sensors or other sensors, noise is inevitably brought in during information conversion. In weak signal detection, signals are often submerged in noise, so how to effectively eliminate the influence of noise on signal measurement accuracy is very important in a measurement system, detection of weak sinusoidal signals is the most critical in weak voltage signal detection, and especially, the urgent requirements of measuring the nanovolt or even subnanovolt sinusoidal signals are provided by people due to continuous and deep research in the fields of physics optics, quantum mechanics, biomedicine and the like.

The limitation of the conventional weak signal detection method is mainly represented by that the threshold value of the signal-to-noise ratio of the detected weak signal is higher, although the threshold value of the input signal-to-noise ratio of the existing frequency domain method is lower than that of the time domain method, the method mainly detects the weak signal taking stable Gaussian distribution noise as background noise, and simultaneously needs a large amount of prior probability distribution knowledge to estimate the parameters of the signal to be detected. If the signal is weaker than the noise, it is very difficult to measure and extract the signal by general measurement methods, such as narrowband measurement techniques, which use the coherence of the signal to measure. Coherent detection techniques can be used to filter out noise that is not coherent with the signal, and by limiting the bandwidth of the measurement system, noise outside a large amount of bandwidth can be removed, but the signal can only be detected at a higher signal-to-noise ratio.

Disclosure of Invention

The invention provides a chaotic oscillator circuit and a weak signal detection system based on a chaos theory, aiming at the defects of low reliability, poor signal anti-interference capability and low accuracy of the weak signal detection system in the prior art and improving requirements, and aiming at automatically judging whether the chaotic system is in a chaos state or a stable periodic motion state according to the state of the chaotic system, so as to detect whether a signal contains a periodic signal, avoid misjudgment and improve the accuracy and reliability of the detection system.

To achieve the above object, according to a first aspect of the present invention, there is provided a chaotic oscillator circuit, which is composed of a summing integration circuit, a first feedback branch, and a second feedback branch;

the summation and integration circuit is used for carrying out summation and integration on each path of input signals;

the first feedback branch comprises a first feedback coefficient adjustable amplifier which is used for amplifying an output signal of the summing integration circuit and feeding the output signal back to the input end of the summing integration circuit;

the second feedback branch comprises a cubic operational amplifier and a second feedback coefficient adjustable amplifier which are connected in series, and is used for cubic operation, amplifying the output signal of the summation integration circuit and feeding back the output signal to the summation integration circuit.

Preferably, the summation and integration circuit is composed of a summation operation unit and an integration operation unit;

the summation operation unit is used for carrying out summation operation on the signal to be detected after filtering and amplification processing and output signals of the first feedback branch and the second feedback branch and outputting the summation operation to the integral operation unit;

and the integral operation unit is used for finishing integral operation.

To achieve the above object, according to a second aspect of the present invention, there is provided a weak signal detection system based on chaos theory, comprising:

the filter is used for filtering clutter interference in the electric signal to be detected and outputting the electric signal to the amplifying circuit;

the amplifying circuit is used for amplifying the filtered signal to a millivolt level and outputting the signal to the chaotic oscillator circuit in the first aspect, and the output end of the chaotic oscillator circuit is connected with the parameter adjusting and measuring module;

a parameter adjustment measurement module comprising: the device comprises a standard signal source, a frequency divider and a control module; the standard signal source is used for generating a standard sinusoidal signal of 6GHz and outputting the standard sinusoidal signal to the frequency divider; the frequency divider is used for equally dividing the standard signal into signals with frequencies of 1/2 and 1/4 … and outputting the signals to the control module; the control module is used for generating a frequency sweeping range according to the frequency-divided signals and processing each frequency in the frequency sweeping range as follows:

adjusting the amplification scale factors of the first feedback coefficient adjustable amplifier and the second feedback coefficient adjustable amplifier according to the selected frequency, so that the chaotic oscillator circuit is in a chaotic critical state; and sampling the output signal of the chaotic oscillator circuit at the moment, and if the variance of the output signal exceeds a set threshold, determining that the signal to be detected comprises a signal of the current selected frequency.

Preferably, the control module comprises: the device comprises a signal source, a frequency control module, a phase accumulator, a synchronous accumulation module, a coherent calculation module, a frequency control word determination module, a data control word first determination module, a data control word second determination module, a digital potentiometer I and a digital potentiometer II;

the signal source and the frequency control are used for generating an original reference signal with a set frequency and outputting the original reference signal to the phase accumulator;

the phase accumulator is used for acquiring phase information of a signal source waveform, accumulating the accumulated phase data output last time and the current stored data when a clock signal arrives, storing the acquired data, taking the data as the accumulated signal at the next moment, and outputting the accumulated signal to the coherent calculation module;

the digital-to-analog conversion is used for collecting output signals of the chaotic array sub-circuit and outputting the output signals to the synchronous accumulation;

the synchronous accumulation and coherence calculation module is used for calculating the coherence between the signal generated after the signal source passes through the frequency control and phase accumulator and the signal acquired by the system output end through digital-to-analog conversion and outputting the signal to the frequency control word determination module;

the frequency control word determining module is used for further judging the frequency range of the signal according to the correlation between the output signal of the frequency divider and the signal output by the coherent computing module and outputting the frequency range to the first data signal control determining module and the second data signal control determining module;

the data signal control first determining module and the data signal control second determining module are respectively used for generating a data signal control first and a data signal control second according to the frequency control word and sending the data signal control first and the data signal control second to the corresponding digital potentiometer;

and the first digital potentiometer and the second digital potentiometer are respectively controlled by the first data control word and the second data control word and are used for generating an amplification scale factor and outputting the amplification scale factor to the first feedback coefficient adjustable amplifier and the second feedback coefficient adjustable amplifier, so that the amplification factor of the feedback loop is adjusted.

Preferably, the output frequency of the frequency divider is freely scanned in the range of 0-3GHz, when the frequency sweep is a certain frequency, the cross-correlation coefficient between the system output signal and the reference signal is the maximum, and the frequency of the current frequency sweep is the frequency of the detection signal.

Preferably, the parameters are adjusted to the application range by adopting the normalized scale change of the chaotic system steady-state system model and the system barrier height:

frequency scale transformation formula:

formula of barrier height: h is a²/4b；

Where x and y represent the signals before and after frequency conversion, respectively, and a and b represent the first and second feedback coefficients, respectively.

Preferably, if the maximum lyapunov characteristic index is greater than zero, the chaotic oscillator circuit is determined to be in a chaotic critical state.

Generally, by the above technical solution conceived by the present invention, the following beneficial effects can be obtained:

(1) the invention provides a chaotic oscillator circuit, which adopts a double-feedback signal processing structure, wherein a system output signal is fed back to a front end to be summed with an input signal and then acts on the system, the sensitivity of the system to weak signals with different frequencies is adjusted by adjusting a feedback coefficient, the system is extremely sensitive to external periodic pulse signals when in a chaotic critical state, and when the input signal contains periodic sinusoidal signals, the phase track of the system is immediately changed so as to detect the periodic sinusoidal signals.

(2) The invention provides a weak signal detection system based on a chaos theory, which is used for detecting weak signals, extracting the weak signals through matching among circuit parameters and a chaos judgment processing algorithm, realizing spectrum migration and extraction of signals to be detected by utilizing the sensitivity of the chaos system to periodic variation signals, having higher reliability, needing no distribution characteristic of noise, needing less prior knowledge and being suitable for various types of noise backgrounds. Compared with the existing weak signal detection method, the method can detect the weak signal at a lower signal-to-noise ratio, has high detection sensitivity, and has very important significance for a system and a method for detecting the weak signal.

Drawings

FIG. 1 is an overall block diagram of a weak signal detection system based on chaos theory according to the present invention;

FIG. 2 is a block diagram of the internal structure of the control module provided by the present invention;

fig. 3 is a flow chart of a method for detecting signals provided by the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

As shown in fig. 1, the present invention provides a weak signal detection system based on chaos theory, which includes: the chaotic system consists of a low-pass filtering circuit, an amplifying circuit, a summing integral circuit and a double-feedback network feedback, and the parameter adjusting and measuring module. The parameter adjusting and measuring module can realize the calculation and adjustment of the feedback coefficient by preprocessing the output signal so as to detect the signal with lower signal-to-noise ratio.

The signal processing process comprises the following steps: an input signal (about 1nV-20 nV) is subjected to signal conditioning through a low-pass filtering and amplifying circuit (about 10mV-50 mV), the detection of the input signal is realized by adopting a chaotic measurement technology, an output signal of a chaotic system is fed back to an input end through a double feedback network for summation, and the weak signal detection based on stochastic resonance is realized by adjusting parameters.

The variable-scale resonance system optimizes the damping parameters of the system and the corresponding relation between each parameter and the output of the resonance system, and designs a weak signal detection parameter adjustment strategy through parameter adjustment and the sensitivity of the system to various parameter adjustments, including the implementation strategies of the adjustment of the damping parameters, the variable-step-length weak signal detection and the like. And the automatic searching of the optimal point is realized by adopting a variable step length heuristic mode, and the signal is captured by judging whether the system is in a chaotic state or a large-scale periodic state by judging the state of the system. The periodic sinusoidal signals existing in the input information can be searched and judged, and the signals can be detected under the condition of extremely low signal-to-noise ratio.

As shown in fig. 2, the control module includes: the device comprises a signal source, a frequency control module, a phase accumulation module, a coherent calculation module, a frequency control word module, a data control word module, a digital potentiometer module and the like, wherein the signal source and the frequency control module are used for generating an original reference signal with set frequency; the frequency control and phase accumulation can obtain phase information of the acquired waveform, and can convert the amplitude and phase of the waveform into an analog amplitude and phase sequence, and a reference clock is a crystal oscillator generally. When a clock signal arrives, the phase accumulator accumulates the accumulated phase data output last time and the current control word, the obtained data is stored and then used as an accumulated signal of the phase accumulator at the next moment, the output signal of the phase accumulator and the phase control are added to obtain an output signal which is used as phase information and sent to a memory, and the waveform memory obtains corresponding waveform information through phase/amplitude conversion.

The coherent calculation is a narrowband technology, general signals have coherence but no noise, coherent information of standard signals and signals can be extracted by using a coherent detection technology to serve as a basis for parameter adjustment, sinusoidal signals or narrowband signals with narrow frequency bands can judge the approximate frequency range of the signals in the signals through coherent calculation, coherent detection is carried out on the basis of phase-sensitive detection, frequency conversion and coherent integration and filtering are carried out, and finally parameter adjustment coefficients of the chaotic system are generated.

The frequency control word and the data control word are used as control information of the digital potentiometer, when a sampling period is determined, the frequency of the signal can be determined by phase increment, namely, only the phase increment of the signal is determined, narrow-band signals such as sine wave signals, if a period 2 pi is divided into M equal parts according to the phase, the phase value corresponding to each equal part is 2 pi/M, when the phase increment is changed in a stepping mode, the phase corresponding to each step is 2 pi/M, and the frequency control word can determine the frequency of the signal, so that the frequency resolution of the signal and the control information of the digital potentiometer can be calculated.

The first digital potentiometer and the second digital potentiometer can perform parameter adjustment on a feedback network of the chaotic system, the first feedback network feeds a signal at an output end of the chaotic system back to an input end, the second feedback network performs cubic operation on the signal at the output end of the chaotic system and then feeds the signal to the input end, two paths of output signals and an input signal pass through a summation integration unit to obtain an output signal, coefficients of the two feedback networks can be adjusted in real time according to a test scene, and a parameter adjusting and measuring module adjusts a feedback network coefficient and a feedback second network parameter controlled by a parameter adjusting and controlling unit according to the detected output signal, so that the chaotic system achieves a large-period operation state from critical chaos, and extracts signal frequency information at the moment.

The input signal is preprocessed through a low-pass filtering and amplifying circuit; the sensitivity to the initial condition is a basic characteristic of chaotic motion, the system characteristic is changed by adjusting system parameters, namely a feedback coefficient and a feedback coefficient, the Lyapunov exponent can be used for measuring the sensitivity, the maximum Lyapunov exponent represents the maximum characteristic index value, the number of the measurement system dimension is equal to that of the Lyapunov exponent, and the maximum Lyapunov characteristic index is larger than zero under the sufficient condition that the system is in a chaotic state. The critical value of the chaotic motion can be determined by measuring the periodic state of the system, the maximum lyapunov characteristic index is smaller than zero at the moment, and the maximum lyapunov characteristic index is larger than zero when the system is in the chaotic state, so that the critical value of the measuring system can be found according to the characteristic. The chaotic system is a nonlinear system, the periodic variation characteristic of the system can be fundamentally changed when the parameters of the chaotic system are changed within a certain disturbance range, when a weak signal is detected by adopting a nonlinear oscillator, namely, the detected signal and the nonlinear oscillator are in a critical state between chaotic solution and periodic solution, when a target signal appears, the state of the system is converted, and whether a signal with specific frequency exists or not can still be clearly detected under strong background noise.

As shown in fig. 3, the control process includes: adjusting the coefficient and judging the Lyapunov exponent, wherein the Lyapunov exponent is a quantity of average convergence or average divergence of similar orbits in a phase space, the maximum Lyapunov exponent of the Lyapunov attractor is positive, and the larger the maximum exponent is, the stronger the chaos of the system is. The Lyapunov exponent can be solved or estimated according to a kinetic equation of the chaotic system, is taken as an important basis for whether the system is chaotic or not and is applied to signal detection, and whether the chaotic system is in a chaotic state or a stable periodic motion state is automatically judged through system identification. It is also detected whether the input signal contains a periodic signal and the frequency of the periodic signal is measured.

The method overcomes the defect that the traditional signal analysis method weakens the target signal while removing noise to a certain extent, and improves the signal-to-noise ratio in the signal detection process of the system. The signal-to-noise ratio of detection is improved by the characteristic that the output variance of the system is maximum when the signal frequency of the chaotic system is related to the period driving force, and the reliability and the accuracy of detection are improved.

The mathematical model of the chaotic system adopted by the signal detection can be described by the following equation:

wherein x is the system output function, fsin ω t is the input signal to be detected, ξ (t) is the additive white noise signal, d is the system damping, ω is the input signal to be detected, f is the additive white noise signal, f is the input signal to be detected, f is the system damping, f is the input signal to be detected, f is the system damping, f is the input signal to be detected, f is the input signal to be detected, f is the input to be detected, f is the system damping, f is the input to be detected, f is the input function of the system damping, f is the system damping, f is the input function, f is the input function of the system damping, f is the system damping, f is the system damping, f is the input function, f is the system damping, f is the input to be detected, f is the input function, f is the system damping, f is the input function of the system₀Beta is the system gain parameter for the system resonant frequency. The following equation can be obtained by mathematical transformation:

where ξ (t) is white Gaussian noise with an intensity of D,as a function of the system potential. In the system, a synergistic effect is generated among a weak periodic signal, noise and the system, and a part of noise energy is transferred to ordered signal energy, so that a system output signal can move between two potential wells of the system, and the amplitude of the weak periodic signal is enhanced after passing through the system because the amplitude of vibration, namely the horizontal distance between a system steady-state point and a potential barrier, is far greater than the amplitude of the input periodic signal, and the spectral density of the dynamic system is as follows:

wherein S is the system output spectral density, omega is the system signal change angular frequency, delta (omega) is the pulse function, and in the expression, the coefficientWhen the conditions generated by the frequency following effect and the amplitude enhancement effect are simultaneously satisfied, the vibration frequency of the output signal of the chaotic system is the same as the frequency of the input periodic signal. The spectral characteristics of signals and noise in the chaotic system are respectively expressed as:

signal:noise:

wherein S is_SAs a function of the frequency spectrum of the signal, S_nAs a function of the noise spectrum, ω₀When external driving signals and noise exist simultaneously, periodic variation is introduced to the potential of the system by the signals to inhibit noise energy in the output state of the system, and the periodic component of the output of the system is enhanced by the synergistic effect of the signals and the noise under the condition of the nonlinear chaotic system, so that the signal-to-noise ratio of the output is improved. If the external driving signal plus noise does not meet the static triggering condition of the system, the height of the potential barrier can be changed by adjusting the structural parameters of the system, so that the energy of the mixed signal input by the system can cross the potential barrier to generate a random resonance phenomenon, and the signal-to-noise ratio is as follows:

wherein h is₊Is the height of the system barrier, where f is the signal frequency to be extracted and D is the noise intensity. In order to ensure the sensitivity of the system to weak signals with various frequencies, the system adopts frequency variable scale adjustment and adjusts the module structure parameters according to different frequency signals, thereby realizing frequency sweep detection of variable frequency signals and acquiring frequency characteristic information of the detected signals.

The technical indexes of the main modules of the weak signal tracking and frequency sweeping circuit based on the chaos theory are as follows: 1. the frequency detection range of the input signal is 1-200 MHz; 2. inputting the amplitude detection sensitivity of a sinusoidal signal to be 1 nanovolt; 3. the data sampling rate of the digital-to-analog converter reaches 0.5 GS/s; 4. the data synchronous storage module: the capacity of the memory of the large-capacity memory chip reaches 1GB, and the working voltage is 1.5V.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.