Signal enhancement method and device for terahertz pulse based on time domain reflection technology

Abstract

The present invention provides a signal enhancement method and device for terahertz pulses based on time domain reflection technology, which can be applied to the field of signal processing technology. The signal enhancement method comprises: when a probe is equipped with a circuit sample, a terahertz pulse signal is emitted to the circuit sample by the probe to obtain a reflection signal of the circuit sample; correlation calculation is performed on the reflection signal and the background signal to obtain a correlation value sequence, wherein the background signal is obtained when the probe is unloaded; envelope calculation is performed on the correlation value sequence to obtain the envelope of the correlation value sequence; and integration operation is performed on the envelope to obtain an enhanced terahertz pulse signal.

Description

Technical Field

[0001] The present invention relates to the technical field of signal processing, and more specifically to a method and device for enhancing a terahertz pulse signal based on a time domain reflection technology. Background Art

[0002] In the production process of integrated circuits, the various process flows are complicated, and slight changes in the materials used, production environment and other factors may cause faults and defects. Common defect detection technologies currently have various shortcomings, including the inability to locate the fault location, structural damage, and difficulty in distinguishing complex packaging and high-density wiring. Therefore, packaged integrated circuit defect detection technology with high resolution and accurate positioning is needed.

[0003] The principle of time domain reflection technology is to inject a pulse signal into the component to be tested. The pulse signal will propagate along the internal wire. When encountering impedance changes, part of the pulse signal will be reflected back to the transmitting end. According to the time difference between the transmitted and reflected pulse signals and the propagation speed of the pulse, the exact location of the defect point in the integrated circuit can be calculated. The detection accuracy of time domain reflection technology is mainly determined by the rising edge time and jitter of the pulse signal. For example, the shorter the rising edge time and the smaller the jitter, the higher the detection accuracy. The signal jitter of a general time domain reflectometer is usually greater than 1ps, and the rising edge time is generally greater than 30ps. The resolution is only in the millimeter level, which makes it difficult to achieve high-resolution positioning of integrated circuits. The terahertz pulse width is in the picosecond level, with the advantages of short rising edge time and small signal jitter. Summary of the invention

[0004] In view of the above problems, the present invention provides a signal enhancement method and device for terahertz pulses based on time domain reflection technology, which can improve the fault detection accuracy.

[0005] According to a first aspect of the present invention, a signal enhancement method for terahertz pulses based on time domain reflection technology is provided, comprising: in the case where a probe is equipped with a circuit sample, transmitting a terahertz pulse signal to the circuit sample through the probe to obtain a reflection signal of the circuit sample; performing correlation calculation on the reflection signal and a background signal to obtain a correlation value sequence, wherein the background signal is obtained when the probe is in an unloaded state; performing envelope calculation on the correlation value sequence to obtain an envelope of the correlation value sequence; and performing integration operation on the envelope to obtain an enhanced terahertz pulse signal.

[0006] According to an embodiment of the present invention, the above-mentioned performing correlation calculation on the above-mentioned reflected signal and the background signal to obtain the correlation value sequence includes: intercepting a reference signal from the above-mentioned background signal according to the signal fluctuation comparison result between the above-mentioned reflected signal and the above-mentioned background signal; performing correlation calculation on the above-mentioned reference signal and the above-mentioned reflected signal to obtain the above-mentioned correlation value sequence.

[0007] According to an embodiment of the present invention, the above-mentioned correlation calculation is performed based on the above-mentioned reference signal and the above-mentioned reflected signal to obtain the above-mentioned correlation value sequence, which includes: taking the length of the above-mentioned reference signal as the window width, and utilizing a sliding window to determine a plurality of sub-signals from the above-mentioned reflected signal; and performing correlation calculation on the plurality of the above-mentioned sub-signals and the above-mentioned reference signal respectively to obtain the above-mentioned correlation value sequence.

[0008] According to an embodiment of the present invention, the above-mentioned envelope calculation of the above-mentioned correlation value sequence to obtain the envelope of the above-mentioned correlation value sequence includes: performing envelope calculation on the above-mentioned correlation value sequence to obtain an upper envelope and a lower envelope; when it is determined that the absolute value of the i-th point of the above-mentioned upper envelope is greater than the absolute value of the i-th point of the above-mentioned lower envelope, the value of the i-th point of the above-mentioned upper envelope is stored at the i-th point position of the above-mentioned envelope; and when it is determined that the absolute value of the i-th point of the above-mentioned upper envelope is less than or equal to the absolute value of the i-th point of the above-mentioned lower envelope, the value of the i-th point of the above-mentioned lower envelope is stored at the i-th point position of the above-mentioned envelope, wherein i is equal to a positive integer.

[0009] According to an embodiment of the present invention, performing an integration operation on the envelope to obtain the enhanced terahertz pulse signal includes: performing a definite integral operation on the envelope to obtain the enhanced terahertz pulse signal.

[0010] The second aspect of the present invention provides a signal enhancement device for terahertz pulses based on time domain reflection technology, and the device includes: an acquisition module, which is used to transmit a terahertz signal to the circuit sample through a probe when the probe is equipped with a circuit sample, so as to obtain a reflection signal of the circuit sample; a correlation analysis module, which is used to perform correlation calculation on the reflection signal and the background signal to obtain a correlation value sequence; an envelope analysis module, which is used to perform envelope calculation on the correlation value sequence to obtain the envelope of the correlation value sequence; and a definite integral calculation module, which is used to perform integration operation on the envelope to obtain an enhanced terahertz pulse signal.

[0011] According to an embodiment of the present invention, the above-mentioned correlation analysis module includes: an interception submodule, used to intercept a reference signal from the above-mentioned background signal based on the signal fluctuation comparison result between the above-mentioned reflection signal and the above-mentioned background signal; and a correlation calculation submodule, used to perform correlation calculation based on the above-mentioned reference signal and the above-mentioned reflection signal to obtain the above-mentioned correlation value sequence.

[0012] According to an embodiment of the present invention, the above-mentioned correlation calculation submodule includes: a determination unit, used to use the length of the above-mentioned reference signal as the window width, and use a sliding window to determine multiple sub-signals from the above-mentioned reflected signal; and a correlation calculation unit, used to perform correlation calculation on the multiple sub-signals and the above-mentioned reference signal respectively to obtain the above-mentioned correlation value sequence.

[0013] According to an embodiment of the present invention, the above-mentioned envelope analysis module includes: an envelope calculation submodule, which is used to perform envelope calculation on the above-mentioned correlation value sequence to obtain an upper envelope and a lower envelope; a first judgment submodule, which is used to store the value of the i-th point of the above-mentioned upper envelope at the i-th point position of the above-mentioned envelope when it is determined that the absolute value of the i-th point of the above-mentioned upper envelope is greater than the absolute value of the i-th point of the above-mentioned lower envelope; and a second judgment submodule, which is used to store the value of the i-th point of the above-mentioned lower envelope at the i-th point position of the above-mentioned envelope when it is determined that the absolute value of the i-th point of the above-mentioned upper envelope is less than or equal to the absolute value of the i-th point of the above-mentioned lower envelope, wherein i is equal to a positive integer.

[0014] According to an embodiment of the present invention, the definite integral calculation module includes: a definite integral calculation submodule, which is used to perform a definite integral operation on the envelope to obtain the enhanced terahertz pulse signal.

[0015] According to an embodiment of the present invention, by calculating the correlation between the background signal and the reflected signal, the approximate location information of the fault location point in the circuit sample can be obtained. By performing envelope calculation on the correlation value sequence, an envelope line can be obtained to remove the interference noise that is closer to the reflected signal. By performing an integral operation on the envelope line, the terahertz pulse signal in the reflected signal is enhanced. The signal enhancement method of the terahertz pulse based on the time domain reflection technology of the embodiment of the present invention improves the detection accuracy of the fault detection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above contents and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0017] Figure 1 A diagram showing an application scenario of a method for signal enhancement of terahertz pulses based on time domain reflection technology according to an embodiment of the present invention is shown.

[0018] Figure 2 A flow chart of a method for signal enhancement of terahertz pulses based on time domain reflection technology according to an embodiment of the present invention is shown.

[0019] Figure 3A schematic diagram showing a background signal of a method for signal enhancement of terahertz pulses based on time domain reflection technology according to an embodiment of the present invention is shown.

[0020] Figure 4 A schematic diagram of a reflected signal of a terahertz pulse signal enhancement method based on time domain reflection technology according to an embodiment of the present invention is shown.

[0021] Figure 5 A schematic diagram of a reference signal of a terahertz pulse signal enhancement method based on time domain reflection technology according to an embodiment of the present invention is shown.

[0022] Figure 6 A schematic diagram showing a correlation value sequence of a signal enhancement method for terahertz pulses based on time domain reflection technology according to an embodiment of the present invention is shown.

[0023] Figure 7 A schematic diagram showing an envelope of a signal enhancement method for terahertz pulses based on time domain reflection technology according to an embodiment of the present invention is shown.

[0024] Figure 8 A schematic diagram of a definite integral curve of a signal enhancement method for terahertz pulses based on time domain reflection technology according to an embodiment of the present invention is shown.

[0025] Fig. 9 A structural block diagram of a terahertz pulse signal enhancement device based on time domain reflection technology according to an embodiment of the present invention is shown.

[0026] Fig.10 A block diagram of an electronic device suitable for implementing a signal enhancement method for terahertz pulses based on time domain reflection technology according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0027] Below, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of concepts of the present invention.

[0028] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0029] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0030] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0031] In the related art, a fault detection system based on time-domain reflection of terahertz pulses can emit a terahertz pulse signal to the component to be tested through a probe, and the terahertz pulse signal returns to the probe after detecting the component to be tested. When there is no fault in the wire of the component to be tested, the waveform of the terahertz pulse signal returning to the probe is consistent with the waveform of the terahertz pulse signal emitted by the probe. When there is a fault in the wire, the terahertz pulse signal will be reflected at the fault site, so the waveform of the reflected terahertz pulse signal returning to the probe is different from that of the terahertz pulse signal emitted by the probe. However, since the signal-to-noise ratio of the collected time-domain reflection signal is relatively low, it is difficult to directly determine the positive and negative and position of the reflected terahertz pulse signal based on the original reflection signal.

[0032] The application of terahertz pulses in defect detection of integrated circuits can achieve high-precision defect location detection. Although the fault detection system based on time domain reflection of terahertz pulses has many outstanding advantages over other systems, when the fault detection system based on time domain reflection of terahertz pulses is actually used to detect the fault defects of the components to be tested, the real reflected terahertz pulse signal is submerged in the noise due to the large noise fluctuations of the system itself, as well as the nonlinear aliasing of various interference noises such as changes in temperature and humidity, air flow, and working voltage jitter in the actual application environment. Therefore, the use of terahertz pulses for direct detection has the problem of difficulty in resolving reflected signals and low detection accuracy.

[0033] Therefore, a method for signal enhancement of terahertz pulses is urgently needed.

[0034] An embodiment of the present invention provides a signal enhancement method and device for terahertz pulses based on time domain reflection technology. The signal enhancement method includes: when a probe is equipped with a circuit sample, a terahertz pulse signal is emitted to the circuit sample by the probe to obtain a reflection signal of the circuit sample; correlation calculation is performed on the reflection signal and a background signal to obtain a correlation value sequence, wherein the background signal is obtained when the probe is in an unloaded state; envelope calculation is performed on the correlation value sequence to obtain an envelope curve of the correlation value sequence; and integration operation is performed on the envelope curve to obtain an enhanced terahertz pulse signal.

[0035] Figure 1 A diagram showing an application scenario of a method for signal enhancement of terahertz pulses based on time domain reflection technology according to an embodiment of the present invention is shown.

[0036] like Figure 1 As shown, the application scenario 100 according to this embodiment may include a circuit sample 101, a probe 102, a signal generating device 103, a network 104, and a server 105. The network 104 is used to provide a medium for a communication link between the probe 102 and the server 105. The network 104 may include various connection types, such as wired, wireless communication links or optical fiber cables, etc.

[0037] The signal generator 103 generates a terahertz pulse signal, which is transmitted to the circuit sample 101 through the probe 102. The terahertz pulse signal returns to the probe 102 after detecting the circuit sample. The probe 102 interacts with the server 105 through the network 104.

[0038] The server 105 may be a server that provides various services and may perform analysis and other processing on the received data.

[0039] It should be noted that the terahertz pulse signal enhancement method based on time domain reflection technology provided in the embodiment of the present invention can generally be executed by the server 105. Accordingly, the terahertz pulse signal enhancement device based on time domain reflection technology provided in the embodiment of the present invention can generally be set in the server 105.

[0040] The following will be based on Figure 1 The described scenario is described in detail by illustrating the signal enhancement method of terahertz pulse based on time domain reflection technology in an embodiment of the present invention.

[0041] Figure 2 A flow chart of a method for signal enhancement of terahertz pulses based on time domain reflection technology according to an embodiment of the present invention is shown.

[0042] like Figure 2 As shown, the signal enhancement method of terahertz pulse based on time domain reflection technology of this embodiment includes operation S210 to operation S240.

[0043] In operation S210 , when the probe carries the circuit sample, a terahertz pulse signal is emitted to the circuit sample through the probe to obtain a reflection signal of the circuit sample.

[0044] According to an embodiment of the present invention, the probe can be a waveguide probe or a coaxial probe. It is used to transmit and receive terahertz pulse signals and has strong directionality. It can transmit terahertz pulse signals from the waveguide to the circuit sample, or from the circuit sample to the waveguide. The probe can also be a photoconductive probe, which directly uses the principle of terahertz photoconductive antenna for measurement.

[0045] According to an embodiment of the present invention, the circuit sample includes an integrated circuit. The integrated circuit may have defects during the manufacturing process, such as design defects, material defects, process defects, packaging defects, etc., which may cause the integrated circuit to fail to work properly. Factors that cause the integrated circuit to fail during use may also include voltage fluctuations, open circuits, short circuits, overheating, physical damage, aging, etc. caused by long-term operation. The circuit sample may also be an electronic component, or an electronic assembly, or a multi-layer packaged chip.

[0046] According to an embodiment of the present invention, the terahertz pulse signal is an electromagnetic wave in the range of 0.1THz to 10THz, with a wavelength between microwaves and infrared light. The terahertz pulse signal has high transmission and coherence.

[0047] According to an embodiment of the present invention, the reflection signal is a signal generated by a fault in a circuit sample and detected by a probe. The reflection signal is a mixed signal of a reflected terahertz pulse signal and system noise with an irregular waveform.

[0048] In operation S220, correlation calculation is performed between the reflection signal and the background signal to obtain a correlation value sequence.

[0049] According to an embodiment of the present invention, correlation calculation is used to reveal the intrinsic connection and regularity of signals by evaluating the similarity or correlation between two signals in the time dimension, and is applicable to non-periodic signals and non-stationary signals.

[0050] According to an embodiment of the present invention, the correlation calculation method includes a Pearson correlation coefficient calculation method, which is used to measure the linear relationship strength between two sequences. The correlation calculation method also includes a Spearman rank correlation coefficient calculation method, which is based on the rank of the variable rather than the actual value. The correlation calculation method also includes a dynamic time warping correlation coefficient calculation method, which is used to measure the similarity of two time series.

[0051] In operation S230, envelope calculation is performed on the correlation value sequence to obtain an envelope curve of the correlation value sequence.

[0052] According to an embodiment of the present invention, envelope calculation means determining the envelope of a signal, that is, the upper and lower bounds of the high-frequency oscillation part of the signal, for extracting the amplitude change trend of the signal. The envelope calculation method includes the Hilbert transform method, which obtains the envelope and phase information of the signal by analyzing the signal. The envelope calculation method also includes the wavelet transform method, which can more flexibly extract the envelope of the signal by analyzing the signal at different scales. The envelope calculation method also includes the peak envelope method, which determines the envelope by performing spline interpolation on the local maximum value of the signal.

[0053] In operation S240, an integration operation is performed on the envelope to obtain an enhanced terahertz pulse signal.

[0054] According to an embodiment of the present invention, the background signal is obtained when the probe is in an empty state.

[0055] According to an embodiment of the present invention, by calculating the correlation between the background signal and the reflected signal, the approximate location information of the fault location point in the circuit sample can be obtained. By performing envelope calculation on the correlation value sequence, an envelope curve can be obtained to remove the interference noise that is closer to the reflected signal. By performing an integral operation on the envelope curve, the terahertz pulse signal in the reflected signal is enhanced, thereby improving the fault detection accuracy of the fault detection system based on the time domain reflection of the terahertz pulse.

[0056] Figure 3 A schematic diagram showing a background signal of a terahertz pulse signal enhancement method based on time domain reflection technology according to an embodiment of the present invention is shown.

[0057] like Figure 3 As shown, the background signal obtained can be represented by S0 (x0, y0). x0 represents the horizontal axis coordinate of the background signal, representing the time, and the unit is ps (picoseconds), and y0 represents the vertical axis coordinate of the background signal, representing the amplitude of the background signal.

[0058] In one example, x0 can represent any moment on the horizontal axis, and correspondingly, y0 can represent the amplitude of the background signal corresponding to the time point. The time interval between adjacent horizontal axis coordinate points can be 0.0467 picoseconds. In a sampling interval with a time length of 900ps, there can be tens of thousands of sampling points to identify the fault location with an accuracy of less than 15 microns. The time interval can be adjusted. For example, the time interval can also be 0.0133 picoseconds to identify the fault location with an accuracy of less than 5 microns.

[0059] Figure 4 A schematic diagram of a reflected signal of a terahertz pulse signal enhancement method based on time domain reflection technology according to an embodiment of the present invention is shown.

[0060] like Figure 4 As shown, the acquired reflection signal can be represented by S1 (x1, y1). x1 represents the horizontal axis coordinate of the reflection signal, representing the time, and the unit is ps, and y1 represents the vertical axis coordinate of the reflection signal, representing the amplitude of the reflection signal.

[0061] According to an embodiment of the present invention, a reference signal is intercepted from the background signal according to a comparison result of signal fluctuations between the reflection signal and the background signal, and a correlation calculation is performed according to the reference signal and the reflection signal to obtain a correlation value sequence.

[0062] In one example, if Figure 3 and Figure 4 As shown, in the range of 45ps to 65ps, the signal fluctuation of the reflection signal is stronger than that of the background signal.

[0063] According to an embodiment of the present invention, based on the comparison result of the signal fluctuation between the reflected signal and the background signal, the interval corresponding to the fault location area in the background signal can be obtained. The background signal in this interval is intercepted and used as a reference signal. The reference signal and the reflected signal are correlated to obtain the interval in the reflected signal with the maximum correlation with the reference signal.

[0064] According to an embodiment of the present invention, the length of the reference signal is used as the window width, and a sliding window is used to determine multiple sub-signals from the reflected signal. Correlation calculations are performed on the multiple sub-signals and the reference signal to obtain a correlation value sequence.

[0065] Figure 5 A schematic diagram of a reference signal of a terahertz pulse signal enhancement method based on time domain reflection technology according to an embodiment of the present invention is shown.

[0066] In one example, the reference signal can be represented by P0, the starting time point of the reference signal interval can be represented by t1, and the ending time point can be represented by t2. The length of the reference signal interval is used as the window width, and the window width can be represented by =t2-t1. Using a sliding window, the window width is , the step length is 1 time point, and multiple lengths are determined from the reflected signal The kth sub-signal can be expressed as P(k).

[0067] In one example, if Figure 5 As shown, the starting time point t1=45, the ending time point t2=65, and the time window width =20.

[0068] In an example, correlation calculations are performed on the plurality of sub-signals P(k) and the reference signal P0 to obtain a correlation value sequence, and the correlation value sequence can be expressed as R(k).

[0069] Figure 6 A schematic diagram showing a correlation value sequence of a signal enhancement method for terahertz pulses based on time domain reflection technology according to an embodiment of the present invention is shown.

[0070] In one example, if Figure 6 As shown, the horizontal axis of the correlation value sequence R(k) represents the time point, and the vertical axis represents the correlation value. In the range of 800ps to 1000ps, the relatively high correlation values ​​are relatively dense, and the time point corresponding to the fault location can be roughly obtained.

[0071] According to the embodiment of the present invention, by analyzing the correlation between the reflected signal and the reference signal, the reflected terahertz pulse signal becomes obvious, so as to identify the location of the wire fault.

[0072] According to an embodiment of the present invention, an envelope calculation is performed on a correlation value sequence to obtain an upper envelope and a lower envelope. When it is determined that the absolute value of the i-th point of the upper envelope is greater than the absolute value of the i-th point of the lower envelope, the value of the i-th point of the upper envelope is stored at the i-th point position of the envelope. When it is determined that the absolute value of the i-th point of the upper envelope is less than or equal to the absolute value of the i-th point of the lower envelope, the value of the i-th point of the lower envelope is stored at the i-th point position of the envelope, where i is equal to a positive integer.

[0073] In one example, an envelope calculation is performed on a correlation value sequence R(k), where i=k. The value of the upper envelope obtained can be represented by up(i), the value of the lower envelope obtained can be represented by low(i), and the value of the final envelope obtained can be represented by even(i). The value of the upper envelope corresponding to each time point is compared with the value of the lower envelope. For example, if i=10, when the absolute value of the upper envelope value up(10) is greater than the absolute value of the lower envelope value low(10), the value of up(10) is stored in even(10). For example, if i=50, when the absolute value of the upper envelope value up(50) is less than the absolute value of the lower envelope value low(50), the value of low(50) is stored in even(50).

[0074] Figure 7 A schematic diagram showing an envelope of a signal enhancement method for terahertz pulses based on time domain reflection technology according to an embodiment of the present invention is shown.

[0075] like Figure 7 As shown, Figure 6In comparison, through envelope calculation, most of the noise is removed, leaving only the reflected THz pulse signal with fault information.

[0076] According to the embodiment of the present invention, the noise in the signal can be effectively removed through envelope calculation.

[0077] According to an embodiment of the present invention, a definite integral operation is performed on the envelope to obtain an enhanced terahertz pulse signal. In one example, the time window width is = 20, set the starting point of the integration time to x(j), and use the sliding window to calculate the envelope even(j) in the time window x(j) to x(j+ ) to obtain the definite integral curve. The definite integral curve can be represented by R(j), where j is a positive integer.

[0078] Figure 8 A schematic diagram of a definite integral curve of a signal enhancement method for terahertz pulses based on time domain reflection technology according to an embodiment of the present invention is shown.

[0079] right Figure 7 After performing definite integral operation on the envelope in, we get Figure 8 The definite integral curve in . Figure 8 The definite integral curve in can characterize the enhanced terahertz pulse signal. Figure 8 It can be seen that the terahertz pulse signal in the reflected signal has been enhanced and the characteristics are more obvious.

[0080] According to an embodiment of the present invention, the integral operation refers to enhancing the characteristics of the signal through an integral operation, and the purpose of accumulation is achieved by obtaining the definite integral of the envelope within a specific interval, thereby achieving the effect of enhancing the signal characteristics.

[0081] The signal enhancement method of terahertz pulse based on time domain reflection technology in the embodiment of the present invention can be applied to a circuit fault detection system, and can also be applied to a fault detection system based on time domain reflection of terahertz pulse, for processing signal enhancement of fault detection of one or more circuit samples. The signal enhancement method of terahertz pulse based on time domain reflection technology in the embodiment of the present invention obtains two reflection signals according to whether a circuit sample has a fault, and the fault location and fault type of the circuit sample can be determined based on the enhanced terahertz pulse signal of the two reflection signals.

[0082] According to an embodiment of the present invention, by calculating the correlation between the background signal and the reflected signal, the approximate location information of the fault location point in the circuit sample can be obtained. By performing envelope calculation on the correlation value sequence, an envelope line can be obtained to remove the interference noise that is relatively close to the reflected signal. By integrating the envelope line, the signal enhancement of the reflected terahertz pulse at the fault location point in the circuit sample is achieved, and the fault detection accuracy of the fault detection system based on the time domain reflection of the terahertz pulse is improved. The signal enhancement method of the terahertz pulse based on the time domain reflection technology of the embodiment of the present invention improves the signal-to-noise ratio, improves the fault detection accuracy, and solves the problem of strong noise interference and weak reflection signal faced by the fault detection system based on the time domain reflection of the terahertz pulse when diagnosing internal faults of the integrated circuit.

[0083] Based on the above-mentioned terahertz pulse signal enhancement method based on time domain reflection technology, the present invention also provides a terahertz pulse signal enhancement device based on time domain reflection technology. Fig. 9 The device is described in detail.

[0084] Fig. 9 A structural block diagram of a terahertz pulse signal enhancement device based on time domain reflection technology according to an embodiment of the present invention is shown.

[0085] like Fig. 9 As shown, the terahertz pulse signal enhancement device 900 based on the time domain reflection technology of this embodiment includes an acquisition module 910, a correlation analysis module 920, an envelope analysis module 930 and a definite integral calculation module 940.

[0086] The acquisition module 910 is used to transmit a terahertz pulse signal to the circuit sample through the probe when the probe carries the circuit sample, and acquire a reflection signal of the circuit sample. In one embodiment, the acquisition module 910 can be used to perform the operation S210 described above, which will not be repeated here.

[0087] The correlation analysis module 920 is used to perform correlation calculation on the reflection signal and the background signal to obtain a correlation value sequence. In one embodiment, the correlation analysis module 920 can be used to perform the operation S220 described above, which will not be described in detail here.

[0088] The envelope analysis module 930 is used to perform envelope calculation on the correlation value sequence to obtain the envelope of the correlation value sequence. In one embodiment, the envelope analysis module 930 can be used to perform the operation S230 described above, which will not be described in detail here.

[0089] The definite integral calculation module 940 is used to perform an integral operation on the envelope to obtain an enhanced terahertz pulse signal. In one embodiment, the definite integral calculation module 940 can be used to perform the operation S240 described above, which will not be described in detail here.

[0090] According to an embodiment of the present invention, the correlation analysis module 920 includes a truncation submodule and a correlation calculation submodule.

[0091] The interception submodule is used to intercept the reference signal from the background signal according to the signal fluctuation comparison result between the reflection signal and the background signal.

[0092] The correlation calculation submodule is used to perform correlation calculation based on the reference signal and the reflected signal to obtain a correlation value sequence.

[0093] According to an embodiment of the present invention, the correlation calculation submodule includes a determination unit and a correlation calculation unit.

[0094] The determination unit is used to determine a plurality of sub-signals from the reflected signal by using a sliding window with the length of the reference signal as the window width.

[0095] The correlation calculation unit is used to perform correlation calculation on the multiple sub-signals and the reference signal respectively to obtain a correlation value sequence.

[0096] According to an embodiment of the present invention, the envelope analysis module 930 includes an envelope calculation submodule, a first judgment submodule and a second judgment submodule.

[0097] The envelope calculation submodule is used to perform envelope calculation on the correlation value sequence to obtain an upper envelope line and a lower envelope line.

[0098] The first judgment submodule is used to store the value of the i-th point of the upper envelope at the i-th point position of the envelope when it is determined that the absolute value of the i-th point of the upper envelope is greater than the absolute value of the i-th point of the lower envelope.

[0099] The second judgment submodule is used to store the value of the i-th point of the lower envelope at the i-th point position of the envelope when it is determined that the absolute value of the i-th point of the upper envelope is less than or equal to the absolute value of the i-th point of the lower envelope, where i is equal to a positive integer.

[0100] According to an embodiment of the present invention, the definite integral calculation module 940 includes a definite integral calculation submodule.

[0101] The definite integral calculation submodule is used to perform definite integral operation on the envelope to obtain an enhanced terahertz pulse signal.

[0102] According to an embodiment of the present invention, any multiple modules among the acquisition module 910, the correlation analysis module 920, the envelope analysis module 930 and the definite integral calculation module 940 can be combined into one module for implementation, or any one of the modules can be split into multiple modules. Alternatively, at least part of the functions of one or more of these modules can be combined with at least part of the functions of other modules and implemented in one module. According to an embodiment of the present invention, at least one of the acquisition module 910, the correlation analysis module 920, the envelope analysis module 930 and the definite integral calculation module 940 can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application specific integrated circuit (ASIC), or can be implemented by hardware or firmware such as any other reasonable way of integrating or packaging the circuit, or implemented in any one of the three implementation methods of software, hardware and firmware or in a suitable combination of any of them. Alternatively, at least one of the acquisition module 910, the correlation analysis module 920, the envelope analysis module 930 and the definite integral calculation module 940 may be at least partially implemented as a computer program module, and when the computer program module is executed, the corresponding function may be executed.

[0103] Fig.10 A block diagram of an electronic device suitable for implementing a signal enhancement method for terahertz pulses based on time domain reflection technology according to an embodiment of the present invention is shown.

[0104] like Fig.10 As shown, the electronic device 1000 according to an embodiment of the present invention includes a processor 1001, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 1002 or a program loaded from a storage part 1008 into a random access memory (RAM) 1003. The processor 1001 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or a related chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 1001 may also include an onboard memory for caching purposes. The processor 1001 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present invention.

[0105] In RAM 1003, various programs and data required for the operation of electronic device 1000 are stored. Processor 1001, ROM 1002 and RAM 1003 are connected to each other via bus 1004. Processor 1001 performs various operations of the method flow according to the embodiment of the present invention by executing the program in ROM 1002 and / or RAM 1003. It should be noted that the program can also be stored in one or more memories other than ROM 1002 and RAM 1003. Processor 1001 can also perform various operations of the method flow according to the embodiment of the present invention by executing the program stored in the one or more memories.

[0106] According to an embodiment of the present invention, the electronic device 1000 may further include an input / output (I / O) interface 1005, which is also connected to the bus 1004. The electronic device 1000 may further include one or more of the following components connected to the input / output (I / O) interface 1005: an input portion 1006 including a keyboard, a mouse, etc.; an output portion 1007 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage portion 1008 including a hard disk, etc.; and a communication portion 1009 including a network interface card such as a LAN card, a modem, etc. The communication portion 1009 performs communication processing via a network such as the Internet. A drive 1010 is also connected to the input / output (I / O) interface 1005 as needed. A removable medium 1011, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 1010 as needed, so that a computer program read therefrom is installed into the storage portion 1008 as needed.

[0107] The present invention also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiment; or may exist independently without being assembled into the device / apparatus / system. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed, the method according to the embodiment of the present invention is implemented.

[0108] According to an embodiment of the present invention, the computer-readable storage medium may be a non-volatile computer-readable storage medium, for example, it may include but is not limited to: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present invention, the computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, an apparatus or a device. For example, according to an embodiment of the present invention, the computer-readable storage medium may include the ROM 1002 and / or RAM 1003 described above and / or one or more memories other than ROM 1002 and RAM 1003.

[0109] The embodiment of the present invention also includes a computer program product, which includes a computer program, and the computer program contains program code for executing the method shown in the flowchart. When the computer program product is run in a computer system, the program code is used to enable the computer system to implement the signal enhancement method of terahertz pulses based on time domain reflection technology provided by the embodiment of the present invention.

[0110] The computer program executes the above functions defined in the system / device of the embodiment of the present invention when it is executed by the processor 1001. According to the embodiment of the present invention, the system, device, module, unit, etc. described above can be implemented by a computer program module.

[0111] In one embodiment, the computer program may rely on tangible storage media such as optical storage devices, magnetic storage devices, etc. In another embodiment, the computer program may also be transmitted and distributed in the form of signals on a network medium, and downloaded and installed through the communication part 1009, and / or installed from the removable medium 1011. The program code contained in the computer program may be transmitted using any appropriate network medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0112] In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 1009, and / or installed from the removable medium 1011. When the computer program is executed by the processor 1001, the above functions defined in the system of the embodiment of the present invention are performed. According to the embodiment of the present invention, the system, device, means, module, unit, etc. described above can be implemented by a computer program module.

[0113] According to an embodiment of the present invention, the program code for executing the computer program provided by the embodiment of the present invention can be written in any combination of one or more programming languages. Specifically, these computing programs can be implemented using high-level process and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, Java, C++, python, "C" language or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on the remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., using an Internet service provider to connect through the Internet).

[0114] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present invention. In this regard, each box in the flow chart or block diagram can represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flow chart, and the combination of the boxes in the block diagram or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0115] It will be appreciated by those skilled in the art that the features described in the various embodiments of the present invention may be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, without departing from the spirit and teachings of the present invention, the features described in the various embodiments of the present invention may be combined and / or combined in various ways. All of these combinations and / or combinations fall within the scope of the present invention.

[0116] The embodiments of the present invention are described above. However, these embodiments are only for the purpose of illustration, and are not intended to limit the scope of the present invention. Although the embodiments are described above, this does not mean that the measures in the various embodiments cannot be used in combination. The invention does not depart from the scope of the present invention, and those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A terahertz pulse signal enhancement method based on time domain reflection technology, characterized in that: The signal enhancement method comprises: When the probe carries a circuit sample, a terahertz pulse signal is emitted to the circuit sample through the probe to obtain a reflection signal of the circuit sample; Performing correlation calculation on the reflection signal and the background signal to obtain a correlation value sequence, wherein the background signal is obtained when the probe is in an empty state; The step of performing correlation calculation on the reflected signal and the background signal to obtain a correlation value sequence includes: intercepting a reference signal from the background signal according to a comparison result of signal fluctuations between the reflection signal and the background signal; and Performing correlation calculation according to the reference signal and the reflected signal to obtain the correlation value sequence; The performing correlation calculation according to the reference signal and the reflected signal to obtain the correlation value sequence includes: Using the length of the reference signal as the window width, using a sliding window to determine a plurality of sub-signals from the reflected signal; and respectively performing correlation calculations on the plurality of sub-signals and the reference signal to obtain the correlation value sequence; Performing envelope calculation on the correlation value sequence to obtain an envelope curve of the correlation value sequence; The step of performing envelope calculation on the correlation value sequence to obtain an envelope line of the correlation value sequence includes: Performing envelope calculation on the correlation value sequence to obtain an upper envelope line and a lower envelope line; When it is determined that the absolute value of the i-th point of the upper envelope is greater than the absolute value of the i-th point of the lower envelope, the value of the i-th point of the upper envelope is stored at the i-th point position of the envelope; and When it is determined that the absolute value of the i-th point of the upper envelope is less than or equal to the absolute value of the i-th point of the lower envelope, the value of the i-th point of the lower envelope is stored at the i-th point position of the envelope, wherein i is equal to a positive integer; and An integration operation is performed on the envelope to obtain an enhanced terahertz pulse signal.

2. The signal enhancement method according to claim 1, characterized in that: The step of performing an integration operation on the envelope to obtain an enhanced terahertz pulse signal comprises: A definite integral operation is performed on the envelope to obtain the enhanced terahertz pulse signal.

3. A terahertz pulse signal enhancement device based on time domain reflection technology, characterized in that: The signal enhancement device comprises: An acquisition module, used for transmitting a terahertz signal to the circuit sample through the probe when the probe carries the circuit sample, and acquiring a reflection signal of the circuit sample; A correlation analysis module, used for performing correlation calculation on the reflection signal and the background signal to obtain a correlation value sequence; Wherein, the correlation analysis module includes: an interception submodule, configured to intercept a reference signal from the background signal according to a comparison result of signal fluctuations between the reflection signal and the background signal; and A correlation calculation submodule, used to perform correlation calculation based on the reference signal and the reflected signal to obtain the correlation value sequence; Wherein, the correlation calculation submodule includes: a determining unit, configured to determine a plurality of sub-signals from the reflection signal using a sliding window, using the length of the reference signal as a window width; and A correlation calculation unit, used for respectively performing correlation calculation on the plurality of sub-signals and the reference signal to obtain the correlation value sequence; An envelope analysis module, used to perform envelope calculation on the correlation value sequence to obtain the envelope of the correlation value sequence; Wherein, the envelope analysis module includes: An envelope calculation submodule, used for performing envelope calculation on the correlation value sequence to obtain an upper envelope line and a lower envelope line; a first judgment submodule, configured to store the value of the i-th point of the upper envelope at the i-th point position of the envelope when it is determined that the absolute value of the i-th point of the upper envelope is greater than the absolute value of the i-th point of the lower envelope; and a second judgment submodule, configured to store the value of the i-th point of the lower envelope at the i-th point position of the envelope when it is determined that the absolute value of the i-th point of the upper envelope is less than or equal to the absolute value of the i-th point of the lower envelope, wherein i is equal to a positive integer; and The definite integral calculation module is used to perform an integral operation on the envelope to obtain an enhanced terahertz pulse signal.

4. The signal enhancement device according to claim 3, characterized in that: The definite integral calculation module comprises: The definite integral calculation submodule is used to perform a definite integral operation on the envelope to obtain the enhanced terahertz pulse signal.

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