University of Electronic Science and Technology of China

Hao Zeng

Lianping Guo

Jun Jiang

Qinchuan Zhang

Peng Ye

Kuojun Yang

Feng Tan

Duyu Qiu

Wuhuang Huang

Huiqing Pan

Shulin Tian

Guang Yang

Yu Li

Jia Zhao

Jian Gao

Houjun Wang

Yong Zhao

Shuhao Wu

Pan Wang

Luonan Zheng

Jinpeng Song

Chuanyun Xiang

Xianggong Guo

Shuo Wang

Xiaoman Jiao

The present invention provides a method for equivalent high sampling rate FIR filtering based on FPGA, first, the coefficients h(k) of FIR filter are found by using MATLAB, multiplied by an integer and then rounded for the purpose that the rounded coefficients h(k) can be directly used into a FPGA, then the ADC's output of high data rate fs is lowered by dividing the ADC's output x(n) into M parallel data streams xi(n) of low data rate, and the M&#xd7;L samples in one clock cycle is obtained by delaying the M parallel data streams xi(n) simultaneously by 1, 2, . . . , L' periods of the synchronous clock, at last, the samples yi(n) of FIR filtering output is calculated according to the samples selected from the M&#xd7;L samples, and the filtered data y(n) of data rate fs is obtained by putting the samples yi(n) together in ascending order of i. Thus, the continuous FIR filtering of an ADC's output sampled with high sampling rate is realized, while the data rates before and after the FIR filtering are unchanged.

Method for equivalent high sampling rate FIR filtering based on FPGA

The present invention provides a method for 3D waveform mapping of full-parallel structure, first, a 3D waveform mapping database is created according to the size of a 3D waveform image, the number of bits of probability value and the ADC's resolution of data acquisition module, then the 3D waveform mapping database is divided into M&#xd7;Mindependent mapping storage areas along the time axis and the amplitude axis, and each independent mapping storage area is assigned a RAM, then RAMs are selected and addresses are calculated based on the sampling values and the structure of created 3D waveform mapping database, finally, parallel mappings are performed simultaneously on the time axis and the amplitude axis according to the selected RAMs and calculated addresses. Thus, the mapping time are shorten, especially in vector mapping mode, several RAMs are used for mapping, so the WCR of DSO is improved.

Method for 3D waveform mapping of full-parallel structure

The present invention provides a method and apparatus for automatically adjusting the hold-off time of a DSO based on real-time cycle measurements of the system trigger signal: obtaining a cycle sequence by measuring the system trigger signal, the maximum cycle and minimum cycle, then judging the difference of the maximum cycle and minimum cycle: if the difference is greater than a threshold set by user, setting the hold-off time to the maximum cycle, the minimum cycle or the median cycle, then returning; otherwise terminating the adjustment of the hold-off time. At this point, the hold-off time is correctly set. Therefore, the present invention reduces the complexity and time consumption of the hold-off adjustment, and allows the test signal to be quickly and stably displayed on screen of DSO, meanwhile, which makes the trigger adjustment of DSO more convenient.

Method and apparatus for automatically adjusting the hold-off time of a DSO

The present invention provides a method and system for oscilloscope triggering. The power spectrum entropy threshold Gand the singular spectrum entropy threshold Gare obtained by calculating the averages of the power spectrum entropy Hand the singular spectrum entropy Eof the first a waveform data frames respectively. Then, for the waveform data frame x(&#x3c4;) and thereafter, If the power spectrum entropy His greater than power spectrum entropy threshold Gand the singular spectrum entropy Eis greater than the singular spectrum entropy threshold G, the waveform data frame x(&#x3c4;) is an abnormal signal, the second trigger occurs, storing and displaying the waveform data frame. Thus the storage and display of abnormal signal is realized.

Method and system for oscilloscope triggering

A method for oscilloscope 3D mapping in scan mode. The input signal is acquired using a real-time sampling rate which is Dtimes higher, thus more sampling points, i.e. Dacquired data can be obtained during the time interval between two consecutive horizontal pixels. The Dacquired data are mapped into a same column of the screen to implement fluorescent waveform display. In addition, to realize the scanning display, a flag X is introduced into the three-dimensional database, when the screen refresh signal arrives, the first Dacquired data are read out from the unread acquired data in FIFO memory. The three-dimensional database is updated from the flag X, which make the leftmost waveform always be the oldest waveform, the rightmost waveform always be the newest waveform. Thus the 3D mapping is realized in scan mode, letting the DSO have a fluorescent waveform display at slow time-base.

Method for oscilloscope 3D mapping in scan mode

The present invention provides a method for a method for measuring the properties of liquid based on a quartz crystal microbalance sensor, which employs two measurements to obtain two frequency shifts of the QCM sensor induced by two different volume of the sample liquid. The present invention creatively established the relationship between the density and viscosity of sample liquid and the frequency shifts of QCM sensor. With present invention, the density and viscosity of sample liquid can be obtained through two frequency shifts. Comparing to the conventional liquid property measurement. The measuring procedure of present invention are more simple, and the measuring results are more accurate. Moreover, the present invention consumes less volume of sample liquid, and has the features such as online, real time and quantitative.

Method for measuring the properties of liquid based on a quartz crystal microbalance sensor

A method for measuring waveform capture rate (WRC) of DSO based on average dead time measurement. First generating ramp signal or symmetric triangular wave signal as base signal, a trigger signal, the frequency which is higher than the nominal maximum waveform capture rate of the DSO under measurement; secondly, setting the parameters of DSO for measuring; then obtaining a plurality of test signals by delaying base signal K times with different delay time, for each test signal, inputting it the trigger signal simultaneously to DSO, calculating dead time between two adjacent captured waveforms according to their initial voltages, finally calculating waveform capture rate based on average dead times. The waveform capture rate obtained can effectively reflect the overall capturing capacity of DSO, more tellingly, the waveform capturing capacity of acquisition system of DSO.

Method for measuring the waveform capture rate of a digital storage oscilloscope based on average dead time measurement

The present invention provides a method for measuring the waveform capture rate of parallel digital storage oscilloscope. On the basis of double pulse measurement, and in consideration of the asymmetry of acquisition and the refreshing time of parallel DSO, the present invention provides a step amplitude-frequency combined pulse measurement to measure the time for waveform acquisition and mapping T, the number of captured waveforms before LCD refreshing Wand the dead time caused by LCD refreshing T, and then calculates the measured average WCR of parallel DSO, according to the measured data, so that the WCR of parallel can be measured.

Method for measuring the waveform capture rate of parallel digital storage oscilloscope

For the signal under acquisition which varies monotonically before and after the trigger time, a method for full-digital random sampling employs first sampled data before the trigger time and first sampled data after the trigger time to fit a curve, and obtains an intersection point of triggering level and the fitted curve, then, calculates the time interval between sampled data after the trigger time and the intersection point in the end, reconstructs the original signal, i.e. the signal under acquisition by a time interval of each acquisition. Thus, an analog trigger circuit and a time measurement circuit of conventional random sampling system can be eliminated, that simplifies the circuit design of data acquisition system and decreases its hardware complexity. Moreover, the higher sampling rate for the signal under acquisition is attained, and more waveform details are obtained.

Method for full-digital random sampling

A method for adjusting the waveform brightness for a waveform formatted to be displayed on a digital three-dimensional (3D) oscilloscope having M brightness gradation levels to display the waveform on a digital 3D oscilloscope having L brightness gradation levels is includes, creating a ROM in an FPGA and storing a look-up table of screen display brightness value of LCD that is corresponding to the waveform occurrence N(T,A) at the current brightness gradation L. The ROM is divided into 2sub ROMs, each sub ROM has the capacity of 2&#xd7;d bits. A value of round(p&#xb7;N(T,A) is assigned to waveform brightness value D(T,A) and is stored correspondingly into the subROMof 2&#xd7;d bits by ascending order of the b bits of binary data of waveform occurrence N(T,A). In this way, using the b bits of binary data of waveform occurrence N(T,A) as the binary address of the subROM, corresponding waveform brightness value D(T,A) at the current brightness gradation L can be obtained through look-up table in the subROM.

Growing community of inventors

Chengdu, China

Hao Zeng