公开(公告)号：JPH05223860A

公开(公告)日：1993-09-03

申请号：JP2819592

申请日：1992-02-14

Applicant: ADVANTEST CORP

Inventor： EGUCHI EIICHI ,  OGAWA MASAYUKI

IPC: G01R23/16

Abstract: PURPOSE:To provide possibility of analyzing with high precision even after averaging by performing Fourier's transform upon weighing with the window function even if the input signal varies. CONSTITUTION:The input sampling data train is taken out step by step at intervals of period Tf while the period Td is overlapped and subjected to weighing process with a flat pass function by a weighing part 21, The weighed data train is FFT converted by a Fourier transform part 15, and the same frequency component of each data train having corresponding FFT transform result is averaged by an averaging part 16, and the resultant is given on a display 17.

公开(公告)号：JPH01105183A

公开(公告)日：1989-04-21

申请号：JP26329187

申请日：1987-10-19

Applicant: ADVANTEST CORP

Inventor： YAMAGUCHI TAKAHIRO ,  ENOMOTO KOJI ,  OGAWA MASAYUKI ,  CHIYOMURA YUUZOU

IPC: G01R29/02 ,  G01R13/20 ,  H04L25/02

Abstract: PURPOSE:To measure the generation frequency of the variation width (jitter) of an eye pattern at a previously specified sampling point by inputting an input signal according to a dropout trigger as a reference. CONSTITUTION:The input signal is A/D-converted 12 and stored in a memory 13, and also inputted to the trigger deciding circuit 15 of a dropout trigger detecting means 14. The circuit 15 outputs '1' or '0' according to the trigger level of the input signal and the signal is converted by a series-parallel converting circuit 16 into a parallel signal by every N bits and supplied to a comparator 17. The comparator 17 inputs N-bit dropout patterns from a dropout pattern register 18 and those inputs are compared. Then every time the comparator 17 generates a dropout trigger, a CPU 21 detects the maximum and minimum values at each sampling point in a digital signal passed through a processing memory 22 and finds the generation frequency of the digital signal value at the previously specified sampling point.

公开(公告)号：JPS6319567A

公开(公告)日：1988-01-27

申请号：JP16329186

申请日：1986-07-11

Applicant: ADVANTEST CORP

Inventor： YAMAGUCHI TAKAHIRO ,  OZAWA HIROMI ,  OGAWA MASAYUKI ,  KASAHARA TOSHIHARU

IPC: G01R23/20

Abstract: PURPOSE:To eliminate a reference wave component included in a response output signal by adding/subtracting an output signal of an eliminating signal generating means to/from an output signal of an object to be tested to cancel a required signal. CONSTITUTION:The signal eliminating device has two signal generators 100, 200 to be driven by the same clock pulse, the generator 100 supplies an oscillation signal to an object 3 to be tested and the generator 200 generates an eliminating signal for eliminating a reference wave outputted from the object 3 to be detect 3. Then, the eliminating signal is added/subtracted to/from the output signal of the object 3 to be tested by an adding/subtracting means 300 to remove the reference wave. Since the signals outputted from both the signal generators 100, 200 are synchronized with each other and the initial setting state is stably held, no residual is generated in the reference wave.

公开(公告)号：JPS5956170A

公开(公告)日：1984-03-31

申请号：JP16737182

申请日：1982-09-24

Applicant: Advantest Corp

Inventor： YAMAGUCHI TAKAHIRO ,  OGAWA MASAYUKI

IPC: G01R27/28

CPC classification number: G01R27/28

Abstract: PURPOSE:To measure a transfer function digitally with high precision, by finding frequencies of peak power spectra of an input and an output signals and those peak values, and performing averaging and dividing processing regarding only the peak values. CONSTITUTION:A sine wave signal from a sweep sine wave signal generator 11 is inputted to a body 12 to be measured and its input signal and output signals are written in buffer memories 22 and 24 through AD converters 21 and 23. Their sampled values are inputted to an FFT processor 29 through a multiplexer 25 to perform fast Fourier transform and then the product of the input and output spectrum is calculated to find a cross spectrum. Then, the frequencies and values of peak spectra are detected and when the peak value is greater than a specific level, the mean value of peak values so far is found. When sweep within a desired frequency range is completed, amplitude characteristics and phase characteristics are found by a CPU27 from the mean value of the input/ output power spectra of every frequency of each peak and the mean value of cross spectra.

Abstract translation: 目的：通过查找输入和输出信号的峰值功率谱的峰值以及峰值，以高精度数字地测量传递函数，并且仅对峰值执行平均和除法处理。 构成：来自扫描正弦波信号发生器11的正弦波信号被输入到待测量的主体12，并且其输入信号和输出信号通过AD转换器21和23被写入缓冲存储器22和24中。它们的采样值被输入 通过多路复用器25到FFT处理器29执行快速傅里叶变换，然后计算输入和输出频谱的乘积以找到交叉频谱。 然后，检测峰频谱的频率和值，当峰值大于特定电平时，发现峰值的平均值。 当在期望频率范围内的扫描完成时，CPU27根据每个峰值的每个频率的输入/输出功率谱的平均值和交叉频谱的平均值找到振幅特性和相位特性。

公开(公告)号：JPH04229B2

公开(公告)日：1992-01-06

申请号：JP18164183

申请日：1983-09-28

Applicant: ADVANTEST CORP

Inventor： YAMAGUCHI TAKAHIRO ,  OGAWA MASAYUKI ,  KASAHARA TOSHIHARU

IPC: G01R27/28 ,  G01R23/16

公开(公告)号：JPS6340869A

公开(公告)日：1988-02-22

申请号：JP18451986

申请日：1986-08-06

Applicant: ADVANTEST CORP

Inventor： YAMAGUCHI TAKAHIRO ,  OZAWA HIROMI ,  OGAWA MASAYUKI ,  KASAHARA TOSHIHARU

IPC: G01R23/16 ,  G01R23/20 ,  G11B20/18

Abstract: PURPOSE:To enhance accuracy, by forming the anti-phase signal of the fundamental wave of a response output signal to remove the fundamental wave component. CONSTITUTION:A sine wave signal is applied to a body 3 tested by a signal generating means 100. The response output signal of the body 3 tested is inputted to the input terminal A of a measuring means 400 and subjected to frequency analysis to be stored. A sine wave signal having the same frequency as the signal from the means 100 is generated from a division signal generating means 200 to be inputted to the means 400 through an adder means 300 and compared with an amplitude value Ap stored already and the comparing result is transmitted to CPU131 to set a gain or attenuation quantity for generating a division signal having amplitude equal to Ap to the means 200. By turning a switch SW-O ON in such a state that the division signal is outputted from the means 200, a signal to be measured and the division signal are applied to the adder means 300 and the greater part of a fundamental wave is removed from the signal to be measured. Since only a high frequency waveform which the fundamental wave is removed is inputted to a measuring means 400, measuring accuracy is enhanced.

公开(公告)号：JP2539637B2

公开(公告)日：1996-10-02

申请号：JP24867987

申请日：1987-09-30

Applicant: ADVANTEST CORP

Inventor： YAMAGUCHI TAKAHIRO ,  ENOMOTO KOJI ,  TAKAYAMA KOJI ,  OGAWA MASAYUKI

IPC: H04N17/02 ,  G01R29/26 ,  H04N9/64

公开(公告)号：JPH0339270B2

公开(公告)日：1991-06-13

申请号：JP16737182

申请日：1982-09-24

Applicant: ADVANTEST CORP

Inventor： YAMAGUCHI TAKAHIRO ,  OGAWA MASAYUKI

IPC: G01R27/28

公开(公告)号：JPS6490695A

公开(公告)日：1989-04-07

申请号：JP24867987

申请日：1987-09-30

Applicant: ADVANTEST CORP

Inventor： YAMAGUCHI TAKAHIRO ,  ENOMOTO KOJI ,  TAKAYAMA KOJI ,  OGAWA MASAYUKI

IPC: H04N17/02 ,  G01R29/26 ,  H04N9/64

Abstract: PURPOSE:To measure a noise for a picture element unit for constituting a TV picture by obtaining the instantaneous phase of a chrominance signal from a hill belt converted signal and a non-converted signal and detecting the fluctuating part of the instantaneous phase. CONSTITUTION:A color TV signal to be measured is converted to a digital signal by an A/D converter 32 and a horizontal synchronizing signal is separated from the signal. A signal synchronizing with a color burst signal is converted to the digital signal in an A/D converter 45. The digital signal fetched to a memory 47 is separated to a luminance signal and the chrominance signal and the separated chrominance signal is hill belt converted and further squared. The squared signal and an original chrominance signal are added and an added output is extracted square root by an extraction of square root arithmetic means 57, thereby, an amplitude modulating noise is obtained. The instantaneous phase of the chrominance signal from the hill belt converted signal and the original chrominance signal is operated in a subtracting means 64 to detect the fluctuating part from the reference of the instantaneous phase as the phase modulating noise.