Abstract: A signal under measurement is transformed into a complex analytic signal using Hilbert transformation to estimate an instantaneous phase of the signal under measurement from the complex analytic signal. A least mean square line of the instantaneous phase is calculated to obtain a linear instantaneous phase of the signal under measurement, and a zero-crossing timing of the signal under measurement is estimated using an interpolation method. Then a difference between the instantaneous phase and the linear instantaneous phase at the zero-crossing timing is calculated to estimate a timing jitter sequence. A jitter of the signal under measurement is obtained from the jitter sequence.

Abstract: Embodiments of the present invention apply wavelets to radio frequency (RF) signals to extract specific characteristics (e.g., jitter, phase variations, frequency variations) so that their timing, phase, and frequency components can be characterized. In one embodiment of the present invention, a Haar wavelet is used to extract timing characteristics. In another embodiment, a Morlet wavelet is used to extract phase characteristics. In still another embodiment, a Morlet wavelet is used to extract frequency characteristics.

Abstract: A clock skew measuring apparatus for measuring a clock skew between a plurality of clock signals to be measured in a device under test, includes: a clock signal selecting element for receiving clock signals and outputting them by selecting one of the clock signals one by one; and a clock skew estimator for receiving a reference signal input to the device under test and the clock signals to be measured selected by the clock signal selecting element one by one and for obtaining the clock skew between the clock signals to be measured.

Abstract: A clock signal xc(t) that has been converted into a digital signal is transformed into a complex analytic signal zc(t), and an instantaneous phase &THgr; of the zc(t) is estimated. A linear phase is removed from the &THgr; to obtain a phase noise waveform &Dgr;&phgr;(t). The &Dgr;&phgr;(t) is sampled at a timing close to a zero crossing timing of the xc(t) to extract the &Dgr;&phgr;(t) sample. A root-mean-square value &sgr;t of the &Dgr;&phgr;(t) samples is obtained, and a differential waveform of the extracted &Dgr;&phgr;(t) samples is also obtained to obtain a period jitter Jp. Then a root-mean-square value &sgr;p of the Jp is obtained to calculate a correlation coefficient &rgr;tt=1−(&sgr;p2/(2&sgr;t2)). If necessary, an SNRt=&rgr;tt2/(1−&rgr;tt2) is obtained. The &rgr;tt and/or the SNRt is defined as a quality measure of a clock signal.

Abstract: A jitter measurement apparatus for measuring a jitter of a signal under measurement includes: a delay circuit which generates a delayed signal that is delayed from the signal under measurement by a predetermined delay time; and a phase detector which detects an instantaneous phase error between the signal under measurement and the delayed signal.

Abstract: A processing apparatus for processing an electronic device having a light emitting unit, includes: a light receiving unit for receiving light emitted by the light emitting unit; a position detector for detecting the position of the electronic device; and a processing unit for processing the electronic device based on the position of the electronic device detected by the position detector.

Abstract: A clock waveform XC(t) is transformed into a complex analytic signal using a Hilbert transformer and an instantaneous phase of this analytic signal is estimated. A linear phase is subtracted from the instantaneous phase to obtain a varying term &Dgr;&phgr;(t). A difference between the maximum value and the minimum value of the varying term &Dgr;&phgr;(t) is obtained as a peak-to-peak jitter, and a root-mean-square of the varying term &Dgr;&phgr;(t) is calculated to obtain an RMS jitter.

Abstract: An electronic device having a semiconductor circuit formed therein includes a semiconductor device in which the semiconductor circuit is formed; and a light emitting device, formed integrally with the semiconductor device, for emitting light indicating a reference position of the semiconductor device.

Abstract: A measuring apparatus is provided that includes: a timing jitter calculator for calculating the first timing jitter sequence of the first signal and the second timing jitter sequence of the second signal; and a jitter transfer function estimator for calculating a jitter transfer function between the first and second signals based on frequency components of the first and second timing jitter sequences. The jitter transfer function estimator calculates the jitter transfer function, for a plurality of frequency component pairs each of which is formed by a frequency component of a timing jitter in the first timing jitter sequence and a frequency component of a timing jitter in the second timing jitter sequence which correspond to approximately equal frequencies, based on frequency component ratios of the timing jitters in the first and second timing jitter sequences.

Abstract: There is provided an apparatus for and a method of measuring a jitter wherein a clock waveform XC(t) is transformed into an analytic signal using Hilbert transform and a varying term &Dgr;&phgr;(t) of an instantaneous phase of this analytic signal is estimated.

Abstract: A signal under measurement is converted into a digital signal by an AD converter, and a band-pass filtering process is applied to the digital signal to take out only components around a fundamental frequency of the signal under measurement. A data around a zero-crossing of the components around the fundamental frequency is interpolated to estimate a timing close to a zero-crossing point. A difference between adjacent timings in the estimated zero-crossing timing sequence is calculated to obtain an instantaneous period data sequence. A period jitter is obtained from the instantaneous period data sequence.

Abstract: Timing jitter sequences &Dgr;&phgr;j[n] and &Dgr;&phgr;k[n] of respective clock signals under measurement xj(t) and xk(t) are obtained, and a covariance &sgr;tj,tk=(1/N)&Sgr;i=1N&Dgr;&phgr;j[i]·&Dgr;&phgr;k[i] is obtained. In addition, root-mean-square values &sgr;tj and &sgr;tk of the respective &Dgr;&phgr;j[n] and &Dgr;&phgr;k[n] are obtained, and a cross-correlation coefficient &rgr;=&sgr;tj,tk/(&sgr;tj·&sgr;tk) between the xj(t) and xk(t) is calculated.

Abstract: There is provided a jitter estimating apparatus for calculating phase noise waveform of an input signal and for estimating a peak value, a peak-to-peak value and a worst value of jitter of the input signal, and probability to generate jitter based on the phase noise waveform. Timing jitter sequence, period jitter sequence, and cycle to cycle period jitter sequence of the input signal are calculated and the peak value and the peak to peak value for each jitter, as well as probability to generate jitter may be estimated.

Abstract: A clock skew measuring apparatus for measuring a clock skew between a plurality of clock signals to be measured in a device under test, includes: a clock signal selecting element for receiving clock signals and outputting them by selecting one of the clock signals one by one; and a clock skew estimator for receiving a reference signal input to the device under test and the clock signals to be measured selected by the clock signal selecting element one by one and for obtaining the clock skew between the clock signals to be measured.

Abstract: A signal under measurement is transformed into a complex analytic signal using Hilbert transformation to estimate an instantaneous phase of the signal under measurement from the complex analytic signal. A zero-crossing timing sequence of the signal under measurement is estimated using the instantaneous phase. An instantaneous period sequence of the signal under measurement is estimated from the zero-crossing timing sequence to obtain a jitter of the signal under measurement from the instantaneous period sequence.

Abstract: A probability estimating apparatus and method for peak-to-peak clock skews for testing the clock skews among a plurality of clock signals distributed by a clock distributing circuit, and for estimating the generation probability of the peak-to-peak value or peak value of the clock skews. The probability estimating apparatus for peak-to-peak values in clock skews includes a clock skew estimator for estimating clock skew sequences among the plurality of clock signals under test and a probability estimator for determining a generation probability of the peak-to-peak values in the clock skews among the plurality of signals under test based on the clock skew sequences from the clock skew estimator.

Abstract: Timing jitter sequences &Dgr;&phgr;j[n] and &Dgr;&phgr;k[n] of respective clock signals under measurement xj(t) and xk(t) are obtained, and a covariance &sgr;tj,tk=(1/N)&Sgr;i=1N&Dgr;&phgr;j[i]·&Dgr;&phgr;k[i] is obtained. In addition, root-mean-square values &sgr;tj and &sgr;tk of the respective &Dgr;&phgr;j[n] and &Dgr;&phgr;k[n] are obtained, and a cross-correlation coefficient &rgr;=&sgr;tj,tk/(&sgr;tj·&sgr;tk) between the xj(t) and xk(t) is calculated.

Abstract: Timing jitter sequences &Dgr;&phgr;j[n] and &Dgr;&phgr;k[n] of respective clock signals under measurement xj(t) and xk(t) are estimated, and a timing difference sequence between those timing jitter sequences is calculated. In addition, initial phase angles &phgr;0j and &phgr;0k of linear instantaneous phases of the xj(t) and xk(t) are estimated, respectively. A sum of a difference between those initial angles and the timing difference sequence is calculated to obtain a clock skew sequence between the xj(t) and xk(t).

Abstract: A signal under measurement x(t) is transformed into a complex analytic signal zc(t), and an instantaneous phase of the xc(t) is estimated using the zc(t). A linear phase is removed from the instantaneous phase to obtain a phase noise waveform &Dgr;®(t) of the x(t), and the &Dgr;&phgr;(t) is sampled at a timing close to a zero-crossing timing of the x(t) to obtain a timing jitter sequence. Then a difference sequence of the timing jitter sequence is calculated to obtain a period jitter sequence. The period jitter sequence is multiplied by a ratio T0/Tk,k+1 of the fundamental period T0 of the x(t) and the sampling time interval Tk,k+1 to make a correction of the period jitter sequence. A period jitter value of the x(t) is obtained from the corrected period jitter sequence.

Abstract: An input clock signal is transformed into a complex analytic signal zc(t) by an analytic signal transforming means 13 and an instantaneous phase of its real part xc(t) is estimated using the analytic signal zc(t). A linear phase is removed from the instantaneous phase to obtain a phase noise waveform &Dgr;&phgr;(t). A peak value &Dgr;&phgr;max of absolute values of the &Dgr;&phgr;(t) is obtained, and 4&Dgr;&phgr;max is defined as the worst value of period jitter of the input signal. The &Dgr;&phgr;(t) is sampled at a timing close to a zero-crossing point of the xc(t) to extract the sample value. A differential between adjacent samples is obtained in the sequential order to calculate a root-mean-square value of the differentials (period jitters). An exp(−(2&Dgr;&phgr;max)2/(2&sgr;j2)) is calculated from the mean-square value &sgr;j and 2&Dgr;&phgr;max, and the calculated value is defined as a probability that a period jitter exceeds 2&Dgr;&phgr;max.