Abstract: A system for investigating a sample, the system including a detector having non-linear current voltage characteristics and being configured to mix two radiation signals having frequencies in the range from 25 GHz to 100 THz, one of the signals being a local oscillator signal and the other signal being a sample signal carrying information about the sample being investigated, the system further having a quantum cascade laser for providing at least the local oscillator signal.

Abstract: The detection of electromechanical oscillations in power systems and the estimation of their frequency and damping parameters are based on a linear time-varying model. The parameters of the linear model are on-line adapted by means of Kalman filtering techniques to optimally approximate the measured signal representing the behavior of the power system based on a quadratic criterion. The estimated model parameters are then the basis for the calculation of parameters of the oscillations. Adaptive algorithms are based on a recursive calculation of the estimated parameter vector for each time-step based on the new value of the measured signal and the old values of the estimated parameters.

Abstract: A method and apparatus for digitizing a data signal, the method comprising the steps of receiving an input analog data signal, splitting the received input analog data signal into a plurality of split signals, and mixing at least one of the split signals with a predetermined periodic function with a predetermined frequency. The split signals are then digitized and combined mathematically to form a single output data stream that is a substantially correct representation of the original input signal.

Abstract: A method of and device for detecting a leak in reciprocating machinery, comprising at least two pistons, by the volume flow at least out of the reciprocating machinery being monitored and analysed, e.g. by means of Fourier analysis, in order to make it possible to detect a flow component, where the flow component has a frequency that differs from the fundamental frequency of the reciprocating machinery, the fundamental frequency of the reciprocating machinery being constituted by the rotational frequency of the reciprocating machinery multiplied by the number of pistons in the reciprocating machinery.

Abstract: A scheme to provide a spectral view of the signals present at the customer premises equipment by the network operator and includes a digital signal processor (DSP) or other signal processing apparatus integrated into a customer premises equipment (CPE) tuner in which the DSP or other signal processing apparatus is operational to perform a spectral analysis.

Abstract: The performance of a plasma processing apparatus which is disassembled, transferred, and reassembled is evaluated. The plasma processing apparatus has a plasma processing chamber having an electrode for exciting a plasma, a radiofrequency generator connected to the electrode, and an impedance matching circuit for performing the impedance matching between the plasma processing chamber and the radiofrequency generator. The performance of the apparatus is evaluated whether or not three times the first series resonant frequency of the plasma processing chamber is larger than the power frequency supplied to the plasma processing chamber.

Abstract: A user interface for an electronic instrument includes a display that displays a signal and a band marker. The band marker demarks a bandwidth of the signal by marking both a start frequency of the bandwidth and a stop frequency of the bandwidth. The electronic instrument performs a function on the bandwidth of the signal between the start frequency and the stop frequency.

Abstract: When a sample stream is decimated, frequency components from outside of a desired frequency band are aliased into the desired band, causing interference and loss of information. Different decimating ratios result in different frequencies aliasing into the desired frequency band. A current-mode sampling mixer 800 with capacitor banks 811 and 812 that are controlled by a digital control unit 820 with a capability to integrate and decimate an RF current at different decimating ratios is able to measure the frequency spectrum with different decimating ratios. The measured frequency spectrum is then analyzed to detect the presence of interferers aliased into the desired frequency band. The interferers can then be eliminated or avoided.

Abstract: A method and apparatus for interrogating a sample that exhibits molecular rotation are disclosed. In practicing the method, the sample is placed in a container having both magnetic and electromagnetic shielding, and Gaussian noise is injected into the sample. An electromagnetic time-domain signal composed of sample source radiation superimposed on the injected Guassian noise is detected, and this signal is cross-correlated with a second time-domain signal produced by the same or similar sample, to produce a cross-correlated signal with frequency domain components. The latter is plotted in the frequency domain by a fast Fourier transform to produce a frequency domain spectrum in a frequency range within DC to 50 KHz. From this spectrum, one or more low-frequency signal components that are characteristic of the sample being interrogated are identified.

Abstract: A method for calculating the capacitance of a transducer (C0) without knowing the exact resonance frequency of a transducer/blade combination is achieved by sweeping across a broad frequency range which contains resonant and non-resonant frequencies where C0 can be measured. A pre-defined frequency range is set independently of the resonance frequency of a specific transducer/blade combination. C0 of the transducer/blade is measured at several different frequencies within the pre-defined frequency range to ensure that invalid C0 measurements are disregarded, and the temperature of the transducer is calculated based on valid C0 measurements. The determined transducer temperature, based on C0 measurements, can be used to optimize performance and/or provide a safety shutdown mechanism for the generator.

Abstract: Some embodiments provide a sensor element, a shield element capacitively coupled to the sensor element and to ground, a coupling circuit to receive an input signal, and to electrically couple the received input signal to the sensor element and to the shield element, an output circuit to generate an output signal, the output signal based on a capacitance between the sensor element and an object, and a classifier to determine a material based on the output signal, and to transmit a material signal to the output circuit based on the determined material, wherein the output circuit is adjustable based on the material signal.

Abstract: Method for analysing the frequency in real-time of a non-stationary signal and corresponding analysis circuit. According to the invention, the signal is sampled, it is digitised, it is broken up into sub-bands. In each sub-band, the signal is modelled by an auto-regressive filter the transfer function of which is of the form 1/A(z). By an adaptive method that is recursive in time and in order, all the polynomials A(z) that have a degree between 1 and a maximum value are calculated. The order of the model is estimated and the polynomial that has this order is retained. The roots of this polynomial are calculated and the components are monitored. The frequency and the amplitude of the sinusoidal components of the signal are thus obtained. Application in aeronautics, electromagnetic, mechanics, seismic prospecting, zoology, etc.

Abstract: The invention refers to a method of resonance spectroscopy for the analysis of statistical properties of samples, comprising the following steps: a) recording of a complex resonance frequency spectrum of each sample by means of phase sensitive quadrature detection; b) numerical differentiation of the recorded complex resonance frequency spectra versus frequency; c) determination of the absolute value of each differentiated complex resonance frequency spectrum (=fingerprint); d) allocation of each fingerprint to a point of a multidimensional point set; and e) performing a pattern analysis of the generated points for characterizing the statistical properties of the samples. The inventive method tolerates unintended variances of measurement in the recorded resonance frequency spectra, in particular caused by phase errors, and allows reliable automated spectral analysis.

Abstract: Disclosed are a method of estimating a Doppler frequency shift and a method of transmitting data using the same. The method of estimating the Doppler frequency shift includes the steps of calculating difference values of a received pilot signal between i-th slot and (i?1)-th slot, for i=1, 2, . . . , N; and estimating a Doppler frequency shift based on the difference values.

Abstract: Frequency rectification system using a Van der Pol oscillator for processing an asset signal by obtaining a complex signal from an asset comprised of a noise signal and a signal of interest having a corresponding frequency of interest wherein the complex signal includes a first spectrum having all of its largest spectral peaks corresponding to the noise signal such that the signal of interest is hidden under the noise signal. The system processes the complex signal with the Van der Pol oscillator with selected parameters for rectifying the complex signal into a rectified signal such that the noise signal is abated and the rectified signal is comprised of a second spectrum having a largest spectral peak corresponding to the signal of interest with all other spectral peaks smaller. The system extracts the frequency of interest from the rectified signal with an extraction module for use in providing asset information.

Abstract: An embodiment of the present invention includes a method to analyze processor performance. A processor is saturated with a workload. The processor has a specified operating frequency and a thermal throttling range from a minimum throttling state to a maximum throttling state. Events are sampled for a pre-determined time interval at a sampling rate during the workload. An effective processor frequency is calculated using the sampled events, the pre-determined time interval, and the sampling rate.

Abstract: A frequency converter is tested. Labels for a plurality of mixing products are displayed. In response to a user selecting a first mixing product from the plurality of mixing products, appropriate frequencies for the first mixing product are calculated. Also, a measurement configuration for the first mixing product is determined.

Abstract: A method and apparatus for digitizing a data signal. An input analog data signal, is received and split into a plurality of split signals. At least one of the split signals is mixed with a predetermined periodic function with a predetermined frequency. The split signals are then digitized and combined mathematically to form a single output data stream that is a substantially correct representation of the original input signal.

Abstract: A dynamic model of non-linear tuning behavior is used to tune a tunable device. The model quantifies a difference between a tuning characteristic of an ideal device and an actual tuning characteristic of the device. The model adjusts the tuning according to the difference. A method of compensated tuning of tunable device comprises employing a dynamic model of the tunable device to produce a compensated tuning control input to the tunable device during tuning. A tuning compensator for a tunable device comprises the dynamic model that is employed with an input tuning command to generate a compensated tuning command. A tuning-compensated YTF comprises a dynamic model-based tuning compensator and a YTF. A spectrum analyzer having a tuning-compensated preselector comprises a YTF preselector, a frequency converter, a video signal processor unit, a tuning compensator, and a controller. The tuning compensator uses the dynamic model to tune the preselector.

Abstract: An analogue output signal of a sensor which comprises a carrier signal with a carrier frequency ?C which is modulated by a measurement size is sampled with a sampling frequency ?A to receive a sampled sensor output signal. The frequency ?A of the sampling signal is set so that it is an integer divisor n of the carrier frequency ?C, wherein the phase of the sampling signal is set so that the sampling signal is synchronous to the sensor output signal. The sampled sensor output signal is filtered now to remove periodically repeated signal components from the sampled sensor output signal. Then a filtered useful signal is received, wherein its amplitude is proportional to the measurand detected by the sensor.

Abstract: A method and system characterize jitter of an applied signal. The characterization includes acquiring a set of pseudo-randomly timed samples at a designated position on the signal, assigning a jitter value to each of the pseudo-randomly timed samples in the acquired set, and selecting a frequency from an array of frequencies based on a correlation of the assigned jitter values with the frequencies in the array. The periodic jitter associated with the signal is designated to have the frequency within the array of frequencies that has the highest correlation to the assigned jitter values.

Abstract: A frequency error detection apparatus and method based on histogram information of an input signal. The apparatus includes an A/D converter for and converting an analog signal into digital values; a zero crossing point detector for detecting sign changes of the digital values, and detecting zero crossing points; a period information detector for detecting period information which is the number of the digital values corresponding to a periodic signal; a histogram information calculator for counting the number of detections for the respective period information based on the period information, and calculating error-detection-target histogram information; and a frequency error calculator for detecting a difference between the error-detection-target histogram information and a reference histogram information, and calculating a frequency error value based on the difference. This can shorten time for frequency error detections and improve accuracy of the detected frequency error value.

Abstract: A method generating wander noise includes predefining frequency, amplitude and phase values for each of a plurality of tones for various predefined frequency profiles. A digital noise signal having a particular profile can then be generated by a summation of a plurality of tones based on the predefined frequency, amplitude and phase values for each of the plurality of tones for the selected profile. The wander noise signal is then generated from the digital noise signal.

Abstract: Signal processing techniques and systems and, in particular, an apparatus, system, algorithm and method of extraction of sinusoidal signals of time-varying nature is described. The apparatus, system, algorithm and method provide for extraction of a specified single sinusoidal component of an input signal, potentially containing other components and noise, and tracking variations of the amplitude, phase and frequency of such a sinusoid component over time. A “tool” or “core unit,” embodying the apparatus, system, algorithm or method may be used in isolation or as the fundamental building block of single-core or multi-core systems.

Abstract: A method and apparatus for interrogating a sample that exhibits molecular rotation includes placing the sample in a container having both magnetic and electromagnetic shielding, where Gaussian noise is injected into the sample. An electromagnetic time-domain signal composed of sample source radiation superimposed on the injected Guassian noise is detected, and this signal is used to generate a spectral plot that displays, at a selected power setting of the Gaussian noise source, low-frequency spectral components characteristic of the sample in a selected frequency range between DC and 50 kHz. In one embodiment, the spectral plot that is generated is a histogram of stochastic resonance events over the selected frequency range. From this spectrum, one or more low-frequency signal components that are characteristic of the sample being interrogated are identified.

Abstract: This invention presents a method for computing Instantaneous Frequency by applying Empirical Mode Decomposition to a signal and using Generalized Zero-Crossing (GZC) and Extrema Sifting. The GZC approach is the most direct, local, and also the most accurate in the mean. Furthermore, this approach will also give a statistical measure of the scattering of the frequency value. For most practical applications, this mean frequency localized down to quarter of a wave period is already a well-accepted result. As this method physically measures the period, or part of it, the values obtained can serve as the best local mean over the period to which it applies. Through Extrema Sifting, instead of the cubic spline fitting, this invention constructs the upper envelope and the lower envelope by connecting local maxima points and local minima points of the signal with straight lines, respectively, when extracting a collection of Intrinsic Mode Functions (IMFs) from a signal under consideration.

Abstract: A frequency measuring device can measure the frequency of a noisy power system at high speed. The system voltage is measured at timings obtained by equally dividing one reference-wave period. Voltage vectors are calculated which have tip ends, each voltage vector consisting of a real part of a first measured voltage and an imaginary part of another voltage measured at timing 90 degrees before the first measured voltage. The length of a chord connecting tip ends of adjacent voltage vectors is calculated. A voltage root-mean-square value is calculated from voltages measured between two timings spaced from each other by the one reference-wave period. Chord lengths obtained between two timings spaced from each other by the one reference-wave period are summed. Based on the total of the chord lengths and the voltage root-mean-square value, there is calculated a phase angle between two adjacent voltage vectors, from which the system frequency is calculated.

Abstract: A chaotic communication system employs transmitting and receiving chaotic oscillating circuits. In an embodiment of the invention employing a Chua circuit as the basic chaotic circuit, the transmitter has a tank circuit portion and a Chua diode portion linked through a resistance. The capacitance of the tank circuit is varied by selectively switching in and out of the tank circuit an auxiliary capacitance isolated by an optoisolator. Switching of the optosiolator is controlled by an information signal to generate a perturbed oscillation in the transmitting circuit. A voltage is tapped from the Chua diode circuit and transmitted to carry the information from the information signal. A receiver in another embodiment applies the transmitted signal to both the tank circuit and Chua diode portions of the receiving circuit. The transmitted signal is applied through a resistor to the Chua diode portion as well as the tank circuit portion.

Abstract: A method, apparatus, and system for spectrum analysis. The method, apparatus, and system for spectrum analysis include measuring energy incident at a frequency in a frequency spectrum corresponding to a channel, but not all frequencies in the frequency spectrum, and determining whether the energy measured at the frequency exceeds a valid channel threshold.

Abstract: A method compensates for phase differences between sampled values of first and second AC waveforms. The method employs a phase angle compensation factor and sequentially samples a plurality of values of each of the waveforms. For a positive compensation factor, second sampled values are adjusted to correspond with first sampled values by employing, for a corresponding second sampled value, a preceding second sampled value plus the product of: (i) the compensation factor and (ii) the difference between the corresponding second sampled value and the preceding second sampled value. Alternatively, for a negative compensation factor, the second sampled values are adjusted by employing, for the corresponding second sampled value, the preceding second sampled value minus the product of: (i) the sum of one plus the compensation factor and (ii) the difference between the preceding second sampled value and the second sampled value preceding the preceding second sampled value.

Abstract: The invention detects loft time and/or speed of a vehicle and/or person during activities of moving and jumping. A loft sensor detects leaving the ground and returning to the ground. A microprocessor subsystem converts the sensed information to determine a loft time. A display shows the recorded loft time to a user of the system. A speed sensor can detect speed for selective display to the user, and height may also be determined during airtime.

Abstract: In contrast with a known dynamic gate-level simulation method, a method of analyzing electromagnetic interference (an EMI analysis method) according to the present invention enables estimation of EMI noise, by means of calculating signal propagation of each node through use of the signal propagation probability technique, and calculating variation time of each node through use of “the Static timing analysis technique”. In short, the present invention is characterized in calculating a frequency characteristic from the relationship between toggle probability of each node and delay in each node.

Abstract: A method of measuring frequencies of multiple sinusoidal bursts in a signal uses a time-domain window that includes all the bursts which are then transformed to the frequency by domain an FFT. The magnitudes of the frequency bins are filtered and smoothed to create a minimum magnitude threshold array. An adaptive threshold is calculated from the minimum magnitude threshold array, maximum magnitudes of the frequency bins and an adjustable constant. The magnitudes are then compared to the adaptive threshold and the number of consecutive frequency bins above the adaptive threshold are counted and, if correct for the given signal, a centroid is determined for each frequency bin. If the number of bursts is not correct, then the adjustable constant is altered and the adaptive threshold recalculated. The centroids are converted to measured frequencies for the multiple sinusoidal bursts.

Abstract: A system and method is provided for analyzing data obtained during manufacture of a web of paper or paperboard on a machine. The system comprises a computer including a database module, a statistical analysis module, and a processor for executing the modules. The database module contains measurements of quality parameters obtained from the web during manufacture. The statistical analysis module is executed by the processor to analyze the measurement data and estimate a target shift in at least one quality parameter that could be made if the controllable variations were removed. The target shift can be transformed into an economic amount (i.e., dollar value) by the statistical analysis module to assist the mill operator with making well informed, economic based decisions. The system further includes a diagnostic module capable of automatically identifying machine parameters that correlate to quality parameters that caused the web to fall outside the desired quality specifications.

Abstract: The present invention provides an apparatus and method for inspecting electrical continuity of a circuit board, capable of decreasing the impedance in a current path as an inspection object to achieve enhanced SN ratio. A coupling capacitance is formed at one of terminals of a pattern wire on a board as an inspection object in a non-contact manner, and an inductance (450) and a lead wire are connected to this capacitance. An AC inspection signal is applied to the other terminal through the lead wire in a contact manner. A resonance circuit is defined by the capacitance, inductance and pattern wire, and thereby an output signal can be detected with lowering the impedance.

Abstract: Some embodiments provide a sensor element, a shield element capacitively coupled to the sensor element and to ground, a coupling circuit to receive an input signal, and to electrically couple the received input signal to the sensor element and to the shield element, an output circuit to generate an output signal, the output signal based on a capacitance between the sensor element and an object, and a classifier to determine a material based on the output signal, and to transmit a material signal to the output circuit based on the determined material, wherein the output circuit is adjustable based on the material signal.

Abstract: FFT section 102 transforms a windowed input noise signal into a frequency spectrum. Spectral model storing section 103 stores model information on spectral models. Spectral model series calculating section 104 calculates spectral model number series corresponding to amplitude spectral series of the input noise signal, using the model information stored in spectral model storing section 103. Duration model/transition probability calculating section 105 outputs model parameters using the spectral model number series calculated in spectral model series calculating section 104. It is thereby possible to synthesize a background noise with perceptual high quality.

Abstract: A user interface is presented for a tester that tests a frequency converter having an input port, an output port and a local oscillator port. In a first area, a user can specify frequency for an input signal to be placed on the input port. In a second area, the user can specify frequency for a local oscillator signal to be placed on the local oscillator port. The tester calculates expected frequency values of an output signal on the output port output based on values entered in the first area and the second area.

Abstract: A bridge circuit disposed between a device under test (DUT) and conventional automatic test equipment (ATE) extends the performance of the ATE. The bridge circuit allows the ATE to test ICs capable of operating at frequencies above the ATE's normal performance limits. In some embodiments, the bridge circuit also extends ATE functionality, providing frame alignment and automatic test-vector generation, for example, and can increase the number of available test channels.

Abstract: The start up performance of an ultrasonic system under zero load conditions is improved by setting a phase set point in a frequency control loop such that, at start up under zero load conditions, the phase set point intersects a point on a phase-frequency response curve which has a low positive slope. This intersection point on the phase-frequency response curve changes as the load is increased and the system Q is decreased. The controller “seeks” a target 0° impedance phase angle. The frequency of the ultrasonic generator is set to an off-resonance frequency which is lower than the resonance of any known hand piece/blade combination. In order for the drive voltage to not exceed the physical limit of the system, the drive current is set to a low level. The drive frequency is then smoothly increased in steps until the target 0° impedance phase delta is located.

Abstract: A simultaneous rapid open and closed loop bode measurement plot is described in which testing of the servo controlled instrument occurs under closed loop conditions using a binary pseudo-random sequence. The binary pseudo-random sequence is injected into the servo while the system under test is operating closed loop in order to generate bode plots for open loop and closed loop conditions. The present invention provides measurement results approximately 1,000 times faster than a swept sinusoid approach and provides superior dynamic range as compared to random white noise test input sources.

Abstract: A measuring apparatus includes a spectrum analysis unit having an input for receiving an input signal to be measured. The input signal includes a carrier signal located within a predetermined band of frequencies and the spectrum analysis unit is arranged to store a set of user definable parameters including the location of the carrier signal within the predetermined band of frequencies, and to use the set of user definable parameters to measure a quantity associated with the carrier signal.

Abstract: Representative embodiments are directed to systems and methods for processing analyzer trace data of a multi-tone signal to more accurately estimate the frequencies and amplitudes of the tones of the multi-tone signal. Specifically, trace data may be processed to determine peak trace points. For each identified peak point, an error minimization algorithm minimizes the sum of differences between a plurality of trace points surrounding the respective peak point and the predicted Fourier transform through a raised-cosine window of a theoretical tone. The result of the minimization algorithm identifies the amplitude and frequency of a tone of the multi-tone signal with appreciable degree of accuracy.

Abstract: In a method and a device for carrying frequency synthesis, in particular in a distance measuring device based on the principle of evaluating the change over time in the phase of an electromagnetic radiation emitted by a radiation source and remitted by an object aimed at, a frequency, which is preferably furnished by a quartz oscillator, is regulated in a ring oscillator with N delay elements (V1, V2, V3, . . . , VN) to a desired first high frequency (F), which is used as a mixer frequency or as a modulation frequency. The signals at the N delay elements (V1, V2, V3, . . . , VN) are delivered to a multiplexer, which is switched over with a cadence that is equivalent to 2*N times the frequency of the low-frequency measurement signal to be evaluated to produce a modulation frequency or mixer frequency.

Abstract: A frequency margin testing blade is adapted for use in a bladed server. The testing blade is further adapted to provide one or more output clock signals for use as clock inputs to one or more server blades internal to the bladed server in which the testing blade is installed and/or one or more server blades external to the bladed server in which the testing blade is installed.

Abstract: When a sample stream is decimated, frequency components from outside of a desired frequency band are aliased into the desired band, causing interference and loss of information. Different decimating ratios result in different frequencies aliasing into the desired frequency band. A current-mode sampling mixer 800 with capacitor banks 811 and 812 that are controlled by a digital control unit 820 with a capability to integrate and decimate an RF current at different decimating ratios is able to measure the frequency spectrum with different decimating ratios. The measured frequency spectrum is then analyzed to detect the presence of interferers aliased into the desired frequency band. The interferers can then be eliminated or avoided.

Abstract: The spectrum of a PCM signal is divided into bands. Combinations of a reference band inclusive of a highest frequency band and another band, one of the reference band and other band being normalized, are checked to identify a combination having a highest spectrum distribution correlation. The spectrum having the same distribution as the spectrum distribution of the reference band contained in the identified combination is scaled along an envelope function and added to a higher frequency side than the reference band to generate an output signal. A presence/absence of high frequency components of a PCM signal is detected. Only if there are high frequency components, the spectrum components are added to generate an output signal.

Abstract: A frequency measuring device can measure the frequency of a noisy power system at high speed. The system voltage is measured at timings obtained by equally dividing one reference-wave period. Voltage vectors are calculated which have tip ends, each voltage vector consisting of a real part of a first measured voltage and an imaginary part of another voltage measured at timing 90 degrees before the first measured voltage. The length of a chord connecting tip ends of adjacent voltage vectors is calculated. A voltage root-mean-square value is calculated from voltages measured between two timings spaced from each other by the one reference-wave period. Chord lengths obtained between two timings spaced from each other by the one reference-wave period are summed. Based on the total of the chord lengths and the voltage root-mean-square value, there is calculated a phase angle between two adjacent voltage vectors, from which the system frequency is calculated.

Abstract: A noise injection method for characterizing common clock timing margin (jitter) includes injecting a single tone frequency, varying the amplitude of the injected frequency; measuring the signal produced at various signal amplitudes and analyzing the data obtained from measuring the signal. The obtained measurements may be analyzed using various characterizations such as measured jitter on input, measured jitter transfer, measured jitter tolerance, etc.

Abstract: Circuitry for detecting tonal signals, each of which has a particular nature in the frequency or time domain, while distinguishing them from each other. A rough frequency analyzer roughly analyzes an input signal in an entire frequency band with lower accuracy in the frequency or time domain, thereby roughly distinguishing the tonal signals. Detectors, each of which is associated with a subband occupied by a particular target tonal signal, detect the attribute of the power variation of the target tonal signal with respect to time with higher accuracy in the direction of the frequency or time domain to thereby finely identify the target tonal signal. A controller selectively enables and disables the detectors in accordance with the results from the detectors. One of the detectors is enabled which is selected under the control of the controller.