# Frequency spectrum

## Subclass of:

## 702 - Data processing: measuring, calibrating, or testing

## 702001000 - MEASUREMENT SYSTEM IN A SPECIFIC ENVIRONMENT

## 702057000 - Electrical signal parameter measurement system

## 702066000 - Waveform analysis

## 702075000 - Frequency

### Patent class list (only not empty are listed)

#### Deeper subclasses:

Class / Patent application number | Description | Number of patent applications / Date published |
---|---|---|

702076000 | Frequency spectrum | 72 |

20110178750 | FREQUENCY SPECTRUM ANALYZING APPARATUS - A frequency spectrum analyzing apparatus for performing a frequency spectrum analysis with respect to a detected value of an operating parameter of an internal combustion engine in synchronism with rotation of the engine, is provided. The operating parameter is sampled at predetermined time intervals, and a sampled value is converted to a digital value. Intensities of first and second elements are calculated with respect to a predetermined number of the sampled values. The first elements and second elements respectively correspond to a plurality of frequency components contained in the detected value, and a phase of the second element differs from a phase of the first element by 90 degrees. Frequency component intensities corresponding to the plurality of frequency components are calculated in synchronism with rotation of the engine, using the first element intensities and the second element intensities. The frequency component intensities are calculated by replacing a part of an integrated value of the first element intensities, and a part of an integrated value of the second element intensities respectively with corresponding preceding calculated values, when an rotational speed of the engine is higher than or equal to a set threshold value. | 07-21-2011 |

20100274511 | SIGNAL ANALYSIS METHOD, SIGNAL ANALYSIS DEVICE AND SIGNAL ANALYSIS PROGRAM - Provided is a signal analysis device that has a high frequency resolution not depending on an analysis window length and can analyze a frequency with considerably high accuracy. When the signal analysis device inputs therein an analysis object signal to be analyzed, the device obtains a frequency f′, amplitude A′ and an initial phase φ′ such that the sum of squares of a difference between the analysis object signal and a sinusoidal model signal expressed by a phase using the frequency f′ and the initial phase φ′ and by the amplitude A′ is a minimum value. | 10-28-2010 |

20090192741 | METHOD FOR MEASURING FIELD DYNAMICS - The method patented enables robust and reliable relative measurements of the dynamics of a physical field (or: of a conceptual system). The patented method extends least squares spectral analysis (LSSA) technique's unique features. The LSSA has been proven over the past thirty years as being able of fully replacing the Fourier and Fourier-based spectral analysis methods (as the most used methods of spectral analysis in all sciences). The patented method uses the known feature of the LSSA as a reliable periodicity estimator, and expands its application by claiming its variance-spectral magnitudes are also most useful in terms of their epochal averages (meaning: averages from variance-spectra of data belonging to successive and equal time-intervals) being directly correlated to the energy levels exciting (i.e., supplied into) the field/system. Thus by taking the average (over certain band) spectral magnitude after analyzing datasets that sample a field/system at different instances or/and under various conditions, one can easily and accurately measure the dynamics of the observed field/system in relative terms, using only the changes of such an average. | 07-30-2009 |

20090125259 | APPARATUS AND METHODS OF DEFINING SPECTRAL REGIONS OF INTEREST FOR SIGNAL ANALYSIS - Apparatus and methods are provided to allow multiple, possibly overlapping, regions of interest within a frequency spectrum to be defined, and managed. Each of these regions of interest may be selected for further testing or identification. Unselected regions are allowed to collapse into narrow bars so as not to interfere with the selected region. Multiple rows are provided to allow for the definition and selection of overlapping regions of interest. Furthermore, in some embodiments aid is provided for identifying the signal type by providing a list of signal type candidates based upon such parameters as region of interest bandwidth, region of interest center frequency and geographic location. | 05-14-2009 |

20130158923 | FREQUENCY MASK TRIGGER WITH NON-UNIFORM BANDWIDTH SEGMENTS - Disclosed is a test and measurement instrument having a multiple variable bandwidth frequency mask. The instrument includes an input processor for receiving an input signal and producing a digital signal, as well as a trigger signal generator for generating a trigger signal on the occurrence of a trigger event. A time to frequency converter converts a frame of digital data from the digital signal into a frequency spectrum having at least two frequency bins of dissimilar frequency widths. Each frequency bin has a power amplitude value. The trigger signal is generated when the power amplitude value of any of the at least two frequency bins violates an associated reference power level. In some cases the output may be shown as a density trace, and the trigger signal generated when any point of the density trace violates an associated density threshold. | 06-20-2013 |

20100268499 | INTERFEROMETER SYSTEM AND METHOD FOR ITS OPERATION - In an interferometer system and a method for its operation, the interferometer system includes an interferometer having an interferometer light source whose emitted radiation is able to be split into a measuring arm and a reference arm, an object to be measured being disposed in the measuring arm, and the interferometer delivering interferometer signals as a function of the position of the object to be measured. In addition, a detecting device is provided for detecting fluctuations in the refractive index of the air in the measuring arm and/or reference arm. The detecting device includes a spectrometer unit; the spectrometer unit has at least one spectrometer light source, as well as at least one spectrometer detector unit. The bundles of rays emitted by the spectrometer light source are superimposed on the bundles of rays from the interferometer light source, the spectrometer light source emitting radiation having a wavelength which lies in the range of an absorption line of at least one specific air component. The spectrometer detector unit is used to generate spectrometer signals which characterize the absorption of the air component in terms of the spectrometer light-source wavelength in the measuring arm and/or reference arm. | 10-21-2010 |

20120010836 | ELECTROMAGNETIC RADIATION MAPPING SYSTEM - Apparatus for radiation mapping of a region comprises a spectrum analyzer for analyzing a local radiation field according to wavelength, and a positioning unit for obtaining a position reading to correlate with said local radiation field, thereby to provide said radiation mapping. The results may be provided as layers to a map, and different layers may be provided for different frequencies and different times of the day. | 01-12-2012 |

20110288802 | Spectrometer, Measuring Apparatus, and Method of Data Processing - A spectrometer has: Accumulation means to obtain a data set containing N data points, repeating the measurement M times to obtain M spectral data sets or time-domain data sets S | 11-24-2011 |

20090299665 | Method for automatically detecting and characterizing spectral activity - The invention disclosed herein provides a computer implementable method for characterizing signals in a frequency domain spectrum where such signals may comprise a wideband signal while individually being of varied formats such as tones, analog modulation, digital modulation, etc. The invention employs statistical probability models where mean, standard deviation, histograms, and probability density functions are analogous to center frequency, bandwidth, frequency spectrum, and signal models, respectively. The invention reconstructs a frequency spectrum showing signals of interest. | 12-03-2009 |

20090240452 | SYSTEM AND METHOD FOR WIRELESS AND DYNAMIC INTRA-PROCESS MEASUREMENT OF INTEGRATED CIRCUIT PARAMETERS - Disclosed are embodiments of a system and a method that allow for wireless and dynamic intra-process (i.e., during and/or between process steps) measurements of integrated circuit parameters. The embodiments incorporate the use of a passive circuit, such as an inductor-capacitor-resistor (LCR) circuit resonator, that has a predetermined sensitivity to process variations in one or more physical or electrical integrated circuit parameters. The passive circuit can be wirelessly interrogated between and/or process steps. Then, the actual behavior exhibited by the passive circuit in response to the interrogation is compared to the expected behavior of an optimal circuit in the absence of process variations in order to determine the one or more parameters. Also disclosed is an embodiment of an exemplary passive circuit that can be used to implement the disclosed system and method embodiments. | 09-24-2009 |

20100204938 | AMPLITUDE DISCRIMINATION USING THE FREQUENCY MASK TRIGGER - A frequency mask trigger having frequency selective amplitude discrimination capability is provided for triggering when selected frequency components of an input signal fail to reach a desired power level. A frame of digital data representing an input signal is transformed into a frequency spectrum having at least one frequency bin, each frequency bin having a power amplitude value. Each power amplitude value is compared to an upper lower reference power levels and a lower reference power level. A trigger signal is generated when the power amplitude value in any frequency bin is above the lower reference power level and below the upper reference power level for a specified time duration. | 08-12-2010 |

20090105980 | PLASMA PROCESSING APPARATUS AND METHOD FOR DETECTING STATUS OF SAID APPARATUS - The invention provides a method for detecting and managing the status of a plasma processing apparatus with high sensitivity so as to enable long-term stable processing. In a plasma processing apparatus comprising a vacuum processing chamber | 04-23-2009 |

20100191493 | Spectrum Searching Method That Uses Non-Chemical Qualities of the Measurement - Methods and systems for determining information about a sample are disclosed. The methods can include measuring spectral information for the sample and determining a quantity related to a signal-to-noise ratio for the spectral information, repeating the measuring and determining until a value of the quantity is beyond a threshold value, and comparing the spectral information to reference information to determine the information about the sample. | 07-29-2010 |

20110153247 | Method and Device for Determining a Frequency Mask for a Frequency Spectrum - A method and a device for determining a frequency mask disposed above or below a frequency spectrum of a detected signal determines every individual ordinate value of a first envelope curve disposed completely above or below the frequency spectrum as the maximum value or minimum value of a given number of respectively adjacent ordinate values of the frequency spectrum linked to a window function. Following this, each individual ordinate value of a second envelope curve disposed completely above or below the frequency spectrum and completely above or below the first envelope curve is determined as the maximum value or minimum value of a given number of respectively adjacent ordinate values of the frequency spectrum linked to a window function. Finally, a minimum number of ordinate values of the frequency mask from ordinate values of the first and/or second envelope curve disposed completely between the first and second envelope curve is determined, wherein in each case two successive ordinate values of the frequency mask with a maximum horizontal spacing distance within the first and second envelope curve can be reached in a linear manner relative to one another. | 06-23-2011 |

20110257918 | SPECTRUM SEARCHING METHOD THAT USES NON-CHEMICAL QUALITIES OF THE MEASUREMENT - Methods and systems for determining information about a sample are disclosed. The methods can include measuring spectral information for a sample and determining a quantity related to a signal-to-noise ratio for the spectral information, repeating the measuring and determining until a value of the quantity is beyond a threshold value, and comparing the spectral information to reference information to determine information about the sample. | 10-20-2011 |

20110077886 | SYSTEM AND METHOD OF SELECTING WHITE GAUSSIAN NOISE SUB-BAND USING SINGULAR VALUE DECOMPOSITION - Provided is a method of selecting a white Gaussian noise sub-band using singular value decomposition (SVD). The method includes selecting a first frequency band, verifying whether a signal is included in the selected first frequency band, determining the first frequency band as a target measurement frequency when the signal is not included in the selected first frequency band, and measuring a background radio noise in the determined target measurement frequency. | 03-31-2011 |

20090132189 | METHOD FOR DETERMINING PLASMA CHARACTERISTICS - Methods for determining characteristics of a plasma are provided. In one embodiment, a method for determining characteristics of a plasma includes obtaining metrics of current and voltage information for first and second waveforms coupled to a plasma at different frequencies, determining at least one characteristic of the plasma using the metrics obtained from each different frequency waveform. In another embodiment, the method includes providing a plasma impedance model of a plasma as a function of frequency, and determining at least one characteristic of a plasma using model. In yet another embodiment, the method includes providing a plasma impedance model of a plasma as a function of frequency, measuring current and voltage for waveforms coupled to the plasma and having at least two different frequencies, and determining ion mass of a plasma from model and the measured current and voltage of the waveforms. | 05-21-2009 |

20120065911 | METHOD AND APPARATUS FOR SPECTRUM SENSING OF FM WIRELESS MICROPHONE SIGNALS - Methods and apparatus for spectrum sensing for FM wireless microphone signals are provided. The spectrum sensing algorithm developed makes use of the property that the autocorrelation function of an FM signal is a sinusoidal function provided that the frequency) deviation is much smaller than the carrier frequency and the correlation delay is small. Based on this property, a simple spectrum sensing algorithm for the FM signal is designed by computing the autocorrelation function of the received signal and matched filtering of the sinusoidal function. The spectrum sensor provided by this approach can reliably detect the target signals when a strong adjacent channel interference exists and the signal power is as low as −114 dBm. | 03-15-2012 |

20100153045 | METHOD, COUPLER AND APPARATUS FOR MEASURING RADIATED POWER - In a method for measuring a radiation power, an elliptical mirror is prepared so as to have a elliptical spherical space enclosed by a metal wall surface, the space having a rotating axis passing through two focal points. A device under test is placed in a position of one of the two focal points such that a center of radiation of a radio wave substantially coincides with the focal point, and a receiving antenna is placed in an position of an other one of the two focal points. The device under test is caused to radiate a radio wave and the radiated radio wave is reflected at the wall surface to allow the receiving antenna to receive the radio wave. Then, total radiation power of the radio wave is measured at a measurement end of the receiving antenna in accordance with an output signal from the receiving antenna. | 06-17-2010 |

20100153044 | SIGNAL ANALYZER AND METHOD FOR PRODUCING DATE THEREFORE - To produce data of an initial analysis range and a range zooming a part of it while updating them in parallel. | 06-17-2010 |

20100299092 | Fundamental wave beat component detecting method and measuring target signal sampling apparatus and waveform observation system using the same - A fundamental wave beat component frequency detecting method includes steps of obtaining the frequency fb[i] of plural peak signals which appear in a band ½ of a frequency fs from a spectrum obtained from measuring target signals sampled with the sampling frequency fs in order to detect the repetition frequency (fundamental wave component) of the measuring target signal having plural harmonic components having a similar power, assuming that each of the plural peak signals is a beat component (fundamental wave beat component) originating from the fundamental wave of the measuring target signal before and after the sampling frequency is changed so as to successively calculate each theoretical frequency fc[i,j] of the beat component (harmonic beat component) originating from the harmonic component of the measuring target signal, successively comparing the each theoretical frequency fc[i,j] with the frequency fb[i] of the plural peak signals, and determining that the peak signal which gives the theoretical frequency fc[k,j] which mostly agrees with the frequency fb[i] of the plural peak signals is a fundamental wave beat component originating from the fundamental wave of the measuring target signal. | 11-25-2010 |

20110106472 | SPECTROMETRIC MEASUREMENT APPARATUS, IMAGE EVALUATION APPARATUS, AND IMAGE FORMING APPARATUS - A spectrometric measurement apparatus includes a light radiation unit for radiating light onto a medium; a hole array including openings arranged one-dimensionally for transmitting diffusion light from the medium; an imaging optical system configured to focus an image from the hole array; a diffraction element configured to diffract the light for focusing the image; and a light receiving unit including pixels arranged one-dimensionally configured to receive the light that has been dispersed by the diffraction element and spectrometric sensors each corresponding to a predetermined number of the pixels. The light transmitted through each of the openings of the hole array is dispersed by the diffraction element, and then the light enters the pixels so that spectral properties of the diffusion light are acquired. The structure of the diffraction element includes variations that are formed in accordance with the height of the image that is focused by the imaging optical system. | 05-05-2011 |

20100094577 | SIGNAL QUALITY MEASUREMENT DEVICE, SPECTRUM MEASUREMENT CIRCUIT, AND PROGRAM - Spectrum measurement circuit ( | 04-15-2010 |

20090192742 | PROCEDURE FOR INCREASING SPECTRUM ACCURACY - The method patented enables increase in reliability of periodicity estimates, and consequently of the natural band (of an object; of a body; of a system; etc.) definition too. The patented method is based on the least squares spectral analysis (LSSA) method. The LSSA has been proven over the past thirty years to be fully able of replacing the Fourier and Fourier-based spectral analysis methods (as the most used methods of spectral analysis in all sciences). The here patented method then uses this known feature of the LSSA as a reliable periodicity estimator, and expands its application by claiming that periodicity estimates generally (in all sciences and in all situations) could be improved by removing a number of measurements from the original dataset. Thus, by removing the least reliable (where ‘least’ is according to some, e.g., well-known, criteria) measurements from the dataset of interest, one can estimate periodicities in any (complete or not) type of a numerical record to the logically greatest extent possible. | 07-30-2009 |

20100070226 | Analysis of Chirp Frequency Response Using Arbitrary Resampling Filters - Log chirp testing where a log chirp may be provided to a device under test and a first time domain response from the device under test may be received. The first time domain response may be in the time domain. The first time domain response may be converted to the angular domain to create an angular domain response. Converting to the angular domain response may include resampling the time domain response from the time domain to the angular domain. The angular domain response may be filtered and/or analyzed. The angular domain response may be converted to a second time domain response. Similar to above, the conversion may include resampling the angular domain response from the angular domain to the time domain. The first time domain response and the second time domain response may be analyzed. Testing results of the device under test may be generated and stored based on said analyzing. | 03-18-2010 |

20080319692 | TRANSDUCER HEALTH DIAGNOSTICS FOR STRUCTURAL HEALTH MONITORING (SHM) SYSTEMS - A method for diagnosing the health of a transducer may include transmitting a signal to a transducer to cause the transducer to transmit a stress wave into an object being monitored, wherein the signal has a predetermined frequency range or bandwidth. The method may also include receiving response data for the transducer and transforming the response data to data representative of an impedance curve of impedance versus frequency for the predetermined frequency range. The method may further include extracting selected parameters from the impedance curve to diagnose the health of the transducer. | 12-25-2008 |

20130018615 | METHOD AND SYSTEM FOR MEASURING FREQUENCYAANM CHOU; MING-HUNGAACI TAIPEI CITYAACO TWAAGP CHOU; MING-HUNG TAIPEI CITY TWAANM WANG; NAI-JIANAACI TAIPEI CITYAACO TWAAGP WANG; NAI-JIAN TAIPEI CITY TWAANM HSIEH; CHING-FENGAACI TAIPEI CITYAACO TWAAGP HSIEH; CHING-FENG TAIPEI CITY TW - A method for measuring frequency includes the steps of obtaining the cycle number of the clock rate of a signal under test based on a reference signal and a clock mask synchronous with the signal under test; obtaining a frequency of the signal under test based on the cycle number; correcting the frequency of the signal under test based on a plurality of phase shift signals generated based on the reference signal; and minimizing an error of the frequency of the signal under test by increasing the quantity of the phase shift signals. The method enhances the accuracy of the obtained frequency of the signal under test, speeds up frequency measurement, and reduces the required circuit areas. A system for measuring frequency is further introduced for use with the method. | 01-17-2013 |

20100235124 | OCCUPANCY MEASUREMENT AND TRIGGERING IN FREQUENCY DOMAIN BITMAPS - A method is disclosed for triggering upon signal events occurring in frequency domain signals. The method includes repeatedly sampling a time-varying signal and generating a plurality of digital frequency domain spectrums based on the samples of the time-varying signal. A frequency domain bitmap for the time-varying signal is repeatedly updated via application of the digital frequency domain spectrums. The method further includes selecting a portion of the frequency domain bitmap, determining a signal occupancy in the selected portion, and triggering a capture of the time-varying signal based on and in response to the occupancy determination for the selected portion of the bitmap. | 09-16-2010 |

20100204939 | TIME QUALIFIED FREQUENCY MASK TRIGGER - A time qualified frequency mask trigger triggers on signals that violate a frequency mask for at least a specified time duration. A frame of digital data representing an input signal is transformed into a frequency spectrum having at least one frequency bin, with each frequency bin having a power amplitude value. A trigger signal is generated when any of the power amplitude values violates an associated reference power level for at least a specified time duration. | 08-12-2010 |

20090326845 | PROBABILITY DENSITY FUNCTION SEPARATING APPARATUS, PROBABILITY DENSITY FUNCTION SEPARATING METHOD, NOISE SEPARATING APPARATUS, NOISE SEPARATING METHOD, TESTING APPARATUS, TESTING METHOD, CALCULATING APPARATUS, CALCULATING METHOD, PROGRAM, AND RECORDING MEDIUM - There is provided a probability density function separating apparatus that separates a predetermined component in a given probability density function, including: a domain transforming section that is supplied with the probability density function and transforms the probability density function into a spectrum in a frequency domain; and a standard deviation computing section that computes standard deviation of a random component included in the probability density function based on the spectrum. | 12-31-2009 |

20100070225 | System and method for identifying appliances by electrical characteristics - Illustrative embodiments provide systems, applications, apparatuses, computer software program products, and methods related to identification of electrical appliances by electrical characteristics. | 03-18-2010 |

20130024150 | Signal processing in guided wave cutoff spectroscopy - The present invention includes a guided microwave spectroscopy system ( | 01-24-2013 |

20100305894 | METHOD AND DEVICE FOR DETERMINING THE FREQUENCY DISTRIBUTION OF THE SIGNAL LEVELS OF A MEASURED SIGNAL MEASURED IN OVERLAPPING OBSERVATION INTERVALS - A method for determining the frequency distribution of the signal level of a measured signal measured respectively in overlapping observation intervals via a time or frequency raster. The method includes determining the incrementation of a memory cell in a first memory to be implemented for each measured signal level of the measured signal at a value of the time or frequency raster, and un-delayed summation of the incrementation determined for every memory cell of the first memory in every measurement cycle. The method also includes delayed summation of the incrementation determined for every memory cell of the first memory in every measurement cycle, and subtracting the result of the delayed summation of the incrementation determined for every memory cell of the first memory in every measurement cycle from the result of the un-delayed summation of the incrementation determined for every memory cell of the first memory in every measurement cycle. | 12-02-2010 |

20110276293 | FREQUENCY SPECTRUM ANALYZING APPARATUS - A frequency spectrum analyzing apparatus for performing a frequency spectrum analysis with respect to a detected value of an operating parameter of an internal combustion engine in synchronism with rotation of the engine, is provided. The operating parameter is sampled at predetermined time intervals, and the sampled value is converted to a digital value. Intensities of first and second elements are calculated with respect to a predetermined number of the sampled values, wherein the first and second elements respectively correspond to a plurality of frequency components contained in the detected value, and a phase of the second element differs from a phase of the first element by 90 degrees. Frequency component intensities corresponding to the plurality of frequencies are calculated in synchronism with rotation of the engine, using the first element intensities and the second element intensities. Offset components contained in the first element intensities and the second element intensities are calculated, and the frequency component intensities are calculated after removing the offset components from the first and second element intensities. | 11-10-2011 |

20140142880 | COMBINATORIAL MASK TRIGGERING IN TIME OR FREQUENCY DOMAIN - Embodiments of the invention include methods and instruments for performing combinatorial mask triggering. One or more mask triggers can be configured. Combinatorial mask triggering logic can make various determinations about the relationship between a digitized signal and the one or more mask triggers. The various determinations about the relationship can include considerations of both space and time. When the combinatorial trigger criteria have been satisfied, a trigger signal is generated, and the digital data associated with an incoming signal is stored to memory. The combinatorial mask triggering logic can operate on signals in the frequency domain, the time domain, or both. | 05-22-2014 |

20130253867 | Signal Processing Method and Associated Apparatus - A signal processing apparatus for receiving a spectral line of an original signal includes a starting point determining module, a searching module and a symbol rate determining module. The starting point determining module finds a maximum energy in the spectral line and determines at least one search starting point according to the maximum energy. From the at least one search starting point, the searching module searches along the spectral line towards a region with a lower energy for at least one minimum energy satisfying a predetermined condition. The symbol rate determining module determines a symbol rate of the original signal according to the at least one minimum energy. | 09-26-2013 |

20130066577 | ROBUST SPECTRAL ANALYZER FOR ONE-DIMENSIONAL AND MULTI-DIMENSIONAL DATA ANALYSIS - A method of analyzing a spectrum of one-dimensional or multi-dimensional signal X(t) requires a number of steps including deriving coefficients [A | 03-14-2013 |

20130325383 | Monitoring and Analysis of Power System Components - Various methods and systems are provided for monitoring and analysis of electrical components. In one embodiment, a method includes obtaining raw radio frequency (RF) component data associated with an electrical component, cross-correlating the raw RF component data with a synchronized pseudo-random sequence (PRS) signal injected into the electrical component to determine a correlated impulse response, and determining a condition of the electrical component based at least in part upon the correlated impulse response. In another embodiment, a system includes a signal injection system coupled to an electrical component. The signal injection system injects a synchronized PRS signal into the electrical component. A data capture device obtains raw RF component data synchronized with the PRS signal through a RF antenna. A data analysis device cross-correlates the raw RF component data with the PRS signal to determine characteristics associated with the electrical component. | 12-05-2013 |

20130030742 | METHOD AND SYSTEM FOR MONITORING A SYNCHRONOUS MACHINE - A method for monitoring a synchronous machine is described. The method includes injecting a narrowband sinusoidal signal at a first end of a field winding of the synchronous machine. The method further includes monitoring a voltage at a second end of the field winding with respect to ground. The method then identifies a resonant frequency based on the monitored voltage, and generates a winding health indicator based on the identified resonant frequency and an expected resonant frequency. | 01-31-2013 |

702077000 | Using Fourier method | 33 |

20090125261 | METHOD FOR ANALYZING AC VOLTAGE SIGNALS - A method is disclosed for efficiently analyzing an AC voltage signal with a transformation which transforms the signal from a representation in the time-domain to a representation in the frequency-domain. This transformation can be a fast Fourier transform, a discrete Fourier transform or a Laplace transform. By selecting a higher sampling frequency which is an integer multiple of the standard sampling frequency, the zero crossings of the AC voltage signal can be determined more accurately, which improves the quality of the frequency analysis. | 05-14-2009 |

20090125260 | METHOD AND DEVICE FOR PERFORMING A FREQUENCY ANALYSIS OF AN AC VOLTAGE SIGNAL, IN PARTICULAR ON A POWER GRID - In a method for performing a frequency analysis of an AC voltage signal, in particular in a power mains, an upper limit of the period length of a fundamental oscillation in the AC voltage signal is determined. A sequence of sampling values of the AC voltage signal is obtained over a duration longer than the upper limit of the period length, thereby ensuring that more than a period of the fundamental oscillation is sampled. Selected from the sequence of sampling values is a subset of sampling values, with the subset sampling substantially one period of the fundamental oscillation. At least a portion of the sampling values not included in the subset is altered, and a frequency is calculated based on the obtained sequence of sampling values, the subset of sampling values and the altered portion of the sampling values. | 05-14-2009 |

20100106442 | GENERATION OF CONSTANT ENVELOPE OR NEARLY-CONSTANT ENVELOPE SIGNALS SATISFYING A GIVEN FOURIER TRANSFORM MAGNITUDE - One or more embodiments of the present invention relates to an iterative method for generating an almost-constant, nearly constant, or substantially-constant envelope time signal with prescribed Fourier transform magnitude in the frequency domain, and a constant envelope time signal whose Fourier transform magnitude closely matches the prescribed Fourier transform magnitude in the frequency domain. Different starting points for the iterative algorithm give rise to different solutions and their accuracy can be adjusted using a monotonic error criterion presented here. | 04-29-2010 |

20090306920 | COMPUTER SYSTEM WITH INTEGRATED ELECTROMAGNETIC-INTERFERENCE DETECTORS - Embodiments of a system that determines a condition associated with an integrated circuit disposed on a circuit board are described. During operation, the system receives electromagnetic-interference (EMI) signals from one or more antennas while the integrated circuit is operating, where the one or more antennas are disposed on the circuit board. Then, the system analyzes the received EMI signals to determine the condition. | 12-10-2009 |

20090093980 | REAL TIME SD-OCT WITH DISTRIBUTED ACQUISITION AND PROCESSING - The present invention relates to distributed computing system to acquire, process, and display OCT images at real-time frame rates. | 04-09-2009 |

20090082981 | METHOD AND APPARATUS FOR MEASUREMENT OF AMPLITUDE OF PERIODIC SIGNAL AND METHOD AND APPARATUS FOR TEST OF MAGNETIC HEAD - A method for measurement of amplitude of a periodic signal which is noise-robust, free of the effects of leakage of the frequency component, and free of any unbalance between the + side amplitude and − side amplitude, comprising (i) converting a periodic signal to a digital signal, (ii) applying a discrete Fourier transform to this digital periodic signal, calculating the magnitudes and phases of a fundamental frequency component and harmonic frequency components of the periodic signal in the frequency domain, (iii) applying an inverse discrete Fourier transform to the calculated frequency components to reconstruct the waveform in the time domain, and (iv) measuring the amplitude of the periodic signal from the waveform data at the center part of the reconstructed waveform on the time axis. | 03-26-2009 |

20090144004 | Method and Device for Spectral Analysis in Several Frequency Bands with Different Frequency Resolution - A method for spectral analysis of a signal (s | 06-04-2009 |

20090177423 | SIGNAL DETECTION USING DELTA SPECTRUM ENTROPY - Disclosed is a method of signal detection. A received input signal is divided into a frame unit and each input signal present in a first frame and a second frame is transformed into a frequency signal. Then, first power spectrum information and second power spectrum information are computed utilizing the transformed frequency signal and a delta spectrum entropy value corresponding to a difference of the two computed power spectrum information is obtained. A predetermined input signal is included in a predetermined frame among the input signal after judging through comparing the delta spectrum entropy value with a critical value. Desired signal can be detected in a noisy environment including a noise signal by using the delta spectrum entropy value. | 07-09-2009 |

20080208496 | Device for identifying consumer devices in an electric network and process for operating the device - The invention relates to a device for identifying consumer devices in an electric network ( | 08-28-2008 |

20090082982 | TRIGGER EVENT DETECTION APPARATUS AND METHOD THEREFOR - A method of detecting a trigger event comprises receiving an input signal for analysis. The received input signal is used to generating first data corresponding to energy of a frequency content of the input signal as the input signal changes with time. At least part of the first data is then compared with second data, the second data corresponding to a predetermined time-varying spectrum indicative of the trigger event. A trigger signal is then generated in response to a change in a state of match between the at least part of first and the second data. | 03-26-2009 |

20090187363 | Method for optimization of a frequency spectrum - A method for optimization of a frequency spectrum includes the following steps: sampling a time domain signal to obtain an initial sampling signal based upon a first subset of sample points; transforming the initial sampling signal to a frequency domain signal; determining a frequency parameter and an amplitude parameter for each of harmonic components of the frequency domain signal; establishing a leakage energy equation and a graduation shifting quantity; determining an optimum number of sample points that will result in minimum leakage energy; obtaining an adjusted sampling signal based on a second subset of the sample points, wherein the number of the sample points in the second subset is equal to the optimum number; and transforming the adjusted sampling signal to an optimized frequency domain signal having harmonic components associated with graduations of an optimized frequency spectrum, wherein the graduations are calculated based upon the graduation shifting quantity. | 07-23-2009 |

20090254292 | FREQUENCY RESOLUTION USING COMPRESSION - In a frequency analysis system, such as a signal detection system or a spectrum analyzer, the frequency domain resolution is enhanced by compression and decompression of the signal samples. The limited capacity of the data storage and/or data transfer resources limit the number of samples that can be stored or transferred. A compressor forms a compressed signal prior to data transfer or storage. A decompressor decompresses the compressed signal prior to transformation to the frequency domain, by a fast Fourier transform or other frequency domain transform. The frequency domain resolution is enhanced because more decompressed samples are available for the frequency domain transform. The compressor and decompressor apply computationally efficient algorithms that can be implemented to operate in real time. | 10-08-2009 |

20100228509 | SPECTRAL ANALYSIS - A method of processing an input signal for performing spectrum analysis is disclosed. The input signal comprises a desired signal and an interference signal. A crosslation is performed to process an input signal to efficiently produce discrete-time crosslation function values for the input signal. A Fourier Transform is then performed to generate frequency-dependent values. The method is particularly useful when the interference is of an impulsive or transient nature. | 09-09-2010 |

20090150102 | Spectral Analysis with adaptive resolution - The present invention discloses a method of spectral analysis, backward compatible (both methodically and computationally) with traditional Fourier-based techniques, but free from limitation of static time-frequency resolution, which is often a cause of measurement inaccuracy. It is disclosed a techniques to combine convenience of Fourier-based techniques with advantages of MRA. | 06-11-2009 |

20090006016 | System and method for detecting a weak signal in a noisy environment - Systems and methods are disclosed for computing a power spectral density of a signal. One such method computes a Fast Fourier Transform (FFT) of a first signal segment and an FFT of a second signal segment. The first and second segments are adjacent and non-overlapping in time, and the second segment follows the first. The first FFT is multiplied by a complex conjugate of the second FFT. A first complex value is computed from this first product. An FFT of a third signal segment is computed. The second and third segments are adjacent and non-overlapping in time. The third segment follows the second segment. The second FFT is multiplied by a complex conjugate of the third FFT. A second complex value is computed from this second product. The first and second complex values are added, and the power spectral density of the sum is computed. | 01-01-2009 |

20120303307 | CIRCUIT AND METHOD FOR DETECTING OSCILLATING FREQUENCY DRIFT - An oscillating frequency drift detecting method, which comprises: receiving an oscillating signal with an oscillating frequency, wherein the oscillating signal is generated by a crystal oscillator; generating a self-mixing signal according to the oscillating signal; obtaining a self-mixing frequency of a maximum power of the self-mixing signal in a specific frequency range; and computing a frequency drift of the oscillating frequency, according to the self-mixing frequency of the maximum power, and the oscillating frequency. | 11-29-2012 |

20110077887 | WAVELENGTH-MULTIPLEXED OPTICAL SIGNAL MEASUREMENT DEVICE AND THE METHOD THEREOF - Light to be measured L and sampling pulse light L | 03-31-2011 |

20120004878 | DETECTOR ASSEMBLY FOR USE IN ENVIRONMENTS CONTAINING BACKGROUND MAGNETIC NOISE AND METHOD THEREOF - A method and system for detecting a signal source at a specified frequency in the presence of background noise includes a processor; a first sensor mounted at a first location operatively connected to the processor; a second sensor mounted at a second location operatively connected to the processor; the processor operating to compute the amplitudes of the first and second Fourier transforms of the outputs of the first and second sensors, respectively, the difference in the amplitudes of the first and second Fourier transforms being determinative of the existence of a signal being generated at the predetermined frequency. | 01-05-2012 |

20100250169 | METHOD AND APPARATUS FOR EVALUATING DATA REPRESENTING A PLURALITY OF EXCITATIONS OF A PLURALITY OF SENSORS - A method for evaluating data representing a plurality of excitations of a plurality of sensors; the method comprising: (a) storing the data as a plurality of entries in an information store; each respective sensor-excitation pair being a respective entry; (b) exercising a fit relationship employing at least one first sine value to determine a fit value substantially simultaneously for at least a portion of the plurality of entries; (c) ascertaining a measure of fit error between the data and the fit value for the portion of entries; (d) employing the measure of fit error to estimate at least one next sine value; (e) employing the at least one next sine value to perform a fit optimization operation with the data substantially simultaneously for the portion of entries; and (f) repeating steps (c) through (e) until a desired number of the sine values has been exercised. | 09-30-2010 |

20100250170 | INTERROGATION METHOD FOR PASSIVE WIRELESS SENSOR INTERROGATION SYSTEM - A method of wirelessly interrogating a sensing device comprising a plurality of passive sensors, to determine a measurement parameter, comprises the steps of repeatedly interrogating the sensing device using a predetermined transmission signal and detecting the response; estimating the measurement parameter for each sensor by means of an analysis of the data accumulated as a result of the interrogation step, and determining the average of the parameters derived from the estimating step for each sensor, using a weighted average, in which the weightings depend on the amplitude of the sensor response. The measurement parameter may be a resonant frequency where the passive sensors are resonant devices, and the sensors may be SAW devices. | 09-30-2010 |

20120265465 | SIGNAL ANALYZING SYSTEM AND METHOD USING CONTINUOUS SHIFTED TRANSFORM - A signal analyzing system is provided. The signal analyzing system includes a band pass filter (BPF), a sampling unit and a continuous shifted transform (CST) unit. The BPF filters an input signal to obtain a filtered signal. The sampling unit samples the filtered signal to obtain a discrete signal according to a sampling frequency. The CST unit obtains a first frequency spectrum according to the N discrete signals that are sampled continuously, and obtains a second frequency spectrum according to a (N+1) | 10-18-2012 |

20120232821 | MULTI-CHANNEL OPTICAL COHERENCE TOMOGRAPHY FOR IMAGING AND TEMPERATURE AND FORCE SENSING - Embodiments of the invention provide multi-channel OCT (Optical Coherence Tomography) for imaging biological tissue or the like, and for temperature and/or force sensing, preferably in real time. In one embodiment, an optical signal processing system comprises: a processor; a memory; a receiving module to receive in real time input from multiple channels of OCT producing interfering optical signals representing multiple measured distances for a target imaging object; a Fast Fourier Transform (FFT) module to apply FFT on the interfering optical signals in real time to produce Fourier frequencies corresponding to the multiple measured distances; and a calculation module to calculate in real time multiple force components of a force applied on the target imaging object to cause at least some of the multiple measured distances for the target imaging object based on the Fourier frequencies from the FFT module. | 09-13-2012 |

20090198462 | Method, system and analog stimulus-response unit for determining real and imaginary components of an AC response received from a device under test - In one embodiment, samples of an AC response received from a device under test (DUT) are acquired at an interval, Δt, of k/(f | 08-06-2009 |

20110320148 | METHOD AND APPARATUS FOR GENERATING A GATED DENSITY BITMAP - A test and measurement instrument converts digital data that represents an input signal into a series of frequency spectra and accumulates frequency spectra into a bitmap database in response to a gating signal. In some embodiments, the gating signal is generated when the instantaneous power of the input signal violates a power threshold. | 12-29-2011 |

20120150469 | ELECTRONIC DEVICE COOLING FAN TESTING - System and method implementations for testing a cooling fan in an electronic device are disclosed. As one example, a method of testing a cooling fan of a sample electronic device is disclosed that includes generating an audio input at an audio speaker and receiving an audio output at an audio microphone to obtain an audio output signal. The method further includes processing the audio output signal to identify frequency modulation in the audio output signal, and identifying a state of motion of fan blades of the cooling fan based, at least in part, on the frequency modulation. | 06-14-2012 |

20090144005 | Method for ascertaining the harmonic components of an analog electrical signal at a fundamental frequency which changes over time - A method is disclosed for ascertaining the harmonic components of a periodic analog signal at a fundamental frequency which changes over time. The analog signal is digitized and then fast Fourier transformation of the signal is performed. To avoid tracking the sampling frequency, in at least one embodiment the target signal is produced by modulating the analog signal using a first carrier frequency to form two frequency sidebands, the first carrier frequency being chosen to be greater, particularly several orders of magnitude greater, than the fundamental frequency of the analog signal, then filtering one of the two frequency sidebands out of the modulated analog signal, then modulating the filtered-out frequency sideband using a second carrier frequency to form two frequency sidebands again, the second carrier frequency being greater, particularly several orders of magnitude greater, than the fundamental frequency of the analog signal, and the difference between the second and first carrier frequencies respectively being the same as the discrepancy between the fundamental frequency and the target fundamental frequency, and outputting one of these two frequency sidebands as the analog target signal which is to be produced in order to calculate the fast Fourier transformation. | 06-04-2009 |

20120136600 | USING CONTINUOUS SWEEP FREQUENCIES IN A SYSTEM FREQUENCY RESPONSE TEST - A system and method for measuring the frequency response of a system under test using a single swept-frequency chirp signal. A tapered chirp-frequency test signal is created with a bandwidth defined by first and second frequencies. The test signal is routed to a calibration path, and the output of the calibration path is routed to a digitizer. The output of the calibration path is digitized, and a Fourier transform of the calibration path output is generated. The test signal is then routed to a test system, and the output of the test system is coupled to the digitizer. The output of the test system is digitized, and a Fourier transform of the test system output is generated. A normalized frequency-domain representation of the test system created by dividing the Fourier transform of the test system output by the Fourier transform of the calibration path output. | 05-31-2012 |

20090312971 | APPARATUS AND METHOD FOR LOCATING INFERIOR PARTS IN POWER DISTRIBUTION LINE EQUIPMENT BASED ON VARIATION OF RADIO FREQUENCY NOISE SIGNAL - An apparatus for locating inferior parts in distribution line equipment may include a wireless noise receiver for continually receiving multiple noise-free frequencies and converting the received multiple noise-free frequencies into an audio frequency signal, a signal processor for quantifying a power frequency and harmonic frequencies of the audio frequency signal, a signal analyzer for calculating variation of the power frequency and the harmonic frequencies, determining the number of changed frequencies based on the calculated variation, detecting a radio frequency noise signal generated from an inferior part based on the calculated variation and the number of changed frequencies, and a frequency calibrator for determining a noise-free band, selecting the multiple noise-free frequencies from the noise-free band, and managing a list of the selected multiple noise-free frequencies. | 12-17-2009 |

20090299666 | Fourier Transform-Based Phasor Estimation Method and Apparatus Capable of Eliminating Influence of Exponentially Decaying DC Offsets - Disclosed herein is a Fourier transform-based phasor estimation method and apparatus capable of eliminating the S influence of exponentially decaying DC offsets. According to a Fourier transform-based phasor estimation method according to an embodiment of the present invention, an input signal is sampled, and samples of one-cycle data of the input signal are separated into at least two sample groups. A Discrete Fourier Transform (DFT) is performed on each of the sample groups. A DC offset included in the input signal is calculated on a basis of results of the DFT on each of the sample groups, and an error caused by the DC offset is calculated using the calculated DC offset. A phasor of a fundamental frequency component included in the input signal is estimated by eliminating the calculated error, caused by the DC offset, from the results of the DFT on the input signal. | 12-03-2009 |

20100070227 | System and method for identifying appliances by electrical characteristics - Illustrative embodiments provide systems, applications, apparatuses, computer software program products, and methods related to identification of electrical appliances by electrical characteristics. | 03-18-2010 |

20110166814 | ELECTRICAL NETWORK ANALYSIS OF A MULTIPHASE SYSTEM - A method for determining characteristics of a multi-material object is provided. The method includes determining an electric element matrix representing the multi-material object. The electric element matrix is pre-multiplied by a first mathematical transformation matrix to obtain a first transformed electric element matrix. The first transformed electric element matrix is post-multiplied with a second mathematical transformation matrix to obtain a second transformed electric element matrix. The method further includes determining the characteristics of the multi-material object based on the second transformed electric element matrix. | 07-07-2011 |

20120130665 | TIME DOMAIN ELECTROMAGNETIC INTERFERENCE MONITORING METHOD AND SYSTEM - This invention relates to a method of, and a system for, monitoring electromagnetic interference. The method comprising capturing a plurality of time domain waveforms, and a plurality of scatter plots; receiving the plurality of captured time domain waveforms and scatter plots; applying a fast fourier transform (FFT) to each of the received time domain waveforms as it is received thereby to receive FFT outputs; storing the FFT outputs in a database; generating a statistically representative spectrograph or spectrogram in the frequency domain based on at least the stored FFT outputs and scatter plots or data associated with the scatter plots, combining constituent FFTs of the statistically representative spectrograph or spectrogram in such a manner as to emulate the result that would be produced by an EMI (Electromagnetic Interference) receiver or spectrum analyser; and combining resultant outputs from a number of iterations of this process to produce a final result (EMI spectrum). | 05-24-2012 |

20130030743 | METHOD FOR IDENTIFYING HIGH-SPEED FREQUENCY RESPONSE OF MULTIRATE SYSTEM AND APPARATUS THEREFOR - There is provided with a method of identifying a frequency response of a controlled object at a sampling period of control input in a multiplexed-input multirate system in which a sampling period of control output is even “P” multiples of the sampling period of control input wherein the control object is represented by FIR filter, an M-series signal corresponding to an acquisition data length Mp×P−1 is generated, the Mp indicates a period of the M-series signal, an impulse response value of the controlled object is estimated based on the M-series signal and output data outputted from the controlled object by inputting the M-series signal thereto, and the frequency response of the controlled object is identified by performing a discrete Fourier transform on the impulse response value. | 01-31-2013 |