Showing papers on "Spectrum analyzer published in 2003"

Compact apparatus for noninvasive measurement of glucose through near-infrared spectroscopy

Abstract: The invention involves the monitoring of a biological parameter through a compact analyzer. The preferred apparatus is a spectrometer based system that is attached continuously or semi-continuously to a human subject and collects spectral measurements that are used to determine a biological parameter in the sampled tissue. The preferred target analyte is glucose. The preferred analyzer is a near-IR based glucose analyzer for determining the glucose concentration in the body.

System and method for real-time spectrum analysis in a radio device

Abstract: A real-time spectrum analysis engine (SAGE) that comprises a spectrum analyzer component, a signal detector component, a universal signal synchronizer component and a snapshot buffer component. The spectrum analyzer component generates data representing a real-time spectrogram of a bandwidth of radio frequency (RF) spectrum. The signal detector detects signal pulses in the frequency band and outputs pulse event information entries output, which include the start time, duration, power, center frequency and bandwidth of each detected pulse. The signal detector also provides pulse trigger outputs which may be used to enable/disable the collection of information by the spectrum analyzer and the snapshot buffer components. The snapshot buffer collects a set of raw digital signal samples useful for signal classification and other purposes. The universal signal synchronizer synchronizes to periodic signal sources, useful for instituting schemes to avoid interference with those signals.

Real-time spectrum analysis in microstrip technology

Abstract: We report on a time-domain analog in microwave lines to the spatial Fraunhofer (far-field) diffraction in paraxial conditions. Microstrip lines are used to design filtering configurations acting as spectrum analyzers. They are based on linearly chirped distributed Bragg coupling between the fundamental microstrip mode and the same but counterpropagating mode. Linearly chirped continuous impedance modulation in a microstrip line with varying upper plane strip-width is shown to yield a mode-coupling location and group delay linearly distributed in frequency. Under the condition of a temporal equivalent to the spatial Fraunhofer inequality, the energy spectral density of the input signal is directly recoverable from the average output (reflected) power. It is only necessary to take into account a linear axis-change, given by the dispersion coefficient (group-delay slope) of the structure, from time to Fourier frequency. Both pulsed and nonpulsed RF signals are studied. Sequential time-gated segments of the input have to be processed in the nonpulsed case. The maximum frequency resolution achievable in this situation is discussed. The devices developed here could have important potential applications in the field of temporal signal processing, such as filtering using time-division techniques.

Qubits as Spectrometers of Quantum Noise

Abstract: Electrical engineers and physicists are naturally very interested in the noise of circuits, amplifiers and detectors. This noise has many origins, some of which are completely unavoidable. For example, a dissipative element (a resistor) at finite temperature inevitably generates Johnson noise. Engineers long ago developed spectrum analyzers to measure the intensity of this noise. Roughly speaking, these spectrum analyzers consist of a resonant circuit to select a particular frequency of interest, followed by an amplifier and square law detector (e.g. a diode rectifier) which measures the mean square amplitude of the signal at that frequency.

Single-scan interferometric component analyzer

Abstract: We describe a novel interferometric method for characterizing optical components in the 1.5-/spl mu/m communications band. A complete polarization-resolved characterization of optical components is achieved with just one scan of a tunable laser. Measurements of three devices are presented, including a molecular gas cell, an arrayed waveguide grating, and a tunable dispersion compensator. A dynamic range of greater than 80 dB is demonstrated.

Plasma frequency measurements for absolute plasma density by means of wave cutoff method

Abstract: A method for precise measurements of absolute electron density in the plasma using plasma frequency is developed. A microwave perturbation of a frequency is introduced to plasma from a network analyzer and transmits in the plasma. The transmitting wave at a distance from a radiating antenna is monitored using a spectrum analyzer to scan the perturbing frequency. The transmitting wave rapidly decays by a cutoff at the plasma frequency, which gives the absolute electron density. The transmitting waves of some frequency including plasma frequency are characterized. The measured plasma frequency by this method is coincident with that obtained by the plasma oscillation method.

Wideband versatile radio-frequency spectrum analyzer

Abstract: Operation of a wideband, versatile optical spectrum analyzer for radio-frequency (RF) signals is demonstrated. The device is based on spectral hole burning (SHB). The demonstration features 2.3-GHz instantaneous bandwidth, 500-kHz resolution, and a 32-dB dynamic range. A true RF signal, transferred to the optical carrier with the help of a Mach-Zehnder modulator, is analyzed with optical carrier suppression and zooming capabilities. This is to the authors' knowledge the largest instantaneous bandwidth ever demonstrated for a SHB-based processor in rare-earth-doped crystals.

Phased micro analyzer VIII

Abstract: A micro fluid analyzer that may be highly sensitive, fast and very compact. The analyzer may use sufficiently low power per analysis to be easily implemented with an equivalently small battery pack or other portable power source. There may be energy conservation features in the analyzer, such as optimal adsorber film thicknesses in the pre-concentrator, concentrator and chromatographic separators. There may be special timing of the phased heating elements in the concentrators and separators to further reduce energy consumption. Various kinds of detectors and sensors may be incorporated in the analyzer for achieving low probability for false positives and detection versatility. There may be a controller that provides data acquisition and analyses, drive signals for control, management of wireless signal transmission and reception, processing, and other operational uses of the micro analyzer.

Method of providing assay processing in a multi-analyzer system

Abstract: A multi-analyzer system where at least two automatic clinical analyzers (10, 11) are linked together by a bi-directional sample rack shuttle (68), both analyzers initially capable of performing a slightly different menu of assays. The bi-directional incoming and outgoing sample rack transport system (73) of a first one of the two analyzers is automatically converted into a one-way incoming sample rack transport system and the incoming sample tube transport system (76) of a second of the two analyzers is automatically converted into a one-way outgoing transport system adapted to dispose of all sample racks having sample tubes with sample finally tested by either analyzer. In the event that one of the two analyzers experiences an operating failure, the analyzer system may automatically revert to a single analyzer system employing only the operational analyzer.

Dupont Circle Spectrum Utilization During Peak Hours

Abstract: Measurement Procedure and Results Using a Rohde & Schwarz EPSI Spectrum Analyzer connected to a laptop for data gathering purposes, several hours of data were collected over a contiguous range of frequencies between 30MHz and 3GHz. The measurement equipment was placed in an electromagnetically shielded enclosure to ensure the cleanest possible spectrum readings. Two types of antennae, each with particular benefits for use at frequencies above and below 1GHz, were mounted above the highest point of the roof, feeding signals to the spectrum analyzer via several meters of RG-8 coaxial cable.

Method of saving power in communication devices

Abstract: An electronic device with a power saving circuit incorporates a radio frequency receiver with low power consumption and including a frequency down converter. A functional device, which may be a high power radio receiver, is normally turned off during a period of inactivity. An analyzer detects a predetermined identification code in a received radio frequency signal and outputs a signal to turn on the functional device.

Acoustic signal processing apparatus and method, and audio device

Abstract: A first band analyzer divides an acoustic signal received from a sound playback system through an input unit into frequency bands, and generates a first band level. An acoustic signal estimator estimates the band level of the original acoustic signal at the input unit, and generates a second band level for each band. A processor extracts an external noise component which is contained in the acoustic signal using the first band level and the second band level. The external noise can be accurately estimated with less computation than in the related art.

Vibration analyzer and method

Abstract: A tool and method to identify a defect in a vehicle through a vibration frequency is provided. To identify the defect in a vehicle, a sensor senses a vibration frequency and generates a signal in response to the vibration frequency. In addition, a signal spectrum analyzer communicates with the sensor and identifies the defect in response to the signal.

Method and apparatus for thickness decomposition of complicated layer structures

Abstract: Thickness measurement apparatus for measuring layer thicknesses on patterned areas of a semiconductor wafer, comprises: a spectrum analyzer for obtaining reflection data taken from a patterned area and obtaining therefrom a frequency spectrum, a peak detector for searching the spectrum to find peak frequencies within said spectrum, the search being restricted to regions corresponding to peak frequencies found in an earlier learning stage, a frequency filter (56), associated with the peak detector, for filtering the spectrum about said peak frequencies, and a maximum likelihood fitter (60) for using parameters obtained in the learning stage to carry out maximum likelihood fitting of said filtered spectrum to obtain the desired layer thicknesses. By carrying out maximum likelihood fitting (60) using parameters obtained beforehand in a high resolution non-real time learning stage, it is possible to provide high resolution results in real time.

Clock jitter estimation based on PM noise measurements

Abstract: "Jitter" is the noise modulation due to random time shifts on an otherwise ideal, or perfectly on-time, signal transition. In the absence of ultra-high-speed jitter analyzers, spectrum analysis is an alternate noise measurement for timing jitter. Conventionally, jitter has been defined as a the integral of the phase noise. This paper presents a modified way of calculating timing jitter using phase-modulation (PM) noise measurements of high-speed digital clocks, which considers the frequency response of the jitter analyzer, providing a more accurate map. Measurements of phase noise are typically much more sensitive to phase (or time) fluctuations than a jitter analyzer. A summary table is provided for mapping the results of these measurements in the Fourier frequency domain to jitter in the /spl tau/ domain for various random (specifically, power-law) noise types, spurs, vibration, and power-supply ripple. In general, one cannot unambiguously map back, that is, translate from jitter measurements to phase noise.

Oscilloscope based return loss analyzer

Abstract: A system, apparatus and method for performing differential return loss measurements and other measurements as a function of frequency uses a digital storage oscilloscope (DSO) having spectral analysis functions. A waveform generator generates a differential test signal in the form of a series of pulses where each pulse includes spectral components associated with each of a plurality of frequencies of interest. A test fixture presents the differential test waveform to a load including at least one of a device under test (DUT), a short circuit, an open circuit and a balanced load. A signal acquisition device differentially measures the test waveform during each of the load conditions. The signal acquisition device computes an error correction parameter using measurements made during the short circuit, open circuit and balanced load conditions. The correction parameter tends to offset signal acquisition errors within measurements made during the DUT load condition.

Methods for delay-fault testing in field-programmable gate arrays

Abstract: Systems and methods for delay-fault testing field programmable gate arrays (FPGA's), applicable both for off-line manufacturing and system-level testing, as well as for on-line testing within the framework of the roving self-test area (STARs) approach are described. In one method according to the present invention, two or more paths under test receive a test pattern approximately simultaneously. The two paths are substantially identical and thus should propagate the signal in approximately the same amount of time. An output response analyzer receives the signal from each of the paths and determines the interval between them. The output response analyzer next determines whether a delay fault has occurred based at least in part on the interval. In one embodiment, the output response analyzer comprises an oscillator and a counter. The oscillator generates an oscillating signal during the interval between the test signal propagates through the first path under test and when the test signal propagates through the last path under test.

Method and apparatus for analysis of elements in bulk substance

Abstract: A substance analyzer utilizing Prompt Gamma Neutron Activation Analysis for identifying characteristics of a substance and method of manufacturing the same are disclosed. The analyzer is small enough to be portable and to allow its use in many applications where current analyzers cannot be utilized. The analyzer uses a neutron radiation source and a gamma-ray detector to activate the sample material and detect the prompt gamma rays emitted by the sample material. A novel housing for such an analyzer and method for making the housing are also described. Novel methods of operating such an analyzer including via a communications network are also disclosed. Also disclosed are data analysis methods that improve the accuracy and sensitivity of the results of such material analysis.

Increasing throughput of an automatic clinical analyzer system by partitioning assays according to frequency of requested performance

Abstract: A dual analyzer system comprising at least two analyzers where samples to be tested are partitioned into three groups in accord with the frequency the test assays are requested. One analyzer performs a portion of the most frequently menu assays and all of a first subgroup of less frequently requested assays. The second analyzer performs a similar portion of the most frequently menu assays and all of a second subgroup of less frequently requested assays. The first of the analyzers is not equipped to perform any of the second subgroup of assays and the second analyzer is not be equipped to perform any of the second subgroup of assays.

Method and/or apparatus for analyzing the content of a surveillance image

Abstract: An apparatus comprising an input circuit, a content analyzer, a storage circuit and an output circuit. The input circuit may be configured to generate a first intermediate signal from a plurality of input video signals. The content analyzer circuit may be configured to present one or more flags in response to the intermediate signal. The storage circuit may be configured to (i) store and organize the first intermediate signal into a plurality of sequences each related to one of the input video signals and (ii) generate a second intermediate signal from the sequences. The output circuit may be configured to generate an output video signal in response to the second intermediate signal. The output circuit may be configured to embed tracking information into the output video signal in response to the one or more flags.

Calculation and measurement of the time-of-flight spread in a hemispherical electron energy analyzer

Abstract: We have determined the transit time distribution of electrons passing a high resolution hemispherical energy analyzer. Comparison of our measured results with analytical expressions reveals that differing transit times between electrons of equal kinetic energy mainly build up on the Kepler-type orbits on which the electrons travel through the hemispheres. To facilitate the measurements, we have installed a position sensitive electron detector capable of single event detection into our spectrometer. This device is based on a delay-line anode. We briefly report on the energy resolution achieved in comparison with a slower readout system via a fluorescent screen. The transit time distribution is important in coincidence experiments, where electrons detected in the hemispherical analyzer are to be related to events in other detectors. We discuss the feasibility of electron–electron coincidence experiments using a hemispherical detector plus a time-of-flight drift tube for energy discrimination of an electron pair.

Coherent population trapping detector

Abstract: A CPT detector and a method for detecting CPT are disclosed. The CPT detector includes a quantum absorber, a polarization analyzer, and a detector. The quantum absorber includes a material having first and second low energy states coupled to a common high energy state. Transitions between the first low energy state and the common high energy state and between the second low energy state and the common high energy state are induced by electromagnetic radiation having a predetermined polarization state. The polarization analyzer blocks electromagnetic radiation of the predetermined polarization while passing electromagnetic radiation having a polarization state that is orthogonal to the predetermined polarization. The polarization analyzer is irradiated with a portion of the generated electromagnetic radiation that has passed through the quantum absorber. The detector generates a signal related to the intensity of electromagnetic radiation that leaves the polarization analyzer.

Spectrally pure excitation signals: Only a dream?

Abstract: Multi-tone excitation signals become increasingly important for test and measurement purposes. However, the signal sources used to create such multitone signals are not perfect and often create unwanted spectral contributions. This paper presents a method to create spectrally pure signals, such as two-tones or multitones, using signal sources based on arbitrary waveform generators (AWG). Only amplitude information is needed, so that a spectrum analyzer can be used to perform all necessary measurements. Unwanted spectral lines are suppressed, independent of their exact origin. This allows to apply a testsignal with the correct spectral content to the device under test, even if the signal source is not perfect or external disturbances are present. Measurements on an RF amplifier show the capabilities of the method.

Methods and apparatus for transmitting non-contiguous spread spectrum signals for communications and navigation

Abstract: A technique for transmitting a spread spectrum signal using plural non-contiguous frequency bands separated by segments of frequency spectrum excluded from use involves: generating a digital time-domain spread spectrum signal; converting the time-domain signal to a frequency-domain signal via an FFT; excising a portion of the frequency-domain signal by selectively removing frequency bins of the frequency-domain signal to cause spectral nulling of the transmit signal at the frequencies of the excluded segments; and converting the excised frequency-domain signal to an excised time-domain signal via an inverse FFT, which is then converted to an analog signal for transmission. The non-contiguous spectrum selection technique is implemented in a transmitter that transmits data communication signals or navigation signals, and permits use of plural, non-contiguous frequency bands to transmit a wide bandwidth signals that cannot be transmitted in a continuous frequency band due to constrains in the allocated frequency spectrum available for transmission.

Clinical laboratory management systems, management apparatuses, and recording media

Abstract: A clinical laboratory management system is described that includes an analyzer for analyzing a sample, and a management apparatus connected to the analyzer. The management apparatus includes (a) a storage configured for storing a result of an assay output from the analyzer, analyzer identification information for identifying whether or not the analyzer used for the assay has a dilution mode, and diluted sample identification information for identifying whether or not the sample used in the assay is a diluted sample; and (b) a controller configured for correcting the result when the analyzer used in the assay does not have a dilution mode, and the sample used in the assay is a diluted sample. Management apparatuses and recording media are also described.

Light element measurement

Abstract: A spectrometer for detecting and quantifying elements in a sample. An exciter ionizes atoms in the sample, and the atoms thereby produce characteristic x-rays. A detector receives the x-rays and produces signals based on the x-rays. A filter system selectively blocks the x-rays from attaining the detector. The selective blocking of the x-rays is accomplished based on an energy of the x-rays. An analyzer receives the signals from the detector and detects and quantifies the elements in the sample based at least in part on the signals. In this manner, detector receives the light element x-rays, and the medium and heavy element x-rays are filtered out to avoid overwhelming the detector. This invention combines the large solid angle, high efficiency, and ability to measure the continuous background spectrum of the energy dispersive x-ray detector with the selectivity of the wavelength dispersive x-ray detector. It thus enables faster and more accurate measurement of light elements in thin films. This invention enhances the light element performance of a system by enabling higher throughput, lower e-beam and x-ray dose to the sample, and improved accuracy from the capability to measure the background radiation.