Abstract: A spectrum analyzer that may be implemented by a simple microcontroller that does not have a hardware multiply function is disclosed. The spectrum analyzer of the present invention utilizes at least five frequency bins. The input signal is sampled at four times the bin frequency. The input signal is sampled at twice the Nyquist rate, which results in symmetries in the sin(wn) and cos(wn) functions. These symmetries allow the in-phase and quadrature components of the input signal to be calculated by add, ignore or subtract operations instead of the more complex multiplication and integration operations. Accordingly, the energy for each bin may be calculated with a minimum number of multiply operations. Because the number of multiply operations have been significantly reduced, these multiply operations may be performed by software instead of hardware. As a result, the spectrum analyzer may be implemented with a simple processor that does not have a hardware multiply.

Abstract: A system for characterizing periodic structures formed on a sample on a real time basis is disclosed. A multi-parameter measurement module generates output signals as a function of either wavelength or angle of incidence. The output signals are supplied to a parallel processor. The processor creates an initial theoretical model and then calculates the theoretical optical response of that sample. The calculated optical response is compared to measured values. Based on the comparison, the model configuration is modified to be closer to the actual measured structure. The processor recalculates the optical response of the modified model and compares the result to the measured data. This process is repeated in an iterative manner until a best fit is achieved. The steps of calculating the optical response of the model is distributed to the processors as a function of wavelength or angle of incidence so these calculations can be performed in parallel.

Abstract: A measuring device (1), for measuring the spectrum of a measured signal in several neighboring channels (15−9-159) of a working channel (14), includes a selective filter (9) which damps the working channel (14) more strongly than the neighboring channels (15−9-159). Furthermore an analogue/digital converter (5) is provided which detects the filtered measured signal from all the channels to be measured (15−9-159, 14) in a parallel and broadband manner and converts the above to a digital signal. An equaliser (11) in series with the analogue/digital converter (5), equalises the digital signal with a frequency response which is the reciprocal of the frequency response of the selective filter (9).

Abstract: A method for measuring composite distortion levels using a coherent multicarrier RF signal generator having incrementally related frequencies is disclosed. The invention provides for the use of a coherent multicarrier signal generator that permits arbitrary RF carrier phase control on an individual carrier basis in order to enable sequential distortion measurements under varying carrier phase conditions. In order to obtain measurement results that match those obtained by the use of prior art non-coherent signal sources, the present invention provides for averaging of distortion measurement results over a ‘phase configuration ensemble’ that is obtained by multiple sequential measurements, in which the individual carrier phases for each measurement are preselected at random.

Abstract: The present invention, generally speaking, provides a method and apparatus for accurately measuring a communications signal. In accordance with one aspect of the invention, DC offset effects and nonlinearities attributable to a communications amplifier are made spectrally separable from DC offset effects and nonlinearities attributable to the measurement apparatus. Spectral separability may be accomplished, for example, by adding an offset frequency to a local oscillator used by a downconverter of the measurement apparatus. As a result, the signal of interest is moved away from baseband (zero frequency) to the offset frequency. Similarly, other nonlinearities in the video amplifier (such as third order distortion) manifest theselves mostly at harmonics of the offset frequency. Hence spectral separability between the power amplifier characteristics and these nonlinear impairments of the measurement system is achieved.

Abstract: The present invention describes a device for generating microwave signals, particularly for use in a distance and speed sensor in a motor vehicle. To this end, two laser sources are operated, whose emitted radiations are distinguished from each other by a set difference in wavelength. The two lasers are arranged in such a way that the emitted laser beams overlap spatially. A photodiode is disposed in this region in which the two laser beams interfere. From the superimposition product of the two laser beams, this photodiode generates an electrical output signal that has the differential frequency of the two superimposed laser beams. In this context, the frequency difference of the two lasers is selected so that the frequency of the generated microwave radiation lies in the range of the radar beam to be generated.

Abstract: A parallel, frequency domain filter (50) for providing frequency-dependent phase delay for real data includes a fast Fourier transform (FFT) device (52), a complex multiplier (54), a filter memory (56) and an inverse fast Fourier transform (IFFT) device (58). The FFT and IFFT devices (52) and (58) are shown with two inputs and two outputs each. The filter (50) of the present invention allows for increased throughput by filtering two real signals in parallel, one being applied to the real input of FFT device (52) and the other being applied to the imaginary input of FFT device (52). The filter memory 56 of FIG. 2 is provided with sufficient capacity to store several filter frequency characteristics. The appropriate filter frequency characteristic for the particular digitized rf signal being processed can be selected based on factors such as beam focus depth. The parallel, frequency domain filter (50) allows the use of coded waveforms to improve signal to noise ratio in ultrasound images.

Abstract: A preselector is omitted in a spectrum analyzer, for example, which is used to prevent an image signal from being inputted. In addition, an image signal of a signal which is located outside a range of set-up measured frequencies is suppressed as much as possible. For a range of set-up measured frequencies F1˜F2, and for each of a plurality of intermediate frequencies Fi, the frequency of the sweep signal is swept over a range F1+Fi˜F2+Fi to determine first measured data, and is also swept over a range F1-Fi˜F2-Fi to determine second measured data. The first and the second measured data are compared against each other for each measured frequency point, and if they are equal, the data value obtained or a data value having a minimum value unless they are not of an equal value is delivered to obtain measured data in which image data based on image signals has been suppressed.

Abstract: Signal sampling is performed. A sampler takes samples of a sampled signal. A first analog-to-digital (A/D) converter receives the samples from the sampler. A clock reference is synchronous with the sampled signal. A phase comparator produces a difference value that indicates a phase difference between the clock reference and an oscillating signal. A second A/D converter receives the difference value. The oscillating signal is used in controlling when the sampler takes samples of the sampled signal.

Abstract: The invention relates to a method and to a device (1) for system and process supervision in a magneto-inductive sensor. A medium (6) flows through a measuring tube (2) substantially in the direction of the axis (5) of the measuring tube. A magnetic field extends through the measuring tube (2) in a direction substantially perpendicular to the axis (5) of the measuring tube. A measuring voltage is induced in at least one measuring electrode (3; 4) that is disposed substantially perpendicular to the axis (5) of the measuring tube. Said measuring voltage or the measurement data provide information on the volume flow of the measuring medium (6) in the measuring tube (2). The aim of the invention is to provide a method and a device which allow, in addition to the determination of the volume flow, the detection of the modification of a system and/or process parameter.

Abstract: A system, apparatus and method for performing differential return loss measurements and other measurements as a function of frequency using a digital storage oscilloscope (DSO) including spectral analysis functions.

Abstract: An optical/analog/digital pulse detector receives an input signal and drives a Bragg cell illuminated by a collimated light beam. The Bragg cell spatially modulates the collimated light beam and upon exiting the Bragg cell is imaged by lenses of an optics network to the plane of an opaque plate. A binary optical plate replicates the image of the Bragg cell on the opaque plate. The opaque plate contains slits of various lengths located where the images of the Bragg cell are replicated. To obtain the power spectrum of each of the images on the opaque plate an anamorphic lens is positioned in the path of light passing through the opaque plate. Light passing through the anamorphic lens is sensed by a detector array having outputs coupled to a focal plane processor that processes the analog outputs from the detector array into initial tuning commands for detection and characterization of pulses in the input signal.

Abstract: A technique for determining the amplitudes of frequency components of a waveform sampled from an automatic test system includes assembling a list of N frequencies expected to be found in the sampled waveform. A test program running on the tester generally supplies the list of frequencies. The technique assumes that the sampled waveform conforms to an idealized waveform model that mathematically corresponds to a sum of N sinusoids. Each of the N sinusoids that make up the model has unknown amplitude and a frequency that equals one of the N frequencies in the list of frequencies. The technique attempts to solve for the unknown amplitude of each of the N frequencies by mathematically minimizing, via a linear least-squares algorithm, the difference between the model and the actual, sampled waveform.

Abstract: A system and method for application control in measurement devices is disclosed. The method includes installing a new application using the device's graphical user interface, extending the device's menu system for the new application, launching the new application using the device's extended menu system, and controlling the device using the new application through a remote control mechanism of the device. A system of application control in a measurement device is also disclosed.

Abstract: A range of a frequency measuring device having limited range is extended by pre-processing an input signal. The input signal is divided into a plurality of channels. In each channel, the input signal is divided into sub-bands. A frequency of the input signal is determined using a frequency measuring device having limited range. The frequencies are stored in a frequency set. The frequency set is used to determine a frequency associated with the input signal according a set of pre-determined reconstruction rules.

Abstract: A method for optimizing loop bandwidth in a phase locked loop is provided. A representative power supply waveform having noise is input into a simulation of the phase locked loop; an estimate of jitter is determined; and the loop bandwidth of the phase looked loop is adjusted until the jitter falls below a pre-selected value. Further, a computer system for optimizing loop bandwidth in a phase locked loop is provided. Further, a computer-readable medium having recorded thereon instructions adapted to optimize loop bandwidth in a phase locked loop is provided.

Abstract: An analog signal is digitized by an analog-to-digital (A/D) converter clocked by a periodically jittery clock signal. Elements of the digital data sequence (vector) output of the A/D converter are sorted into a set of smaller vectors according to clock signal jitter phase and each of the smaller vectors is then separately subjected to Fourier transform and time shift functions. The resulting vectors are then processed to produce an output vector representing the frequency spectrum of the analog signal.

Abstract: Techniques for use in sweep synchronization test equipment include receiving a simulation setting and displaying a simulated result based on the simulation setting and previously-measured data. The equipment is switched to a measurement mode in response to user activity, and the simulation setting is used as a control setting. A new measurement is performed based on the control setting. The displayed simulated result is updated based on data obtained from the new measurement.

Abstract: A method of measuring the response of an electronic device to a high frequency input signal is performed with an analyzer (1).

Abstract: The present invention provides an apparatus for using time domain analysis of NEXT, Return Loss and the like, in conjunction with the application of time or distance referenced limits to verify and determine compliance of the performance requirements of connections in a typical link. Time domain analysis of NEXT, Return Loss data and the like suitably provides the performance characteristics of a link as a function of time or distance. When coupled with time or distance performance curves for connections, it can be determined if the transmission fault is at a connection or in the cable. The time limit curves for connections can be generated based on the frequency domain performance requirements for connecting hardware of a specific level of performance. The connection time limit curves thus allows one to determine if the connection is within performance standards, allowing improved isolation of the fault condition.

Abstract: In connection with blind source separation, proposed herein, inter alia, are: expectation-maximization equations to iteratively estimate unmixing filters and source density parameters in the context of convolutive independent component analysis where the sources are modeled with mixtures of Gaussians; a scheme to estimate the length of unmixing filters; and two alternative initialization schemes.

Abstract: A phase noise measurement module (PNMM), system and method for measuring phase noise improve accuracy of phase noise measurements of a signal under test (SUT) using a spectrum analyzer. The PNMM includes an RF to hF frequency converter and a selectable frequency divider. The system includes the PNMM connected to the spectrum analyzer and employs an LO signal from a tunable LO in the spectrum analyzer. The method includes directly converting an input SUT to an IF signal having either a second or a third IF frequency that is applied to a corresponding frequency conversion stage of the spectrum analyzer before the phase noise is measured. The present invention bypasses a first conversion stage, and typically a second conversion stage as well, of the spectrum analyzer and directly converts the SUT to either the second or third IF frequency, thereby reducing phase noise added to the SUT.

Abstract: A measuring device (1), for measuring the spectrum of a measured signal in several neighbouring channels (15−9-159) of a working channel (14), comprises a selective filter (9) which damps the working channel (14) more strongly than the neighbouring channels (15−9-159). Furthermore an analogue/digital converter (5) is provided which detects the filtered measured signal from all the channels to be measured (15−9-159, 14) in a parallel and broadband manner and converts the above to a digital signal. An equaliser (11) in series with the analogue/digital converter (5), equalises the digital signal with a frequency response which is the reciprocal of the frequency response of the selective filter (9).

Abstract: Provided is a signal detector and method for spectrum analysis and for measuring power of one or more channels of an electrical or optical signal. Each channel may carry a unique modulation tone. A DSP (digital-signal processor) performs DFTs (discrete Fourier transforms) on the signal. Frequency bands of interest which contain a tone that requires detection are processed. Higher layers of coherent integrations are performed on bands which have not detected a tone with a resolution that is suitable for power measurement. The higher layers of coherent integrations are performed by collecting additional data and performing a coherent integration. Further higher layer coherent integrations are performed until all modulation tones have been detected with a suitable resolution or up to a maximum detection latency.

Abstract: A method for measuring the fundamental frequency component of a fault current or voltage, including measuring a fault current or voltage signal, which includes a DC-offset, a characteristic frequency component, a fundamental frequency component, and harmonics, with a predetermined sampling period, filtering the fault current or voltage signal to remove the harmonics, removing the fundamental frequency component from the filtered fault current or voltage signal, calculating the DC-offset and the characteristic frequency component with the fault current fault current or voltage signal wherein the fundamental frequency component is removed, and determining the fundamental frequency component by subtracting the calculated DC-offset and the characteristic frequency component from the filtered fault current or voltage signal.

Abstract: A lightning detector featuring improved reliability over the conventional radar-type or coherer-type lightning detector that measures the intensity of static electricity or the intensity of electromagnetic waves, includes a coherer with an automatically restoring decoherer. The coherer is equipped with a separate coherer for a lightning circuit. The lightning detector detects and operates the (static) position and/or approaching/separating condition (dynamic) data of the thundercloud while protecting its own circuit.

Abstract: In a recording and reproducing apparatus, and in a time calibration method of the recording and reproducing apparatus, first and second clock units are provided for counting time. A time extraction unit extracts time information included in a received broadcast signal. Also included in the recording and reproducing apparatus is a time setting unit for manually setting the time of the first clock unit. From the extracted time information, the time of the second clock unit is calibrated. And if the time information is extracted within a specific interval, manual time setting of the time setting unit is prohibited, and the time of the first clock unit is calibrated by the time of the second clock unit. But if the time information is not extracted within the specific interval, manual time setting by the time setting unit is allowed, and the time of the second clock unit is calibrated by the time of the first clock unit.

Abstract: A spectrum analysis method and apparatus for processing and displaying time series data. The time series data in digital form is decomposed into a plurality of frequency components by means of a set of band pass filters. Adjacent band pass filters have their cut-off frequencies shifted or offset from each other by their passing band widths. Amplitude information of the frequency components may be obtained. For example, the frequency components generated by the band pass filters may be sampled in amplitude at predetermined time intervals. Such sampled amplitudes are then transformed into corresponding densities of a predetermined color including a gray color according to a color (or gray) scale, and displayed on a screen on the basis of a time base of the screen.

Abstract: The electronic calibration equipment for verifying the high frequency characteristics of electronic test equipment, including oscilloscopes arid time interval analyzers is provided.

Abstract: Bit-error-rate (BER) testing includes a data pattern generator transmitting a known data pattern to a device under test (DUT), which processes the data pattern and outputs the processed data pattern to an error analyzer. BER testing of telecommunications systems often uses data patterns in the form of SONET or SDH frames, which have error-checking bytes known as B bytes. The B Bytes computed for a given SONET or SDH frame are inserted into a next SONET or SDH frame. In memory-based BER tests, a fixed number of SONET or SDH frames is input to the DUT by the pattern generator. The last frame of the data pattern is adjusted so that the B bytes calculated using the last frame match the B bytes present in the first frame, which approach avoids parity errors that can occur in response to B byte mismatches between the last and the first frame.

Abstract: A radio frequency (RF) probe analysis system has a broadband design. The analysis system includes a sampling unit for generating digital power signals based on a plurality of analog signals. The analog signals characterize power delivered from an RF power delivery system to a plasma chamber. The analysis system further includes a digital processing unit for generating a digital spectrum signal based on the digital power signals. The sampling unit simultaneously samples a first plurality of frequencies from the analog signals such the that digital spectrum signal defines signal levels for the first plurality of frequencies. The sampling unit may also simultaneously sample a second plurality of frequencies from the analog signals such that the digital spectrum signal further defines signal levels for the second plurality of frequencies. The broadband architecture of the sampling unit enables closed loop control of power delivered to the chamber to tolerances unachievable through conventional approaches.

Abstract: A system for, and method of, analyzing a forced or unforced oscillator. In one embodiment the system includes: (1) a transformation circuit that transforms a frequency-modulated waveform representing an output of the oscillator into a function based on at least two time scales and (2) a numeric analyzer, associated with the transformation circuit, that warps at least one of the at least two time scales and thereafter numerically analyzes the function to determine a frequency thereof.

Abstract: An inversion in-phase component and a non-inversion in-phase component of a modulation signal inputted from a quadrature modulation section of a sample machine captured in a pair of signal lines, and an inversion quadrature component and a non-inversion quadrature component of the modulation signal, are computed by a pair of computers, respectively. In addition, these components are analog/digital converted at a pair of analog/digital converting sections, and then, are stored in a waveform storage memory. A modulation characteristics analyzing section performs predetermined computation processing of the storage data, thereby analyzing modulation characteristics of the modulation signal. A balance/imbalance switching section is provided at each one of the pair of signal lines, and the signal lines are grounded, whereby a state for transmitting a modulation signal of a balance transmission format is switched to a state for transmitting a modulation signal of an imbalance transmission format.

Abstract: A selectable band-pass filtering apparatus for use at the input of analysis instrumentation, such as a spectrum analyzer for testing a multi-channel communication system, comprises a high-pass filter section including a plurality of separate high-pass filters, each characterized by a respective high-pass cut-off frequency within a predetermined input frequency spectrum characterizing the communication system and a low-pass filter section including a plurality of separate low-pass filters each characterized by a corresponding low-pass cut-off frequency within the input frequency spectrum. The apparatus further comprises switching devices capable of connecting a selected high-pass filter In series with a selected low-pass filter in order to select passband having center frequency and bandwidth characteristics defined by corresponding high-pass cut-off frequency and low-pass cut-off frequency.

Abstract: Circuitry and technique for improving the analysis of a signal, such as radar return, by eliminating the effects of frequency variations of the carrier and thereby stabilizing the modulation spectrum. This is accomplished by tracking the carrier frequency and using it as a reference signal for translating the carrier frequency in the radar return to zero frequency.

Abstract: An improved process and apparatus for measuring performance characteristics of microwave power components. The invention involves the use of a rotating phase reference technique to improve measurement. The process and apparatus result in fast, accurate, reproducible determination of the desired properties. In addition, the apparatus of the present invention is lightweight, compact, and portable.

Abstract: A method is provided of setting grids and/or markers on a screen of a display unit of a measuring apparatus. First, a mode of the apparatus is changed into a mode of setting the grids and/or the markers. Then, the grid and/or the marker serving as a reference is set. Then, a plurality of grids and/or markers are set, each of which provides an arbitrary interval with respect to the grid and/or the marker serving as reference.

Abstract: Absolute delay of a FTD is characterized by applying a stimulus signal to a first port of the FTD. A second port of the FTD is coupled to a delay element having a known delay and a reflective termination. A drive signal is applied to a third port of the FTD. A time domain reflection response to the stimulus signal is obtained and a signal peak within the response that corresponds to a return signal from the reflective termination is identified. Absolute delay of the frequency translation device is then extracted based on the known delay of the delay element and a time that corresponds to the occurrence of the identified signal peak. Delay versus frequency is characterized by isolating a segment of the obtained time domain reflection response that corresponds to a return signal from the reflective termination. Inverse frequency transforming the isolated segment of the time domain reflection response provides delay characteristics of the FTD versus frequency.

Abstract: A spectrum analyzer comprises a mixer, which mixes complex conjugate input signal v*(t) into a base band signal x(t) and a resolution filter, which filters the base band signal for narrow band. In accordance with two aspects of the invention, the resolution filter has either a complex pulse response hused(t)=C1·e−C·2·t2·e−j·C3t2 or a real pulse response hused(t)=C4·e−C5·t2, in which C1, C2, C3, C4 and C5 are constants.

Abstract: The present invention comprises a method and apparatus that generates a waveform consisting of an arbitrary number of frequency sweeps combined from adding and subtracting mini frequency sweeps. Optimization routines determine the best combination order of frequency sweep to minimize or maximize design criteria such as aerodynamic surface deflection or maximum command rate of the wave form. The invention allows for arbitrary output timing, or commands per second issued for the desired waveform, arbitrary starting and ending frequencies and amplitudes, arbitrary number of frequency sweep components, arbitrary frequency sweep exponent, arbitrary amplitude sweep exponent, and arbitrary waveform length. For a given frequency range and sweep exponent, amplitude range and sweep exponent, desired total waveform time and number of frequency sweep components, the algorithm can determine the optimum arrangement of the components to minimize the maximum amplitude or rate.

Abstract: A polarization measuring apparatus in a mobile radio communication system which can accurately measure a polarized wave of a code division multiple access (CDMA) signal. The apparatus can measure the property of an elliptically polarized wave of a received radio wave as well as the property of a linearly polarized wave, and can measure the polarization property of the received radio wave more accurately by compensating for the error of internal radio frequency (RF) elements used for the polarization measurement and the loss on internal paths produced during the polarization measurement.

Abstract: An automatic network analyzer that measures continuous wave radio microwave driven transfer characteristics of nonlinear devices and simultaneously calculates and displays corresponding noise driven transfer characteristics and noise power ratio data. This automatic network analyzer employs software or firmware that uses closed-form equations to exactly calculate noise parameters. This is done in real-time as CW measurements are taken.

Abstract: A spectrum analyzer is combined with the VNA in a housing measuring approximately 4 pounds with the spectrum analyzer portion operating from slightly above DC to above 3.0 GHz. The components for the spectrum analyzer are provided on a separate printed circuit board from the two printed circuit boards for the display and VNA components in the housing. The design of components for the printed circuit board enable a significant reduction of size from a typical spectrum analyzer which weighs 40 pounds or more and measures on the order of 2 feet by 3 feet by 0.5 feet.

Abstract: A data processing system and method included within an oscilloscope for independently analyzing a signal input into the oscilloscope. The oscilloscope includes a plurality of triggering modes. A plurality of trigger parameters are specified for each of the triggering modes. Thereafter, the oscilloscope automatically analyzes the input signal, independently from any user input, utilizing each of the triggering modes and the trigger parameters specified for each of the triggering modes. The input signal includes a desired waveform and a plurality of undesired waveforms. While the oscilloscope is automatically analyzing the input signal, a determination is made regarding whether the oscilloscope triggered on one of the undesired waveforms. When it is determined that the oscilloscope triggered on one of the undesired waveforms, the undesired waveform upon which the oscilloscope triggered is stored.

Abstract: An improved read channel for storage and communication application particularly useful in optical storage applications. The improved read channel includes a Viterbi sequence detector tuned to a preferred partial response target well suited to sensing of pulses in the waveforms typical of optical storage read heads. In particular, the read channel of the present invention implements pulse and sequence detection for a partial response target having a spectral null at the Nyquist frequency and having a relative minimum between zero and the Nyquist frequency. In other words, the partial response target of the improved read channel is not a monotonic decreasing function between zero and the Nyquist frequency as is known in present read channels. More specifically, in the preferred embodiment, the partial response target of the read channel includes a spectral null at the Nyquist frequency and another spectral null at half the Nyquist frequency.

Abstract: A method for operating a spectrum analyzer to provide a marker that follows a peak from sweep to sweep in a spectrum display. The method operates on first and second measured spectrums. The first measured spectrum includes a plot of the signal amplitude against frequency during a first time interval in which the marker has been assigned to a peak at a first frequency and first amplitude. The present invention assigns the marker to a peak in the second spectrum measured during a subsequent time interval in which the marker is to be assigned. Initially, a first frequency range is defined in the second measured spectrum centered on the first frequency. The first frequency range is searched for candidate peaks having amplitudes within a first range centered on the first amplitude. If more than one such candidate peak is found by the search, the marker is assigned to the candidate peak closest to the first frequency.

Abstract: According to one embodiment of the invention, there is provided an N-port automatic calibration device comprising N-ports, wherein each port is adapted to be coupled to a port of an N-port multiport test set. The N-port automatic calibration device comprises a single-pole, N−1 throw switch having a single-pole coupled to a first port of the automatic calibration device and having each throw of the N−1 throws coupled to a corresponding port of the automatic calibration device. In addition, the N-port automatic calibration device comprises at least one single-pole, double-throw switch, having a single-pole coupled to a second port of the N-ports of the automatic calibration device, having a first throw coupled to a first load impedance, and having a second throw coupled to a throw of the N−1 throws of the single-pole, N−1 throw switch.

Abstract: One embodiment of the invention comprises a multiport test set that characterizes a multiterminal DUT. The multiport test set comprises a plurality of ports, a signal generator that provides a test signal over a frequency range, a reference receiver coupled to the signal generator that measures the test signal to determine a reference value, and at least one test channel receiver that measures the test signal at each port of the multiport test set. The multiport test set further comprises a switching device, coupled between the signal generator, the plurality of ports of the multiport test set and the at least one test channel receiver, that couples the test signal to any port of the multiport test set and to the at least one test channel receiver.

Abstract: A method of detecting an abrupt variation in a periodic electrical quantity, where a criterion for the occurrence of the abrupt variation is formed from samples of the periodic quantity. To be able to carry out such a method in such a way that the abrupt variations in the periodic quantity can be detected with a high sensitivity, the periodic quantity is weighted in an FIR filter with a transfer function with a double zero position at the nominal frequency; the output signal of the FIR filter is monitored for whether it reaches a threshold indicating that an abrupt variation in the periodic quantity has occurred.

Abstract: A frequency analyzing device for detecting a signal component of a predetermined analytic frequency to be analyzed in an input signal includes a multiplication circuit and an integration circuit. The multiplication circuit controls a switched capacitor circuit for discretely storing an input signal using a predetermined pulse signal whose frequency changes according to an amplitude of an orthogonal function system signal having the analytic frequency, and outputs charges representing a multiplication result of the input signal and the orthogonal function system signal. The integration circuit integrates the charges output from the multiplication circuit and outputs integration values as signal components of the analytic frequency contained in the input signal.