Abstract: N (N?2) D/A converters convert respective input data at a sampling frequency FS. A digital signal processing unit generates N items of sub-band waveform data. Each of N items of sub-band waveform data is generated by frequency-shifting corresponding one of N sub-band components included in digital waveform data that represents the analog output signal, such that each sub-band waveform data has its maximum frequency below FS/2. A local signal generating circuit generates N local signals having different frequencies.

Abstract: A test apparatus inspects an antenna element or a device including the antenna element as a DUT by OTA. A front-end unit includes a plurality of electric field detection elements provided to face a plurality of points on a radiation surface of the antenna element of the DUT. The plurality of electric field detection elements can simultaneously detect the electric fields formed at the corresponding points by the DUT, respectively. A tester body receives a plurality of detection signals from the front-end unit and evaluates the DUT.

Abstract: A processing apparatus includes a processing portion. The processing portion obtains, in time series, a sensor value of a first sensor output from a predetermined apparatus including the first sensor in correspondence with an operation of the predetermined apparatus, sectionalizes the sensor value of the first sensor on a basis of a predetermined condition, and clusters the sectionalized sensor value of the first sensor.

Abstract: There is provided a calibration device including: a calibration signal supply unit configured to supply, as a calibration input signal, a multitone signal having tones at a plurality of frequency bands to a converter configured to multiply an input signal by each of a plurality of signal patterns and limit a band to obtain each of a plurality of bandpass signals, and reconstruct an output signal in accordance with the input signal from the plurality of bandpass signals; a calibration bandpass signal acquisition unit configured to acquire a plurality of calibration bandpass signals obtained by the converter in response to the multitone signal; and a calibration processing unit configured to calibrate a parameter for the reconstruction in the converter based on the plurality of calibration bandpass signals.

Abstract: There is provided a calibration device including: a calibration signal supply unit configured to supply, as a calibration input signal, a multitone signal having tones at a plurality of frequency bands to a converter configured to multiply an input signal by each of a plurality of signal patterns and limit a band to obtain each of a plurality of bandpass signals, and reconstruct an output signal in accordance with the input signal from the plurality of bandpass signals; a calibration bandpass signal acquisition unit configured to acquire a plurality of calibration bandpass signals obtained by the converter in response to the multitone signal; and a calibration processing unit configured to calibrate a parameter for the reconstruction in the converter based on the plurality of calibration bandpass signals.

Abstract: A test apparatus inspects an antenna element or a device including the antenna element as a DUT by OTA. A front-end unit includes a plurality of electric field detection elements provided to face a plurality of points on a radiation surface of the antenna element of the DUT. The plurality of electric field detection elements can simultaneously detect the electric fields formed at the corresponding points by the DUT, respectively. A tester body receives a plurality of detection signals from the front-end unit and evaluates the DUT.

Abstract: There is provided a calibration device including: a calibration signal supply unit configured to supply, as a calibration input signal, a multitone signal having tones in a plurality of frequency bands to a converter configured to multiply an input signal by each of a plurality of signal patterns and limit a band to obtain each of a plurality of bandpass signals, and reconstruct an output signal in accordance with an input signal from the plurality of bandpass signals; a calibration bandpass signal acquisition unit configured to acquire a plurality of calibration bandpass signals obtained by the converter in response to the multitone signal; and a calibration processing unit configured to calibrate a parameter for the reconstruction in the converter based on the plurality of calibration bandpass signals.

Abstract: A front-end circuit is used to test an RF signal from an RF device. The RF signal is generated by modulating a carrier signal having a carrier frequency with a wideband baseband signal. A variable frequency oscillator generates a local signal having a variable local frequency. The first frequency mixer frequency mixes a local signal and an RF signal to generate an IF signal having a frequency. A band-pass type first filter filters the IF signal. The local frequency can be selected from a plurality of frequencies having a frequency interval equal to or narrower than a bandwidth of the first filter.

Abstract: There is provided a calibration device including: a calibration signal supply unit configured to supply, as a calibration input signal, a multitone signal having tones in a plurality of frequency bands to a converter configured to multiply an input signal by each of a plurality of signal patterns and limit a band to obtain each of a plurality of bandpass signals, and reconstruct an output signal in accordance with an input signal from the plurality of bandpass signals; a calibration bandpass signal acquisition unit configured to acquire a plurality of calibration bandpass signals obtained by the converter in response to the multitone signal; and a calibration processing unit configured to calibrate a parameter for the reconstruction in the converter based on the plurality of calibration bandpass signals.

Abstract: A front-end circuit is used to test an RF signal from an RF device. The RF signal is generated by modulating a carrier signal having a carrier frequency with a wideband baseband signal. A variable frequency oscillator generates a local signal having a variable local frequency. The first frequency mixer frequency mixes a local signal and an RF signal to generate an IF signal having a frequency. A band-pass type first filter filters the IF signal. The local frequency can be selected from a plurality of frequencies having a frequency interval equal to or narrower than a bandwidth of the first filter.

Abstract: A processing apparatus includes a processing portion. The processing portion obtains, in time series, a sensor value of a first sensor output from a predetermined apparatus including the first sensor in correspondence with an operation of the predetermined apparatus, sectionalizes the sensor value of the first sensor on a basis of a predetermined condition, and clusters the sectionalized sensor value of the first sensor.

Abstract: Provided is a measurement apparatus that measures a characteristic of an AD converter, comprising a signal supplying section that supplies the AD converter with an analog input signal having a prescribed waveform; an acquiring section that acquires a digital output signal output by the AD converter as a result of sampling the analog input signal; a measured histogram generating section that generates a histogram of the digital output signal; and a range calculating section that calculates at least one of an analog value corresponding to a lower limit and an analog value corresponding to an upper limit of a prescribed digital range, based on at least one of (i) a frequency corresponding to digital values, in a measured histogram obtained by measuring the digital output signal, that are less than or equal to the digital range and (ii) a frequency corresponding to digital values in the measured histogram that are greater than or equal to the digital range.

Abstract: Provided is a signal processing apparatus for compensating for a non-linear distortion of a digital signal, including: an analysis signal generating section that converts the digital signal into a analysis signal of a complex number, using a digital filter; and a compensation section that compensates for the analysis signal, using a compensation coefficient of a complex number corresponding to the non-linear distortion, where the digital filter divides data of the digital signal into “n” data sequences, assigns (n*L+k)th data of the digital signal to a k-th data sequence, performs filtering on each of the data sequences using a same filter coefficient, and combines each of the data sequences after the filtering, thereby generating an imaginary number portion of the analysis signal, where “n” is an integer equal to or greater than 2, L=0, 1, . . . , and k=1, 2, . . . , n.

Abstract: A measurement apparatus comprising an IQ error measuring section that measures a frequency characteristic of an IQ error of a device under measurement; and an error amount calculating section that calculates EVM based on a constellation error, at each of a plurality of frequencies, between an ideal signal to be output in response to input of a predetermined signal into a model of the device under measurement that does not include an IQ error and a prediction signal that is to be output in response to the input of the predetermined signal into a model of the device under measurement that includes the IQ error measured by the IQ error measuring section, wherein the error amount calculating section corrects a signal component at each of the frequencies in the prediction signal according to a channel characteristic, and calculates the constellation error.

Abstract: A test apparatus configured to test an N-bit (N represents an integer) A/D converter is provided. A voltage generating unit outputs a 2N-valued analog voltage to the A/D converter. A capture unit captures an output code of the A/D converter for each level. A signal processing unit compares the output code captured for each level with the corresponding expected value code, corrects the value of the analog voltage for each level based upon the comparison result, and outputs the corrected analog voltage to the voltage generating unit.

Abstract: An analog-digital converting method comprising measuring, in advance, frequency characteristics of each of a plurality of ADCs; intra-group correction of, for each of a plurality of groups obtained by dividing a plurality of measurement signals, generating measurement signals that would be obtained when the frequency characteristics of the corresponding ADCs are ideal by multiplying the measurement signals by a correction coefficient that is based on the frequency characteristics of all the ADCs in the group; and inter-group correction of correcting and combining the frequency characteristics of the groups based on a difference in the frequency characteristics between the groups formed during the intra-group correction, to generate a frequency spectrum of the digital signal.

Abstract: Provided is a reference data converting section that rearranges each of a plurality of frequency components along the frequency axis such that (i) a fundamental wave component and harmonic wave components of a reference digital signal are within a first Nyquist region of a spectrum of the reference digital signal and (ii) image components of the fundamental wave component and the harmonic wave components are within a second Nyquist region of the spectrum; and a distortion detecting section that detects the non-linear distortion of the reference digital signal caused by each harmonic wave component, based on each harmonic wave component having a prescribed order number in the spectrum in which each frequency component has been rearranged by the reference data converting section.

Abstract: Provided is a signal output control section that inputs to a digitizer a reference signal whose frequency changes at each prescribed measurement cycle; a data extracting section that extracts a number of pieces of data corresponding to an integer multiple of a period of the reference signal in each measurement cycle, from pieces of data of a reference digital signal output by the digitizer according to the reference signal that come after a prescribed wait interval has passed since an initiation timing of each measurement cycle; a distortion identifying section that calculates the non-linear distortion caused by the digitizer for each frequency of the reference signal, based on the data in each measurement cycle extracted by the data extracting section; and a distortion calculating section that calculates the non-linear distortion caused by the digitizer when the analog signal input to the digitizer has a frequency that differs from any of the plurality of frequencies at which the reference signal transitions

Abstract: A test apparatus configured to test an N-bit (N represents an integer) A/D converter is provided. A voltage generating unit outputs a 2N-valued analog voltage to the A/D converter. A capture unit captures an output code of the A/D converter for each level. A signal processing unit compares the output code captured for each level with the corresponding expected value code, corrects the value of the analog voltage for each level based upon the comparison result, and outputs the corrected analog voltage to the voltage generating unit.

Abstract: An analog-digital converting method comprising measuring, in advance, frequency characteristics of each of a plurality of ADCs; intra-group correction of, for each of a plurality of groups obtained by dividing a plurality of measurement signals, generating measurement signals that would be obtained when the frequency characteristics of the corresponding ADCs are ideal by multiplying the measurement signals by a correction coefficient that is based on the frequency characteristics of all the ADCs in the group; and inter-group correction of correcting and combining the frequency characteristics of the groups based on a difference in the frequency characteristics between the groups formed during the intra-group correction, to generate a frequency spectrum of the digital signal.