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公开(公告)号：DE19750349C2
公开(公告)日：2000-05-18
申请号：DE19750349
申请日：1997-11-13
Applicant: ADVANTEST CORP
Inventor： NAGANO MASAO , KOTANI NORIHITO
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公开(公告)号：DE19515037B4
公开(公告)日：2004-05-27
申请号：DE19515037
申请日：1995-04-24
Applicant: ADVANTEST CORP
Inventor： NAGANO MASAO , TAKAHASHI HITOSHI
Abstract: A digital signal modulation analysis device is to shorten the time for modulation analysis, and at the same time to structure a measurement device that is small in scale and inexpensive. A digital signal modulation analysis device includes a frequency converter which converts a signal from a device under test to a first intermediate frequency signal, a sampling part which converts the first intermediate frequency signal to a second intermediate-frequency signal whose frequency is lower than that of the first intermediate frequency to store the second intermediate frequency signal in a memory, a Hilbert converter which converts an incoming signal into orthogonal component signals through a quadrant-modulate detection process, an initial synchronization part which determines a carrier center frequency, a symbol-demodulation/parameter-estimation part which determines optimal parameters to minimize a modulation error and demodulates all symbol data to determine reference data for the all symbol data, and a modulation-precision calculation component which calculates modulation-precision data and modulation-error data for each symbol.
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公开(公告)号：DE19922249A1
公开(公告)日：2000-01-05
申请号：DE19922249
申请日：1999-05-14
Applicant: ADVANTEST CORP
Inventor： NAGANO MASAO
IPC: G01R23/173 , H03D7/00
Abstract: The intermediate frequency signal from an intermediate frequency filter is multiplied by a reverse sweeping signal and fixed frequency component is extracted from multiplication result as a frequency spectrum included to a measured signal.
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公开(公告)号：DE19523343B4
公开(公告)日：2004-05-13
申请号：DE19523343
申请日：1995-06-27
Applicant: ADVANTEST CORP
Inventor： NAGANO MASAO
IPC: G01R29/00 , G01R23/165 , G01R29/08 , H04B3/46 , H04B17/00 , G01R21/133 , H04B7/212 , H04J3/14
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公开(公告)号：DE19647090C2
公开(公告)日：1999-12-09
申请号：DE19647090
申请日：1996-11-14
Applicant: ADVANTEST CORP
Inventor： NAGANO MASAO
IPC: G01R29/08 , H04B7/26 , H04B17/00 , H04B17/15 , H04B17/354 , H04W24/00 , H04W88/02 , G01R23/165
Abstract: A method for measuring an adjacent channel power of a device under test (DUT) such as a radio transmitter. The method comprises the steps of performing a frequency conversion to convert a transmitting signal of the DUT to an intermediate frequency signal; sampling the intermediate frequency signal to convert it to a digital signal; resolving the digital signal into an in-phase component and a quadrature component by a quadrature detection; removing a high frequency component from each of the in-phase and quadrature components; executing a complex Fourier transformation for the in-phase and quadrature components to obtain a frequency spectrum; and computing the leakage power to the adjacent channel from the frequency spectrum.
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Patent Agency Ranking
公开(公告)号：DE19750349A1
公开(公告)日：1998-05-28
申请号：DE19750349
申请日：1997-11-13
Applicant: ADVANTEST CORP
Inventor： NAGANO MASAO , KOTANI NORIHITO
Abstract: The analyser (1) comprises a multiple sine wave signal generator (10) operating with a sample signal generator (11), D-A converters (12,13), deep pass filters (14,15) and a quadrature modulator (16) to produce a signal consisting of a synthesis of several sine waves of different frequencies within a chosen band. This signal is applied to the DUT i.e. component or equipment under test (3). The measuring signal then transmitted from the DUT to the analyser is changed to a digital value through an A-D converter (35), and fed into a signal processor (30) where it is conducted through a quadrature analysis section (36) and fast Fourier transformation (43) to the phase/amplitude comparator (44) for evaluation. The system ensures high accuracy of measurement in a very short time span.
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公开(公告)号：DE19647090A1
公开(公告)日：1997-05-28
申请号：DE19647090
申请日：1996-11-14
Applicant: ADVANTEST CORP
Inventor： NAGANO MASAO
IPC: G01R29/08 , H04B7/26 , H04B17/00 , H04B17/15 , H04B17/354 , H04W24/00 , H04W88/02 , G01R23/165
Abstract: The method involves measuring losses due to transmission signals leaking from a transmission channel to an adjacent channel. The transmission signal for the transmission channel is generated by a device to be tested. A frequency conversion is carried out to convert the transmission signal into an intermediate frequency signal, of a predetermined intermediate frequency. This intermediate frequency signal is then sampled at a predetermined sampling frequency to convert it into a digital signal. The digital signal is resolved into an in-phase and a quadrature component. A high frequency component is removed from the in-phase component and from the quadrature component. A Fourier transformation is then carried out on the in-phase and quadrature components, from which the high frequency components have been taken, to determine a frequency spectrum. The loss due to the leakage to the adjacent channel is calculated from the frequency spectrum.
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公开(公告)号：DE19515037A1
公开(公告)日：1995-10-26
申请号：DE19515037
申请日：1995-04-24
Applicant: ADVANTEST CORP
Inventor： NAGANO MASAO , TAKAHASHI HITOSHI
Abstract: A digital signal modulation analyser has a frequency changer which converts the output signal of the equipment under test to a first intermediate frequency signal using a mixer stage (102). A second mixer stage (202) forms the input module of a signal scanner (250) in which, after further frequency reduction and low-pass filtering (210), the resultant is digitally converted (220) and stored (240) as 252 word symbol data formats.This data is further resolved into its quadrature vector components by a Hilbert converter (310) and demodulation of individual symbols undertaken (740, 400, 900) using self-identified optimum values of the several variable parameters to minimise modulation error.
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公开(公告)号：DE19549600C2
公开(公告)日：1999-09-16
申请号：DE19549600
申请日：1995-09-15
Applicant: ADVANTEST CORP
Inventor： NAGANO MASAO , TAKAHASHI HITOSHI
Abstract: The swing measurement device contains an analogue-to-digital converter (17) which converts a FM input signal into a digital signal, a quadrature detector (19) for computing an in-phase component and quadrature component of the FM signal, a phase computation device (20), a differential computation device (21) and a frequency swing computation device (25,27-29). The phase computation device computes the instantaneous phase of the FM input signal from the quadrature and in-phase components. The differential computation device computes the instantaneous frequency of the modulated signal by differentiating time-serial instantaneous phase data. The frequency swing computation device computes the frequency fluctuation amplitude from the instantaneous frequency of the modulated signal to determine the maximum frequency swing.
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公开(公告)号：DE19922249C2
公开(公告)日：2002-01-24
申请号：DE19922249
申请日：1999-05-14
Applicant: ADVANTEST CORP
Inventor： NAGANO MASAO
IPC: G01R23/173 , H03D7/00
Abstract: There are provided a frequency analysis method permitting a frequency analysis to be performed at a high rate and a sweep type spectrum analyzer using such frequency analysis method. In the case of multiplying a signal to be measured by a main swept frequency signal; extracting the result of the multiplication through an intermediate frequency filter having a predetermined bandwidth to extract frequency components included in the signal to be measured as intermediate frequency signals; and analyzing the frequency components included in the signal to be measured based on the correspondence relation between a power of each of the intermediate frequency signals and a frequency of the main swept frequency signal, an inverse swept signal is multiplied by each intermediate frequency signal, the inverse swept signal being frequency-swept in the reverse direction to the frequency transition direction of the associated intermediate frequency signal, and a constant frequency component obtained from the results of the multiplications is extracted as a frequency spectrum included in the signal to be measured.
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