The present invention relates to a method and a measuring apparatus for testing a device under test. A measuring apparatus applies a first test signal to the device under test and measures at least one frequency response parameter of the device under test for a first plurality of frequency values lying in a first frequency range. The measuring apparatus applies a second test signal to the device under test and measures the at least one frequency response parameter of the device under test for a second plurality of frequency values lying in a second frequency range. The first frequency range at least partially overlaps with the second frequency range and the first plurality of frequency values at least partially differs from the second plurality of frequency values.

A frequency converter receives a predetermined input signal and a predetermined local oscillation signal, and outputs a signal obtained by mixing the input signal with a harmonic signal having a frequency n times the frequency of the local oscillation signal, wherein a circuit that mixes the input signal with the harmonic signal is a harmonic mixer, which mixes the harmonic signal with the input signal using a nonlinear characteristic of a semiconductor element, and wherein the input signal or the output signal is subjected, either before input to the frequency converter or after output from the frequency converter, to correction on the basis of the amplitude and phase frequency characteristics of the frequency converter, which have been determined in advance.

A frequency converter receives a predetermined input signal and a predetermined local oscillation signal, and outputs a signal obtained by mixing the input signal with a harmonic signal having a frequency n times the frequency of the local oscillation signal, wherein a circuit that mixes the input signal with the harmonic signal is a harmonic mixer, which mixes the harmonic signal with the input signal using a nonlinear characteristic of a semiconductor element, and wherein the input signal or the output signal is subjected, either before input to the frequency converter or after output from the frequency converter, to correction on the basis of the amplitude and phase frequency characteristics of the frequency converter, which have been determined in advance.

In certain aspects of the disclosure, a frequency monitor includes a counter configured to receive a monitored clock signal, to count a number of periods of the monitored clock signal over a predetermined time duration, and to output a count value corresponding to the number of periods of the monitored clock signal. The frequency monitor also includes a comparator configured to receive the count value from the counter, to receive an expected count value, to compare the count value from the counter with the expected count value, and to output a pass status signal or a fail status signal based on the comparison.

A method for estimating a property of a signal (1) sensed in an electrical system, comprises the steps of sensing the signal (1) and estimating a fundamental period of a fundamental of the signal (1) by comparing the sensed signal (1) with at least one threshold (2) to detect threshold crossings and estimating the fundamental period from the threshold crossings. The signal property is then estimated from the fundamental period and/or from the sensed signal (1) during an interval of a length of the fundamental period.

An electronic device according to the invention comprises a micro controller and/or an analogue circuitry which performs the method for estimating a property of a signal. Preferably, the micro controller and/or analogue circuitry controls other parts of the electronic device depending on the results obtained by the method for estimating a property of a signal.

A method for estimating a property of a signal (1) sensed in an electrical system, comprises the steps of sensing the signal (1) and estimating a fundamental period of a fundamental of the signal (1) by comparing the sensed signal (1) with at least one threshold (2) to detect threshold crossings and estimating the fundamental period from the threshold crossings. The signal property is then estimated from the fundamental period and/or from the sensed signal (1) during an interval of a length of the fundamental period.

An electronic device according to the invention comprises a micro controller and/or an analogue circuitry which performs the method for estimating a property of a signal. Preferably, the micro controller and/or analogue circuitry controls other parts of the electronic device depending on the results obtained by the method for estimating a property of a signal.

A digital measurement system includes an oscillator, a mixer, and a controller coupled to each other. The oscillator provides a reference signal having a second frequency. The mixer generates a down-converted signal based on the output signal and the reference signal. The controller then determines a characteristic of the output signal (e.g., frequency or phase) based on the down-converted signal. An analog measurement system includes a filter having a center frequency, a rectifier, and a controller. The filter filters the output signal and the rectifier rectifies the filtered signal. The controller samples the rectified signal and determines a characteristic of the output signal based on the level of the rectified signal. The reference signal controller may adjust a characteristic of the output signal based on the determined frequency and/or phase of the output signal.

Disclosed are a detection method and device for a digital intermediate frequency processing system. The method comprises: forming and transmitting excitation data to a digital intermediate frequency processing system; collecting detection data formed by processing the excitation data by the digital intermediate frequency processing system; and performing a bit-by-bit comparison on the detection data and reference data to form a detection result. Further provided is a computer storage medium.

Provided a method comprising: obtaining waveform data sets of a periodic electric waveform signal, with a length set to one cycle time; calculating a frequency spectrum for each waveform data set; extracting and separating odd and even frequency harmonics to create odd and even frequency harmonic matrices on which a canonical correlation analysis (CCA) being applied to obtain CCA features; performing linear transformation on the CCA features to obtain linear transformed features; generating a model based on the linear transformed features; performing magnitude quantization of frequency spectrums of waveform data sets to identify normal and anomalous waveform signals.

In certain aspects of the disclosure, a frequency monitor includes a counter configured to receive a monitored clock signal, to count a number of periods of the monitored clock signal over a predetermined time duration, and to output a count value corresponding to the number of periods of the monitored clock signal. The frequency monitor also includes a comparator configured to receive the count value from the counter, to receive an expected count value, to compare the count value from the counter with the expected count value, and to output a pass status signal or a fail status signal based on the comparison.