An example method includes following operations: (i) receiving a device signal from a device under test (DUT); (ii) setting an attenuation value; (iii) applying the attenuation value to the device signal to produce an attenuated device signal for a frequency spectrum analyzing device, where the frequency spectrum analyzing device produces a noise signal and intermodulation interference; (iv) obtaining a power spectral density value, where the power spectral density value comprises a power, at a frequency value, of a combined signal that is based on the attenuated device signal, the noise signal, and the intermodulation interference; (v) repeating operations (ii), (iii), and (iv) one or more times to produce multiple power spectral density values; (vi) repeating operations (i), (ii), (iii), (iv), and (v) one or more times to add power spectral density values to the multiple power spectral density values; and (vii) obtaining a power spectral density of the device signal.

A stability analyzing apparatus is in cooperation with a DC power system having a bus terminal connected to at least a load, and comprises a perturbation signal generating module, a signal processing module and a determining module. The perturbation signal generating module generates a perturbation signal injected into the bus terminal to obtain a transfer function of the bus terminal impedance. The signal processing module is electrically connected to the perturbation signal generating module and calculates the slope of the transfer function of the bus terminal impedance to obtain a transfer function of the bus terminal impedance slope. The determining module is electrically connected to the signal processing module and determines the stability tendency of the DC power system according to the transfer function of the bus terminal impedance slope. A stability analyzing method is also disclosed.

A stability analyzing apparatus is in cooperation with a DC power system having a bus terminal connected to at least a load, and comprises a perturbation signal generating module, a signal processing module and a determining module. The perturbation signal generating module generates a perturbation signal injected into the bus terminal to obtain a transfer function of the bus terminal impedance. The signal processing module is electrically connected to the perturbation signal generating module and calculates the slope of the transfer function of the bus terminal impedance to obtain a transfer function of the bus terminal impedance slope. The determining module is electrically connected to the signal processing module and determines the stability tendency of the DC power system according to the transfer function of the bus terminal impedance slope. A stability analyzing method is also disclosed.

A double-balance electronic test apparatus can measure inductance, capacitance, and resistance more accurately than a single-balance meter. The double-balance electronic test apparatus includes two circuits to balance the impedance of a device under test, and uses the balance to calculate the inductance, capacitance, and resistance of the impedance device under test.

A double-balance electronic test apparatus can measure inductance, capacitance, and resistance more accurately than a single-balance meter. The double-balance electronic test apparatus includes two circuits to balance the impedance of a device under test, and uses the balance to calculate the inductance, capacitance, and resistance of the impedance device under test.

A method of preventing inter-system interference while acquiring waveforms in a test and measurement instrument with variation in a device under test system S-parameters. The method includes receiving a waveform from a device under test at the test and measurement instrument, digitizing the waveform, identifying portions of the digitized waveform with different S-parameter characteristics, separating the identified portions of the digitized waveform into different waveforms, and displaying the different waveforms to a user.

A method of preventing inter-system interference while acquiring waveforms in a test and measurement instrument with variation in a device under test system S-parameters. The method includes receiving a waveform from a device under test at the test and measurement instrument, digitizing the waveform, identifying portions of the digitized waveform with different S-parameter characteristics, separating the identified portions of the digitized waveform into different waveforms, and displaying the different waveforms to a user.

An example method includes following operations: (i) receiving a device signal from a device under test (DUT); (ii) setting an attenuation value; (iii) applying the attenuation value to the device signal to produce an attenuated device signal for a frequency spectrum analyzing device, where the frequency spectrum analyzing device produces a noise signal and intermodulation interference; (iv) obtaining a power spectral density value, where the power spectral density value comprises a power, at a frequency value, of a combined signal that is based on the attenuated device signal, the noise signal, and the intermodulation interference; (v) repeating operations (ii), (iii), and (iv) one or more times to produce multiple power spectral density values; (vi) repeating operations (i), (ii), (iii), (iv), and (v) one or more times to add power spectral density values to the multiple power spectral density values; and (vii) obtaining a power spectral density of the device signal.

An example method includes following operations: (i) receiving a device signal from a device under test (DUT); (ii) setting an attenuation value; (iii) applying the attenuation value to the device signal to produce an attenuated device signal for a frequency spectrum analyzing device, where the frequency spectrum analyzing device produces a noise signal and intermodulation interference; (iv) obtaining a power spectral density value, where the power spectral density value comprises a power, at a frequency value, of a combined signal that is based on the attenuated device signal, the noise signal, and the intermodulation interference; (v) repeating operations (ii), (iii), and (iv) one or more times to produce multiple power spectral density values; (vi) repeating operations (i), (ii), (iii), (iv), and (v) one or more times to add power spectral density values to the multiple power spectral density values; and (vii) obtaining a power spectral density of the device signal.