Abstract: A test and measurement instrument includes an input configured to receive at least a waveform of a test signal, which includes a plurality of samples. The test and measurement instrument includes a processing circuit connected with the input. The processing circuit is configured to analyze the waveform and to select at least a subset of samples out of the plurality of samples. The subset of samples matches predefined criteria concerning at least one of bandwidth, amplitude distribution, and amplitude percentiles. The test and measurement instrument is configured to generate a modified waveform based on the selected subset of samples and/or to measure only a part of a received measurement signal from a device under test, which corresponds to the selected subset of samples. Further, a test and measurement setup and a method of measuring a device under test are described.

Abstract: A test and measurement instrument includes an input configured to receive at least a waveform of a test signal, which includes a plurality of samples. The test and measurement instrument includes a processing circuit connected with the input. The processing circuit is configured to analyze the waveform and to select at least a subset of samples out of the plurality of samples. The subset of samples matches predefined criteria concerning at least one of bandwidth, amplitude distribution, and amplitude percentiles. The test and measurement instrument is configured to generate a modified waveform based on the selected subset of samples and/or to measure only a part of a received measurement signal from a device under test, which corresponds to the selected subset of samples. Further, a test and measurement setup and a method of measuring a device under test are described.

Abstract: A measurement system for determining a noise figure of a device under test is described. The measurement system determines a first total error power based on the output signal by a first noise canceling technique, wherein the first total error power includes systematic errors originating in the device under test and in the measurement system. The measurement system determines a second total error power based on the output signal by a different, second noise canceling technique. The second total error power includes systematic errors originating in the measurement system. The second total error power further includes noise originating in the device under test and in the measurement system outside of the measurement instrument. The measurement system is configured to subtract the first total error power from the second total error power, thereby obtaining an external noise power.

Abstract: A measurement system for determining a noise figure of a device under test is described. The measurement system determines a first total error power based on the output signal by a first noise canceling technique, wherein the first total error power includes systematic errors originating in the device under test and in the measurement system. The measurement system determines a second total error power based on the output signal by a different, second noise canceling technique. The second total error power includes systematic errors originating in the measurement system. The second total error power further includes noise originating in the device under test and in the measurement system outside of the measurement instrument. The measurement system is configured to subtract the first total error power from the second total error power, thereby obtaining an external noise power.

Abstract: A signal processing method is provided for processing a digital input signal. The method may be carried out by a measurement instrument. The measurement instrument includes a signal input, a measurement circuit, and an analysis circuit. The signal processing method includes the steps of: receiving a digital input signal from a device under test; capturing a first number N1 of IQ measurement sets based on the received digital input signal, wherein each IQ measurement set comprises a plurality of IQ measurement points; determining an IQ average based on the captured IQ measurement sets, thereby obtaining an averaged signal; determining a second number N2 of noise vectors based on the averaged signal and based on the captured IQ measurement sets; and averaging over the determined noise vectors, thereby obtaining an averaged noise vector.

Abstract: A phase noise measurement method of measuring phase noise of a device under test is described. The phase noise measurement method includes the steps of: determining, by a measurement circuit, measurement IQ data based on an output signal of a device under test; setting, by a control circuit, a magnitude threshold; determining, by an analysis circuit, critical samples of reference IQ data for which a magnitude of a reference signal is smaller than the magnitude threshold; discarding the critical samples of the reference IQ data and corresponding critical samples of the measurement IQ data, thereby obtaining modified reference IQ data and modified measurement IQ data; and determining, by the analysis circuit, a phase noise spectrum of the output signal of the device under test based on the modified reference IQ data and based on the modified measurement IQ data. Further, a measurement system is described.

Abstract: The present disclosure relates to a predistortion method and a predistortion system for a non-linear device-under-test, DUT. The predistortion method comprises the steps of: providing a reference input waveform to the DUT; deriving a predistorted waveform for the DUT based on the reference input waveform using an iterative direct digital predistortion technique; analyzing a relationship between the reference input waveform and the calculated predistorted waveform using a mathematical model; deriving a predistortion algorithm for the DUT based on said analysis; and applying said predistortion algorithm to an input signal and feeding the, thus, predistorted input signal to the DUT.