Abstract: A measurement system and a method of removing effects of instability of the measurement system while measuring at least one S-parameter of a device under test (DUT) are provided. The method includes initially determining a characteristic of the measurement system, including identifying a location of an instability in the time domain of the measurement system; determining a change of the characteristic of the measurement system while connected to the DUT; and compensating for the determined change of the characteristic of the measurement system while connected to the DUT by removing effects of the determined change on measurements of the at least one S-parameter of the DUT.

Abstract: A measurement system and a method of removing effects of instability of the measurement system while measuring at least one S-parameter of a device under test (DUT) are provided. The method includes initially determining a characteristic of the measurement system, including identifying a location of an instability in the time domain of the measurement system; determining a change of the characteristic of the measurement system while connected to the DUT; and compensating for the determined change of the characteristic of the measurement system while connected to the DUT by removing effects of the determined change on measurements of the at least one S-parameter of the DUT.

Abstract: A method is provided for detecting power of a periodic signal in a band of interest of the periodic signal having a predetermined bandwidth. The method includes determining frequencies of multiple tones in the periodic signal, respectively; receiving the periodic signal at a signal analyzer; selectively measuring power values at the frequencies of the multiple tones; and determining a band power of the periodic signal over the predetermined bandwidth by summing the power values at the frequencies of the multiple tones.

Abstract: Residual noise of a frequency mixer is detected. A reference clock is used to generate a first radio frequency (RF) signal, a second RF signal and a third RF signal. The first RF signal and the second RF signal serve as input to the frequency mixer. The reference clock is used to generate a third RF signal. The reference clock is also used to control timing in a detector device. A second frequency mixer mixes an output of the DUT with the third RF signal to produce an input signal for a detector device. Mixing the output of the DUT with the third RF signal cancels at least some of the phase noise within the output signal of the DUT that results from phase noise in the first RF signal and from phase noise in the second RF signal. The detector device detects residual phase noise existing within the input signal for the detector device.

Abstract: Nonlinear distortion of a device under test (DUT) is detected by obtaining measurements of a multi-tone input signal from a signal generator to a DUT, to obtain a measured multi-tone input signal. Measurements are also obtained of a multi-tone output signal from the DUT that is generated based on the multi-tone input signal, to obtain a measured multi-tone output signal. A correlated part of the measured multi-tone output signal that is correlated with the measured multi-tone input signal is determined insofar as the correlated part corresponds to a frequency response function of the DUT.

Abstract: A system for measuring residual phase noise of a device under test (DUT) includes first and second signal sources, first and second receivers, and a processor. The first signal source generates a first signal to be input to the DUT as a stimulus signal and provides a second signal that is phase coherent with the first signal. The second signal source receives the second signal and generates a reference signal based on the second signal, which is phase coherent with the stimulus signal. The first receiver measures an output signal from the DUT responsive to the stimulus signal, and the second receiver measures the reference signal from the second signal source. The processor mathematically suppresses a carrier of the output signal by determining a difference between the measured output signal and the measured reference signal, and determines the residual phase noise of the DUT based on the difference.

Abstract: Nonlinear distortion of a device under test (DUT) is detected by obtaining measurements of a multi-tone input signal from a signal generator to a DUT, to obtain a measured multi-tone input signal. Measurements are also obtained of a multi-tone output signal from the DUT that is generated based on the multi-tone input signal, to obtain a measured multi-tone output signal. A correlated part of the measured multi-tone output signal that is correlated with the measured multi-tone input signal is determined insofar as the correlated part corresponds to a frequency response function of the DUT.

Abstract: A method is provided for calibrating a multiport measurement system having a local oscillator and a respective receiver associated with each port. The method includes performing a relative calibration by vector calibrating ports of the multiport measurement system and generating relative error-correction terms for the ports. Further, the method includes performing an absolute calibration by calibrating an amplitude response of the receivers of the multiport measurement system, and removing a local oscillator unknown phase response using a single phase reference coupled to a vector calibrated port and transferring cross-frequency phase correction terms from this vector calibrated port to the receivers of the other vector calibrated ports.

Abstract: A method is provided for detecting power of a periodic signal in a band of interest of the periodic signal having a predetermined bandwidth. The method includes determining frequencies of multiple tones in the periodic signal, respectively; receiving the periodic signal at a signal analyzer; selectively measuring power values at the frequencies of the multiple tones; and determining a band power of the periodic signal over the predetermined bandwidth by summing the power values at the frequencies of the multiple tones.

Abstract: A method of calibrating a test instrument comprises determining a first response of a calibration device on the test instrument over a first set of operating ranges, determining a derived second response of the calibration device on the test instrument over a second set of operating ranges based on the first response, measuring the second response of the calibration device on the test instrument over the second set of operating ranges, and determining correction factors of the test instrument for the second set of operating ranges based on a comparison between the measured second response and the derived second response.

Abstract: A system and method for determining the linearity of a device-under-test combine a first periodic signal and a second periodic signal to produce a combined signal, wherein the second periodic signal has at least one of a phase difference and a frequency difference with respect to the first periodic signal, and applying the combined signal to an input of the device-under-test. The linearity of the device-under-test is determined from an output signal of the device-under-test based on the at least one of the phase difference and frequency difference between the first periodic signal and the second periodic signal.

Abstract: A radio frequency (RF) measurement system acting as a spectrum analyzer and a method of operating the same eliminates image signals from a detected input RF spectrum. The method includes determining at least three local oscillator (LO) frequencies; determining LO offsets between the LO frequencies; and mixing the LO frequencies with the input RF spectrum to provide corresponding intermediate frequency (IF) signals having an IF bandwidth, where at least one of the IF signals has the input RF spectrum mixed to a different portion of the IF bandwidth than at least one other of the IF signals, providing overlapping coverage. The method further includes acquiring ADC time records for the IF signals; performing Fourier transforms (FTs) on the ADC time records to provide IF spectrums; and detecting RF responses from the IF spectrums to determine an RF response trace corresponding to the input RF spectrum.

Abstract: A method is provided for extending dynamic range of a receiver. The method includes receiving a known input signal at the receiver, detecting a first output signal in response to the known input signal, and determining a correction function based on the first output signal and the known input signal for compensating for non-linear distortion introduced by the receiver. The method further includes receiving an unknown input signal at the receiver, detecting a second output signal in response to the unknown input signal, and applying the correction function to the second output signal in a time domain to recover the unknown input signal.

Abstract: A system and method sequentially measure the amplitude and phase of an output signal of a device under test in each of two or more frequency ranges which together span the output signal spectrum, using a local oscillator (LO) signal whose frequency and phase change for each measurement. The measured phase of the output signal is adjusted for at least one of the frequency ranges to account for the change of phase in the LO signal from measurement of one frequency range to another frequency range, including applying to the measured phase a phase offset determined by measuring the phases of two pilot tones in the two or more frequency ranges, using the LO signal. The phase-adjusted measurements of the output signal in the two or more frequency ranges are stitched together to determine the amplitude and phase of the output signal across the output spectrum.

Abstract: A radio frequency (RF) measurement system acting as a spectrum analyzer and a method of operating the same eliminates image signals from a detected input RF spectrum. The method includes determining at least three local oscillator (LO) frequencies; determining LO offsets between the LO frequencies; and mixing the LO frequencies with the input RF spectrum to provide corresponding intermediate frequency (IF) signals having an IF bandwidth, where at least one of the IF signals has the input RF spectrum mixed to a different portion of the IF bandwidth than at least one other of the IF signals, providing overlapping coverage. The method further includes acquiring ADC time records for the IF signals; performing Fourier transforms (FTs) on the ADC time records to provide IF spectrums; and detecting RF responses from the IF spectrums to determine an RF response trace corresponding to the input RF spectrum.

Abstract: A method is provided for extending dynamic range of a receiver. The method includes receiving a known input signal at the receiver, detecting a first output signal in response to the known input signal, and determining a correction function based on the first output signal and the known input signal for compensating for non-linear distortion introduced by the receiver. The method further includes receiving an unknown input signal at the receiver, detecting a second output signal in response to the unknown input signal, and applying the correction function to the second output signal in a time domain to recover the unknown input signal.

Abstract: Scattering parameters of a test fixture having a first port and a second port are measured by providing a test instrument; outputting a one-port reflection test signal from the test instrument to the first port with the second port terminated in a reflective termination having a known reflection coefficient, and receiving at the test instrument a one-port reflection measurement signal from the first port; subjecting the one-port reflection measurement signal to first time gating to generate a first time-gated measurement signal, the first time gating using a first gating function temporally disposed about the first port; subjecting the one-port reflection measurement signal to second time gating to generate a second time-gated measurement signal, the second time gating using a second gating function temporally disposed about the termination; and deriving the scattering parameters from the first time-gated measurement signal and the second time-gated measurement signal.

Abstract: Scattering parameters of a test fixture having a first port and a second port are measured by providing a test instrument; outputting a one-port reflection test signal from the test instrument to the first port with the second port terminated in a reflective termination having a known reflection coefficient, and receiving at the test instrument a one-port reflection measurement signal from the first port; subjecting the one-port reflection measurement signal to first time gating to generate a first time-gated measurement signal, the first time gating using a first gating function temporally disposed about the first port; subjecting the one-port reflection measurement signal to second time gating to generate a second time-gated measurement signal, the second time gating using a second gating function temporally disposed about the termination; and deriving the scattering parameters from the first time-gated measurement signal and the second time-gated measurement signal.

Abstract: A method of calibrating a test instrument comprises determining a first response of a calibration device on the test instrument over a first set of operating ranges, determining a derived second response of the calibration device on the test instrument over a second set of operating ranges based on the first response, measuring the second response of the calibration device on the test instrument over the second set of operating ranges, and determining correction factors of the test instrument for the second set of operating ranges based on a comparison between the measured second response and the derived second response.

Abstract: A network analyzer comprises: a signal source configured to supply an input signal to a device, wherein the device is configured to generate a phase reference signal; a receiver configured to receive the phase reference signal from the device and to measure a phase response of the device according to the phase reference signal; and a calibration component configured to compare the measured phase response of the device with an actual phase response of the device to identify a tracking parameter for the receiver.