IQSTAR allows multiple configurations to measure intermodulation distortion (IMD) with a 2-Tone signal.
Using two combined analog RF sources or one vector signal generator, a spectrum analyzer, or a vector network analyzer, IQSTAR guides you through a simplified calibration procedure and provides high measurement accuracy.
When a scalar setup is used, the software can control the spectrum analyzer to measure the power of each component of the spectrum at the output of the DUT and extract intermodulation distortion up to the ninth order and intercept points. This configuration requires the IQS100B-10 module.
Using the VNA, IQSTAR takes advantage of the dynamic range of the receivers and measures the a-and b-waves to extract the intermodulation product signals and the two carrier tones to calculate the IMD up to the ninth level. The “Frequency Offset” option is required in the VNA for these measurements. As for the generators, IQSTAR handles sources from the VNA, independent sources, or a combination of both and optimizes the tones balance levels for an accurate IMD characterization. This configuration requires the IQS100B-10 and IQS100B-11 modules. A 3D nested sweep, including the carrier frequency, the power, and the spacing of the tones, can be performed to extract a complete IMD characterization of the Power Amplifier in one step.
VBW measurements represent a challenging measurement task. However, IQSTAR handles this measurement efficiently, setting the amplitude of the tones according to the target third-order intermodulation distortion (IMD3) value set by the user. Then, the software sweeps the spacing between the tones and adjusts the balance between them before recording the intermodulation—up to the ninth order. Taking advantage of the speed of VNA sweeps, this measurement takes just a few minutes.