Tektronix Baseband Response Characterization of I-Q Modulators

In modern wideband RF transmitters there are often modulation errors caused by the I-Q modulator section of the system which can significantly degrade the modulation quality. This application note provides a brief theory on the sources causing the modulation error and detailed steps of how to characterize the I-Q modulator to correct for these errors. Learn how an arbitrary waveform generator (AWG) and a mixed domain oscilloscope (MDO) can be used for baseband frequency response, single-sideband suppression, amplitude and phase errors, and intermodulation performance.