I/Q analysis using a spectrum analyzer refers to the examination of in-phase (I) and quadrature (Q) components of a modulated signal. These two components represent the real and imaginary parts of the signal, which together carry amplitude and phase information crucial for understanding the behavior of complex modulated signals such as those used in modern communication systems (e.g., LTE, Wi-Fi, etc.).

I/Q analysis helps engineers evaluate the quality of signal modulation, detect impairments such as phase noise, distortion, or imbalance, and assess how closely the transmitted signal matches the intended design. By using a spectrum analyzer with I/Q capabilities, engineers can visualize the signal's constellation diagram, measure error vector magnitude (EVM), and diagnose signal integrity issues, which are critical for optimizing performance in communication systems and wireless networks.

With the UNI-T UTS3000A Signal Analyzer UTS3000A-I/Q option enabled, users can perform simple and complex analysis of modulated communication signals.