5G and Wi-Fi 6 communication systems offer the promise of fast data rates. Core to achieving this performance is the fidelity of the up and down-conversion signal chains. When symbol errors exist, one potential source is poor phase noise of system local oscillators (LOs). To troubleshoot, engineers can utilize low phase noise synthesizers as an LO substitute or measure the LO’s phase noise. This workshop will explain phase noise, the importance of low phase noise, and the tools to determine the phase noise of the LO’s you are using and the availability of low phase noise LO substitutes.