Phase noise can be viewed as a measure of the spectral purity of a signal, and can be produced by internal effects and external effects. Internal effects are generally in the form of impurities or non-idealities in oscillator circuits and resonators. External effects can be caused by vibration by certain components and circuits. These components and circuits are considered piezoelectric, and ironically they are usually the resonators, oscillators, and filters which most define the source signal’s frequency and spectral purity in a non-vibrational environment. For radar systems operating in very high vibration environments, the vibration-induced phase noise can be orders of magnitude greater than the static phase noise. This article helps the reader to understand the impact that the radar system’s operating environment plays in generating phase noise, and how to mitigate its effects.