《1Vibration-induced PM Noise in Oscillators and its suppression》.pdf

13 Vibration-induced PM Noise in Oscillators and its Suppression Archita Hati, Craig Nelson and David Howe National Institute of Standards and Technology USA 1. Introduction High-precision oscillators have significant applications in modern communication and navigation systems, radars, and sensors mounted in unmanned aerial vehicles, helicopters, missiles, and other dynamic platforms. These systems must provide their required performance even when subject to mild to severe dynamic environmental conditions. Oscillators often can provide sufficiently low intrinsic phase modulation (PM) noise to satisfy particular system requirements when in a static environment. However, these oscillators are sensitive to acceleration that can be in the form of steady acceleration, vibration, shock, or acoustic pickup. In most applications the acceleration experienced by an oscillator is in the form of vibration, which can introduce mechanical deformations that deteriorate the oscillator’s otherwise low PM noise (Filler, 1988; Vig et al., 1992; Howe et al., 2005). This degrades the performance of the entire electronic system that depends on this oscillator’s low phase noise. For example, when radars and sensors mounted on helicopters are subjected to severe low- and medium-frequency vibration environments, the vibration noise induced into the system’s reference oscillator transl