Phase Noise Performance Stabilization of PLL System under Dynamic
Vibration Conditions for Airborne Applications
The purpose of this paper is to disclose the design techniques and
experimental methodologies for the stabilization of X-band phase locked
loop (PLL) phase noise performance during random vibration environment.
Phase noise performance of PLL based unit under test (UUT) is very prone
to disturbance occurred in random vibration profile frequency spectrum.
UUT self-resonance plays vital role in occurrence of disturbance in
random vibration profile. The stabilization of phase noise performance
during dynamic (random vibration) condition is achieved by following
methodologies, i.e. vibration-isolator compensation technique,
purification tactic of crystal reference of PLL and spatial location
analysis for mounting of crystal reference. Spatial analysis helps to
filter out UUT self-resonance from frequency spectrum of random
vibration profile which ultimately leads to reduction of frequency
resonance pickups during random vibration testing.