| Acceleration Sensitivity
Stabilization Techniques Under Random
Vibration
As phase noise of any PLL based frequency synthesizer module is direct
dependent on phase noise performance of reference source. Use of such
modules in electronic warfare environment is limited by phase noise
performance degradation under random vibration experienced. Hence for
stabilizing the phase noise performance of reference source mounted
inside unit under test (UUT) module is important for reduction of its
G-sensitivity nature. G-sensitivity reduction is achieved in two phases
in present article. It is very much dependent on its spatial location as
well as stabilization techniques. The finest spatial location (center of
gravity) for mounting position of reference source is determined by
using structural analysis method. Performance stabilization is achieved
by two different techniques i.e. Mechanical and Electrical [5].
i). Structural Analysis
UUT structural analysis needs to be done to find out center of gravity
for mounting of reference source and trying to filter out UUT resonance
out of random vibration frequency spectrum profile. It avoids
magnification of UUT resonance pickups during testing of Phase noise
performance with in vibration spectrum profile as shown in Fig. 7. From
Fig. 7, it is observed that the standalone housing of UUT having
self-resonance at 1.4 KHz. It demands further modifications (i.e.
positional weight analysis, physical profile alteration etc.) in present
UUT to filter out self-resonance out of random vibration profile.