(i) (ii)
Fig.12. Ambient phase noise performance of i) Reference signal ii)
X-band signal
From equation 1 and 2 it is concluded that ~ 38 - 42 dB
phase noise degradation factor implies on transforming 100 MHz signal
into X-band (8-12GHz) signal. Ambient phase noise performance of
reference signal and X-band signal is shown in Fig.12 (i) and (ii)
respectively at three offset frequency points i.e. 100 Hz, 1 KHz, and 10
KHz. The reference signal having phase noise of -109 dBc/Hz, -131
dBc/Hz, and -138 dBc/Hz while X-band signal having phase noise of -70
dBc/Hz, -96 dBc/Hz, and -95 dBc/Hz at three offset frequency points
respectively.
The phase noise of the signal is very sensitive to any physical
disturbance. Random vibration of high g-value affects the phase purity
of a piezoelectric material reference source. As reference source
clocking PLL any occurrence of phase fluctuation gets directly
translated into X-Band signal. Fig. 13(i) and (ii) shows phase noise
performance degradation pattern during random vibration of high g-value
(7.5g) at an offsets of 100Hz, 1 KHz and 10 KHz for 100MHz and X-band
signal respectively. From Fig.13 it is concluded that the phase noise
performance significantly degrades as compared to ambient condition at
an offsets of 100Hz, 1 KHz and 10 KHz by ~ 50,
~45 and ~15 dB respectively.