Kikusui KJM6335, Operation Manual, Page: 54 / 129

3-20 Operation KJM6335
3.8 Adjusting Delay
To measure the amount of jitter of an RF signal relative to a clock
signal, the ideal average phase difference between the edge of the
clock signal and that of the RF signal is 180
˚ .
RF
CLOCK OK
360゜ 180゜ 0゜
Distribution of time
differences between the edge
of RF signal and that of clock
signal is as shown at right.
Fig. 3-13
RF
CLOCK NG
360゜330゜ 0゜
Fig. 3-14
Two timings in Figs. 3-13 and 3-14 compare the phase difference
between the RF and clock signals at 180
˚ and the phase difference
between them at 330 ˚ . Essentially, jitter should be distributed in the
range 0 to 360 ˚ , as shown in Fig. 3-13, but is distributed at 0 ˚ and
330 ˚ in Fig. 3-14. This results in a higher a standard deviation
value, and jitter cannot be measured accurately. The phase
difference must be adjusted so that the average phase difference
between the two signals is located at 180
˚ .