Agilent Technologies E8267C PSG Manual de usuario descargar pdf (Pagina 17)

Figure 12. Multitone signals to test for in-band and out-of-band distortion.

The peak to average characteristics of the signal can also quickly be determined by plotting

the CCDF (complementary cumulative distribution function) directly on the PSG user inter-

face. This is useful if you need to know the peak power of the signal prior to applying the

signal to the DUT and also provides design insight into headroom tradeoff for devices like

power amplifiers. The CCDF curve plots the percentage of time the DUT will be subjected

to power deviations from the average power, Figure 13. For additional information of CCDF

curves, see the references section.

Figure 13. CCDF curves for 63-tone phase aligned signal vs. 63-tone random phase signal.

Notch In-band distortion Out-of-band distortion

63-tone signal

PSG CCDF plot with all tones at initial phase = 0°

PSG CCDF plot with all tones at initial phase = random

Percentage of time

that composite signal

power is at or above

the average power

Peak power

deviation from

average power