HP 85108, Системное руководство

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Figure 3-11. Pulsed-RF S-P arameters v ersus Frequency (Frequency Domain P oint-in-Pulse)
2. Pulse Prole Domain. A rep etitiv e sampling tec hnique is used to make measuremen ts in
the pulse prole domain. Measuremen ts are taken at a single frequency as determined
b y the start frequency setting. Data is reconstructed from samples taken from a series of
pulses. F or eac h pulse, a single p oint in the pulse is measured. A prole of the pulse is
made b y measuring the rst pulse at the user-sp ecied Start time, then increasing the
measuremen t trigger dela y b y a certain time incremen t for eac h pulse un til the sp ecied
n um b er of p oints is measured. Refer to Figure 3-12 for an example of this pro cess.
Time zero is the leading edge of the in ternally-generated pulse output w a v eform, or the
falling edge of the externally-generated measuremen t trigger w a v eform. The net w ork analyzer
automatically con trols the time incremen t b et w een samples, called the measuremen t resolution
p erio d, using an algorithm that dep ends up on the greater of the user-sp ecied pulse width
or stop time. This automatic selection of the time resolution can b e seen b y c hanging the
n um b er of p oints and th time span. F or narrow pulses and small time spans, the measuremen t
resolution p erio d can b e as small as 100 nanoseconds; for wide pulses and large time spans,
it can increase to m ultiples of 10 microseconds. With the in ternal measuremen t trigger,
the rst sample can b e taken up to 6 resolution p erio ds prior to time zero. When using
Operation 3-13