Using External Triggering And Pulse Modulation; Connect The Pulse Generator - HP 8510 User Manual

9

Using External Triggering and Pulse Modulation

In applications where it is necessary to maintain close control over the PRP and duty
cycle of the pulsed-RF stimulus, you can use external equipment to provide the TTL pulse
modulation and external trigger signals. When using an external pulse modulation signal,
it is necessary to synchronize the network analyzer with the pulse modulation signal so
that the measurement is always made at the same time with respect to the stimulus. This
synchronization is accomplished using the HP 8510 external trigger input.

Connect the Pulse Generator

A simple method to control the PRP and duty cycle of the pulsed-RF stimulus is to use
an external pulse generator to provide the pulse modulation input to the RF source.
Figure 9-1 shows a simple setup. In this example the same TTL pulse train provides the pulse
modulation input to the RF source and to the HP 8510 rear panel TRIGGER IN connector.
However, in your application it may be desireable to use di erent synchronized inputs to the
network analyzer TRIGGER IN and to the pulse modulator.
Please note that for internal triggering, a BNC short circuit is connected to the TRIGGER IN
connector. When the pulse generator is connected to TRIGGER IN, move the BNC short
to the SWEEP IN 0 to 10V connector. Otherwise, signals on the sweep in line could a ect
triggering.
Using External Triggering and Pulse Modulation 9-1