User`s guide

2 User’s and Service Guide Supplement

E4438C Option HEC

Description

The Agilent E4438C Option HEC synchronizes two or more ESG baseband generators

using an external baseband generator clock input. Trigger resolution of 500 ps is caused by

the phase noise of the sampling clock. This is a conservative number based on

measurements made on the stability of the phase between the two outputs. Both ESG’s

baseband generator accept input clocks (200 to 400 MHz) and are driven by the same

external sampling clock source. The baseband output should be consistent in phase over

time at a fixed delay introduce by the internal delay of each ESG. The 500ps is the jitter

between the two phase locked signals.

The baseband generator must also be triggered by a signal synchronized to (a derivative of)

the external sampling clock source. The trigger input on the rear panel clocks required

100 MHz (10 ns) interval external signals that are divided down from the external

sampling clock source. The trigger clock and sampling clock should be synchronized.

Without Option HEC the trigger resolution is 10 ns, which is the trigger clock rate. If the

two ESGs are not driven with the same clock, the two trigger clocks will be independent

and drift within one clock cycle or 10 ns.

Another unique feature to the E4438C Option HEC is using the same external clock to

drive multiple baseband generators to provide simultaneous triggers and precise time

control of the output arbitrary waveform patterns. For this to function properly, all of the

E4438C’s will need to be equipped with Option HEC. Refer to “Repeatable Triggering for

Multiple Baseband Sources” on page 8.

NOTE

This connector accepts an input power from 0 dBm to 6 dBm sinewave

and an external clock frequency range from 200 MHz to 400 MHz.

Damage levels are greater than 8 Volts and less than –8 Volts.