Agilent 33120A User's Guide

Chapter 7 TutorialModulationFor triggered burst operation, the function generator creates an internalmodulation signal which is exactly synchronous with the carrier waveform.This internal modulation signal is used to halt waveform memoryaddressing when the last data point is reached. This modulation signaleffectively “gates” the output “on” and “off” for the specified number ofcarrier wave cycles. The modulation signal is then triggered by anotherinternal burst rate signal generator which controls how often thespecified carrier burst is output. In external triggered burst operation,the modulation signal trigger source is set to the function generator’srear-panel Ext Trig terminal. This source replaces the internal burstrate signal generator for pacing triggered bursts.Changes to the burst count, burst rate, burst phase, or carrier frequencywill cause the function generator to automatically compute a newmodulation signal and download it into modulation RAM. It is notpossible for the function generator to burst single cycles for all carrierfrequencies because the internal modulation signal generator is not ascapable as the main carrier signal generator. The table below shows thefunction generator’s carrier frequency and burst count limitations.CarrierFrequency10 mHz to 1 MHz>1 MHz to 2 MHz>2 MHz to 3 MHz>3 MHz to 4 MHz>4 MHz to 5 MHzMinimumBurst Count12345For sine, square, andarbitrary waveforms only.292