Cascading Signal Generators
This is a handy trick to make a AM signal with a time-variant envelope frequency by cascading signal generators. The Agilent 33220A signal generator, among its many functions, can make frequency sweeps OR modulated signals. It cannot do both.
The solution is simple: Make a frequency sweep on a Generator A, feed the sweep to the BNC external modulation input of Generator B, use Generator B to add the desired carrier frequency and set it to external modulation. The output of Generator B will be a AM signal with a time-variant envelope frequency .