The Agilent 89410A provides a flexible source for circuit stimulation. Sinewaves, periodic chirps (sinewave sweeps), and pseudo-random noise are available, along with user-definable arbitrary waveforms. The arbitrary waveforms operate on a block of up to 4096 complex points. Any of these signals can be used as a stimulus while spectrum measurements are made elsewhere in the circuit. Source level and DC offset of the pattern are all controllable by the user. The second channel makes it possible to measure frequency response or perform vector network analysis, and the built-in math functions facilitate measurement calibration and correction. Two-channel statistical measurements such as cross-correlation and coherence can also be made.