Pulse Building
This topic describes the minimum times supported when generating a pattern with a single pulse.
The figure below shows how the application views a single pulse. It provides individual control over the rise time, the fall time, the pulse width and the pulse repetition interval. The rise time, pulse width, and fall time combine to form the pulse on time. The pulse on time is an important value in that it is used to generate a marker signal that is used to drive the pulse modulator in the signal generator. Driving the pulse modulator insures a pulse on off ratio of at least 80 dB. The I/Q signal alone provides a pulse on off ratio of about 55 dB. The rise time, fall time, and pulse width can be set to any value, including zero. However, the timing resolution is tied to the Arb Sampling Rate.
The PRI timing resolution for a single pulse is tied to the Arb sample rate and the Arb waveform granularity. The Signal Generator's internal Arbs have a waveform granularity of 1.
The single pulse PRI timing resolution is:
|
M9484C VXG |
= 0.333 ns (1/3 Ghz) |
The pulse edge times and the pulse on times are independent of the Arb waveform granularity and can be set to any value including zero. Setting the edge times to zero will result in overshoot and ringing. The actual edge times and on times will be rounded to the sample period resolution.