Modulation
Type
drop-down list box. The Pulse Building application provides the following
built-in modulation types:Radar systems that use modulation within the pulse are referred to as pulse compression radar systems. For a long range radar to "see" a great distance, the radar needs to have a high average output power. However, to obtain good signal resolution, the radar needs a narrow pulse that reduces the average output power. Pulse compression provides a path around this trade-off. Pulse compression radars will transmit a long, high-power pulse with modulation inside the pulse. The returns can be processed through a filter that is matched to the characteristics of the modulation compressing the pulse in time. This compression allows the radar to separate overlapping returns while transmitting a high average power.
The N7620B Signal Studio for Pulse Building software provides several built-in modulation formats available for the available pulse types. For the trapezoidal and raised-cosine pulse types, modulation is applied to the carrier within the 100%-100% pulse width duration (defined for the pulse in the Pulse Library as a Width (100%-100%) parameter). For the Custom Profile and Custom I/Q pulse types, modulation is applied at the first point defining a pulse through to the last point of the pulse.
Each of the modulation types can have its own parameters such as step
size, range and so forth and are unique to a modulation. You can add modulation
by selecting a type from the Modulation
Type
drop-down list box. The Pulse Building application provides the following
built-in modulation types:
None
