Product specifications

Wideband detection

Wideband detection can be used when the majority of the pulsed-RF spectrum

is within the bandwidth of the receiver. In this case, the pulsed-RF signal will

be demodulated in the instrument, producing baseband pulses. With wideband

detection, the analyzer is synchronized with the pulse stream, and data

acquisition only occurs when the pulse is in the “on” state. This means that a

pulse trigger that is synchronized to the PRF must be present; for this reason,

this technique is also called synchronous acquisition mode. The advantage

of the wideband mode is that there is no loss in dynamic range when the

pulses have a low duty cycle (long time between pulses). The measurement

might take longer, but since the analyzer is always sampling when the pulse

is on, the signal-to-noise ratio is essentially constant versus duty cycle. The

disadvantage of this technique is that there is a lower limit to measurable

pulse widths. As shown in Figure 4, as the pulse width becomes narrower,

the spectral energy spreads out – once enough of the energy is outside the

bandwidth of the receiver, the instrument cannot detect the pulses properly.

Figure 4. Pulse width and receiver bandwidth with wideband detection in time and

frequency domain