Using a nonconstant PRF has important applications in radar. This approach is called PRF or PRI staggering.
Uses of staggered PRFs include
Removal of Doppler ambiguities, or blind speeds, where Doppler frequencies that are multiples of the PRF are aliased to zero
Mitigation of the effects of jamming
To implement a staggered PRF, configure your waveform object
using a vector instead of a scalar for the PRF
property
value.
This example shows how to model a linear FM pulse waveform with two PRFs of 1 and 2 kHz. Set the sweep bandwidth to 200 kHz and the duration of 100 μs. The sample rate is 1 MHz. Output 5 pulses.
Note: This example runs only in R2016b or later. If you are using an earlier release, replace each call to the function with the equivalent step
syntax. For example, replace myObject(x)
with step(myObject,x)
.
prfs = [1e3 2e3]; waveform = phased.LinearFMWaveform('PRF',prfs,'SweepBandwidth',200e3,... 'PulseWidth',100e-6,'NumPulses',5); sig = waveform(); T = length(sig)*(1/waveform.SampleRate); t = unigrid(0,1/waveform.SampleRate,T,'[)'); plot(t.*1000,real(sig)) set(gca,'xtick',[0 1 1.5 2.5 3]); xlabel('millisec')