In simulating linear frequency modulated (LFM) chirp signals, with the parameters: Pulse width, bandwidth.

I find the matched filter response to be this:

enter image description here

In particular, there is a increase in the energy over the right side of the plot.

My question is, is this normal, or should the tapering be going down?

  • $\begingroup$ think about this: since your pulse shaper is constant envelope (right?), your MF should be, too. The fact that you're seeing intensity variations at all is probably because of your analysis methods. $\endgroup$ Jul 9, 2018 at 6:12

1 Answer 1


I found that the reason for the spike on the right is due to the inclusion of pulse width of time along the time axis.

  • $\begingroup$ where is this spike on the right? it looks like it should be just touching the bump on the right. where is Nyquist in this frequency-domain plot? this chirp signal must've been windowed with a window of some sort. it looks a little Hannish or Hammish. And it looks like the window closed before the frequency changed a lot (or is the spike at DC)? Turns out that if you're doing linearly-swept frequency chirps, windowing them with a Gaussian window allows for some mathematical properties that can be made use of. $\endgroup$ Sep 10, 2018 at 7:17
  • $\begingroup$ thanks! the "spike" refers to the gradually elevating response on the right side of the plot. Also, the plot x-axis is in time domain, and i simulated the chirps with rectangular windowing $\endgroup$
    – matthew
    Sep 17, 2018 at 13:06

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