Steven G. Johnson <[EMAIL PROTECTED]> writes: > > > I'm trying to generate a LFM Chirp source i.e. freq = f0 +K*t, where K > > is the chirp rate. When I do the envelope of the curve always seems to > > grow bigger. I've tested my chirp function itself and it appears to > > work > > fine. I even put in a slow rising envelope (similar to the built in > > sinusoidal function) and that didn't help. > > What you are seeing, I suspect, is a nice physical demonstration of > the density of states. As the frequency of the current grows, the > amplitude of the field will grow. Just try putting in a continuous- > wave source and varying the frequency, and you'll see that increasing > the frequency will increase the amplitude of the resulting field.
Hi Steven, Could you perhaps explain what you mean by the current. I know that is what we are setting by using the source definitions - I'm just not clear how that fits into Maxwell's equations. In playing around with simple FDTD 1D code examples the E or H field for a point was set directly and that's how the source was used. Thanks for any assistance. Cheers, David _______________________________________________ meep-discuss mailing list [email protected] http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
