Dear Jonathan, Thanks for the reply. I'd forgotten to include my signature in the message. I'm a PhD student at York University working in the physical layer research group for Prof. Jeremy Everard. Your modified ctl file gives the correct answer but I'd be interested if you know why using a prefect metal cylinder to enclose the region of interest doesn't produce the same result? I agree that using my original ctl file will unnecessarily increase the size of the computational cell but I assumed that MEEP would still set the electric field to zero inside the metal region.
Best Regards, Simon Bale. -- Simon Bale PhD Student Department of Electronics University of York Heslington York YO10 5DD Tel: +44 (0)1904 432416 Fax: +44 (0)1904 432335 Email: [EMAIL PROTECTED] > Dear No-name/No-affiliation (York University?), > > For an empty cylindrical cavity, you don't need to define any metal just set: > > (set! k-point false) > > to get perfect conducting walls. > > Here's a modified .ctl file for you,which gives a frequency of 10.446 GHz which agrees very well with the analytical 10.447 GHz: > > ; Calculating 3d cylindrical resonator modes using cylindircal > co-ordinates > ; Metal shield must be over one pixel thick > > (set! dimensions CYLINDRICAL) > (set! eps-averaging? false) > (set! k-point false) ; make boundaries perfect electric conductor (define-param ra 60.0) ; radius of air cylinder > (define-param ha 15.0) ; height of inner air region > (define-param n 1) ; refractive index of the material filling the resonator > (set-param! m 0) > > (set! geometry-lattice (make lattice (size ra no-size ha))) ; generate the computational cell > > (set! geometry (list > (make cylinder (center 0 0 0) (height ha) > (radius ra) (material (make dielectric (index n)))))) > > (set-param! resolution 3 ) ; resolution of the simulation in pixels per unit distance > > (define-param fcen (* 10 (/ 1 300))) ; pulse center frequency in GHz (define-param df (* 1 (/ 1 300))) ; pulse width in GHz > > (set! sources (list > (make source > (src (make gaussian-src (frequency fcen) (fwidth df))) (component Hz) (center 1.5 0 0)))) > > (run-sources+ 200 (at-beginning output-epsilon)(after-sources (harminv Hz > (vector3 1.5 0 0) fcen df))) > > (define freq (car (map harminv-freq-re harminv-results))) > (print "frequency : " (* 299.79 freq) " GHz)\n") > > > I hope this helps! > > Jonathan Breeze > Research Fellow > Department of Materials > Imperial College London > Exhibition Road > London SW7 2AZ > > Phone: + 44 (0)20 7594 6800 > Fax : + 44 (0)20 7594 6757 > Email: [EMAIL PROTECTED] > Web : www.imperial.ac.uk/materials > > > _______________________________________________ meep-discuss mailing list [email protected] http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
