Hi,
I'm simulating an empty cylindrical cavity resonator in meep using the ctl
file attached at the bottom of this message. I would like to excite all
the TE0 modes within a bandwidth of 1 GHz at a centre frequency of 10 GHz.
My base unit is 1mm. I have calculated the frequency of the TE011 mode to
be at 10.45 GHz for this cavity. When I run the simulation harminv outputs
a resonant frequecy of 10.25 GHz. I've tried narrowing the width of the
gaussian pulse and increasing the resolution but the frequency remains
around 10.25.
; Calculating 3d cylindrical resonator modes using cylindircal co-ordinates
; Metal shield must be over one pixel thick
(set! dimensions CYLINDRICAL)
(set! default-material air)
(set! eps-averaging? false)
(define-param ra 60.0) ; radius of air cylinder
(define-param rm 70.0) ; radius of the metal shield
(define-param hm 25.0) ; height of metal shield
(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)
(define sr ( * 1 (+ rm))) ; radial size of the computational cell (cell is
from 0 to sr)
(define sh ( * 1 (+ hm))) ; height of computational cell
(set! geometry-lattice (make lattice (size sr no-size sh))) ; generate the
computational cell
(set! geometry (list
(make cylinder (center 0 0 0) (height hm) ; generate the
metail
shield object
(radius rm) (material metal))
(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))
_______________________________________________
meep-discuss mailing list
[email protected]
http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
