Hi all, I try to simulate EBG(Electromagnetic BandGap) ground plane like an attached picture with Meep to get a band diagram. EBG ground plane is composed of PEC ground, dielectric substrate, periodic patches, connecting vias. I don't know the thickness of metal. I set it 0.1 mm.
I finished a calculation with attached ctl file. But the band diagram seems to be wrong. Precisely, the geometry is wrong. I executed h5topng -0x0. But I got only black long rectangle. I think there are problems in geometry and resolution. Is there someone simulating similar structures? I need your help. Best Regards, Ken ____________________________________________________________________________________ Sucker-punch spam with award-winning protection. Try the free Yahoo! Mail Beta. http://advision.webevents.yahoo.com/mailbeta/features_spam.html
<<inline: EBG.jpg>>
(define-param unit 1e-3) ; base unit in meters (1e-3 = 1
mm)
(define-param fh 12e9) ; frequency in hertz
(define-param res_ppw 20) ; resolution in pixels per
wavelength
(define lam (/ 3e8 fh)) ; free space wavelength (meters)
(define lamu (/ lam unit)) ; wavelength in base units
(define fcen (/ unit lam)) ; source center frequency
(define-param df 1.5) ; pulse freq. width: large
df = short impulse
(define w (* 0.12 lamu)) ; patch width
(define g (* 0.02 lamu)) ; gap
(define h (* 0.04 lamu)) ; substrate thickness
(define r (* 0.005 lamu)) ; vias' radius
(define csize (+ w g)) ; cell size
(define pml_th (/ lamu 2)) ; PML thickness
(define metal_th 0.1) ; metal thickness
(set! eps-averaging? false)
(set! geometry-lattice (make lattice (size csize csize (* 2 lamu))))
(set! pml-layers (list (make pml (direction Z) (thickness pml_th))))
(set-param! resolution (/ res_ppw lamu))
(set! k-point (vector3 0 0 0))
(set! ensure-periodicity true)
(set! geometry (list (make block (center 0 0 0) (size csize csize h)
(material (make dielectric (epsilon
2.2)))) ; substrate
(make cylinder (center 0 0 0) (radius r) (height h)
(material metal)) ; via
(make block (center 0 0 (+ (/ h 2) (/ metal_th 2)))
(size w w
metal_th) (material metal)) ; patch
(make block (center 0 0 (* -1 (+ (/ h 2) (/ metal_th
2))))
(size csize csize
metal_th) (material metal)))) ; ground
(set! sources (list
(make source
(src (make gaussian-src (frequency fcen) (fwidth df)))
(component Ez) (center 0 0 0))))
(define-param k-interp 19) ; # k-points to interpolate, otherwise
(run-k-points 300 (interpolate k-interp (list (vector3 0.1 0 0)
(vector3 0.5 0 0) (vector3 0.5 0.5 0) (vector3 0.1 0 0))))
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