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January 18, 2013 10:54am UTC

electromagntic propagation through three layers

hello
I am student on electronic and I am trying to simulate with comsol on rf module , in summarize my work is to simulate the sun light propagation through three layers bonded to each other and I had used the floquet periodic condition and this witch include this equations :

Parameter

lambda0= 0.5e-6[m]
k0_emwh = 2*pi/lambda0
alpha1 =30[deg]
n1 1.97235
k1x= k0_emwh*real(n1)*cos(alpha1)
k1y =k0_emwh*real(n1)*sin(alpha1)
freq c/lambda0
c= 3*10^8[m/s]
n2 0.125
alpha2= asin(sin(alpha1)*real(n1/n2))
k2x= k0_emwh*real(n2)*cos(alpha2)
K2y= k0_emwh*real(n2)*sin(alpha2)
n3 1.97235
alpha3 =asin(sin(alpha3)*n2/real(n3))
E0z= exp(-i*k1x*x)
Ez1= E0z[V/m]
k3x= k0_emwh*real(n3)*cos(alpha3)
k3y= k0_emwh*real(n3)*sin(alpha3)

and I put the boundary condition above and below the layers
Periodic condition 1
K vector for folquet periodicity :
k1x
k1y
Port 1
In the front of the layer
Put the wave excitation in this port (on)
Pin=1
Téta(in) = 0
E0= Ez1
Beta =k1y
Port 2
Put the wave excitation in this port (off)
E0= Ez1
Beta =k1y

in this simulation i would like to study the propagation of the electromagnetic wave through three micrometer thickness of material, and each material have property , and my problem when reduce the thickness the electromagnetic wave propagate with difficulty and when i increase the thickness the wave propagate easily, i don't know if my simulation is true.

Thank you for your help

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January 19, 2013 7:50am UTC in response to Sergei Yushanov

Re: electromagntic propagation through three layers

thank you sergai

I'll try i'll try to change what are you had tell , just I would like tell you i use the floquet periodic condition, i suppose it's the same , i ll give you the results that i found

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January 21, 2013 5:56pm UTC in response to Belbey Hayet

Re: electromagntic propagation through three layers

Belbey,

I don’t have 4.1, so I am attaching report of your model created with later version. Comparison with analytical solution for the case of TM polarization is also included.

I set the conductivity of the first ZnO layer to zero because it does not make much sense to specify evanescent wave at the input port. If you want to study wave attenuation in the first ZnO layer, then you might want to model structure with four layers: first layer is lossless dielectric (say, air) where you specify incident wave, second layer is ZnO with specified thickness, etc.

Regards,
Sergei

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January 27, 2013 6:58pm UTC in response to Sergei Yushanov

Re: electromagntic propagation through three layers

Could you please attach the mph file; thank you!

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January 28, 2013 5:56pm UTC in response to SR

Re: electromagntic propagation through three layers

SR,

Attached is model file. Please note that this is 4.3a.

Regards,
Sergei

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January 29, 2013 1:42pm UTC in response to Belbey Hayet

Re: electromagntic propagation through three layers

hello ,


I have a small problem with parameter equation when i try to enter this equation in parameter case

sqrt(k0^2*em - kay^2 - j*eps^3)

x-component of wavevector of middle layer (evanescent square root)

the comsol don't accept this , and I would like to know what the
eps

thank you

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January 29, 2013 7:03pm UTC in response to Sergei Yushanov

Re: electromagntic propagation through three layers

Hi

indeed "eps" is a predefined number in COMSOL (as in other numerical tools) it's the smalles real number one can distinguish from "1.0" in the binary representation of real numbers. It's rather FPU dependent, so you can forget to put it to any positive power it will wanish.
Even, as most physics equations are 2nd order PDE's then sqrt(eps) represents, the absolute best, relative ratio, or number of significant digits you could expect from your results

--
Good luck
Ivar

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January 30, 2013 6:04pm UTC in response to Belbey Hayet

Re: electromagntic propagation through three layers

Hi

red means normally typos, or undefined variable name:s so those should be tracked and corrected,
orange is unit inconsistencies, thise might be ignored, with the risk of scaling errors

--
Good luck
Ivar

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