# Discussion Forum

## Angle of incidence, RF modul, Comsol 4.2a

 Topics: 4.2a, RF Module
RSS feed   |   Turn on email notifications   |   5 Replies   Last post: November 19, 2012 4:58am UTC

Samuel Roj

November 3, 2012 11:31am UTC

Angle of incidence, RF modul, Comsol 4.2a

Dear All,

I have issue. I have one metal block on substrate, and I want to illuminate it but at some angle (picture).

One half sphere is substrate, one half air.

Now I want to apply x polarization, scattered field.

I have two cases, first when substrate is also air, and second when substrate is glass (with index refraction ns).

In the case when substrate is air I applied equation: E0*exp(-j*(emw.k0*x*sin(phi)+emw.k0*z*cos(phi)).

In the case when substrate is glass I applied equation: E0*exp(-j*(emw.k*x*sin(phi)+emw.k*z*cos(phi)).

Or maybe in second case I have to write:

(1-sign(z))*E0*(-j*2*pi*x*sin(phi)/Lambda-j*2*pi*z*cos(phi)/Lambda)/2 +

+ (1+sign(z))*E0*(-j*2*pi*x*sin(phi)*ns/Lambda-j*2*pi*z*cos(phi)*ns/Lambda)/2

Tell me please for any of these equations are they correct.

Yuanpeng Wu

November 17, 2012 4:17pm UTC in response to Samuel Roj

Re: Angle of incidence, RF modul, Comsol 4.2a

I want to know that you use the scattering boundary condition or the Port to input the light, and how do you set the wave direction or the propagation constant

Samuel Roj

November 17, 2012 4:53pm UTC in response to

Re: Angle of incidence, RF modul, Comsol 4.2a

I want to know that you use the scattering boundary condition or the Port to input the light, and how do you set the wave direction or the propagation constant

I used scattering boundary condition, but I am nor sure that I understoood second question about equation.

Yuanpeng Wu

November 18, 2012 5:44am UTC in response to Samuel Roj

Re: Angle of incidence, RF modul, Comsol 4.2a

I think you can type E0*exp(-j*(emw.k0*x*sin(phi)+emw.k0*z*cos(phi)) in the "incident field", or you can just set kx=k0*sin(phi), ky=k0*cos(phi) in the "wave direction"

Nikola Bralovic

November 18, 2012 2:42pm UTC in response to Yuanpeng Wu

Re: Angle of incidence, RF modul, Comsol 4.2a

I think you can type E0*exp(-j*(emw.k0*x*sin(phi)+emw.k0*z*cos(phi)) in the "incident field", or you can just set kx=k0*sin(phi), ky=k0*cos(phi) in the "wave direction"

Hello,

I am not sure about second way. I used first way: E0*exp(-j*(emw.k0*x*sin(phi)+emw.k0*z*cos(phi)). I always use incidetn field, not wave direction.

Cheers

Yuanpeng Wu

November 19, 2012 4:58am UTC in response to Nikola Bralovic

Re: Angle of incidence, RF modul, Comsol 4.2a

Hello
Do you find that if you use the same incident field for example E0*exp(-j*(emw.k0*x*sin(phi)+emw.k0*z*cos(phi)), but select the different boundary as the input, the wave direction is different, do you know why?
Cheers！

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