Hi

I have a question about how the Finite Element Method is implemented in EM. Specifically, when you are dealing with a shielded microstrip, whose diagram looks like:

---------------------------- | | | | air | | | _______ | microstrip |-------------------------| |/////////////////////////| |/////////////////////////| dielectric |/////////////////////////| |/////////////////////////| |/////////////////////////|

In the books I am using:

Jin, Jianming, The Finite Element Method in Electromagnetics, John Wiley & Sons, New York, 1993.

Volakis, John L., et. al., Finite Element Method for Electromagnetics, IEEE Press, 1998.

the values of the Relative Permittivity, er = 4.0, and Relative Permeability, ur = 1.0. This seems to be the same for both the air and the dielectric. Can someone tell me why there is no difference in values between the air and the dielectric. I am trying to solve the waveguide problem.

I will say my specialties are in mechanical engineering and numerical methods rather than EE, so I hope the answer isn't too simplistic.

Also, could someone tell me what are the boundary conditions for the electric field on the perimeter, on the microstrip, and the dielectric?

Thanks.

I have a question about how the Finite Element Method is implemented in EM. Specifically, when you are dealing with a shielded microstrip, whose diagram looks like:

---------------------------- | | | | air | | | _______ | microstrip |-------------------------| |/////////////////////////| |/////////////////////////| dielectric |/////////////////////////| |/////////////////////////| |/////////////////////////|

In the books I am using:

Jin, Jianming, The Finite Element Method in Electromagnetics, John Wiley & Sons, New York, 1993.

Volakis, John L., et. al., Finite Element Method for Electromagnetics, IEEE Press, 1998.

the values of the Relative Permittivity, er = 4.0, and Relative Permeability, ur = 1.0. This seems to be the same for both the air and the dielectric. Can someone tell me why there is no difference in values between the air and the dielectric. I am trying to solve the waveguide problem.

I will say my specialties are in mechanical engineering and numerical methods rather than EE, so I hope the answer isn't too simplistic.

Also, could someone tell me what are the boundary conditions for the electric field on the perimeter, on the microstrip, and the dielectric?

Thanks.