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exercise 1.7
ZIP with MATLAB scripts and note:
example 1.1 notes:
eps0=8.854e-12 % [F/m] electric permittivity
mu0=4*pi*1e-7 % [H/m] magnetic permeability
c0=1/(eps0*mu0)^.5 % light velocity
er1=(5-1j*2) % relative permittivity lossy dielectric
mur=1
% c1=c0/er1^.5 % wave velocity in air = c0
f0=1e9
lambda0=c0/f0
k0=2*pi/lambda0
% incident field amplitude, plane wave, right on dielectric-metal interface
E0=4 % [V/m]
gamma=1j*2*pi*f0*(mu0*mur*er1*eps0)^.5 % lossy dielectric propagation constant
alpha=real(gamma)
beta=imag(gamma)
etha=1j*2*pi*f0*mu0*mur/gamma
% lossy dielectric - metal interface reflection coefficient
R=-1
% Ei=E0*exp() ? unknown for any other z~=0, so don't get lost in it
dz=lambda0/200;
z=[-.5:dz:0];
Ei=E0*exp(-gamma*z);
E=Ei+R*E0*exp(gamma*z);
figure(1)
plot(z,abs(E))
grid on
xlabel('z');ylabel('|E|')
title('|E| [V/m]')
figure(2)
plot(z,10*log10(abs(E)/E0))
grid on
xlabel('z');ylabel('L')
title('L(z) [dB] lossy dielectric layer z thick on metal')
thicker paint coating is not going to help much to further attenuate incident field because the one doing the job of nulling field near surface is the metal underneath.
I have included scripts from example 1.1 that show burst reflected on metal.
%% E(t) burst reflected through lossy dielectric
cd fdtd_1d_4_3
fdtd_1d_4_1_3
%% E peak burst reflected through lossy dielectric
cd ..
cd fdtd_1d_4_5
fdtd_1d_4_1_5
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