matlab examples: update to patch-antenna and new patch antenna array example
Thorsten Liebig
parent
14aa47b3c5
commit
5a9b6e1bd5
|
|
@ -8,7 +8,7 @@
|
|||
% Tested with
|
||||
% - Matlab 2009b
|
||||
% - Octave 3.3.52
|
||||
% - openEMS v0.0.14
|
||||
% - openEMS v0.0.17
|
||||
%
|
||||
% (C) 2010 Thorsten Liebig <thorsten.liebig@uni-due.de>
|
||||
|
||||
|
|
@ -16,6 +16,12 @@ close all
|
|||
clear
|
||||
clc
|
||||
|
||||
%% switches & options...
|
||||
postprocessing_only = 0;
|
||||
draw_3d_pattern = 1; % this may take a while...
|
||||
use_pml = 0; % use pml boundaries instead of mur
|
||||
openEMS_opts = '';
|
||||
|
||||
%% setup the simulation
|
||||
physical_constants;
|
||||
unit = 1e-3; % all length in mm
|
||||
|
|
@ -27,40 +33,45 @@ patch.width = 32.86; % resonant length
|
|||
patch.length = 41.37;
|
||||
|
||||
substrate.epsR = 3.38;
|
||||
substrate.width = 120;
|
||||
substrate.length = 120;
|
||||
substrate.kappa = 1e-3 * 2*pi*2.45e9 * EPS0*substrate.epsR;
|
||||
substrate.width = 60;
|
||||
substrate.length = 60;
|
||||
substrate.thickness = 1.524;
|
||||
substrate.cells = 5;
|
||||
substrate.cells = 4;
|
||||
|
||||
feed.pos = -4.5;
|
||||
feed.width = 0.5;
|
||||
feed.pos = -5.5;
|
||||
feed.width = 2;
|
||||
feed.R = 50; % feed resistance
|
||||
|
||||
% size of the simulation box
|
||||
SimBox = [200 200 50];
|
||||
SimBox = [100 100 25];
|
||||
|
||||
%% prepare simulation folder
|
||||
Sim_Path = 'tmp';
|
||||
Sim_CSX = 'patch_ant.xml';
|
||||
if (postprocessing_only==0)
|
||||
[status, message, messageid] = rmdir( Sim_Path, 's' ); % clear previous directory
|
||||
[status, message, messageid] = mkdir( Sim_Path ); % create empty simulation folder
|
||||
end
|
||||
|
||||
%% setup FDTD parameter & excitation function
|
||||
max_timesteps = 30000;
|
||||
min_decrement = 1e-5; % equivalent to -50 dB
|
||||
f0 = 2e9; % center frequency
|
||||
fc = 1e9; % 10 dB corner frequency (in this case 1e9 Hz - 3e9 Hz)
|
||||
f0 = 0e9; % center frequency
|
||||
fc = 3e9; % 10 dB corner frequency (in this case 0 Hz - 3e9 Hz)
|
||||
FDTD = InitFDTD( max_timesteps, min_decrement );
|
||||
FDTD = SetGaussExcite( FDTD, f0, fc );
|
||||
BC = {'MUR' 'MUR' 'MUR' 'MUR' 'PEC' 'MUR'}; % boundary conditions
|
||||
% BC = {'PML_8' 'PML_8' 'PML_8' 'PML_8' 'PEC' 'PML_8'}; % use pml instead of mur
|
||||
BC = {'MUR' 'MUR' 'MUR' 'MUR' 'MUR' 'MUR'}; % boundary conditions
|
||||
if (use_pml>0)
|
||||
BC = {'PML_8' 'PML_8' 'PML_8' 'PML_8' 'PML_8' 'PML_8'}; % use pml instead of mur
|
||||
end
|
||||
FDTD = SetBoundaryCond( FDTD, BC );
|
||||
|
||||
%% setup CSXCAD geometry & mesh
|
||||
% currently, openEMS cannot automatically generate a mesh
|
||||
max_res = c0 / (f0+fc) / unit / 20; % cell size: lambda/20
|
||||
CSX = InitCSX();
|
||||
mesh.x = [-SimBox(1)/2 SimBox(1)/2 -substrate.width/2 substrate.width/2 feed.pos-feed.width/2 feed.pos+feed.width/2];
|
||||
mesh.x = [-SimBox(1)/2 SimBox(1)/2 -substrate.width/2 substrate.width/2 feed.pos];
|
||||
% add patch mesh with 2/3 - 1/3 rule
|
||||
mesh.x = [mesh.x -patch.width/2-max_res/2*0.66 -patch.width/2+max_res/2*0.33 patch.width/2+max_res/2*0.66 patch.width/2-max_res/2*0.33];
|
||||
mesh.x = SmoothMeshLines( mesh.x, max_res, 1.4); % create a smooth mesh between specified mesh lines
|
||||
|
|
@ -81,7 +92,7 @@ CSX = AddBox(CSX,'patch',10,start,stop);
|
|||
|
||||
%% create substrate
|
||||
CSX = AddMaterial( CSX, 'substrate' );
|
||||
CSX = SetMaterialProperty( CSX, 'substrate', 'Epsilon', substrate.epsR );
|
||||
CSX = SetMaterialProperty( CSX, 'substrate', 'Epsilon', substrate.epsR, 'Kappa', substrate.kappa );
|
||||
start = [-substrate.width/2 -substrate.length/2 0];
|
||||
stop = [ substrate.width/2 substrate.length/2 substrate.thickness];
|
||||
CSX = AddBox( CSX, 'substrate', 0, start, stop );
|
||||
|
|
@ -93,28 +104,9 @@ stop(3) =0;
|
|||
CSX = AddBox(CSX,'gnd',10,start,stop);
|
||||
|
||||
%% apply the excitation & resist as a current source
|
||||
% this creates a "port"
|
||||
CSX = AddMaterial( CSX, 'resist' );
|
||||
kappa = substrate.thickness/feed.R/feed.width^2/unit;
|
||||
CSX = SetMaterialProperty( CSX, 'resist', 'Kappa', kappa );
|
||||
start = [feed.pos-feed.width/2 -feed.width/2 0];
|
||||
stop = [feed.pos+feed.width/2 feed.width/2 substrate.thickness];
|
||||
CSX = AddBox( CSX, 'resist', 15, start, stop );
|
||||
|
||||
CSX = AddExcitation( CSX, 'excite', 0, [0 0 1] ); % excitation in z-direction
|
||||
CSX = AddBox( CSX, 'excite', 0, start, stop );
|
||||
|
||||
%% define voltage calc boxes
|
||||
CSX = AddProbe( CSX, 'ut1', 0 );
|
||||
start = [feed.pos 0 0];
|
||||
stop = [feed.pos 0 substrate.thickness];
|
||||
CSX = AddBox( CSX, 'ut1', 0 , stop, start );
|
||||
|
||||
%% define current calc boxes
|
||||
CSX = AddProbe( CSX, 'it1', 1 );
|
||||
start = [feed.pos-feed.width -feed.width substrate.thickness/2];
|
||||
stop = [feed.pos+feed.width feed.width substrate.thickness/2];
|
||||
CSX = AddBox( CSX, 'it1', 0, start, stop );
|
||||
start = [feed.pos -feed.width/2 0];
|
||||
stop = [feed.pos +feed.width/2 substrate.thickness];
|
||||
[CSX port] = AddLumpedPort(CSX,1,feed.R, start, stop,[0 0 1],'excite');
|
||||
|
||||
%% dump magnetic field over the patch antenna
|
||||
CSX = AddDump( CSX, 'Ht_', 'DumpType', 1, 'DumpMode', 2); % cell interpolated
|
||||
|
|
@ -125,6 +117,7 @@ CSX = AddBox( CSX, 'Ht_', 0, start, stop );
|
|||
%%nf2ff calc
|
||||
[CSX nf2ff] = CreateNF2FFBox(CSX, 'nf2ff', -SimBox/2, SimBox/2);
|
||||
|
||||
if (postprocessing_only==0)
|
||||
%% write openEMS compatible xml-file
|
||||
WriteOpenEMS( [Sim_Path '/' Sim_CSX], FDTD, CSX );
|
||||
|
||||
|
|
@ -132,14 +125,13 @@ WriteOpenEMS( [Sim_Path '/' Sim_CSX], FDTD, CSX );
|
|||
CSXGeomPlot( [Sim_Path '/' Sim_CSX] );
|
||||
|
||||
%% run openEMS
|
||||
openEMS_opts = '';
|
||||
openEMS_opts = [openEMS_opts ' --engine=fastest'];
|
||||
RunOpenEMS( Sim_Path, Sim_CSX, openEMS_opts );
|
||||
end
|
||||
|
||||
%% postprocessing & do the plots
|
||||
freq = linspace( f0-fc, f0+fc, 501 );
|
||||
U = ReadUI( {'ut1','et'}, 'tmp/', freq ); % time domain/freq domain voltage
|
||||
I = ReadUI( 'it1', 'tmp/', freq ); % time domain/freq domain current (half time step is corrected)
|
||||
freq = linspace( max([1e9,f0-fc]), f0+fc, 501 );
|
||||
U = ReadUI( {'port_ut1','et'}, 'tmp/', freq ); % time domain/freq domain voltage
|
||||
I = ReadUI( 'port_it1', 'tmp/', freq ); % time domain/freq domain current (half time step is corrected)
|
||||
|
||||
% plot time domain voltage
|
||||
figure
|
||||
|
|
@ -184,19 +176,24 @@ title( 'reflection coefficient S_{11}' );
|
|||
xlabel( 'frequency f / MHz' );
|
||||
ylabel( 'reflection coefficient |S_{11}|' );
|
||||
|
||||
P_in = 0.5*U.FD{1}.val .* conj( I.FD{1}.val );
|
||||
|
||||
%% NFFF contour plots %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||
f0 = freq(find(s11==min(s11)));
|
||||
f_res_ind = find(s11==min(s11));
|
||||
f_res = freq(f_res_ind);
|
||||
|
||||
% calculate the far field at phi=0 degrees and at phi=90 degrees
|
||||
thetaRange = 0:2:359;
|
||||
thetaRange = (0:2:359) - 180;
|
||||
r = 1; % evaluate fields at radius r
|
||||
disp( 'calculating far field at phi=[0 90] deg...' );
|
||||
[E_far_theta,E_far_phi,Prad,Dmax] = AnalyzeNF2FF( Sim_Path, nf2ff, f0, thetaRange, [0 90], r );
|
||||
[E_far_theta,E_far_phi,Prad,Dmax] = AnalyzeNF2FF( Sim_Path, nf2ff, f_res, thetaRange, [0 90], r );
|
||||
|
||||
Dlog=10*log10(Dmax);
|
||||
|
||||
% display power and directivity
|
||||
disp( ['radiated power: Prad = ' num2str(Prad)] );
|
||||
disp( ['directivity: Dmax = ' num2str(Dmax)] );
|
||||
disp( ['radiated power: Prad = ' num2str(Prad) ' Watt']);
|
||||
disp( ['directivity: Dmax = ' num2str(Dlog) ' dBi'] );
|
||||
disp( ['efficiency: nu_rad = ' num2str(100*Prad./real(P_in(f_res_ind))) ' %']);
|
||||
|
||||
% calculate the e-field magnitude for phi = 0 deg
|
||||
E_phi0_far = zeros(1,numel(thetaRange));
|
||||
|
|
@ -204,12 +201,16 @@ for n=1:numel(thetaRange)
|
|||
E_phi0_far(n) = norm( [E_far_theta(n,1) E_far_phi(n,1)] );
|
||||
end
|
||||
|
||||
E_phi0_far_log = 20*log10(abs(E_phi0_far)/max(abs(E_phi0_far)));
|
||||
E_phi0_far_log = E_phi0_far_log + Dlog;
|
||||
|
||||
% display polar plot
|
||||
figure
|
||||
polar( thetaRange/180*pi, E_phi0_far );
|
||||
ylabel( 'theta / deg' );
|
||||
title( ['electrical far field (V/m) @r=' num2str(r) ' m phi=0 deg'] );
|
||||
legend( 'e-field magnitude', 'Location', 'BestOutside' );
|
||||
plot( thetaRange, E_phi0_far_log ,'k-' );
|
||||
xlabel( 'theta (deg)' );
|
||||
ylabel( 'directivity (dBi)');
|
||||
grid on;
|
||||
hold on;
|
||||
|
||||
% calculate the e-field magnitude for phi = 90 deg
|
||||
E_phi90_far = zeros(1,numel(thetaRange));
|
||||
|
|
@ -217,21 +218,25 @@ for n=1:numel(thetaRange)
|
|||
E_phi90_far(n) = norm([E_far_theta(n,2) E_far_phi(n,2)]);
|
||||
end
|
||||
|
||||
% display polar plot
|
||||
figure
|
||||
polar( thetaRange/180*pi, E_phi90_far );
|
||||
ylabel( 'theta / deg' );
|
||||
title( ['electrical far field (V/m) @r=' num2str(r) ' m phi=90 deg'] );
|
||||
legend( 'e-field magnitude', 'Location', 'BestOutside' );
|
||||
E_phi90_far_log = 20*log10(abs(E_phi90_far)/max(abs(E_phi90_far)));
|
||||
E_phi90_far_log = E_phi90_far_log + Dlog;
|
||||
|
||||
% display polar plot
|
||||
plot( thetaRange, E_phi90_far_log ,'r-' );
|
||||
legend('phi=0','phi=90')
|
||||
|
||||
if (draw_3d_pattern==0)
|
||||
return
|
||||
end
|
||||
%% calculate 3D pattern
|
||||
phiRange = 0:15:360;
|
||||
thetaRange = 0:10:180;
|
||||
r = 1; % evaluate fields at radius r
|
||||
disp( 'calculating 3D far field...' );
|
||||
[E_far_theta,E_far_phi] = AnalyzeNF2FF( Sim_Path, nf2ff, f0, thetaRange, phiRange, r );
|
||||
[E_far_theta,E_far_phi] = AnalyzeNF2FF( Sim_Path, nf2ff, f_res, thetaRange, phiRange, r );
|
||||
E_far = sqrt( abs(E_far_theta).^2 + abs(E_far_phi).^2 );
|
||||
E_far_normalized = E_far / max(E_far(:));
|
||||
E_far_normalized = E_far / max(E_far(:)) * Dmax;
|
||||
|
||||
[theta,phi] = ndgrid(thetaRange/180*pi,phiRange/180*pi);
|
||||
x = E_far_normalized .* sin(theta) .* cos(phi);
|
||||
y = E_far_normalized .* sin(theta) .* sin(phi);
|
||||
|
|
|
|||
|
|
@ -0,0 +1,293 @@
|
|||
%
|
||||
% EXAMPLE / antennas / patch antenna array
|
||||
%
|
||||
% This example demonstrates how to:
|
||||
% - calculate the reflection coefficient of a patch antenna array
|
||||
%
|
||||
%
|
||||
% Tested with
|
||||
% - Matlab 2009b
|
||||
% - Octave 3.3.52
|
||||
% - openEMS v0.0.17
|
||||
%
|
||||
% (C) 2010 Thorsten Liebig <thorsten.liebig@uni-due.de>
|
||||
|
||||
close all
|
||||
clear
|
||||
clc
|
||||
|
||||
%% switches & options...
|
||||
postprocessing_only = 0;
|
||||
draw_3d_pattern = 1; % this may take a (very long) while...
|
||||
use_pml = 0; % use pml boundaries instead of mur
|
||||
openEMS_opts = '';
|
||||
|
||||
%% setup the simulation
|
||||
physical_constants;
|
||||
unit = 1e-3; % all length in mm
|
||||
|
||||
% width in x-direction
|
||||
% length in y-direction
|
||||
% main radiation in z-direction
|
||||
patch.width = 32.86; % resonant length
|
||||
patch.length = 41.37;
|
||||
|
||||
% define array size and dimensions
|
||||
array.xn = 4;
|
||||
array.yn = 4;
|
||||
array.x_spacing = patch.width * 3;
|
||||
array.y_spacing = patch.length * 3;
|
||||
|
||||
substrate.epsR = 3.38;
|
||||
substrate.kappa = 1e-3 * 2*pi*2.45e9 * EPS0*substrate.epsR;
|
||||
substrate.width = 60 + (array.xn-1) * array.x_spacing;
|
||||
substrate.length = 60 + (array.yn-1) * array.y_spacing;
|
||||
substrate.thickness = 1.524;
|
||||
substrate.cells = 4;
|
||||
|
||||
feed.pos = -5.5;
|
||||
feed.width = 2;
|
||||
feed.R = 50; % feed resistance
|
||||
|
||||
% size of the simulation box around the array
|
||||
SimBox = [50+substrate.width 50+substrate.length 25];
|
||||
|
||||
%% prepare simulation folder
|
||||
Sim_Path = 'tmp';
|
||||
Sim_CSX = 'patch_array.xml';
|
||||
if (postprocessing_only==0)
|
||||
[status, message, messageid] = rmdir( Sim_Path, 's' ); % clear previous directory
|
||||
[status, message, messageid] = mkdir( Sim_Path ); % create empty simulation folder
|
||||
end
|
||||
|
||||
%% setup FDTD parameter & excitation function
|
||||
max_timesteps = 30000;
|
||||
min_decrement = 1e-5; % equivalent to -50 dB
|
||||
f0 = 0e9; % center frequency
|
||||
fc = 3e9; % 10 dB corner frequency (in this case 0 Hz - 3e9 Hz)
|
||||
FDTD = InitFDTD( max_timesteps, min_decrement );
|
||||
FDTD = SetGaussExcite( FDTD, f0, fc );
|
||||
BC = {'MUR' 'MUR' 'MUR' 'MUR' 'MUR' 'MUR'}; % boundary conditions
|
||||
if (use_pml>0)
|
||||
BC = {'PML_8' 'PML_8' 'PML_8' 'PML_8' 'PML_8' 'PML_8'}; % use pml instead of mur
|
||||
end
|
||||
FDTD = SetBoundaryCond( FDTD, BC );
|
||||
|
||||
%% setup CSXCAD geometry & mesh
|
||||
% currently, openEMS cannot automatically generate a mesh
|
||||
max_res = c0 / (f0+fc) / unit / 20; % cell size: lambda/20
|
||||
CSX = InitCSX();
|
||||
mesh.x = [-SimBox(1)/2 SimBox(1)/2 -substrate.width/2 substrate.width/2];
|
||||
mesh.y = [-SimBox(2)/2 SimBox(2)/2 -substrate.length/2 substrate.length/2];
|
||||
|
||||
mesh.z = [-SimBox(3)/2 linspace(0,substrate.thickness,substrate.cells) SimBox(3) ];
|
||||
mesh.z = SmoothMeshLines( mesh.z, max_res, 1.4 );
|
||||
|
||||
for xn=1:array.xn
|
||||
for yn=1:array.yn
|
||||
midX = (array.xn/2 - xn + 1/2) * array.x_spacing;
|
||||
midY = (array.yn/2 - yn + 1/2) * array.y_spacing;
|
||||
|
||||
% feeding mesh
|
||||
mesh.x = [mesh.x midX+feed.pos];
|
||||
mesh.y = [mesh.y midY-feed.width/2 midY+feed.width/2];
|
||||
|
||||
% add patch mesh with 2/3 - 1/3 rule
|
||||
mesh.x = [mesh.x midX-patch.width/2-max_res/2*0.66 midX-patch.width/2+max_res/2*0.33 midX+patch.width/2+max_res/2*0.66 midX+patch.width/2-max_res/2*0.33];
|
||||
% add patch mesh with 2/3 - 1/3 rule
|
||||
mesh.y = [mesh.y midY-patch.length/2-max_res/2*0.66 midY-patch.length/2+max_res/2*0.33 midY+patch.length/2+max_res/2*0.66 midY+patch.length/2-max_res/2*0.33];
|
||||
end
|
||||
end
|
||||
mesh.x = SmoothMeshLines( mesh.x, max_res, 1.4); % create a smooth mesh between specified mesh lines
|
||||
mesh.y = SmoothMeshLines( mesh.y, max_res, 1.4 );
|
||||
|
||||
mesh = AddPML( mesh, [8 8 8 8 8 8] ); % add equidistant cells (air around the structure)
|
||||
CSX = DefineRectGrid( CSX, unit, mesh );
|
||||
|
||||
%% create substrate
|
||||
CSX = AddMaterial( CSX, 'substrate' );
|
||||
CSX = SetMaterialProperty( CSX, 'substrate', 'Epsilon', substrate.epsR, 'Kappa', substrate.kappa);
|
||||
start = [-substrate.width/2 -substrate.length/2 0];
|
||||
stop = [ substrate.width/2 substrate.length/2 substrate.thickness];
|
||||
CSX = AddBox( CSX, 'substrate', 0, start, stop );
|
||||
|
||||
%% create ground (same size as substrate)
|
||||
CSX = AddMetal( CSX, 'gnd' ); % create a perfect electric conductor (PEC)
|
||||
start(3)=0;
|
||||
stop(3) =0;
|
||||
CSX = AddBox(CSX,'gnd',10,start,stop);
|
||||
%%
|
||||
CSX = AddMetal( CSX, 'patch' ); % create a perfect electric conductor (PEC)
|
||||
number = 1;
|
||||
for xn=1:array.xn
|
||||
for yn=1:array.yn
|
||||
|
||||
midX = (array.xn/2 - xn + 1/2) * array.x_spacing;
|
||||
midY = (array.yn/2 - yn + 1/2) * array.y_spacing;
|
||||
|
||||
% create patch
|
||||
start = [midX-patch.width/2 midY-patch.length/2 substrate.thickness];
|
||||
stop = [midX+patch.width/2 midY+patch.length/2 substrate.thickness];
|
||||
CSX = AddBox(CSX,'patch',10,start,stop);
|
||||
|
||||
% apply the excitation & resist as a current source
|
||||
start = [midX+feed.pos midY-feed.width/2 0];
|
||||
stop = [midX+feed.pos midY+feed.width/2 substrate.thickness];
|
||||
[CSX port] = AddLumpedPort(CSX,number,feed.R, start, stop,[0 0 1],['excite_' int2str(xn) '_' int2str(yn)]);
|
||||
number=number+1;
|
||||
end
|
||||
end
|
||||
|
||||
%%nf2ff calc
|
||||
[CSX nf2ff] = CreateNF2FFBox(CSX, 'nf2ff', -SimBox/2, SimBox/2);
|
||||
|
||||
if (postprocessing_only==0)
|
||||
%% write openEMS compatible xml-file
|
||||
WriteOpenEMS( [Sim_Path '/' Sim_CSX], FDTD, CSX );
|
||||
|
||||
%% show the structure
|
||||
CSXGeomPlot( [Sim_Path '/' Sim_CSX] );
|
||||
|
||||
%% run openEMS
|
||||
RunOpenEMS( Sim_Path, Sim_CSX, openEMS_opts );
|
||||
end
|
||||
|
||||
%% postprocessing & do the plots
|
||||
freq = linspace( max([1e9,f0-fc]), f0+fc, 501 );
|
||||
U = ReadUI( {'port_ut1','et'}, 'tmp/', freq ); % time domain/freq domain voltage
|
||||
I = ReadUI( 'port_it1', 'tmp/', freq ); % time domain/freq domain current (half time step is corrected)
|
||||
|
||||
% plot time domain voltage
|
||||
figure
|
||||
[ax,h1,h2] = plotyy( U.TD{1}.t/1e-9, U.TD{1}.val, U.TD{2}.t/1e-9, U.TD{2}.val );
|
||||
set( h1, 'Linewidth', 2 );
|
||||
set( h1, 'Color', [1 0 0] );
|
||||
set( h2, 'Linewidth', 2 );
|
||||
set( h2, 'Color', [0 0 0] );
|
||||
grid on
|
||||
title( 'time domain voltage' );
|
||||
xlabel( 'time t / ns' );
|
||||
ylabel( ax(1), 'voltage ut1 / V' );
|
||||
ylabel( ax(2), 'voltage et / V' );
|
||||
% now make the y-axis symmetric to y=0 (align zeros of y1 and y2)
|
||||
y1 = ylim(ax(1));
|
||||
y2 = ylim(ax(2));
|
||||
ylim( ax(1), [-max(abs(y1)) max(abs(y1))] );
|
||||
ylim( ax(2), [-max(abs(y2)) max(abs(y2))] );
|
||||
|
||||
% plot feed point impedance
|
||||
figure
|
||||
Zin = U.FD{1}.val ./ I.FD{1}.val;
|
||||
plot( freq/1e6, real(Zin), 'k-', 'Linewidth', 2 );
|
||||
hold on
|
||||
grid on
|
||||
plot( freq/1e6, imag(Zin), 'r--', 'Linewidth', 2 );
|
||||
title( 'feed point impedance' );
|
||||
xlabel( 'frequency f / MHz' );
|
||||
ylabel( 'impedance Z_{in} / Ohm' );
|
||||
legend( 'real', 'imag' );
|
||||
|
||||
% plot reflection coefficient S11
|
||||
figure
|
||||
uf_inc = 0.5*(U.FD{1}.val + I.FD{1}.val * 50);
|
||||
if_inc = 0.5*(I.FD{1}.val - U.FD{1}.val / 50);
|
||||
uf_ref = U.FD{1}.val - uf_inc;
|
||||
if_ref = I.FD{1}.val - if_inc;
|
||||
s11 = uf_ref ./ uf_inc;
|
||||
plot( freq/1e6, 20*log10(abs(s11)), 'k-', 'Linewidth', 2 );
|
||||
grid on
|
||||
title( 'reflection coefficient S_{11}' );
|
||||
xlabel( 'frequency f / MHz' );
|
||||
ylabel( 'reflection coefficient |S_{11}|' );
|
||||
|
||||
%%
|
||||
number = 1;
|
||||
P_in = 0;
|
||||
for xn=1:array.xn
|
||||
for yn=1:array.yn
|
||||
|
||||
U = ReadUI( ['port_ut' int2str(number)], 'tmp/', freq ); % time domain/freq domain voltage
|
||||
I = ReadUI( ['port_it' int2str(number)], 'tmp/', freq ); % time domain/freq domain current (half time step is corrected)
|
||||
|
||||
P_in = P_in + 0.5*U.FD{1}.val .* conj( I.FD{1}.val );
|
||||
number=number+1;
|
||||
end
|
||||
end
|
||||
|
||||
|
||||
%% NFFF contour plots %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||
f_res_ind = find(s11==min(s11));
|
||||
f_res = freq(f_res_ind);
|
||||
|
||||
% calculate the far field at phi=0 degrees and at phi=90 degrees
|
||||
thetaRange = (0:2:359) - 180;
|
||||
r = 1; % evaluate fields at radius r
|
||||
disp( 'calculating far field at phi=[0 90] deg...' );
|
||||
[E_far_theta,E_far_phi,Prad,Dmax] = AnalyzeNF2FF( Sim_Path, nf2ff, f_res, thetaRange, [0 90], r );
|
||||
|
||||
Dlog=10*log10(Dmax);
|
||||
|
||||
% display power and directivity
|
||||
disp( ['radiated power: Prad = ' num2str(Prad) ' Watt']);
|
||||
disp( ['directivity: Dmax = ' num2str(Dlog) ' dBi'] );
|
||||
disp( ['efficiency: nu_rad = ' num2str(100*Prad./real(P_in(f_res_ind))) ' %']);
|
||||
|
||||
% calculate the e-field magnitude for phi = 0 deg
|
||||
E_phi0_far = zeros(1,numel(thetaRange));
|
||||
for n=1:numel(thetaRange)
|
||||
E_phi0_far(n) = norm( [E_far_theta(n,1) E_far_phi(n,1)] );
|
||||
end
|
||||
|
||||
E_phi0_far_log = 20*log10(abs(E_phi0_far)/max(abs(E_phi0_far)));
|
||||
E_phi0_far_log = E_phi0_far_log + Dlog;
|
||||
|
||||
% display radiation pattern
|
||||
figure
|
||||
plot( thetaRange, E_phi0_far_log ,'k-' );
|
||||
xlabel( 'theta (deg)' );
|
||||
ylabel( 'directivity (dBi)');
|
||||
grid on;
|
||||
hold on;
|
||||
|
||||
% calculate the e-field magnitude for phi = 90 deg
|
||||
E_phi90_far = zeros(1,numel(thetaRange));
|
||||
for n=1:numel(thetaRange)
|
||||
E_phi90_far(n) = norm([E_far_theta(n,2) E_far_phi(n,2)]);
|
||||
end
|
||||
|
||||
E_phi90_far_log = 20*log10(abs(E_phi90_far)/max(abs(E_phi90_far)));
|
||||
E_phi90_far_log = E_phi90_far_log + Dlog;
|
||||
|
||||
plot( thetaRange, E_phi90_far_log ,'r-' );
|
||||
legend('phi=0','phi=90')
|
||||
|
||||
drawnow
|
||||
|
||||
if (draw_3d_pattern==0)
|
||||
return
|
||||
end
|
||||
%% calculate 3D pattern
|
||||
tic
|
||||
phiRange = 0:3:360;
|
||||
thetaRange = unique([0:0.5:15 10:3:180]);
|
||||
r = 1; % evaluate fields at radius r
|
||||
disp( 'calculating 3D far field...' );
|
||||
[E_far_theta,E_far_phi] = AnalyzeNF2FF( Sim_Path, nf2ff, f_res, thetaRange, phiRange, r );
|
||||
E_far = sqrt( abs(E_far_theta).^2 + abs(E_far_phi).^2 );
|
||||
|
||||
E_far_normalized = E_far / max(E_far(:)) * Dmax;
|
||||
[theta,phi] = ndgrid(thetaRange/180*pi,phiRange/180*pi);
|
||||
x = E_far_normalized .* sin(theta) .* cos(phi);
|
||||
y = E_far_normalized .* sin(theta) .* sin(phi);
|
||||
z = E_far_normalized .* cos(theta);
|
||||
figure
|
||||
surf( x,y,z, E_far_normalized );
|
||||
axis equal
|
||||
xlabel( 'x' );
|
||||
ylabel( 'y' );
|
||||
zlabel( 'z' );
|
||||
toc
|
||||
|
||||
%% visualize magnetic fields
|
||||
% you will find vtk dump files in the simulation folder (tmp/)
|
||||
% use paraview to visulaize them
|
||||
Loading…
Reference in New Issue