diff --git a/matlab/Tutorials/Conical_Horn_Antenna.m b/matlab/Tutorials/Conical_Horn_Antenna.m
new file mode 100644
index 0000000..4b44edb
--- /dev/null
+++ b/matlab/Tutorials/Conical_Horn_Antenna.m
@@ -0,0 +1,246 @@
+%
+% Tutorials / conical horn antenna
+%
+% Describtion at:
+% http://openems.de/index.php/Tutorial:_Conical_Horn_Antenna
+%
+% Tested with
+%  - Matlab 2011a
+%  - openEMS v0.0.25
+%
+% (C) 2011 Thorsten Liebig <thorsten.liebig@uni-due.de>
+
+close all
+clear
+clc
+
+%% setup the simulation
+physical_constants;
+unit = 1e-3; % all length in mm
+
+% horn radius
+horn.radius  = 20;
+% horn length in z-direction
+horn.length = 50;
+
+horn.feed_length = 50;
+
+horn.thickness = 2;
+
+% horn opening angle
+horn.angle = 20*pi/180;
+
+% size of the simulation box
+SimBox = [100 100 100]*2;
+
+% frequency range of interest
+f_start =  10e9;
+f_stop  =  20e9;
+
+% frequency of interest
+f0 = 15e9;
+
+%% mode functions %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% by David M. Pozar, Microwave Engineering, third edition, page 113
+freq = linspace(f_start,f_stop,201);
+
+p11 = 1.841;
+kc = p11 / horn.radius /unit;
+k = 2*pi*freq/C0;
+fc = C0*kc/2/pi;
+beta = sqrt(k.^2 - kc^2);
+ZL_a = k * Z0 ./ beta;    %analytic waveguide impedance
+
+% mode profile E- and H-field
+kc = kc*unit
+func_Er = [ num2str(-1/kc^2,'%14.13f') '/rho*cos(a)*j1('  num2str(kc,'%14.13f') '*rho)'];
+func_Ea = [ num2str(1/kc,'%14.13f') '*sin(a)*0.5*(j0('  num2str(kc,'%14.13f') '*rho)-jn(2,'  num2str(kc,'%14.13f') '*rho))'];
+func_Ex = ['(' func_Er '*cos(a) - ' func_Ea '*sin(a) ) * (rho<' num2str(horn.radius) ')'];
+func_Ey = ['(' func_Er '*sin(a) + ' func_Ea '*cos(a) ) * (rho<' num2str(horn.radius) ')'];
+
+func_Ha = [ num2str(-1/kc^2,'%14.13f') '/rho*cos(a)*j1('  num2str(kc,'%14.13f') '*rho)'];
+func_Hr = [ '-1*' num2str(1/kc,'%14.13f') '*sin(a)*0.5*(j0('  num2str(kc,'%14.13f') '*rho)-jn(2,'  num2str(kc,'%14.13f') '*rho))'];
+func_Hx = ['(' func_Hr '*cos(a) - ' func_Ha '*sin(a) ) * (rho<' num2str(horn.radius) ')'];
+func_Hy = ['(' func_Hr '*sin(a) + ' func_Ha '*cos(a) ) * (rho<' num2str(horn.radius) ')'];
+
+disp([' Cutoff frequencies for this mode and wavguide is: ' num2str(fc/1e9) ' GHz']);
+
+if (f_start<fc)
+    warning('openEMS:example','f_start is smaller than the cutoff-frequency, this may result in a long simulation... ');
+end
+
+%% setup FDTD parameter & excitation function
+FDTD = InitFDTD( 30000, 1e-5 );
+FDTD = SetGaussExcite(FDTD,0.5*(f_start+f_stop),0.5*(f_stop-f_start));
+BC = {'PML_8' 'PML_8' 'PML_8' 'PML_8' 'PML_8' 'PML_8'}; % boundary conditions
+FDTD = SetBoundaryCond( FDTD, BC );
+
+%% setup CSXCAD geometry & mesh
+% currently, openEMS cannot automatically generate a mesh
+max_res = c0 / (f_stop) / unit / 15; % cell size: lambda/20
+CSX = InitCSX();
+
+%create fixed lines for the simulation box, substrate and port
+mesh.x = [-SimBox(1)/2 -horn.radius 0 horn.radius SimBox(1)/2];
+mesh.x = SmoothMeshLines( mesh.x, max_res, 1.4); % create a smooth mesh between specified fixed mesh lines
+
+mesh.y = mesh.x;
+
+%create fixed lines for the simulation box and given number of lines inside the substrate
+mesh.z = [-horn.feed_length 0 SimBox(3) ];
+mesh.z = SmoothMeshLines( mesh.z, max_res, 1.4 );
+
+CSX = DefineRectGrid( CSX, unit, mesh );
+
+%% create horn
+% horn + waveguide, defined by a rotational polygon
+CSX = AddMetal(CSX, 'Conical_Horn');
+p(1,1) = horn.radius+horn.thickness;   % x-coord point 1
+p(2,1) = -horn.feed_length;     % z-coord point 1
+p(1,end+1) = horn.radius+horn.thickness;   % x-coord point 1
+p(2,end) = 0;     % z-coord point 1
+p(1,end+1) = horn.radius+horn.thickness + sin(horn.angle)*horn.length; % x-coord point 2
+p(2,end) = horn.length; % y-coord point 2
+p(1,end+1) = horn.radius + sin(horn.angle)*horn.length; % x-coord point 2
+p(2,end) = horn.length; % y-coord point 2
+p(1,end+1) = horn.radius;  % x-coord point 1
+p(2,end) = 0;     % z-coord point 1
+p(1,end+1) = horn.radius;   % x-coord point 1
+p(2,end) = -horn.feed_length;     % z-coord point 1
+CSX = AddRotPoly(CSX,'Conical_Horn',10,0,2,p);
+
+% horn aperture
+A = pi*((horn.radius + sin(horn.angle)*horn.length)*unit)^2;
+
+% %% apply the excitation %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% xy-mode profile excitation located directly on top of pml (first 8 z-lines)
+CSX = AddExcitation(CSX,'excite',0,[1 1 0]);
+weight{1} = func_Ex;
+weight{2} = func_Ey;
+weight{3} = 0;
+CSX = SetExcitationWeight(CSX,'excite',weight);
+start=[0 0 mesh.z(8)-0.1 ];
+stop =[0 0 mesh.z(8)+0.1 ];
+CSX = AddCylinder(CSX,'excite',0 ,start,stop,horn.radius);
+
+%% voltage and current definitions using the mode matching probes %%%%%%%%%
+%port 1
+start = [-horn.radius -horn.radius mesh.z(1)+horn.feed_length/2];
+stop  = [ horn.radius  horn.radius mesh.z(1)+horn.feed_length/2]
+CSX = AddProbe(CSX, 'ut1', 10, 1, [], 'ModeFunction',{func_Ex,func_Ey,0});
+CSX = AddBox(CSX,  'ut1',  0 ,start,stop);
+CSX = AddProbe(CSX,'it1', 11, 1, [], 'ModeFunction',{func_Hx,func_Hy,0});
+CSX = AddBox(CSX,'it1', 0 ,start,stop);
+
+%% nf2ff calc
+start = [mesh.x(9) mesh.y(9) mesh.z(9)];
+stop  = [mesh.x(end-8) mesh.y(end-8) mesh.z(end-8)];
+[CSX nf2ff] = CreateNF2FFBox(CSX, 'nf2ff', start, stop, [1 1 1 1 0 1]);
+
+%% prepare simulation folder
+Sim_Path = 'tmp';
+Sim_CSX = 'horn_ant.xml';
+
+[status, message, messageid] = rmdir( Sim_Path, 's' ); % clear previous directory
+[status, message, messageid] = mkdir( Sim_Path ); % create empty simulation folder
+
+%% 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 ,'--debug-PEC');
+
+%% postprocessing & do the plots
+U = ReadUI( 'ut1', Sim_Path, freq ); % time domain/freq domain voltage
+I = ReadUI( 'it1', Sim_Path, freq ); % time domain/freq domain current (half time step is corrected)
+
+% plot reflection coefficient S11
+figure
+uf_inc = 0.5*(U.FD{1}.val + I.FD{1}.val .* ZL_a);
+if_inc = 0.5*(I.FD{1}.val + U.FD{1}.val ./ ZL_a);
+uf_ref = U.FD{1}.val - uf_inc;
+if_ref = if_inc - I.FD{1}.val;
+s11 = uf_ref ./ uf_inc;
+plot( freq/1e9, 20*log10(abs(s11)), 'k-', 'Linewidth', 2 );
+ylim([-60 0]);
+grid on
+title( 'reflection coefficient S_{11}' );
+xlabel( 'frequency f / GHz' );
+ylabel( 'reflection coefficient |S_{11}|' );
+
+P_in = 0.5*uf_inc .* conj( if_inc ); % antenna feed power
+
+%% NFFF contour plots %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% 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, f0, thetaRange, [0 90], r );
+
+Dlog=10*log10(Dmax);
+G_a = 4*pi*A/(c0/f0)^2;
+e_a = Dmax/G_a;
+
+% display some antenna parameter
+disp( ['radiated power: Prad = ' num2str(Prad) ' Watt']);
+disp( ['directivity: Dmax = ' num2str(Dlog) ' dBi'] );
+disp( ['aperture efficiency: e_a = ' num2str(e_a*100) '%'] );
+
+%%
+% 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 polar plot
+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;
+
+% display polar plot
+plot( thetaRange, E_phi90_far_log ,'r-' );
+legend('phi=0','phi=90')
+
+%% calculate 3D pattern
+phiRange = sort( unique( [-180:5:-100 -100:2.5:-50 -50:1:50 50:2.5:100 100:5:180] ) );
+thetaRange = sort( unique([ 0:1:50 50:2.:100 100:5:180 ]));
+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 = 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, 'EdgeColor','none' );
+axis equal
+axis off
+xlabel( 'x' );
+ylabel( 'y' );
+zlabel( 'z' );
+
+%%
+DumpFF2VTK('Conical_Horn_Pattern.vtk',E_far_normalized,thetaRange,phiRange,1e-3);
diff --git a/matlab/Tutorials/Horn_Antenna.m b/matlab/Tutorials/Horn_Antenna.m
new file mode 100644
index 0000000..1d7b61d
--- /dev/null
+++ b/matlab/Tutorials/Horn_Antenna.m
@@ -0,0 +1,272 @@
+%
+% Tutorials / horn antenna
+%
+% Describtion at:
+% http://openems.de/index.php/Tutorial:_Horn_Antenna
+%
+% Tested with
+%  - Matlab 2011a
+%  - openEMS v0.0.25
+%
+% (C) 2011 Thorsten Liebig <thorsten.liebig@uni-due.de>
+
+close all
+clear
+clc
+
+%% setup the simulation
+physical_constants;
+unit = 1e-3; % all length in mm
+
+% horn width in x-direction
+horn.width  = 20;
+% horn height in y-direction
+horn.height = 30;
+% horn length in z-direction
+horn.length = 50;
+
+horn.feed_length = 50;
+
+horn.thickness = 2;
+
+% horn opening angle in x, y
+horn.angle = [20 20]*pi/180;
+
+% size of the simulation box
+SimBox = [200 200 200];
+
+% frequency range of interest
+f_start =  10e9;
+f_stop  =  20e9;
+
+% frequency of interest
+f0 = 15e9;
+
+%waveguide TE-mode definition
+m = 1;
+n = 0;
+
+%% mode functions %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% by David M. Pozar, Microwave Engineering, third edition, page 113
+freq = linspace(f_start,f_stop,201);
+a = horn.width;
+b = horn.height;
+k = 2*pi*freq/c0;
+kc = sqrt((m*pi/a/unit)^2 + (n*pi/b/unit)^2);
+fc = c0*kc/2/pi;          %cut-off frequency
+beta = sqrt(k.^2 - kc^2); %waveguide phase-constant
+ZL_a = k * Z0 ./ beta;    %analytic waveguide impedance
+
+% mode profile E- and H-field
+x_pos = ['(x-' num2str(a/2) ')'];
+y_pos = ['(y-' num2str(b/2) ')'];
+func_Ex = [num2str( n/b/unit) '*cos(' num2str(m*pi/a) '*' x_pos ')*sin('  num2str(n*pi/b) '*' y_pos ')'];
+func_Ey = [num2str(-m/a/unit) '*sin(' num2str(m*pi/a) '*' x_pos ')*cos('  num2str(n*pi/b) '*' y_pos ')'];
+
+func_Hx = [num2str(m/a/unit) '*sin(' num2str(m*pi/a) '*' x_pos ')*cos('  num2str(n*pi/b) '*' y_pos ')'];
+func_Hy = [num2str(n/b/unit) '*cos(' num2str(m*pi/a) '*' x_pos ')*sin('  num2str(n*pi/b) '*' y_pos ')'];
+
+disp([' Cutoff frequencies for this mode and wavguide is: ' num2str(fc/1e9) ' GHz']);
+
+if (f_start<fc)
+    warning('openEMS:example','f_start is smaller than the cutoff-frequency, this may result in a long simulation... ');
+end
+
+%% setup FDTD parameter & excitation function
+FDTD = InitFDTD( 30000, 1e-5 );
+FDTD = SetGaussExcite(FDTD,0.5*(f_start+f_stop),0.5*(f_stop-f_start));
+BC = {'PML_8' 'PML_8' 'PML_8' 'PML_8' 'PML_8' 'PML_8'}; % boundary conditions
+FDTD = SetBoundaryCond( FDTD, BC );
+
+%% setup CSXCAD geometry & mesh
+% currently, openEMS cannot automatically generate a mesh
+max_res = c0 / (f_stop) / unit / 15; % cell size: lambda/20
+CSX = InitCSX();
+
+%create fixed lines for the simulation box, substrate and port
+mesh.x = [-SimBox(1)/2 -a/2 a/2 SimBox(1)/2];
+mesh.x = SmoothMeshLines( mesh.x, max_res, 1.4); % create a smooth mesh between specified fixed mesh lines
+
+mesh.y = [-SimBox(2)/2 -b/2 b/2 SimBox(2)/2];
+mesh.y = SmoothMeshLines( mesh.y, max_res, 1.4 );
+
+%create fixed lines for the simulation box and given number of lines inside the substrate
+mesh.z = [-horn.feed_length 0 SimBox(3)-horn.feed_length ];
+mesh.z = SmoothMeshLines( mesh.z, max_res, 1.4 );
+
+CSX = DefineRectGrid( CSX, unit, mesh );
+
+%% create horn
+% horn feed rect waveguide
+CSX = AddMetal(CSX, 'horn');
+start = [-a/2-horn.thickness -b/2 mesh.z(1)];
+stop  = [-a/2                 b/2 0];
+CSX = AddBox(CSX,'horn',10,start,stop);
+start = [a/2+horn.thickness -b/2 mesh.z(1)];
+stop  = [a/2                 b/2 0];
+CSX = AddBox(CSX,'horn',10,start,stop);
+start = [-a/2-horn.thickness b/2+horn.thickness mesh.z(1)];
+stop  = [ a/2+horn.thickness b/2                0];
+CSX = AddBox(CSX,'horn',10,start,stop);
+start = [-a/2-horn.thickness -b/2-horn.thickness mesh.z(1)];
+stop  = [ a/2+horn.thickness -b/2                0];
+CSX = AddBox(CSX,'horn',10,start,stop);
+
+% horn opening
+p(2,1) = a/2;
+p(1,1) = 0;
+p(2,2) = a/2 + sin(horn.angle(1))*horn.length;
+p(1,2) = horn.length;
+p(2,3) = -a/2 - sin(horn.angle(1))*horn.length;
+p(1,3) = horn.length;
+p(2,4) = -a/2;
+p(1,4) = 0;
+CSX = AddLinPoly( CSX, 'horn', 10, 1, -horn.thickness/2, p, horn.thickness, 'Transform', {'Rotate_X',horn.angle(2),'Translate',['0,' num2str(-b/2-horn.thickness/2) ',0']});
+CSX = AddLinPoly( CSX, 'horn', 10, 1, -horn.thickness/2, p, horn.thickness, 'Transform', {'Rotate_X',-horn.angle(2),'Translate',['0,' num2str(b/2+horn.thickness/2) ',0']});
+
+p(1,1) = b/2+horn.thickness;
+p(2,1) = 0;
+p(1,2) = b/2+horn.thickness + sin(horn.angle(2))*horn.length;
+p(2,2) = horn.length;
+p(1,3) = -b/2-horn.thickness - sin(horn.angle(2))*horn.length;
+p(2,3) = horn.length;
+p(1,4) = -b/2-horn.thickness;
+p(2,4) = 0;
+CSX = AddLinPoly( CSX, 'horn', 10, 0, -horn.thickness/2, p, horn.thickness, 'Transform', {'Rotate_Y',-horn.angle(2),'Translate',[ num2str(-a/2-horn.thickness/2) ',0,0']});
+CSX = AddLinPoly( CSX, 'horn', 10, 0, -horn.thickness/2, p, horn.thickness, 'Transform', {'Rotate_Y',+horn.angle(2),'Translate',[ num2str(a/2+horn.thickness/2) ',0,0']});
+
+% horn aperture
+A = (a + 2*sin(horn.angle(1))*horn.length)*unit * (b + 2*sin(horn.angle(2))*horn.length)*unit;
+
+% %% apply the excitation %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% xy-mode profile excitation located directly on top of pml (first 8 z-lines)
+CSX = AddExcitation(CSX,'excite',0,[1 1 0]);
+weight{1} = func_Ex;
+weight{2} = func_Ey;
+weight{3} = 0;
+CSX = SetExcitationWeight(CSX,'excite',weight);
+start=[-a/2 -b/2 mesh.z(8) ];
+stop =[ a/2  b/2 mesh.z(8) ];
+CSX = AddBox(CSX,'excite',0 ,start,stop);
+
+%% voltage and current definitions using the mode matching probes %%%%%%%%%
+%port 1
+start(3) = mesh.z(1)+horn.feed_length/2;
+stop(3)  = start(3);
+CSX = AddProbe(CSX, 'ut1', 10, 1, [], 'ModeFunction',{func_Ex,func_Ey,0});
+CSX = AddBox(CSX,  'ut1',  0 ,start,stop);
+CSX = AddProbe(CSX,'it1', 11, 1, [], 'ModeFunction',{func_Hx,func_Hy,0});
+CSX = AddBox(CSX,'it1', 0 ,start,stop);
+
+%% nf2ff calc
+start = [mesh.x(9) mesh.y(9) mesh.z(9)];
+stop  = [mesh.x(end-8) mesh.y(end-8) mesh.z(end-8)];
+[CSX nf2ff] = CreateNF2FFBox(CSX, 'nf2ff', start, stop, [1 1 1 1 0 1]);
+
+%% prepare simulation folder
+Sim_Path = 'tmp';
+Sim_CSX = 'horn_ant.xml';
+
+[status, message, messageid] = rmdir( Sim_Path, 's' ); % clear previous directory
+[status, message, messageid] = mkdir( Sim_Path ); % create empty simulation folder
+
+%% 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);
+
+%% postprocessing & do the plots
+U = ReadUI( 'ut1', Sim_Path, freq ); % time domain/freq domain voltage
+I = ReadUI( 'it1', Sim_Path, freq ); % time domain/freq domain current (half time step is corrected)
+
+% plot reflection coefficient S11
+figure
+uf_inc = 0.5*(U.FD{1}.val + I.FD{1}.val .* ZL_a);
+if_inc = 0.5*(I.FD{1}.val + U.FD{1}.val ./ ZL_a);
+uf_ref = U.FD{1}.val - uf_inc;
+if_ref = if_inc - I.FD{1}.val;
+s11 = uf_ref ./ uf_inc;
+plot( freq/1e9, 20*log10(abs(s11)), 'k-', 'Linewidth', 2 );
+ylim([-60 0]);
+grid on
+title( 'reflection coefficient S_{11}' );
+xlabel( 'frequency f / GHz' );
+ylabel( 'reflection coefficient |S_{11}|' );
+
+P_in = 0.5*uf_inc .* conj( if_inc ); % antenna feed power
+
+%% NFFF contour plots %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% 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, f0, thetaRange, [0 90], r );
+
+Dlog=10*log10(Dmax);
+G_a = 4*pi*A/(c0/f0)^2;
+e_a = Dmax/G_a;
+
+% display some antenna parameter
+disp( ['radiated power: Prad = ' num2str(Prad) ' Watt']);
+disp( ['directivity: Dmax = ' num2str(Dlog) ' dBi'] );
+disp( ['aperture efficiency: e_a = ' num2str(e_a*100) '%'] );
+
+%%
+% 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 polar plot
+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;
+
+% display polar plot
+plot( thetaRange, E_phi90_far_log ,'r-' );
+legend('phi=0','phi=90')
+
+%% calculate 3D pattern
+phiRange = sort( unique( [-180:5:-100 -100:2.5:-50 -50:1:50 50:2.5:100 100:5:180] ) );
+thetaRange = sort( unique([ 0:1:50 50:2.:100 100:5:180 ]));
+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 = 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, 'EdgeColor','none' );
+axis equal
+axis off
+xlabel( 'x' );
+ylabel( 'y' );
+zlabel( 'z' );
+
+%%
+DumpFF2VTK('Horn_Pattern.vtk',E_far_normalized,thetaRange,phiRange,1e-3);