Tutorials: use new waveguide ports
Signed-off-by: Thorsten Liebig <Thorsten.Liebig@gmx.de>pull/1/head
Thorsten Liebig
parent
c2078f5c39
commit
0ba70f0a27
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@ -6,9 +6,9 @@
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%
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% Tested with
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% - Matlab 2011a / Octave 3.4.3
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% - openEMS v0.0.26
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% - openEMS v0.0.31
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%
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% (C) 2010-2012 Thorsten Liebig <thorsten.liebig@gmx.de>
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% (C) 2010-2013 Thorsten Liebig <thorsten.liebig@gmx.de>
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close all
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clear
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@ -28,33 +28,8 @@ f_stop = 500e6;
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mesh_res = [10 2*pi/49.999 10]; %targeted mesh resolution
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%% mode functions %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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% by David M. Pozar, Microwave Engineering, third edition
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freq = linspace(f_start,f_stop,201);
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p11 = 1.841;
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kc = p11 / rad /unit;
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k = 2*pi*freq/C0;
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fc = C0*kc/2/pi;
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beta = sqrt(k.^2 - kc^2);
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n_eff = (beta/k);
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ZL_a = k * Z0 ./ beta; %analytic waveguide impedance
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% TE_11 mode profile E- and H-field
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kc = kc*unit; %functions must be defined in drawing units
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func_Er = [ num2str(-1/kc^2,15) '/rho*cos(a)*j1(' num2str(kc,15) '*rho)'];
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func_Ea = [ num2str(1/kc,15) '*sin(a)*0.5*(j0(' num2str(kc,15) '*rho)-jn(2,' num2str(kc,15) '*rho))'];
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func_Ha = [ num2str(-1/kc^2,15) '/rho*cos(a)*j1(' num2str(kc,15) '*rho)'];
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func_Hr = [ '-1*' num2str(1/kc,15) '*sin(a)*0.5*(j0(' num2str(kc,15) '*rho)-jn(2,' num2str(kc,15) '*rho))'];
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disp([' Cutoff frequencies for this mode and wavguide is: ' num2str(fc/1e6) ' MHz']);
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if (f_start<fc)
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warning('openEMS:example','f_start is smaller than the cutoff-frequency, this may result in a long simulation... ');
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end
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%% setup FDTD parameter & excitation function %%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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FDTD = InitFDTD(1e6,1e-5,'CoordSystem',1);
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FDTD = InitFDTD('EndCriteria',1e-4,'CoordSystem',1);
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FDTD = SetGaussExcite(FDTD,0.5*(f_start+f_stop),0.5*(f_stop-f_start));
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% boundary conditions
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@ -68,36 +43,15 @@ mesh.a = SmoothMeshLines([0 2*pi], mesh_res(2)); % mesh in aziumthal dir.
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mesh.z = SmoothMeshLines([0 length], mesh_res(3));
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CSX = DefineRectGrid(CSX, unit,mesh);
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%% apply the excitation %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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% ra-mode profile excitation located directly on top of pml (first 8 z-lines)
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CSX = AddExcitation(CSX,'excite',0,[1 1 0]);
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weight{1} = func_Er;
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weight{2} = func_Ea;
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weight{3} = 0;
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CSX = SetExcitationWeight(CSX,'excite',weight);
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start=[mesh.r(1) mesh.a(1) mesh.z(8) ];
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stop =[mesh.r(end) mesh.a(end) mesh.z(8) ];
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CSX = AddBox(CSX,'excite',0 ,start,stop);
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%% apply the waveguide port %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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start=[mesh.r(1) mesh.a(1) mesh.z(8)];
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stop =[mesh.r(end) mesh.a(end) mesh.z(15)];
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[CSX, port{1}] = AddCircWaveGuidePort( CSX, 0, 1, start, stop, rad*unit, 'TE11', 0, 1);
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%% voltage and current definitions using the mode matching probes %%%%%%%%%
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%port 1
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start = [mesh.r(1) mesh.a(1) mesh.z(15)];
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stop = [mesh.r(end) mesh.a(end) mesh.z(15)];
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CSX = AddProbe(CSX, 'ut1', 10, 'ModeFunction',{func_Er,func_Ea,0});
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CSX = AddBox(CSX, 'ut1', 0 ,start,stop);
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CSX = AddProbe(CSX,'it1', 11, 'ModeFunction',{func_Hr,func_Ha,0});
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CSX = AddBox(CSX,'it1', 0 ,start,stop);
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start=[mesh.r(1) mesh.a(1) mesh.z(end-13)];
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stop =[mesh.r(end) mesh.a(end) mesh.z(end-14)];
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[CSX, port{2}] = AddCircWaveGuidePort( CSX, 0, 2, start, stop, rad*unit, 'TE11');
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%port 2
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start(3) = mesh.z(end-14);
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stop(3) = mesh.z(end-14);
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CSX = AddProbe(CSX, 'ut2', 10, 'ModeFunction',{func_Er,func_Ea,0});
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CSX = AddBox(CSX, 'ut2', 0 ,start,stop);
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CSX = AddProbe(CSX,'it2', 11, 'ModeFunction',{func_Hr,func_Ha,0});
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CSX = AddBox(CSX,'it2', 0 ,start,stop);
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port_dist = mesh.z(end-14) - mesh.z(15);
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%% define dump box... %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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CSX = AddDump(CSX,'Et','FileType',1,'SubSampling','4,4,4');
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start = [mesh.r(1) mesh.a(1) mesh.z(1)];
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@ -106,7 +60,7 @@ CSX = AddBox(CSX,'Et',0 , start,stop);
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%% Write openEMS compatoble xml-file %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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Sim_Path = 'tmp';
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Sim_CSX = 'rect_wg.xml';
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Sim_CSX = 'circ_wg.xml';
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[status, message, messageid] = rmdir(Sim_Path,'s');
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[status, message, messageid] = mkdir(Sim_Path);
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@ -116,29 +70,16 @@ WriteOpenEMS([Sim_Path '/' Sim_CSX],FDTD,CSX);
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RunOpenEMS(Sim_Path, Sim_CSX)
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%% postproc %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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U = ReadUI({'ut1','ut2'},[Sim_Path '/'],freq);
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I = ReadUI({'it1','it2'},[Sim_Path '/'],freq);
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Exc = ReadUI('et',Sim_Path,freq);
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freq = linspace(f_start,f_stop,201);
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port = calcPort( port, Sim_Path, freq);
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uf1 = U.FD{1}.val./Exc.FD{1}.val;
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uf2 = U.FD{2}.val./Exc.FD{1}.val;
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if1 = I.FD{1}.val./Exc.FD{1}.val;
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if2 = I.FD{2}.val./Exc.FD{1}.val;
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s11 = port{1}.uf.ref./ port{1}.uf.inc;
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s21 = port{2}.uf.ref./ port{1}.uf.inc;
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ZL = port{1}.uf.tot./port{1}.if.tot;
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uf1_inc = 0.5 * ( uf1 + if1 .* ZL_a );
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if1_inc = 0.5 * ( if1 + uf1 ./ ZL_a );
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uf2_inc = 0.5 * ( uf2 + if2 .* ZL_a );
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if2_inc = 0.5 * ( if2 + uf2 ./ ZL_a );
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uf1_ref = uf1 - uf1_inc;
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if1_ref = if1_inc - if1;
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uf2_ref = uf2 - uf2_inc;
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if2_ref = if2_inc - if2;
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%% plot s-parameter %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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figure
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s11 = uf1_ref./uf1_inc;
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s21 = uf2_inc./uf1_inc;
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plot(freq*1e-6,20*log10(abs(s11)),'k-','Linewidth',2);
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xlim([freq(1) freq(end)]*1e-6);
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grid on;
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@ -151,14 +92,14 @@ xlabel('frequency (MHz) \rightarrow','FontSize',12);
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%% compare analytic and numerical wave-impedance %%%%%%%%%%%%%%%%%%%%%%%%%%
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figure
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ZL = uf1./if1;
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plot(freq*1e-6,real(ZL),'Linewidth',2);
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hold on;
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grid on;
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plot(freq*1e-6,imag(ZL),'r--','Linewidth',2);
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plot(freq*1e-6,ZL_a,'g-.','Linewidth',2);
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plot(freq*1e-6,port{1}.ZL,'g-.','Linewidth',2);
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ylabel('ZL (\Omega)','FontSize',12);
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xlabel('frequency (MHz) \rightarrow','FontSize',12);
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xlim([freq(1) freq(end)]*1e-6);
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l = legend('\Re(Z_L)','\Im(Z_L)','Z_L analytic','Location','Best');
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set(l,'FontSize',12);
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@ -5,8 +5,8 @@
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% http://openems.de/index.php/Tutorial:_Conical_Horn_Antenna
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%
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% Tested with
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% - Matlab 2011a / Octave 3.4.3
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% - openEMS v0.0.27
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% - Matlab 2011a / Octave 3.6.3
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% - openEMS v0.0.31
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%
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% (C) 2011,2012 Thorsten Liebig <thorsten.liebig@uni-due.de>
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@ -40,35 +40,6 @@ f_stop = 20e9;
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% frequency of interest
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f0 = 15e9;
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%% mode functions %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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% by David M. Pozar, Microwave Engineering, third edition, page 113
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freq = linspace(f_start,f_stop,201);
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p11 = 1.841;
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kc = p11 / horn.radius /unit;
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k = 2*pi*freq/C0;
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fc = C0*kc/2/pi;
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beta = sqrt(k.^2 - kc^2);
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ZL_a = k * Z0 ./ beta; %analytic waveguide impedance
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% mode profile E- and H-field
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kc = kc*unit;
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func_Er = [ num2str(-1/kc^2,'%14.13f') '/rho*cos(a)*j1(' num2str(kc,'%14.13f') '*rho)'];
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func_Ea = [ num2str(1/kc,'%14.13f') '*sin(a)*0.5*(j0(' num2str(kc,'%14.13f') '*rho)-jn(2,' num2str(kc,'%14.13f') '*rho))'];
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func_Ex = ['(' func_Er '*cos(a) - ' func_Ea '*sin(a) ) * (rho<' num2str(horn.radius) ')'];
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func_Ey = ['(' func_Er '*sin(a) + ' func_Ea '*cos(a) ) * (rho<' num2str(horn.radius) ')'];
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func_Ha = [ num2str(-1/kc^2,'%14.13f') '/rho*cos(a)*j1(' num2str(kc,'%14.13f') '*rho)'];
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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))'];
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func_Hx = ['(' func_Hr '*cos(a) - ' func_Ha '*sin(a) ) * (rho<' num2str(horn.radius) ')'];
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func_Hy = ['(' func_Hr '*sin(a) + ' func_Ha '*cos(a) ) * (rho<' num2str(horn.radius) ')'];
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disp([' Cutoff frequencies for this mode and wavguide is: ' num2str(fc/1e9) ' GHz']);
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if (f_start<fc)
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warning('openEMS:example','f_start is smaller than the cutoff-frequency, this may result in a long simulation... ');
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end
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%% setup FDTD parameter & excitation function
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FDTD = InitFDTD( 30000, 1e-4 );
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FDTD = SetGaussExcite(FDTD,0.5*(f_start+f_stop),0.5*(f_stop-f_start));
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@ -112,31 +83,17 @@ CSX = AddRotPoly(CSX,'Conical_Horn',10,0,2,p);
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% horn aperture
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A = pi*((horn.radius + sin(horn.angle)*horn.length)*unit)^2;
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% %% apply the excitation %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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% xy-mode profile excitation located directly on top of pml (first 8 z-lines)
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CSX = AddExcitation(CSX,'excite',0,[1 1 0]);
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weight{1} = func_Ex;
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weight{2} = func_Ey;
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weight{3} = 0;
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CSX = SetExcitationWeight(CSX,'excite',weight);
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start=[0 0 mesh.z(8)-0.1 ];
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stop =[0 0 mesh.z(8)+0.1 ];
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CSX = AddCylinder(CSX,'excite',0 ,start,stop,horn.radius);
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%% apply the excitation %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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start=[-horn.radius -horn.radius mesh.z(10) ];
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stop =[+horn.radius +horn.radius mesh.z(1)+horn.feed_length/2 ];
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[CSX, port] = AddCircWaveGuidePort( CSX, 0, 1, start, stop, horn.radius*unit, 'TE11', 0, 1);
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%%
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CSX = AddDump(CSX,'Exc_dump');
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start=[-horn.radius -horn.radius mesh.z(8)-0.1 ];
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stop =[+horn.radius +horn.radius mesh.z(8)+0.1 ];
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start=[-horn.radius -horn.radius mesh.z(8)];
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stop =[+horn.radius +horn.radius mesh.z(8)];
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CSX = AddBox(CSX,'Exc_dump',0,start,stop);
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%% voltage and current definitions using the mode matching probes %%%%%%%%%
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%port 1
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start = [-horn.radius -horn.radius mesh.z(1)+horn.feed_length/2];
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stop = [ horn.radius horn.radius mesh.z(1)+horn.feed_length/2];
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CSX = AddProbe(CSX, 'ut1', 10, 1, [], 'ModeFunction',{func_Ex,func_Ey,0});
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CSX = AddBox(CSX, 'ut1', 0 ,start,stop);
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CSX = AddProbe(CSX,'it1', 11, 1, [], 'ModeFunction',{func_Hx,func_Hy,0});
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CSX = AddBox(CSX,'it1', 0 ,start,stop);
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%% nf2ff calc
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start = [mesh.x(9) mesh.y(9) mesh.z(9)];
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stop = [mesh.x(end-8) mesh.y(end-8) mesh.z(end-8)];
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@ -159,16 +116,17 @@ CSXGeomPlot( [Sim_Path '/' Sim_CSX] );
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RunOpenEMS( Sim_Path, Sim_CSX);
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%% postprocessing & do the plots
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U = ReadUI( 'ut1', Sim_Path, freq ); % time domain/freq domain voltage
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I = ReadUI( 'it1', Sim_Path, freq ); % time domain/freq domain current (half time step is corrected)
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freq = linspace(f_start,f_stop,201);
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port = calcPort(port, Sim_Path, freq);
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Zin = port.uf.tot ./ port.if.tot;
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s11 = port.uf.ref ./ port.uf.inc;
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P_in = 0.5 * port.uf.inc .* conj( port.if.inc ); % antenna feed power
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% plot reflection coefficient S11
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figure
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uf_inc = 0.5*(U.FD{1}.val + I.FD{1}.val .* ZL_a);
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if_inc = 0.5*(I.FD{1}.val + U.FD{1}.val ./ ZL_a);
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uf_ref = U.FD{1}.val - uf_inc;
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if_ref = if_inc - I.FD{1}.val;
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s11 = uf_ref ./ uf_inc;
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plot( freq/1e9, 20*log10(abs(s11)), 'k-', 'Linewidth', 2 );
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ylim([-60 0]);
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grid on
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@ -176,8 +134,6 @@ title( 'reflection coefficient S_{11}' );
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xlabel( 'frequency f / GHz' );
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ylabel( 'reflection coefficient |S_{11}|' );
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P_in = 0.5*uf_inc .* conj( if_inc ); % antenna feed power
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drawnow
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%% NFFF contour plots %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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@ -43,37 +43,12 @@ f_stop = 20e9;
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f0 = 15e9;
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%waveguide TE-mode definition
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m = 1;
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n = 0;
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%% mode functions %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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% by David M. Pozar, Microwave Engineering, third edition, page 113
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freq = linspace(f_start,f_stop,201);
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TE_mode = 'TE10';
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a = horn.width;
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b = horn.height;
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k = 2*pi*freq/c0;
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kc = sqrt((m*pi/a/unit)^2 + (n*pi/b/unit)^2);
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fc = c0*kc/2/pi; %cut-off frequency
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beta = sqrt(k.^2 - kc^2); %waveguide phase-constant
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ZL_a = k * Z0 ./ beta; %analytic waveguide impedance
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% mode profile E- and H-field
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x_pos = ['(x-' num2str(a/2) ')'];
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y_pos = ['(y-' num2str(b/2) ')'];
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func_Ex = [num2str( n/b/unit) '*cos(' num2str(m*pi/a) '*' x_pos ')*sin(' num2str(n*pi/b) '*' y_pos ')'];
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func_Ey = [num2str(-m/a/unit) '*sin(' num2str(m*pi/a) '*' x_pos ')*cos(' num2str(n*pi/b) '*' y_pos ')'];
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func_Hx = [num2str(m/a/unit) '*sin(' num2str(m*pi/a) '*' x_pos ')*cos(' num2str(n*pi/b) '*' y_pos ')'];
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func_Hy = [num2str(n/b/unit) '*cos(' num2str(m*pi/a) '*' x_pos ')*sin(' num2str(n*pi/b) '*' y_pos ')'];
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disp([' Cutoff frequencies for this mode and wavguide is: ' num2str(fc/1e9) ' GHz']);
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if (f_start<fc)
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warning('openEMS:example','f_start is smaller than the cutoff-frequency, this may result in a long simulation... ');
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end
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%% setup FDTD parameter & excitation function
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FDTD = InitFDTD( 30000, 1e-4 );
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FDTD = InitFDTD('EndCriteria', 1e-4);
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FDTD = SetGaussExcite(FDTD,0.5*(f_start+f_stop),0.5*(f_stop-f_start));
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BC = {'PML_8' 'PML_8' 'PML_8' 'PML_8' 'PML_8' 'PML_8'}; % boundary conditions
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FDTD = SetBoundaryCond( FDTD, BC );
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@ -138,25 +113,10 @@ CSX = AddLinPoly( CSX, 'horn', 10, 0, -horn.thickness/2, p, horn.thickness, 'Tra
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% horn aperture
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A = (a + 2*sin(horn.angle(1))*horn.length)*unit * (b + 2*sin(horn.angle(2))*horn.length)*unit;
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% %% apply the excitation %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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% xy-mode profile excitation located directly on top of pml (first 8 z-lines)
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CSX = AddExcitation(CSX,'excite',0,[1 1 0]);
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weight{1} = func_Ex;
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weight{2} = func_Ey;
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weight{3} = 0;
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CSX = SetExcitationWeight(CSX,'excite',weight);
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%% apply the excitation %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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start=[-a/2 -b/2 mesh.z(8) ];
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stop =[ a/2 b/2 mesh.z(8) ];
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CSX = AddBox(CSX,'excite',0 ,start,stop);
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%% voltage and current definitions using the mode matching probes %%%%%%%%%
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%port 1
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start(3) = mesh.z(1)+horn.feed_length/2;
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stop(3) = start(3);
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CSX = AddProbe(CSX, 'ut1', 10, 1, [], 'ModeFunction',{func_Ex,func_Ey,0});
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CSX = AddBox(CSX, 'ut1', 0 ,start,stop);
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CSX = AddProbe(CSX,'it1', 11, 1, [], 'ModeFunction',{func_Hx,func_Hy,0});
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CSX = AddBox(CSX,'it1', 0 ,start,stop);
|
||||
stop =[ a/2 b/2 mesh.z(1)+horn.feed_length/2 ];
|
||||
[CSX, port] = AddRectWaveGuidePort( CSX, 0, 1, start, stop, 2, a*unit, b*unit, TE_mode, 1);
|
||||
|
||||
%% nf2ff calc
|
||||
start = [mesh.x(9) mesh.y(9) mesh.z(9)];
|
||||
|
|
@ -180,16 +140,14 @@ CSXGeomPlot([Sim_Path '/' Sim_CSX]);
|
|||
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)
|
||||
freq = linspace(f_start,f_stop,201);
|
||||
|
||||
port = calcPort(port, Sim_Path, freq);
|
||||
|
||||
Zin = port.uf.tot ./ port.if.tot;
|
||||
s11 = port.uf.ref ./ port.uf.inc;
|
||||
P_in = 0.5 * port.uf.inc .* conj( port.if.inc ); % antenna feed power
|
||||
|
||||
% 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
|
||||
|
|
@ -197,8 +155,6 @@ 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
|
||||
|
||||
drawnow
|
||||
|
||||
%% NFFF contour plots %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||
|
|
|
|||
|
|
@ -6,9 +6,9 @@
|
|||
%
|
||||
% Tested with
|
||||
% - Matlab 2011a / Octave 3.4.3
|
||||
% - openEMS v0.0.26
|
||||
% - openEMS v0.0.31
|
||||
%
|
||||
% (C) 2010-2012 Thorsten Liebig <thorsten.liebig@gmx.de>
|
||||
% (C) 2010-2013 Thorsten Liebig <thorsten.liebig@gmx.de>
|
||||
|
||||
close all
|
||||
clear
|
||||
|
|
@ -17,7 +17,6 @@ clc
|
|||
%% setup the simulation %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||
physical_constants;
|
||||
unit = 1e-3; %drawing unit in mm
|
||||
numTS = 50000; %max. number of timesteps
|
||||
|
||||
% waveguide dimensions
|
||||
length = 5000;
|
||||
|
|
@ -29,35 +28,12 @@ f_start = 300e6;
|
|||
f_stop = 500e6;
|
||||
|
||||
%waveguide TE-mode definition
|
||||
m = 1;
|
||||
n = 1;
|
||||
TE_mode = 'TE11';
|
||||
|
||||
mesh_res = [10 10 10]; %targeted mesh resolution
|
||||
|
||||
%% mode functions %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||
% by David M. Pozar, Microwave Engineering, third edition, page 113
|
||||
freq = linspace(f_start,f_stop,201);
|
||||
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
|
||||
func_Ex = [num2str( n/b/unit) '*cos(' num2str(m*pi/a) '*x)*sin(' num2str(n*pi/b) '*y)'];
|
||||
func_Ey = [num2str(-m/a/unit) '*sin(' num2str(m*pi/a) '*x)*cos(' num2str(n*pi/b) '*y)'];
|
||||
|
||||
func_Hx = [num2str(m/a/unit) '*sin(' num2str(m*pi/a) '*x)*cos(' num2str(n*pi/b) '*y)'];
|
||||
func_Hy = [num2str(n/b/unit) '*cos(' num2str(m*pi/a) '*x)*sin(' num2str(n*pi/b) '*y)'];
|
||||
|
||||
disp([' Cutoff frequencies for this mode and wavguide is: ' num2str(fc/1e6) ' MHz']);
|
||||
|
||||
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(numTS,1e-5);
|
||||
FDTD = InitFDTD();
|
||||
FDTD = SetGaussExcite(FDTD,0.5*(f_start+f_stop),0.5*(f_stop-f_start));
|
||||
|
||||
% boundary conditions
|
||||
|
|
@ -71,36 +47,15 @@ mesh.y = SmoothMeshLines([0 b], mesh_res(2));
|
|||
mesh.z = SmoothMeshLines([0 length], mesh_res(3));
|
||||
CSX = DefineRectGrid(CSX, unit,mesh);
|
||||
|
||||
%% 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=[mesh.x(1) mesh.y(1) mesh.z(8) ];
|
||||
stop =[mesh.x(end) mesh.y(end) mesh.z(8) ];
|
||||
CSX = AddBox(CSX,'excite',0 ,start,stop);
|
||||
%% apply the waveguide port %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||
start=[mesh.x(1) mesh.y(1) mesh.z(8)];
|
||||
stop =[mesh.x(end) mesh.y(end) mesh.z(15)];
|
||||
[CSX, port{1}] = AddRectWaveGuidePort( CSX, 0, 1, start, stop, 2, a*unit, b*unit, TE_mode, 1);
|
||||
|
||||
%% voltage and current definitions using the mode matching probes %%%%%%%%%
|
||||
%port 1
|
||||
start = [mesh.x(1) mesh.y(1) mesh.z(15)];
|
||||
stop = [mesh.x(end) mesh.y(end) mesh.z(15)];
|
||||
CSX = AddProbe(CSX, 'ut1', 10, 'ModeFunction',{func_Ex,func_Ey,0});
|
||||
CSX = AddBox(CSX, 'ut1', 0 ,start,stop);
|
||||
CSX = AddProbe(CSX,'it1', 11, 'ModeFunction',{func_Hx,func_Hy,0});
|
||||
CSX = AddBox(CSX,'it1', 0 ,start,stop);
|
||||
start=[mesh.x(1) mesh.y(1) mesh.z(end-13)];
|
||||
stop =[mesh.x(end) mesh.y(end) mesh.z(end-14)];
|
||||
[CSX, port{2}] = AddRectWaveGuidePort( CSX, 0, 2, start, stop, 2, a*unit, b*unit, TE_mode);
|
||||
|
||||
%port 2
|
||||
start = [mesh.x(1) mesh.y(1) mesh.z(end-14)];
|
||||
stop = [mesh.x(end) mesh.y(end) mesh.z(end-14)];
|
||||
CSX = AddProbe(CSX, 'ut2', 10, 'ModeFunction',{func_Ex,func_Ey,0});
|
||||
CSX = AddBox(CSX, 'ut2', 0 ,start,stop);
|
||||
CSX = AddProbe(CSX,'it2', 11, 'ModeFunction',{func_Hx,func_Hy,0});
|
||||
CSX = AddBox(CSX,'it2', 0 ,start,stop);
|
||||
|
||||
port_dist = mesh.z(end-14) - mesh.z(15);
|
||||
|
||||
%% define dump box... %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||
CSX = AddDump(CSX,'Et','FileType',1,'SubSampling','4,4,4');
|
||||
start = [mesh.x(1) mesh.y(1) mesh.z(1)];
|
||||
|
|
@ -108,7 +63,7 @@ stop = [mesh.x(end) mesh.y(end) mesh.z(end)];
|
|||
CSX = AddBox(CSX,'Et',0 , start,stop);
|
||||
|
||||
%% Write openEMS compatoble xml-file %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||
Sim_Path = 'tmp';
|
||||
Sim_Path = 'tmp_mod';
|
||||
Sim_CSX = 'rect_wg.xml';
|
||||
|
||||
[status, message, messageid] = rmdir(Sim_Path,'s');
|
||||
|
|
@ -119,29 +74,16 @@ WriteOpenEMS([Sim_Path '/' Sim_CSX],FDTD,CSX);
|
|||
RunOpenEMS(Sim_Path, Sim_CSX)
|
||||
|
||||
%% postproc %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||
U = ReadUI({'ut1','ut2'},[Sim_Path '/'],freq);
|
||||
I = ReadUI({'it1','it2'},[Sim_Path '/'],freq);
|
||||
Exc = ReadUI('et',Sim_Path,freq);
|
||||
freq = linspace(f_start,f_stop,201);
|
||||
port = calcPort( port, Sim_Path, freq);
|
||||
|
||||
uf1 = U.FD{1}.val./Exc.FD{1}.val;
|
||||
uf2 = U.FD{2}.val./Exc.FD{1}.val;
|
||||
if1 = I.FD{1}.val./Exc.FD{1}.val;
|
||||
if2 = I.FD{2}.val./Exc.FD{1}.val;
|
||||
|
||||
uf1_inc = 0.5 * ( uf1 + if1 .* ZL_a );
|
||||
if1_inc = 0.5 * ( if1 + uf1 ./ ZL_a );
|
||||
uf2_inc = 0.5 * ( uf2 + if2 .* ZL_a );
|
||||
if2_inc = 0.5 * ( if2 + uf2 ./ ZL_a );
|
||||
|
||||
uf1_ref = uf1 - uf1_inc;
|
||||
if1_ref = if1_inc - if1;
|
||||
uf2_ref = uf2 - uf2_inc;
|
||||
if2_ref = if2_inc - if2;
|
||||
s11 = port{1}.uf.ref./ port{1}.uf.inc;
|
||||
s21 = port{2}.uf.ref./ port{1}.uf.inc;
|
||||
ZL = port{1}.uf.tot./port{1}.if.tot;
|
||||
ZL_a = port{1}.ZL; % analytic waveguide impedance
|
||||
|
||||
%% plot s-parameter %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||
figure
|
||||
s11 = uf1_ref./uf1_inc;
|
||||
s21 = uf2_inc./uf1_inc;
|
||||
plot(freq*1e-6,20*log10(abs(s11)),'k-','Linewidth',2);
|
||||
xlim([freq(1) freq(end)]*1e-6);
|
||||
grid on;
|
||||
|
|
@ -154,7 +96,6 @@ xlabel('frequency (MHz) \rightarrow','FontSize',12);
|
|||
|
||||
%% compare analytic and numerical wave-impedance %%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||
figure
|
||||
ZL = uf1./if1;
|
||||
plot(freq*1e-6,real(ZL),'Linewidth',2);
|
||||
hold on;
|
||||
grid on;
|
||||
|
|
|
|||
Loading…
Reference in New Issue