matlab: MRStub implementation; LumpedPort implementation

matlab/AddLumpedPort.m

@@ -0,0 +1,138 @@
+function [CSX,port] = AddLumpedPort( CSX, portnr, R, start, stop, dir, excitename )
+% [CSX,port] = AddLumpedPort( CSX, portnr, materialname, start, stop, dir, evec, excitename )
+%
+% CSX: CSX-object created by InitCSX()
+% portnr: (integer) number of the port
+% R: internal resistance of the port
+% start: 3D start rowvector for port definition
+% stop:  3D end rowvector for port definition
+% dir: direction of wave propagation (choices: [1 0 0], [0 1 0] or [0 0 1])
+% excitename (optional): if specified, the port will be switched on (see AddExcitation())
+%
+% the mesh must be already initialized
+%
+% example:
+%   start = [0 0 height]; stop = [length width height]; dir = [1 0 0];
+%   this defines a lumped port in x-direction (dir)
+%   the excitation/probe is placed between start(1) and stop(1)
+%
+% Sebastian Held <sebastian.held@gmx.de>
+% Jun 1 2010
+%
+% See also InitCSX AddExcitation
+
+% check dir
+if ~(dir(1) == dir(2) == 0) && ~(dir(1) == dir(3) == 0) && ~(dir(2) == dir(3) == 0) || (sum(dir) == 0)
+	error 'dir must have exactly one component ~= 0'
+end
+dir = dir ./ sum(dir); % dir is now a unit vector
+
+% get grid
+mesh{1} = sort(CSX.RectilinearGrid.XLines);
+mesh{2} = sort(CSX.RectilinearGrid.YLines);
+mesh{3} = sort(CSX.RectilinearGrid.ZLines);
+drawingunit = CSX.RectilinearGrid.ATTRIBUTE.DeltaUnit;
+
+% snap to grid
+idx_plane = 0;
+for n=1:3
+    start_idx = interp1( mesh{n}, 1:numel(mesh{n}), start(n), 'nearest' );
+    stop_idx  = interp1( mesh{n}, 1:numel(mesh{n}), stop(n),  'nearest' );
+    if start_idx == stop_idx
+        idx_plane = n; % two dimensional port: this is the correct index
+    end
+    start(n)  = mesh{n}(start_idx);
+    stop(n)   = mesh{n}(stop_idx);
+end
+
+if idx_plane == 0
+    error( 'the port must be two-dimensional!' );
+end
+
+% normalize start and stop
+nstart = min( [start;stop] );
+nstop  = max( [start;stop] );
+
+% determine index (1, 2 or 3) of calibration (e-) line
+idx_cal = dir * [1;2;3];
+
+% direction of calibration line
+if stop(idx_cal)-start(idx_cal) > 0
+    direction = +1;
+else
+    direction = -1;
+end
+
+% determine the other direction (FIXME is there a better way?)
+idx1 = [1 2 3];
+idx1 = idx1(idx1 ~= idx_plane);
+idx1 = idx1(idx1 ~= idx_cal);
+
+% calculate position of resistive material
+idx = interp1( mesh{idx_plane}, 1:numel(mesh{idx_plane}), nstart(idx_plane), 'nearest' );
+delta2_n = mesh{idx_plane}(idx) - mesh{idx_plane}(idx-1);
+delta2_p = mesh{idx_plane}(idx+1) - mesh{idx_plane}(idx);
+m_start = nstart;
+m_stop  = nstop;
+m_start = m_start - delta2_n/2;
+m_stop  = m_stop  + delta2_p/2;
+
+% calculate kappa
+l = (m_stop(idx_cal) - m_start(idx_cal)) * drawingunit; % length of the "sheet"
+A = (m_stop(idx1) - m_start(idx1)) * (m_stop(idx_plane) - m_start(idx_plane)) * drawingunit^2; % area of the "sheet"
+kappa = l/A / R; % [kappa] = S/m
+CSX = AddMaterial( CSX, ['port' num2str(portnr) '_sheet_resistance'] );
+CSX = SetMaterialProperty( CSX, ['port' num2str(portnr) '_sheet_resistance'], 'Kappa', kappa );
+CSX = AddBox( CSX, ['port' num2str(portnr) '_sheet_resistance'], 0, m_start, m_stop );
+
+% calculate position of the voltage probe
+center1 = interp1( mesh{idx1}, 1:numel(mesh{idx1}), (nstart(idx1)+nstop(idx1))/2, 'nearest' );
+v_start(idx_plane) = start(idx_plane);
+v_start(idx1) = center1;
+v_stop = v_start;
+v_start(idx_cal) = nstart(idx_cal);
+v_stop(idx_cal)  = nstop(idx_cal);
+
+% calculate position of the current probe
+idx = interp1( mesh{idx1}, 1:numel(mesh{idx1}), nstart(idx1), 'nearest' );
+delta1_n = mesh{idx1}(idx) - mesh{idx1}(idx-1);
+idx = interp1( mesh{idx1}, 1:numel(mesh{idx1}), nstop(idx1), 'nearest' );
+delta1_p = mesh{idx1}(idx+1) - mesh{idx1}(idx);
+idx = interp1( mesh{idx_cal}, 1:numel(mesh{idx_cal}), (nstart(idx_cal)+nstop(idx_cal))/2, 'nearest' );
+i_start(idx_cal)   = mesh{idx_cal}(idx-1);
+i_stop(idx_cal)    = mesh{idx_cal}(idx-1);
+i_start(idx1)      = nstart(idx1) - delta1_n/2;
+i_start(idx_plane) = nstart(idx_plane) - delta2_n/2;
+i_stop(idx1)       = nstop(idx1) + delta1_p/2;
+i_stop(idx_plane)  = nstop(idx_plane) + delta2_p/2;
+
+% create the probes
+name = ['port_ut' num2str(portnr)];
+CSX = AddProbe( CSX, name, 0 );
+CSX = AddBox( CSX, name, 999, v_start, v_stop );
+name = ['port_it' num2str(portnr)];
+CSX = AddProbe( CSX, name, 1 );
+CSX = AddBox( CSX, name, 999, i_start, i_stop );
+
+% create port structure
+port.nr = portnr;
+port.drawingunit = CSX.RectilinearGrid.ATTRIBUTE.DeltaUnit;
+port.start = start;
+port.stop = stop;
+port.v_start = v_start;
+port.v_stop  = v_stop;
+port.i_start = i_start;
+port.i_stop  = i_stop;
+port.dir = dir;
+port.direction = direction;
+port.idx_cal = idx_cal;
+port.idx1 = idx1;
+port.idx1 = idx1;
+port.excite = 0;
+
+% create excitation
+if (nargin >= 7) && ~isempty(excitename)
+	% excitation of this port is enabled
+	port.excite = 1;
+	CSX = AddBox( CSX, excitename, 999, v_start, v_stop );
+end

matlab/AddMRStub.m

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+function CSX = AddMRStub( CSX, materialname, prio, MSL_width, len, alpha, resolution, orientation, normVector, position )
+% CSX = AddMRStub( CSX, materialname, prio, MSL_width, len, alpha,
+% resolution, orientation, normVector, position )
+%
+% Microstrip Radial Stub
+%
+% CSX: CSX-object created by InitCSX()
+% materialname: property for the MSL (created by AddMetal() or AddMaterial())
+% prio: priority
+% MSL_width: width of the MSL to connect the stub to (m)
+% len: length of the radial stub (m)
+% alpha: angle subtended by the radial stub (degrees) 
+% resolution: discrete angle spacing (degrees)
+% orientation: angle of main direction of the radial stub (degrees)
+% normVector: normal vector of the stub
+% position: position of the end of the MSL
+%
+% This radial stub definition is equivalent to the one Agilent ADS uses.
+%
+% example:
+% CSX = AddMRStub( CSX, 'PEC', 10, 1000, 5900, 30, 1, -90, [0 0 1], [0 -10000 254] );
+%
+%
+% Sebastian Held <sebastian.held@gmx.de>
+% Jun 1 2010
+%
+% See also InitCSX AddMetal AddMaterial
+
+% check normVector
+if ~(normVector(1) == normVector(2) == 0) && ...
+        ~(normVector(1) == normVector(3) == 0) && ...
+        ~(normVector(2) == normVector(3) == 0) || (sum(normVector) == 0)
+	error 'normVector must have exactly one component ~= 0'
+end
+normVector = normVector ./ sum(normVector); % normVector is now a unit vector
+
+% convert angles to radians
+alpha_rad = alpha/180*pi;
+orientation_rad = orientation/180*pi;
+resolution_rad = resolution/180*pi;
+
+%
+% build stub at origin (0,0,0) and translate/rotate it later
+%
+
+D = 0.5 * MSL_width / sin(alpha_rad/2);
+R = cos(alpha_rad/2) * D;
+
+% point at the center of the MSL
+p(1,1) = 0;
+p(2,1) = -MSL_width/2;
+p(1,2) = 0;
+p(2,2) = MSL_width/2;
+
+for a = alpha_rad/2 : -resolution_rad : -alpha_rad/2
+    p(1,end+1) = cos(a) * (D+len) - R;
+    p(2,end)   = sin(a) * (D+len);
+end
+
+% rotate
+rot = [cos(-orientation_rad), -sin(-orientation_rad); sin(-orientation_rad), cos(-orientation_rad)];
+p = (p.' * rot).';
+
+% translate
+idx_elevation = [1 2 3];
+idx_elevation = idx_elevation(normVector>0);
+dim1 = mod( idx_elevation, 3 ) + 1;
+dim2 = mod( idx_elevation+1, 3 ) + 1;
+p(1,:) = p(1,:) + position(dim1);
+p(2,:) = p(2,:) + position(dim2);
+
+elevation = position(idx_elevation);
+CSX = AddPolygon( CSX, materialname, prio, normVector, elevation, p );

matlab/SetDiracExcite.m

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+function FDTD = SetDiracExcite(FDTD)
+
+FDTD.Excitation.ATTRIBUTE.Type=2;

matlab/SetStepExcite.m

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+function FDTD = SetStepExcite(FDTD)
+
+FDTD.Excitation.ATTRIBUTE.Type=3;