diff --git a/FDTD/engine_cylinder.cpp b/FDTD/engine_cylinder.cpp
index 9f979f3..ea8a5dc 100644
--- a/FDTD/engine_cylinder.cpp
+++ b/FDTD/engine_cylinder.cpp
@@ -26,18 +26,191 @@ Engine_Cylinder* Engine_Cylinder::New(const Operator_Cylinder* op)
 
 Engine_Cylinder::Engine_Cylinder(const Operator_Cylinder* op) : Engine(op)
 {
+	cyl_Op = op;
+	if (cyl_Op->GetClosedAlpha())
+	{
+		++numLines[1]; //necessary for dobled voltage and current line in alpha-dir, operator will return one smaller for correct post-processing
+	}
 }
 
 Engine_Cylinder::~Engine_Cylinder()
 {
+	Reset();
 }
 
 void Engine_Cylinder::Init()
 {
 	Engine::Init();
+
+//	if (cyl_Op->GetClosedAlpha())
+//	{
+//		unsigned int lastLine = Op->numLines[1]-1; //number of last alpha-line
+//		unsigned int pos[3];
+//		for (pos[0]=0;pos[0]<Op->numLines[0];++pos[0])
+//		{
+//			for (int n=0;n<3;++n)
+//			{
+//				delete[] volt[n][pos[0]][lastLine];
+//				volt[n][pos[0]][lastLine] = volt[n][pos[0]][0];
+//				delete[] curr[n][pos[0]][lastLine];
+//				curr[n][pos[0]][lastLine] = curr[n][pos[0]][0];
+//			}
+//		}
+//	}
 }
 
 void Engine_Cylinder::Reset()
 {
-	Engine::Reset();
+//	if (cyl_Op->GetClosedAlpha())
+//	{
+//		unsigned int lastLine = Op->numLines[1]-1; //number of last alpha-line
+//		unsigned int pos[3];
+//		for (pos[0]=0;pos[0]<Op->numLines[0];++pos[0])
+//		{
+//			for (int n=0;n<3;++n)
+//			{
+//				volt[n][pos[0]][lastLine] = NULL;
+//				curr[n][pos[0]][lastLine] = NULL;
+//			}
+//		}
+//	}
 }
+
+inline void Engine_Cylinder::CloseAlphaVoltages()
+{
+	unsigned int pos[3];
+	// copy voltages from last alpha-plane to first
+	unsigned int last_A_Line = numLines[1]-1;
+	for (pos[0]=0;pos[0]<numLines[0];++pos[0])
+	{
+		for (pos[2]=0;pos[2]<numLines[2];++pos[2])
+		{
+			volt[0][pos[0]][0][pos[2]] = volt[0][pos[0]][last_A_Line][pos[2]];
+			volt[1][pos[0]][0][pos[2]] = volt[1][pos[0]][last_A_Line][pos[2]];
+			volt[2][pos[0]][0][pos[2]] = volt[2][pos[0]][last_A_Line][pos[2]];
+		}
+
+	}
+}
+
+inline void Engine_Cylinder::CloseAlphaCurrents()
+{
+	unsigned int pos[3];
+	// copy currents from first alpha-plane to last
+	for (pos[0]=0;pos[0]<numLines[0]-1;++pos[0])
+	{
+		unsigned int last_A_Line = numLines[1]-1;
+		for (pos[2]=0;pos[2]<numLines[2]-1;++pos[2])
+		{
+			curr[0][pos[0]][last_A_Line][pos[2]] = curr[0][pos[0]][0][pos[2]];
+			curr[1][pos[0]][last_A_Line][pos[2]] = curr[1][pos[0]][0][pos[2]];
+			curr[2][pos[0]][last_A_Line][pos[2]] = curr[2][pos[0]][0][pos[2]];
+		}
+	}
+}
+
+bool Engine_Cylinder::IterateTS(unsigned int iterTS)
+{
+	if (cyl_Op->GetClosedAlpha()==false)
+		return Engine::IterateTS(iterTS);
+
+	for (unsigned int iter=0;iter<iterTS;++iter)
+	{
+		UpdateVoltages();
+		ApplyVoltageExcite();
+
+		CloseAlphaVoltages();
+
+		UpdateCurrents();
+		ApplyCurrentExcite();
+
+		CloseAlphaCurrents();
+
+		++numTS;
+	}
+
+	return true;
+}
+
+
+//inline void Engine_Cylinder::UpdateVoltages()
+//{
+//	unsigned int pos[3];
+//	bool shift[3];
+//
+//	if (cyl_Op->GetClosedAlpha()==false)
+//		return Engine::UpdateVoltages();
+//
+//	//voltage updates
+//	for (pos[0]=0;pos[0]<Op->numLines[0];++pos[0])
+//	{
+//		shift[0]=pos[0];
+//		for (pos[1]=1;pos[1]<Op->numLines[1];++pos[1])
+//		{
+//			shift[1]=pos[1];
+//			for (pos[2]=0;pos[2]<Op->numLines[2];++pos[2])
+//			{
+//				shift[2]=pos[2];
+//				//do the updates here
+//				//for x
+//				volt[0][pos[0]][pos[1]][pos[2]] *= Op->vv[0][pos[0]][pos[1]][pos[2]];
+//				volt[0][pos[0]][pos[1]][pos[2]] += Op->vi[0][pos[0]][pos[1]][pos[2]] * ( curr[2][pos[0]][pos[1]][pos[2]] - curr[2][pos[0]][pos[1]-shift[1]][pos[2]] - curr[1][pos[0]][pos[1]][pos[2]] + curr[1][pos[0]][pos[1]][pos[2]-shift[2]]);
+//
+//				//for y
+//				volt[1][pos[0]][pos[1]][pos[2]] *= Op->vv[1][pos[0]][pos[1]][pos[2]];
+//				volt[1][pos[0]][pos[1]][pos[2]] += Op->vi[1][pos[0]][pos[1]][pos[2]] * ( curr[0][pos[0]][pos[1]][pos[2]] - curr[0][pos[0]][pos[1]][pos[2]-shift[2]] - curr[2][pos[0]][pos[1]][pos[2]] + curr[2][pos[0]-shift[0]][pos[1]][pos[2]]);
+//
+//				//for z
+//				volt[2][pos[0]][pos[1]][pos[2]] *= Op->vv[2][pos[0]][pos[1]][pos[2]];
+//				volt[2][pos[0]][pos[1]][pos[2]] += Op->vi[2][pos[0]][pos[1]][pos[2]] * ( curr[1][pos[0]][pos[1]][pos[2]] - curr[1][pos[0]-shift[0]][pos[1]][pos[2]] - curr[0][pos[0]][pos[1]][pos[2]] + curr[0][pos[0]][pos[1]-shift[1]][pos[2]]);
+//			}
+//		}
+//
+//		// copy voltages from last alpha-plane to first
+//		unsigned int last_A_Line = Op->numLines[1]-1;
+//		for (pos[2]=0;pos[2]<Op->numLines[2];++pos[2])
+//		{
+//			volt[0][pos[0]][0][pos[2]] = volt[0][pos[0]][last_A_Line][pos[2]];
+//			volt[1][pos[0]][0][pos[2]] = volt[1][pos[0]][last_A_Line][pos[2]];
+//			volt[2][pos[0]][0][pos[2]] = volt[2][pos[0]][last_A_Line][pos[2]];
+//		}
+//
+//	}
+//}
+//
+//inline void Engine_Cylinder::UpdateCurrents()
+//{
+//	if (cyl_Op->GetClosedAlpha()==false)
+//		return Engine::UpdateCurrents();
+//
+//	unsigned int pos[3];
+//	for (pos[0]=0;pos[0]<Op->numLines[0]-1;++pos[0])
+//	{
+//		for (pos[1]=0;pos[1]<Op->numLines[1]-1;++pos[1])
+//		{
+//			for (pos[2]=0;pos[2]<Op->numLines[2]-1;++pos[2])
+//			{
+//				//do the updates here
+//				//for x
+//				curr[0][pos[0]][pos[1]][pos[2]] *= Op->ii[0][pos[0]][pos[1]][pos[2]];
+//				curr[0][pos[0]][pos[1]][pos[2]] += Op->iv[0][pos[0]][pos[1]][pos[2]] * ( volt[2][pos[0]][pos[1]][pos[2]] - volt[2][pos[0]][pos[1]+1][pos[2]] - volt[1][pos[0]][pos[1]][pos[2]] + volt[1][pos[0]][pos[1]][pos[2]+1]);
+//
+//				//for y
+//				curr[1][pos[0]][pos[1]][pos[2]] *= Op->ii[1][pos[0]][pos[1]][pos[2]];
+//				curr[1][pos[0]][pos[1]][pos[2]] += Op->iv[1][pos[0]][pos[1]][pos[2]] * ( volt[0][pos[0]][pos[1]][pos[2]] - volt[0][pos[0]][pos[1]][pos[2]+1] - volt[2][pos[0]][pos[1]][pos[2]] + volt[2][pos[0]+1][pos[1]][pos[2]]);
+//
+//				//for z
+//				curr[2][pos[0]][pos[1]][pos[2]] *= Op->ii[2][pos[0]][pos[1]][pos[2]];
+//				curr[2][pos[0]][pos[1]][pos[2]] += Op->iv[2][pos[0]][pos[1]][pos[2]] * ( volt[1][pos[0]][pos[1]][pos[2]] - volt[1][pos[0]+1][pos[1]][pos[2]] - volt[0][pos[0]][pos[1]][pos[2]] + volt[0][pos[0]][pos[1]+1][pos[2]]);
+//			}
+//		}
+//		// copy currents from first alpha-plane to last
+//		unsigned int last_A_Line = Op->numLines[1]-1;
+//		for (pos[2]=0;pos[2]<Op->numLines[2]-1;++pos[2])
+//		{
+//			curr[0][pos[0]][last_A_Line][pos[2]] = curr[0][pos[0]][0][pos[2]];
+//			curr[1][pos[0]][last_A_Line][pos[2]] = curr[1][pos[0]][0][pos[2]];
+//			curr[2][pos[0]][last_A_Line][pos[2]] = curr[2][pos[0]][0][pos[2]];
+//		}
+//	}
+//}
diff --git a/FDTD/engine_cylinder.h b/FDTD/engine_cylinder.h
index af4d122..60ab5a3 100644
--- a/FDTD/engine_cylinder.h
+++ b/FDTD/engine_cylinder.h
@@ -25,13 +25,21 @@ class Engine_Cylinder : public Engine
 {
 public:
 	static Engine_Cylinder* New(const Operator_Cylinder* op);
+	virtual ~Engine_Cylinder();
 
 	virtual void Init();
 	virtual void Reset();
 
+	//!Iterate a number of timesteps
+	virtual bool IterateTS(unsigned int iterTS);
+
 protected:
 	Engine_Cylinder(const Operator_Cylinder* op);
-	~Engine_Cylinder();
+
+	virtual inline void CloseAlphaVoltages();
+	virtual inline void CloseAlphaCurrents();
+
+	const Operator_Cylinder* cyl_Op;
 };
 
 #endif // ENGINE_CYLINDER_H
diff --git a/FDTD/operator_cylinder.cpp b/FDTD/operator_cylinder.cpp
index 51ad60b..c643162 100644
--- a/FDTD/operator_cylinder.cpp
+++ b/FDTD/operator_cylinder.cpp
@@ -45,6 +45,16 @@ void Operator_Cylinder::Reset()
 	Operator::Reset();
 }
 
+inline unsigned int Operator_Cylinder::GetNumberOfLines(int ny) const
+{
+	//this is necessary for a correct field processing... cylindrical engine has to reset this by adding +1
+	if (CC_closedAlpha && ny==1)
+		return numLines[1]-1;
+
+	return numLines[ny];
+}
+
+
 bool Operator_Cylinder::SetGeometryCSX(ContinuousStructure* geo)
 {
 	if (Operator::SetGeometryCSX(geo)==false) return false;
@@ -53,10 +63,20 @@ bool Operator_Cylinder::SetGeometryCSX(ContinuousStructure* geo)
 //			cerr << minmaxA -2*PI << " < " << (2*PI)/10/numLines[1] << endl;
 	if (fabs(minmaxA-2*PI) < (2*PI)/10/numLines[1]) //check minmaxA smaller then a tenth of average alpha-width
 	{
-		CC_closedAlpha = true;
-		--numLines[1];
 		cout << "Operator_Cylinder::SetGeometryCSX: Alpha is a full 2*PI => closed Cylinder..." << endl;
-		cerr << "Operator_Cylinder::SetGeometryCSX: closed cylinder not yet implemented... exit... " << endl; exit(1);
+		CC_closedAlpha = true;
+		discLines[1][numLines[1]-1] = discLines[1][0] + 2*PI;
+		cerr << "Operator_Cylinder::SetGeometryCSX: Warning, not handling the disc-line width and material averaging correctly yet for a closed cylinder..." << endl;
+		if (MainOp->GetIndexDelta(1,0)-MainOp->GetIndexDelta(1,numLines[1]-2) > (2*PI)/10/numLines[1])
+		{
+			cerr << "Operator_Cylinder::SetGeometryCSX: first and last angle delta must be the same... deviation to large..." << MainOp->GetIndexDelta(1,0) - MainOp->GetIndexDelta(1,numLines[1]-2) << endl;
+			exit(1);
+		}
+		if (MainOp->GetIndexDelta(1,0)-MainOp->GetIndexDelta(1,numLines[1]-2) > 0)
+		{
+			cerr << "Operator_Cylinder::SetGeometryCSX: first and last angle delta must be the same... auto correction of deviation: " << MainOp->GetIndexDelta(1,0) - MainOp->GetIndexDelta(1,numLines[1]-2) << endl;
+			discLines[1][numLines[1]-2] = discLines[1][numLines[1]-1]-MainOp->GetIndexDelta(1,0);
+		}
 	}
 	else if (minmaxA>2*PI)
 		{cerr << "Operator_Cylinder::SetGeometryCSX: Alpha Max-Min must not be larger than 2*PI!!!" << endl; Reset(); return false;}
diff --git a/FDTD/operator_cylinder.h b/FDTD/operator_cylinder.h
index de4c3ef..8a98a20 100644
--- a/FDTD/operator_cylinder.h
+++ b/FDTD/operator_cylinder.h
@@ -33,6 +33,11 @@ public:
 
 	virtual void Reset();
 
+	virtual unsigned int GetNumberOfLines(int ny) const;
+
+	bool GetClosedAlpha() const {return CC_closedAlpha;}
+	bool GetR0Included() const {return CC_R0_included;}
+
 protected:
 	Operator_Cylinder();
 	virtual void Init();
diff --git a/matlab/examples/Coax_CylinderCoords.m b/matlab/examples/Coax_CylinderCoords.m
new file mode 100644
index 0000000..94fca1b
--- /dev/null
+++ b/matlab/examples/Coax_CylinderCoords.m
@@ -0,0 +1,129 @@
+close all;
+clear all;
+clc
+
+EPS0 = 8.85418781762e-12;
+MUE0 = 1.256637062e-6;
+C0 = 1/sqrt(EPS0*MUE0);
+Z0 = sqrt(MUE0/EPS0);
+
+f0 = 0.5e9;
+epsR = 1;
+
+abs_length = 500;
+length = 3000;
+port_dist = 1500;
+rad_i  = 100;
+rad_a = 230;
+max_mesh = 10;
+max_alpha = max_mesh;
+N_alpha = ceil(rad_a * 2*pi / max_alpha);
+mesh_res = [max_mesh 2*pi/N_alpha max_mesh];
+
+openEMS_Path = [pwd() '/../../'];
+openEMS_opts = '';
+openEMS_opts = [openEMS_opts ' --disable-dumps'];
+% openEMS_opts = [openEMS_opts ' --debug-material'];
+
+Sim_Path = 'tmp';
+Sim_CSX = 'coax.xml';
+
+mkdir(Sim_Path);
+
+%setup FDTD parameter
+FDTD = InitCylindricalFDTD(1e5,1e-5,'OverSampling',10);
+FDTD = SetGaussExcite(FDTD,f0,f0);
+BC = [0 0 1 1 0 0];
+FDTD = SetBoundaryCond(FDTD,BC);
+
+%setup CSXCAD geometry
+CSX = InitCSX();
+mesh.x = rad_i : mesh_res(1) : rad_a;
+mesh.y = linspace(0,2*pi,N_alpha);
+% mesh.y = mesh.y + mesh_res(2)/2;
+mesh.z = 0 : mesh_res(3) : length;
+CSX = DefineRectGrid(CSX, 1e-3,mesh);
+
+%%%fake pml
+finalKappa = 0.3/abs_length^4;
+finalSigma = finalKappa*MUE0/EPS0/epsR;
+CSX = AddMaterial(CSX,'pml');
+CSX = SetMaterialProperty(CSX,'pml','Kappa',finalKappa,'Epsilon',epsR);
+CSX = SetMaterialProperty(CSX,'pml','Sigma',finalSigma);
+CSX = SetMaterialWeight(CSX,'pml','Kappa',['pow(abs(z)-' num2str(length-abs_length) ',4)']);
+CSX = SetMaterialWeight(CSX,'pml','Sigma',['pow(abs(z)-' num2str(length-abs_length) ',4)']);
+
+start = [rad_i mesh.y(1) length-abs_length];
+stop = [rad_a mesh.y(end) length];
+CSX = AddBox(CSX,'pml',0 ,start,stop);
+
+
+CSX = AddMaterial(CSX,'fill');
+CSX = SetMaterialProperty(CSX,'fill','Epsilon',epsR);
+start = [mesh.x(1) mesh.y(1) 0];
+stop = [mesh.x(end) mesh.y(end) length];
+CSX = AddBox(CSX,'fill',0 ,start,stop);
+
+start = [rad_i mesh.y(1) 0];
+stop = [rad_a mesh.y(end) 0];
+
+CSX = AddExcitation(CSX,'excite',0,[1 0 0]);
+weight{1} = '1/rho';
+weight{2} = 0;
+weight{3} = 0;
+CSX = SetExcitationWeight(CSX, 'excite', weight );
+CSX = AddBox(CSX,'excite',0 ,start,stop);
+ 
+%dump
+CSX = AddDump(CSX,'Et_','DumpMode',0);
+start = [mesh.x(1) , 0 , mesh.z(1)];
+stop = [mesh.x(end) , 0 , mesh.z(end)];
+CSX = AddBox(CSX,'Et_',0 , start,stop);
+
+CSX = AddDump(CSX,'Ht_','DumpType',1,'DumpMode',0);
+CSX = AddBox(CSX,'Ht_',0,start,stop);
+
+% voltage calc (take a voltage average to be at the same spot as the
+% current calculation)
+CSX = AddProbe(CSX,'ut1_1',0);
+start = [ rad_i 0 port_dist ];stop = [ rad_a 0 port_dist ];
+CSX = AddBox(CSX,'ut1_1', 0 ,start,stop);
+CSX = AddProbe(CSX,'ut1_2',0);
+start = [ rad_i 0 port_dist+mesh_res(3) ];stop = [ rad_a 0 port_dist+mesh_res(3) ];
+CSX = AddBox(CSX,'ut1_2', 0 ,start,stop);
+
+% current calc
+CSX = AddProbe(CSX,'it1',1);
+mid = 0.5*(rad_i+rad_a);
+start = [ 0 mesh.y(1) port_dist ];stop = [ mid mesh.y(end) port_dist ];
+CSX = AddBox(CSX,'it1', 0 ,start,stop);
+
+%Write openEMS compatoble xml-file
+WriteOpenEMS([Sim_Path '/' Sim_CSX],FDTD,CSX);
+
+%cd to working dir and run openEMS
+savePath = pwd();
+cd(Sim_Path); %cd to working dir
+command = [openEMS_Path 'openEMS.sh ' Sim_CSX ' ' openEMS_opts];
+disp(command);
+system(command)
+cd(savePath);
+
+UI = ReadUI({'ut1_1','ut1_2','it1'},'tmp/');
+u_f = (UI.FD{1}.val + UI.FD{2}.val)/2;          %averaging voltages to fit current
+i_f = UI.FD{3}.val;
+
+delta_t = UI.TD{3}.t(1) - UI.TD{1}.t(1);        % half time-step (s) 
+i_f2 = i_f .* exp(-1i*2*pi*UI.FD{1}.f*delta_t); % compensate half time-step advance of H-field
+
+ZL = Z0/2/pi/sqrt(epsR)*log(rad_a/rad_i); %analytic line-impedance of a coax
+plot(UI.FD{1}.f,ZL*ones(size(u_f)),'g');
+hold on;
+grid on;
+Z = u_f./i_f2;
+plot(UI.FD{1}.f,real(Z),'Linewidth',2);
+plot(UI.FD{1}.f,imag(Z),'r','Linewidth',2);
+xlim([0 2*f0]);
+legend('Z_L','\Re\{Z\}','\Im\{Z\}','Location','Best');
+
+