Frequency = 300;  // MHz
Lambda    = 300/Frequency;   // meter

lc = Lambda/20;
R = 2*Lambda/20;
L = 5*Lambda/20;

Point(1)  = {-R,0,0,lc};
Point(2)  = {0,-R,0,lc};
Point(3)  = {R,0,0,lc};
Point(4)  = {0,R,0,lc};
Point(5)  = {0,0,0,lc};

Point(6)  = {-R,0,L,lc};
Point(7)  = {0,-R,L,lc};
Point(8)  = {R,0,L,lc};
Point(9)  = {0,R,L,lc};
Point(10) = {0,0,L,lc};

Circle(1) = {1,5,2};
Circle(2) = {2,5,3};
Circle(3) = {3,5,4};
Circle(4) = {4,5,1};

Circle(5) = {6,10,7};
Circle(6) = {7,10,8};
Circle(7) = {8,10,9};
Circle(8) = {9,10,6};

Line(9)   = {1,6};
Line(10)  = {3,8};

Extrude Line {1, {1,0,0}, {0,0,0},  Pi/2};
Extrude Line {2, {1,0,0}, {0,0,0},  Pi/2};
Extrude Line {3, {1,0,0}, {0,0,0}, -Pi/2};
Extrude Line {4, {1,0,0}, {0,0,0}, -Pi/2};

Extrude Line {5, {1,0,0}, {0,0,L}, -Pi/2};
Extrude Line {6, {1,0,0}, {0,0,L}, -Pi/2};
Extrude Line {7, {1,0,0}, {0,0,L},  Pi/2};
Extrude Line {8, {1,0,0}, {0,0,L},  Pi/2};

Extrude Line {9, {0,0,1}, {0,0,0},  Pi/2};
Extrude Line {9, {0,0,1}, {0,0,0}, -Pi/2};
Extrude Line {10,{0,0,1}, {0,0,0},  Pi/2};
Extrude Line {10,{0,0,1}, {0,0,0}, -Pi/2};


Physical Surface(101) = {50,-16,-19,-22,25,28,31,34,-38,42,-46,-13};
Physical Surface(10) = {-50,16,19,22,-25,-28,-31,-34,38,-42,46,13};