Post on 13-Mar-2016
description
Electromagnetic Theory55:170
Professor Karl E. Lonngren[lonngren@engineering.uiowa.edu
]4312 SC
office hours: 12:15-1:00 T & ThKent Hutchinson – teaching
assistant
Books
• References:• Fields and Waves in
Communication Systems• Fundamentals of
Electromagnetics with MATLAB 2007
Topics• MATLAB in EM • Electrostatics • Magnetostatics • Maxwell’s equations; boundary conditions• Transmission lines • Plane waves • Waveguides • Cavities • Radiation
Grading• Mid-term exam ¼ • Final exam ¼ • Term paper/lecture/movie ¼• Homework ¼
MATLAB• in the college computers•easy to use & learn•easy to produce 2-d & 3-d plots•ODE & PDE• integrate & differentiate•get pictures -- .m files in 070
web page
math• >> MATLAB icon• >> x = 1• x = • 1• >>• complex numbers• >> y = 1+1j (or 1+ 1i)• y =• 1.0000 + 1.0000i• >> z = x - y• z =• 0 - 1.0000i• >>
• >> x = 1; SAVE SPACE TRICK “ ; “• >> y = 2;• >> z = x * y; % multiply• >> z• z =• 2• >> w = x / y; % divide• >> w• w =• 0.5000
vectors - addition•a = 1ux + 2uy + 3uz
•b = 3ux + 2uy + 1uz•c = a + b •c = 4ux + 4uy + 4uz•a = [1 2 3];•b = [3 2 1];•c = a + b;•c • 4 4 4
vectors - dot product•a = 1ux + 2uy + 3uz
•b = 3ux + 2uy + 1uz•a • b = b • a •= 3 + 4 + 3 = 10•a = [1 2 3];•b = [3 2 1];•c = dot(a, b);•c• = 10
vectors - cross product
•a = 1ux + 0uy + 0uz ==> a = [1 0 0]
•b = 0ux + 1uy + 0uz ==> b = [0 1 0]
•d = cross (a,b)•d = • 0 0 1
vectors - cross product
•a = 1ux + 0uy + 0uz ==> a = [1 0 0]
•b = 0ux + 1uy + 0uz ==> b = [0 1 0]
•e = cross (b, a)•e =• 0 0 -1
x
y
z
A BB - A
|B - A| = norm(B -A)
• In MATLAB• >>colormap(hot) or cool or • >>whitebg(‘black’) or ‘green’ or • “print screen”• “paint”
simple graph
0 2 4 60
2
4
6
#x
>> x = [1 2 3 4 5]
x=
1 2 3 4 5
>> plot(x)
>> xlabel(‘#’)
>> ylabel(‘value’)
two valuessemicolon
1 2 3 4 51
2
3
4
5
y
x
>>x=[1 2 3 4 5];
>>y=[5 4 3 2 1];
>>plot(x,y,’*’)
>>xlabel(‘x’)
>>ylabel(‘y’)
clear;clfx=0:.1:4*pi;plot(sin(x),'linewidth',3)hold onplot(cos(x),'linewidth',3,'linestyle','--')xlabel('x','fontsize',18)ylabel('V','fontsize',18)set(gca,'fontsize',18)whitebg('black')
0 50 100 150-1
0
1
x
V
Add to graph
>>[x,y]=meshgrid(-xa:x:xb,-ya:y:yb)
>>[x,y]=meshgrid(-1:.1:1,-2:.4:4);
>>R=(x.^2+(y+1).^2).^.5;
>>Z=(1./R);
>>surf(x,y,Z)
>>view(-37.5-90,30)
>>[x,y]=meshgrid(-1:.1:1,-2:.4:4);
>>R=(x.^2+(y+1).^2).^.5;
>>Z=(1./R);
>>surf(x,y,Z)
>>view(-37.5-90,30)
>>[x,y]=meshgrid(-1:.1:1,-2:.4:4);
>>R=(x.^2+(y+1).^2).^.5;
>>Z=(1./R);
>>surf(x,y,Z)
>>view(-37.5-90,30)
>>[x,y]=meshgrid(-1:.1:1,-2:.4:4);
>>R=(x.^2+(y+1).^2).^.5;
>>Z=(1./R);
>>surf(x,y,Z)
>>view(-37.5-90,30)
>>[x,y]=meshgrid(-1:.1:1,-2:.4:4);
>>R=(x.^2+(y+1).^2).^.5;
>>Z=(1./R);
>>surf(x,y,Z)
>>view(-37.5-90,30)
>>[x,y]=meshgrid(-2:.2:2,-2:.2:2);>>r1=(x.^2+(y-.5).^2).^.5;>>r2=(x.^2+(y+.5).^2).^.5;>>V=(1./r1)-(1./r2);
>>mesh(x,y,V)
>>view(-37.5-90,10)
>>colormap(hot)
>>mesh(x,y,V)
>>view(-37.5-90,10)
>>colormap(hot)
>>[ex,ey]=gradient(V,.2,.2);
>>quiver(x,y,ex,ey)
>>grid
>>[ex,ey]=gradient(V,.2,.2);
>>quiver(x,y,ex,ey)
>>grid
divergence
curl
customize graphs -subplotsIterate labels
Change styles
Integration technique
quad (func, xmin, xmax)dblquad (func, xmin, xmax, ymin, ymax)triplequad (func, xmin, xmax, ymin, ymax, zmin, zmax)
func = inline (‘x.*y.*z’)
func = inline (‘x’) quad (func, 0, 1)0.5000
movies
There are “.m” programs for all of the figures and examples that are included in the book “Fundamentals of Electromagnetics with MATLAB” on the class web page for 55: 070.
.m files • text editor or unix editor• !vi name.m• [esc] i ---- start typing• [esc] x ---- remove one letter• [esc] dd --- remove one line• [esc] r ---- change one letter• [esc] h ---- return to start• a - [esc] - [shift] zz ---- leave unix