Electromagnetic Theory55:070

Professor Karl E. Lonngren[lonngren@eng.uiowa.edu]

4312 SCoffice hours: 12:30 – 1:15 MWF

Demonstration in 2005

207 CC

TA: Qiao Hu1313 SC qiao-hu@uiowa.edu

Text: “Fundamentals of electromagnetics with MATLAB” 2nd edition/2nd printing SciTech Press

Grading 2 exams @ 100 -------- 200Final exam ---------------- 150Homework ---------------- 50Total ----------------------- 400

Arthur Andersen

who was recently

fired by the Enron

Corp. will audit the

scores and the

addition.

Work together?

Assignments

This is what happens to someone who does not want to learn

electromagnetic theory!

EM Theory• MATLAB & vectors

• static em fields

• mathematics & MATLAB

• Maxwell’s equations

• electromagnetic waves & MATLAB

• transmission lines & MATLAB

• radiation & antennas & MATLAB

example

This course will not be

one of those!

http://www.jsonline.com/story/index.aspx?id=641947

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• more MATLAB information on the CD

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

• 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 - addition

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

• d = cross (a,b)• d = • 0 0 1

• e = cross (b, a)• e =• 0 0 -1

vectors - cross producta = 1ux + 0uy + 0uz ==> a = [1 0 0];b = 0ux + 1uy + 0uz ==> b = [0 1 0];

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’)

Add to the graph> clear;clf> x=0:.1:4*pi;> plot(sin(x),'linewidth',3)> hold on> plot(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

>>[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(-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)

>>[ex,ey]=gradient(V,.2,.2);

>>quiver(x,y,ex,ey)

>>grid

customize graphs -subplots

Change styles

Iterate labels

-The figures and the examples in the text-Additional programs may be added on an irregular basis

Government regulation may be required such as stop

signs, stoplights, etc.

Babies knows something!