plane waves in a lossy material

x y z E H Poynting’s theorm k x y z E k Poynting’s theorm H

we cannot neglect the conduction current

Waves in metal

copper @ f=10 GHz

Reflection and transmission coefficients

Reflection and transmission of a pulse signal at an interface of two different dielectrics.

boundary conditions for time-varying fields normal D differ by a surface charge density tangential E is continuous normal B is continuous tangential H differ by a surface current density

E H E H Why? E H

Etan is continuous E E Htan is continuous X H E H H

Reflection coefficient X E H Transmission coefficient

impedance meter conductor

Reflection of an electromagnetic pulse from a conducting surface.

Special cases short matched open

two materials X E H

Reflection coefficient for wave from left Transmission coefficient for wave from left

F 22 Special cases matched

How to avoid a speeding ticket while driving a bulldozer through University Heights!

“time of flight” = DT EM pulses @ dt intervals

“stealth bulldozer”

There is a new McDonald’s in Ames, Iowa on the Iowa State University campus