What'a difference between TEM wave and plane wave?

[baby_1]

Hello
what'a difference between tem wave and plane wave?
I think in tem is the same as plane wave but it's electromagnetic amplitude decrease ,is it right?if yes how does amplitude decrease?

 

[berkeman]

Hello
what'a difference between tem wave and plane wave?
I think in tem is the same as plane wave but it's electromagnetic amplitude decrease ,is it right?if yes how does amplitude decrease?

What makes you think they are different? What definitions have you found in your reading?

 

[baby_1]

Hello
Thank you for your response
because of different reasons:
1)if they are the same why we use different definition
2)when we want to derive helmholtz equation we declare it for Plane wave not TEM
3)if they are the same why we tell them in some transmission line(such as coaxial) TEM not plane wave

any help would greatly appreciate

 

[berkeman]

Hello
Thank you for your response
because of different reasons:
1)if they are the same why we use different definition
2)when we want to derive helmholtz equation we declare it for Plane wave not TEM
3)if they are the same why we tell them in some transmission line(such as coaxial) TEM not plane wave

any help would greatly appreciate

I'm not familiar with any differences. This entry at wikipedia implies they are the same: http://en.wikipedia.org/wiki/Wave_impedance

Can you post a link to the Helmholtz equation reference that seems to make a distinction?