why EM wave can not be radiated from the open end of transmission line?

[xuexucheng]

why EM wave can not be radiated from the open end of transmission line?

The open end has vary electro field.

I think vary electro field can generate vary megnetic field. and continue!

Thank you!

 

[redcrystalline]

hi, its matter of impedance miss match , for open end return loss is equal to 1 and therefore nothing radiate is'nt?

 

[FvM]

An open transmission line of non-zero diameter will surely radiate EM waves, as long as an electromagnetic field extents into open space. The efficiency depends on the cable diameter to lambda ratio.

 

[xuexucheng]

how much will be radiated?
why it can totally radiated?

 

[jiripolivka]

Radiation from the open waveguide is possible, and it is a complex function of waveguide type, the field distribution in it, and the wave length. It also depends on external medium properties, so the open-end structures are often used as sensors.
Check Wikipedia and good textbooks on electromagnetics on details.

 

[xuexucheng]

Radiation from the open waveguide is possible, and it is a complex function of waveguide type, the field distribution in it, and the wave length. It also depends on external medium properties, so the open-end structures are often used as sensors.
Check Wikipedia and good textbooks on electromagnetics on details.

But how to explain this using Maxwell equations intuitively?

Thank you a lot!

 

[FvM]

1. Consider a TL with open end
2. Sketch the E field lines
3. Imagine the coupling with H-field

 

[jiripolivka]

I never solved the Maxwell equations "intuitively". The problem of an open line end is the boundary-definition problem, not the equations, BTW.

 

[xuexucheng]

I never solved the Maxwell equations "intuitively". The problem of an open line end is the boundary-definition problem, not the equations, BTW.

Thank you very much for your reply.
Could you explain the detail of your boundary-definition problem?
I can not understand intuitively. I think the Maxwell equations are the basic principle of the EM.