How bandwidth depends on transmission line or channel?

[mannu2612]

While reading a book over information theory i came across with a statement that "due to some physical limitations communication channels have finite bandwidth".But i don't quite understand what kind of limitation can affect the bandwidth and even if it does then how? So anyone please clear me this. :?:

 

[emresel]

Hi;
Consider a coaxial cable, there are two conductors, outside shielding and inside dataline. Between them there is isolator. This is a simple capacitor. And any capacitor filters/distorts after a certain frequency range (consider reactance of a capacitor 1/wC). This parasitic capasitor determines your channel bandwidth. Above those frequencies your data will be highly distorted and cannot be recovered. So your signal bandwith should be within the channel bandwitdth.

Hope clears your mind.

 

[mannu2612]

Hi;
Consider a coaxial cable, there are two conductors, outside shielding and inside dataline. Between them there is isolator. This is a simple capacitor. And any capacitor filters/distorts after a certain frequency range (consider reactance of a capacitor 1/wC). This parasitic capasitor determines your channel bandwidth. Above those frequencies your data will be highly distorted and cannot be recovered. So your signal bandwith should be within the channel bandwitdth.

Hope clears your mind.

For coaxial cable its clear but what about hollow waveguides and other channels? Plz help with this as well.

 

[dot4]

Hello,

bandwidth in a hollow waveguide is limited by the cutoff frequency of the first higher mode. If you exceed this frequency you are having at least two modes that are superimposed and thus deteriorates your signal. With increasing frequency, more and more modes are allowed to propagate....