Question about single tone signals

[mazen_zone]

what is the bandwidth of single tone signals?

taking the F.T. for a cosine signal gives a delta at the signal's frequency, so does it mean that its bandwidth is zero since it is occupying only a single freq. in the FD.

 

[berkeman]

what is the bandwidth of single tone signals?

taking the F.T. for a cosine signal gives a delta at the signal's frequency, so does it mean that its bandwidth is zero since it is occupying only a single freq. in the FD.

You get deltas at both the positive and negative frequencies, right? And yes, I believe it would be correct to say that an infinite tone has zero BW.