Signal Modulation

  • #1
How come a signal modulated using Amplitud Shift Keying and/or Phase Shift Keying (such as QAM) require a bandwidth? I mean, since the frequence is constant; only the amplitude and phase is changed.

Thanks in advance!
 

Answers and Replies

  • #2
NoTime
Science Advisor
Homework Helper
1,568
0
LostInSpace said:
I mean, since the frequence is constant
It is not constant! The slope dV/dT changes from that of the unmodulated sine wave. This means that for a small periods of time it is different frequencies.
 

Related Threads on Signal Modulation

  • Last Post
Replies
6
Views
4K
  • Last Post
Replies
3
Views
820
  • Last Post
Replies
3
Views
10K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
2
Views
3K
  • Last Post
Replies
5
Views
7K
  • Last Post
Replies
19
Views
2K
  • Last Post
Replies
4
Views
1K
  • Last Post
Replies
4
Views
3K
Top