Period of a complex exponential signal

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SUMMARY

The discussion centers on determining the period of a complex exponential signal defined as x(t) = ejωt. The user derived the general period expression T = 2πk/ωn, demonstrating that multiple values for T can be obtained based on integer selections for k and n. This leads to confusion, as a signal should have a unique period. The conclusion emphasizes that while multiples of the fundamental period can exist, only the smallest value should be recognized as the true period of the signal.

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  • Understanding of complex exponential functions
  • Familiarity with signal periodicity concepts
  • Knowledge of integer properties in mathematics
  • Basic grasp of angular frequency (ω)
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  • Study the properties of complex exponential signals in depth
  • Learn about the concept of fundamental frequency and its relation to period
  • Explore the implications of integer multiples in signal processing
  • Investigate the mathematical foundations of periodic functions
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Electrical engineers, signal processing students, and anyone involved in analyzing periodic signals will benefit from this discussion.

lahanadar
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I have a simple complex exponential signal of the form x(t)=ejωt. To find period of the signal I tested if x(t)=x(t+nT) for all n:

ejωt=ejω(t+nT) ⇒ ejωnT=1=ej2πk

where n and k are integers. Then I find a general period expression as

T=2πk/ωn​

Period T means it is the least time a signal repeat itself. As an example, pick k=1, n=1, then T1=2π/ω. Now pick k=3, n=2, then T2=3π/ω. These two periods seem valid for the same signal x(t) in contrary it shouldn't, since a signal should have only one period. Am I missing something here?
 
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If x(t)=x(t+nT) for all n, then x(t)=x(t+nT)=x(t+n(2T)) for all n by using the same step twice. If T is a period, then 2T is a period as well, and 3T and so on. Usually, just the smallest value is called period of a signal.
 

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