fourier series frequency spectrum

[gregoost]

what does the negative frequency means in a frequency spectrum.????does it have a physical meaning????or just a concept????

 

[LvW]

what does the negative frequency means in a frequency spectrum.????does it have a physical meaning????or just a concept????

No, it has no physical meaning.
It results only from introducing Eulers formula into the description of trigonometric functions. Each double-sided spectrum can be transferred to a single-sided spectrum by doubling the amplitudes.

 

[syeda amna]

In communication we always deal with double sided spectrum that is negative and positive. the amplitude is evenly distributed on positive and negative axis. this double sided spectrum comes from Eulers identity.
in actual negative frequencies are not exist. we just do it for doing mathematical analysis.

 

[bejoy]

while doing mathematical calculations using freq spectrum we use double sided spectrum..
its for ease of calculation...
physical existence of negative freq is a matter of debate.
but whn we find cos 90 = cos (-90) = 1.
it say there is an finite value for negative frequency...;-)

 

[LvW]

...............
but whn we find cos 90 = cos (-90) = 1.
it say there is an finite value for negative frequency...;-)

That's pure mathematics but no physics or electronics.
Negative frequencies do not exist in reality.

 

[bejoy]

LvW,

YA ofcourse i agree...

every thing -ve and imaginary are just imaginary...

but MAthematics is mother of all science...

bjoy

 

[deepuj]

You are right about negative frequencies... it is purely there for the ease of calculation.


Just for a healthy debate:
But even when Mathematics is the strongest tool to understand and analyze science... it can never be the mother of all sciences... It is just a tool...

Math always uses lots of approximations to do calculations... it just serves as a tool for us to comprehend the incomprehensible world of science!