Signal excited by square wave

[faen]

Homework Statement

11. What kind of frequency components can be observed in the output if a linear system is excited by a symmetric square wave?

12. What kind of frequency components can be observed in the output if a non-linear system is excited by a symmetric square wave?

Homework Equations

I have no idea

The Attempt at a Solution

Well, all I was given to answer this problem was the following wikipedia page about Fourier transforms http://en.wikipedia.org/wiki/Fourier_transform. I still feel that I am not sufficiently informed to answer these questions.

I have a test about this in an hour so I please hope somebody can help me out. Thanks a lot.

 

[berkeman]

Homework Statement

11. What kind of frequency components can be observed in the output if a linear system is excited by a symmetric square wave?

12. What kind of frequency components can be observed in the output if a non-linear system is excited by a symmetric square wave?

Homework Equations

I have no idea

The Attempt at a Solution

Well, all I was given to answer this problem was the following wikipedia page about Fourier transforms http://en.wikipedia.org/wiki/Fourier_transform. I still feel that I am not sufficiently informed to answer these questions.

I have a test about this in an hour so I please hope somebody can help me out. Thanks a lot.

Well, what is the frequency spectrum of a symmetric square wave? What harmonics are present, and how do they fall off with frequency?

When you have a linear system, what does that mean in terms of how it can affect the fundamental and the harmonic components?

And if you have a non-linear system (think of a diode in the circuit), what can you say about what can happen to the fundamental and the harmonics, in terms of amplitude and frequency effects?