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What's negative frequency?

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hmsheng

hmsheng

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In the following paper, on page 4:
**broken link removed**

It is said:

In ideal case, the spectrum of the complex LO should consist of a single tone (positive LO in this case); the mismatch of the LOs generates a small negative LO component.

How to understand this?
 

A +ve frequency sinewave can be represented as a counterclockwise rotating vector in the complex plane. A -ve frequency sinusoid will be represented as a clockwise rotating vector in the complex plane.

You can read more on complex signal processing in K. Martin's paper:
complex signal processing is not complex
 

    hmsheng

    hmsheng

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hmsheng said:
In the following paper, on page 4:
**broken link removed**

It is said:

In ideal case, the spectrum of the complex LO should consist of a single tone (positive LO in this case); the mismatch of the LOs generates a small negative LO component.

How to understand this?
Click to expand...

I don't understand too, but the mismatch must reduce the image rejection.
So the negative LO component may be the difference of I/Q path.
 

Hi,

See the attachment on describing the negative frequency.
 

    hmsheng

    hmsheng

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mbyoussef said:
A +ve frequency sinewave can be represented as a counterclockwise rotating vector in the complex plane. A -ve frequency sinusoid will be represented as a clockwise rotating vector in the complex plane.

You can read more on complex signal processing in K. Martin's paper:
complex signal processing is not complex
Click to expand...

Can someone provide me the paper?
complex signal processing is not complex
 

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