bluetooth interference 2009

Hi,

What's the "image frequency interference" and "Adjacent (1 MHz) interference to in-band image frequency" in bluetooth standards?

thanks!

Yubing

http://en.wikipedia.org/wiki/Image_frequency
http://en.wikipedia.org/wiki/Adjacen...l_interference

Thanks!

But if i use low IF architecture, how image frequency go into the in-band?

thank you very much

Imagine that you use a 1 MHz IF freq and you want to receive 2420 MHz.

You set your LO to 2421 MHz, for example.

If an interferer appears at 2422 MHz, it will be downcoverted to 1 MHz in the IF strip and will be rejected by the amount of image rejection (that is dominated by inaccuracy of I/Q LO phase).

I hope this is clear enough.

Max

In Low-IF receiver, generally the image frequency is converted to IF frequency nears the channel bandwidth. The image can be rejected at IF using a band-pass filter. If the IF represents the Adjacent Channel of the receiver you get maximum suppression of Adjacent Channel Interferer.

Thanks Mazz! It's so clear.
But I still don't understand "Adjacent (1 MHz) interference to in-band image frequency" .