Want to find more information on Baseband chip

[lowkb]

Hi all, i am looking around for baseband information recently. this baseband im refering to the baseband chip to be interface with the RF chip. I wanna find out more on this area. however dun seems to find much useful material with the basic of baseband chips. i would like to know things like why are baseband chip needed? what are the functions and what are its blocks like...

i have a rough idea that the blocks will include the ucontroller, DSP core and the RF interface. what are its topology if any, and what other tpes of basband chips are there?

Hope you can give me a link to some of this information so i can learn more and hopefully do a writeup...

Thanks in adnvance...

 

[Papabravo]

I'm not exactly familiar with what you are talking about. Baseband is a generic term used in data communication networks to describe any signaling method that occupies the frequency spectrum from DC to some upper limit.

So for example RS-232 at 9600 baud is an example of baseband signaling. One of the ethernet variants refered to as 10Base-T is another example of baseband signaling.

What the RF deck will do is to mix a baseband signal with the output of a local oscillator. The circuit block called a mixer takes two signals in and produces four outputs. If the two inputs have frequencies f1 and f2 then the output will contain signals at f1, and f2, and f1 + f2, and f1 - f2. Either the mixer itself or subsequent filter stages can remove unwanted components.

I think the answer to your question is, yes a baseband chip is required to create the modulationg signal that is sent to the RF chip.

The information you gave was kinda vague so this answer could be off the mark. Could you tell us what kind of system we are talking about, maybe give us some part numbers or manufacturers application notes?