I want to make a LFM (chirp) signal generator which will generate 4 different frequency LFM pulses.
Any suggestions what hardware I can use to design it? I wanted to use MAX4725 DAC, but now I find out it can't work with high frequencies.
I guess I have to use VCO PLL circuit connected to Atmega with DAC but designing it will make things even more complicated.
Any recommendations?
Thanks in advance.

 

Don't you think it might be useful to let people know what frequencies you are trying to work with, especially since you've already established that it is an issue that precludes some of the devices you've considered?

 

As already said, you need to be more specific about your requirements: eg centre freq, bandwidth, pulse width, etc before we can give any meaningful suggestions.

For the unintiated, LFM = linear freq modulation, defined as where the 'instantaneous' frequency, or, more accurately, the rate of change of phase, changes linearly across the pulse width.