some questions about FM chirp source

[dushan1]

fm chirp

Is anybody can help me about the basic knowledge about FM chirp source ,or some examples about it. thanks!

 

[vfone]

FM chirp modulation is used in advanced radar, anti-jam electronic warfare, and similar system architectures.
In an FM-CW radar, a chirp signal is transmitted for certain duration. While it is transmitting, the echoes are received by the receiver and mixed with the transmit signal, and the result is low-pass filtered to produce a superposition of beat frequencies.
DDS is unquestionably the fastest switching technique for this application.
Check DDS applications from ADI or from other companies.

 

[dushan1]

thanks! but how to estimate the quality of a FM chirp.what is the key specification?

 

[dushan1]

how to design such a chirp
frequency rang :7600mhz~8400mhz
pulse width:100us
linearity:0.1%
step frequency:1hz
thanks

 

[dushan1]

I want to use ad9858,and a I Q mixer.but the pulse width is only 100us ,I can't generate the singal with 1hz step. only 64khz.can anybody tell me whether the dds step frequency will influence the chirp linearity.thanks!