Why do I want this? When a 24GHz radar signal hits an object that has a relative velocity, the frequency of the signal will shift by a frequency on the order of kilohertz. I want to create this process of frequency shift electronically.
I receive a 24GHz(100MHz bandwidth) signal from the antenna. I want to shift the frequency by something on the order of kilohertz (from -4kHz to +4kHz).
(the carrier signal is 24GHz, I want to turn it into what it would have been, had the carrier frequency been 24.000004Ghz)
I have a few ideas:
(+4kHz here is just an example, it could be anything between -4kHz and +4kHz)
I will put the received signal to LO. Put cos(2pi 4kHz t) and -sin(2pi 4kHz t) to IF1 and IF2 ports. Does this have any chance of working? Would it cause problems to put a 100MHz bandwidth signal to a LO port?
Another idea is: I can demodulate it by, say 20GHz. Put 20GHz to the IQ modulator I posted above and shift it above by putting cos(2pi 4kHz t) and -sin(2pi 4kHz t) into IF1 and IF2. And then modulating the signal by 20.000004GHz.