frequency ulation

hello,i am trying to make a receiver for frequency modulated continous wave radar system and my problem is how i can detect frequncy of mixer output to calculat range of target

Answer 1

[Honglei Chen]

You can do an FFT to the output of the mixer to find the beat frequency. You can then convert beat frequency to the range using the equation associated with FMCW waveform. You can find the equation itself in Skolnik's Introduction to Radar Systems, either 1st or 2nd edition.

[mohamed al-asklany]

sir , i know the equation but how i can get freq. from fft please give an example

[Honglei Chen]

http://www.mathworks.com/products/matlab/demos.html?file=/products/demos/shipping/matlab/fftdemo.html

To automate the peak finding process, you can consider using findpeaks function in Signal Processing Toolbox.

doc findpeaks