I trying to develop a FMCW Radar application using the ADF4159 PLL. Using this PLL, I'm generating a sawtooth waveform which looks like below image(taken from the ADIsimPLL software when I was analyzing whether the ramp generation is meeting my specifications are not)
As you can see, when ramp reached the final step it fell rapidly but the next ramp is starting from somewhere 9.375GHz instead of desired start freq., which is 9.385GHz. Though surprisingly, the ramp is covering a range of 30MHz and ending at 9.415GHz, which is a desired specification.
Using the spectrum analyzer, the sawtooth ramp generation from PLL looked like below image
which I believe is not suitable in a Linear FMCW Radar application.
My questions are as follows
- Is it possible to eliminate the frequency component (highlighted in the above image)?
- If the answer is no for the above question, does that frequency component has any affect on target range detection?
- Looking at 2nd image, what are your thoughts on using that signal in FMCW radar application? Is it a good practice?
- If possible, please enlighten on Linear FMCW and how can one use ADF4159 PLL is such Radar application?
Thanks in advance.
*2nd image not suitable in a Linear FMCW radar application.
[edited by: geeth_anurag_uts at 3:23 PM (GMT -4) on 31 Mar 2022]