Range FFT Peak Shifting Issue with Hamming Window in FMCW Radar Simulation

Hi,

I’m working on an FMCW radar simulation in MATLAB to generate the frequency plot of the Range FFT. However, I’m facing an issue where the detected peak is not aligning with the actual target range. Specifically, the peak is consistently detected at a shorter range than the actual target distance.

For example, when I simulate a target at 450 meters, the detected peak appears around 368 meters. Moreover, I’ve observed that as I increase the target range, the error (delta between actual and detected range) increases as well.

I’m using a Hamming window in the FFT processing stage. Could this be contributing to the range shift? Or is there something wrong in how I’m mapping frequency bins to distance?

Here are some details:

• I’m using a standard FMCW setup with linear chirps.
• The Range FFT is performed after mixing and low-pass filtering.
• Windowing is applied before performing the FFT.

Could anyone help me understand why this shift is occurring and how I can correct it?

Thanks in advance!