SPRADU7 October   2026 AWRL1432

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Frequency Hopping Modulation of Millimeter-Wave Radar
  6. 3Waveform Configuration Flow of AWRL1432
    1. 3.1 Conventional Configuration Method of AWRL1432
    2. 3.2 Look-Up Table Configuration Method of AWRL1432
    3. 3.3 Detailed Explanation of Look-Up Table RF APIs
  7. 4Implementation of Frequency Hopping on AWRL1432
  8. 5Verification of Frequency Hopping Results
    1. 5.1 Preparation Work Before Data Capture
    2. 5.2 Data Acquisition Using DCA1000EVM with mmw_demo
    3. 5.3 Data Post-Processing
  9. 6Conclusion
  10. 7References

2 Frequency Hopping Modulation of Millimeter-Wave Radar

Millimeter-wave radar sensors often use FMCW (Frequency Modulated Continuous Wave) for modulation. A typical radar signal frame consists of multiple continuous and repetitive chirps; therefore, the range resolution Δd is determined by the bandwidth B of a single chirp. However, the sweep slope and sweep duration of a single chirp are limited, the value of bandwidth B is relatively small, and the theoretically calculated range resolution will also be relatively ambiguous. If the bandwidth of a single chirp is simply increased to improve range resolution, the chirp duration Tc will increase, and the measurable maximum velocity metric will also decrease.

To expand the effective bandwidth, users can gradually accumulate a fixed frequency offset Δf on the sweep start frequency of each chirp. Although the bandwidth of each chirp remains unchanged, the equivalent bandwidth of the entire frame is significantly stretched to B+nΔf. This strategy is called Stepped Frequency Continuous Wave (SFCW). The differences between SFCW and FMCW are shown in Figure 2-1. While increasing the bandwidth, the effective period Tc of the chirp does not change.

Waveform Differences between FMCW and SFCWFigure 2-1 Waveform Differences between FMCW and SFCW

The frequency hopping strategy SFCW will cause the target to generate an offset along the Doppler direction on the Range-Doppler heatmap. The offset distance is related to the frequency hopping frequency Δf and the target distance R. When the offset is too large, folding may occur in the Doppler dimension, while the target position (Index) in the range direction remains unchanged. During subsequent processing, additional processing steps and processing time are required to correct this offset.Figure 2-2 This illustrates the Range-Doppler map differences between FMCW and SFCW. From the heatmap, we can not only intuitively see the improvement in range resolution brought by SFCW, but the Doppler-direction offset and folding brought by frequency hopping are also displayed in the figure.

Range-Doppler Heatmap Differences between FMCW and SFCWFigure 2-2 Range-Doppler Heatmap Differences between FMCW and SFCW