Description

mmWave radar operates in the 30–300 GHz band — typically 60 GHz (consumer Wi-Fi-band radar like Soli) or 77 GHz (automotive-derived TI / NXP chips). Short wavelengths give very fine range and angle resolution, and chest-wall vital-sign sensitivity unmatched by sub-6 GHz CSI. The trade-off is short coverage and severe wall attenuation, which makes mmWave radar a complementary modality to WiFi-CSI rather than a replacement.

When it's used

  • High-resolution gesture / micro-movement sensing
  • Vehicle-cabin occupancy and vital-sign monitoring
  • Single-room high-resolution HAR
  • Reference for CSI sensing accuracy benchmarks

Limitations

  • Severe attenuation through walls and furniture
  • Coverage limited to a few metres
  • Cost vs commodity Wi-Fi

Source Papers

  • ren2023_8cfe — mmWave radar primer
  • cakoni2023_7150 — mmWave radar HAR
  • sakhnini2024_de9b — mmWave people counting
  • ullmann2023_0ac3 — mmWave HAR comparison