5 A 0.5° - Resolution Hybrid Dual-Band Ultrasound Imaging SoC for UAV Applications

The key element for navigating an Unmanned Aerial Vehicles (UAV) is a lightweight yet high-resolution imaging system. Visible light 1 provides high-resolution imaging but lacks depth information and is severely impaired under low-light conditions. LiDAR 2 provides depth information and has long-range detection, but it is limited under foggy/complex lighting conditions. In contrast, an Ultrasound Imaging System (UIS) is not affected by lighting conditions and can provide depth information with less power and smaller form factor. However, conventional UISs 3–5 are only based on single-frequency scan, resulting in low resolution; consequently, only object existence can be detected, but not object shapes. This work presents a hybrid dual-band UIS SoC that has up to 7m detection range using 40kHz low-frequency (LF) mode and concurrently achieves high spatial resolution (0.5°) in 1m range using a 145kHz high-frequency (HF) mode (Fig. 6.5.1), with maximum throughput of 11.04Mvoxels/s.