A 0.1–4.0-GHz Inductorless Direct-Sequence Spread-Spectrum-Based Ground-Penetrating Radar System-on-Chip

This letter presents a 0.1-4.0-GHz broadband serial direct-sequence spread-spectrum (DS/SS)-based inductor-free ground-penetrating radar (GPR) system-on-chip (SoC). A time-domain digital correlation-based time-of-flight measurement is employed for radar ranging instead of using a frequency chirp or pulse, which allows a higher degree of flexibility. With no conventional RF up/down conversion present, the radar offers complete programmability over frequency and bandwidth (BW) up to 4.0 GHz. In-field GPR test with actual rover prototype is performed to validate the capability and characterize the overall performance of the DS/SS radar system. Implemented in 28-nm CMOS, the demonstrated prototype radar SoC offers a fine resolution of 3.75 cm and consumes 46.2 mW from 1-V supply. This makes it suitable for low-power applications such as planetary exploration.