Design of frequency-domain ground penetrating radar system based on microcontroller

To address limitations in resolution and dynamic range of traditional ground penetrating radar (GPR) for deep-layer medium detection, this study proposes a large-depth frequency-domain GPR system based on an STM32H7 control architecture. The system utilizes an AD9910 digital frequency synthesizer to generate programmable stepped-frequency continuous wave (SFCW) signals (20–122.4 MHz) with peak power exceeding 5 W for continuous-wave excitation. An ADS1256 multi-channel synchronous sampling module (dynamic range >120 dB) quantizes echo signals, combined with a customized wideband air-coupled antenna to achieve low-loss coupling and suppress near-surface interference. Experiments on layered medium models demonstrate: In soil with relative permittivity εr = 9, the system achieves a maximum detection depth of 15 m. Compared to conventional time-domain impulse radars, the system exhibits an 18.3 dB dynamic range improvement in bedrock-soil interface detection. This innovation provides a high signal-to-noise ratio, low-power solution for UAV-borne GPR applications in engineering geological surveys.