نبذة مختصرة : We develop a compact ultra-wideband (UWB) ground-penetrating radar (GPR) transmitter that extends the bandwidth of a low-cost, lightweight arbitrary waveform generator (AWG) to improve imaging resolution. Two transmitter architectures are explored: a non-linear transmission line (NLTL)-based transmitter, which enhances bandwidth through pulse shaping, and a stepped-pulse transmitter, which synthesizes an equivalent 13 GHz bandwidth by sequentially modulating pulses across multiple carrier frequencies.The NLTL-based transmitter compresses the pulse width of a 2.5 GHz AWG-generated signal, expanding its 20-dB bandwidth to 8.3 GHz through non-linear pulse sharpening. Further, a digital pre-distortion (DPD) algorithm is applied through the AWG to minimize distortion and improve pulse fidelity. The stepped-pulse transmitter achieves an equivalent 13 GHz bandwidth, and an adaptive weighting technique is applied during imaging to emphasize frequency-dependent features, improving target visibility at varying depths.Beyond hardware development, software-defined radar (SDR) techniques are explored to leverage an AWG's flexibility for GPR applications. This includes dual-pulse transmission, which optimizes imaging performance by leveraging the benefits of both high- and low-frequency pulses simultaneously, and frequency-modulated continuous wave (FMCW) radar, which demonstrates multi-mode operation within a single system.We validate these approaches by evaluating both transmitters in a controlled laboratory sandbox environment. Imaging results demonstrate significant improvements in resolution and target detection, confirming the benefits of bandwidth expansion and waveform flexibility. Finally, the NLTL-based transmitter is integrated into a fully functional, lightweight, compact GPR system, demonstrating the feasibility of combining high-bandwidth transmission with software-defined adaptability for field-deployable GPR applications.
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