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Venkatachalam, Anbu Selvam

Electrical Engineering

2013

MS

This work presents the development of a new air coupled Ultra-Wideband (UWB) Ground Penetrating Radar (GPR) for evaluating highway pavement and bridge deck subsurface conditions. Most of the existing highway GPRs are single channel systems, bulky and operate with low survey speed, making highway pavement and bridge deck survey a cumbersome process and creating traffic disturbances. In this project, a compact high-speed GPR system is developed with radio frequency (RF) front end circuit integrated in a single circuit board that can be easily installed at the bottom of a truck to allow survey at normal highway driving speed (~ 60 mph) and high evaluation resolution.
Primary focus of this project is the RF circuit development of a performance enhanced Gaussian pulse generator using step recovery diode that can generate UWB Gaussian pulse over a wide range of repetition frequency. An integrated Field-programmable Gate Array (FPGA) based control system is designed to switch between multiple channels in real-time, and to synchronize UWB pulse generation, high-speed sampling data acquisition unit and other peripheral devices. For design validations, rebar detection experiments in different setups are conducted under laboratory conditions and in the field.