Design of ultra-wideband Gaussian pulse source for ground penetrating radar

The pulse source is the hard-core in ground penetrating radar(GPR), whose high voltage and ultra-wideband assure surveying depth and accuracy. Besides that, the smoothness and stability of pulse waveforms also affect imaging quality. Avalanche transistors are chosen in the Marx circuit to produce unipolar pulses. Improving methods are put forward to remove the unsmoothness of pulse waveforms. Microstrip line is placed at the end of the circuit, and delay time occurred in it makes signals to be bipolar. Comblike PCB is available to minimize the pulse source. The measured results show that the width between minus peak and plus peak is 1.64 ns, the voltage value is 812 V (50 load resistance), and the trailer is less than 10% of the whole voltage value, which match the simulation results very well. The pulse source could meet the requirements of GPR.