Design of a High-Power Gaussian Pulse Transmitter for Sensing and Imaging of Buried Objects

This paper aims to investigate a high-power and low-cost monopulse transmitter circuit for underground and underwater sensing and imaging. The transmitter utilizes two Marx transistor-based pulse generators, a balun, and a Vivaldi antenna. A simple output network, including an inductor and Schottky diode, is employed to compensate for the ringing level and distortion and improve the pulse width. The ringing level of the developed circuit is around 6 percent. The output is a Gaussian pulse with pulse width and amplitude of 481 ps and 50 V, respectively. In order to have a high amplitude monopulse, an exact replica of this network in parallel is exploited. The outputs of the parallel circuits are subtracted through the balun to have a dc-free monopulse with amplitude and pulse width of 26 V and 483 ps, respectively. The monopulse is radiated by a Vivaldi antenna toward a buried object. The image of the target is generated using the time-domain global back projection (TD-GBP) method. Three imaging experiments are conducted to verify the functionality of the designed sensor system. The reconstructed images and the reference images are shown high structural similarity indexes of 98.6%, 95.4%, and 97.6%.