A low-cost sub-nanosecond trapezoidal pulse generator for radar imaging

Applications of Microwave Radar imaging based on UWB systems are increasing significantly and the need to design low-cost and efficient system components became vital. In this paper, a novel design for a low-cost baseband sub-nanosecond narrow pulse generator (NPG) is presented. This NPG suits microwave Radar imaging applications like object detection and through-the-wall detection. The design methodology was based on minimizing rise and fall times for the generated pulses in order to increase the bandwidth of the narrow pulse and hence the reconstructed image resolution. The proposed NPG generates clock pulses with the trapezoidal waveform of which duration time is 820 ps and fall time of 68 ps only. Simulation results on an object detection application proved that the trapezoidal pulse of the proposed NPG produced sharper and clearer image than that reconstructed from a Gaussian pulse of the same duration. In order to produce a similar quality, the Gaussian pulse width has to be reduced to about one-fifth of that of the NPG pulse.