An antenna array and four semiconductor based sub-ns sources, each of about 1 kHz repetition rate, 30 kV output voltage and 120 ps rise time, build a scalable ultrawideband system. One fully synchronized pulse or pulse sequences consisting of four pulses with predefined delay T are measured. The appropriate spectral distributions of electrical field pulse sequences are compared to signal theoretical calculations. As a consequence of these calculations, pulse sequences affect, even enhance, the spectral electrical field strength at 1/T. The influence of the variable spectral field distributions on electronic circuits is experimentally demonstrated