Design of an ultra compact UWB pulse former

This paper presents the design of a compact monocycle pulse former (MPF) to be used as a shaping component in a polyvalent high-power ultra-wide-band source for field and lab applications. The described MPF was designed with a strong compactness constraint to comply with such embedded applications as UAVs or vehicle-mounted UWB systems. The architecture of the MPF was inspired by the one described in[1]. The MPF comprises a pulse sharpening assembly with a biconical peaking and an annular grounding spark gaps under a pressure of 6 MPa. The design allows an adjustment of the electrode distances within the range of 0.0-15 mm for the peaking switch and 0.0-3 mm for the grounding switch, without it being necessary to depressurize the vessel. The spark gaps are followed by a Blumlein pulse forming line in order to convert the monopolar pulse into a fast monocyle. The MPF is driven by compact, coaxial, modular ISL-Marx generators with rise times less than 25 ns and operating voltages up to 650 kV. The 50 ohms output of the MPF can be connected to the feeder of a TEM horn antenna designed at ISL. First experiments were performed. A rise time of 260 ps and an output power of 500 MW were obtained.