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.