ending the pulse. As in other charge-line generators, the pulse duration is equal to 2D/c, where D is the length of the individual transmission lines. A second advantage of the Blumlein geometry is that the switching device can be grounded, rather than located in the high-voltage side of the transmission line as in the typical charged line, which complicates the triggering electronics. Uses of PFNs Upon command, a high-voltage switch transfers the energy stored within the PFN into the load. When the switch "fires" (closes), the network of capacitors and inductors within the PFN creates an approximately square output pulse of short duration and high power. This high-power pulse becomes a brief source of high power to the load. Sometimes a specially designed pulse transformer is connected between the PFN and load. This technique improves the impedance match between the PFN and the load so as to improve power-transfer efficiency. A pulse transformer is typically required when driving higher-impedance devices such as klystrons or magnetrons from a PFN. Because the PFN is charged over a relatively long time and then discharged over a very short time, the output pulse may have a peak power of megawatts or even terawatts. The combination of high-voltage source, PFN, HV switch, and pulse transformer (when required) is sometimes called a "power modulator" or "pulser". See also Pulse (signal processing) Pulse generator Pulsed power Thyratron Thyristor Triggered spark gaps Marx generator Crossatron Pulsed laser Radar References External links Eric Heine, "Conversion". NIKHEF Electronic Department, Amsterdam, The Netherlands. Riepe, Kenneth B., "High-voltage microsecond pulse-forming network". Review of Scientific Instruments Vol 48(8) pp. 1028–1030. August 1977. (Abstract) Glasoe, G. Norris, Lebacqz, Jean V., "Pulse Generators", McGraw-Hill, MIT Radiation Laboratory Series, Volume 5, 1948. Pulsed power