Research And Development Of A High-voltage Picosecond Pulse Generator For Biological Applications

Picosecond electric pulse with impulse radiating antenna attracts researchers'strong interest in the non-invasive diagnosis and treatment field for its excellent direction and precision controllability. But the existing picosecond pulse generator is due to the restrictions of switches and other components, its output picosecond pulse amplitude is Limited and can not produce high-intensity picosecond pulse signal, limiting its application.In this paper, a kind of high-voltage picosecond pulses has been obtained through the processing of front steep and tail cut on the Marx generator according to the related pulsed-power principle about nanosecond and picosecond pulse generation. The simulation and test results show that the picosecond pulse generator designed by the author can produce the high-voltage picosecond pulse signal with peak-to-peak value of 31.85 kV, less than 250 ps rising edge and 600 ps pulse width, which has been proved to be discharge stable and reproducible and can be used as an ideal signal source of impulse radiating antenna. These support the solid foundation for the non-invasive treatment based on the target-based high-intensity picosecond pulse.First, this paper describes the picosecond high-voltage pulse generator how to work and methematically analyzes some key components, namely Marx generator and steep switch-based equivalent circuit model. On this basis, the generator device equivalent circuit model with few parameters was established. Besides, difficult issues in the development process were discussed, respectively. The major units of generator were designed reasonably. Marx generator have many fine characteristics, such as smaller size, compact structure, 11 ns output pulse risinging edge, high-voltage nanosecond pulse signal with the 20 kV amplitude. The peaking switch clever use of stray parameters between components,and formed peaking capacitance and minimized the introduction of stray inductance. The design on tail-cut switch and coaxial load maximize the introduction of stray inductance at the same time to meet the function. The main components of the generator circuit model have been simulated combined with PSpice simulation software. The simulation results verify the theoretical feasibility of the program.Coaxial capacitive divider design is smart and reasonable avoiding the wiring inductance and improving the measurement system bandwidth. At the same time according to the divider measurement principle, the measurement system was designed to meet measurement requirements of a picosecond high-voltage pulse signals. The output pulse waveform shapes were actually measured using the picosecond high-voltage pulse generator designed in this paper at atmospheric pressure and in the inflated state of Marx generator switches, respectively. Experimental results and theoretical analysis of mutual authentication, further evidence of the generator device developed in this paper is consistent with the design requirements, and meet the actual needs.Finally, this paper did try for the ultra-wideband antenna technology applied in the biomedical treatment. The impulse radiating antenna (IRA) as the load, the test results were analyzed through testing pulse output waveform in conjunction with the antenna work principle.