High-voltage subnanosecond pulse transformer composed of parallel-strip transmission lines

A subnanosecond pulse isolation transformer composed of a parallel-strip transmission line was designed, constructed, and tested. The insertion loss and effective time constant of the transformer were calculated with transmission line analysis. To facilitate the analysis, the reflection diagram method was applied. The experiments indicate that the transformer can transmit subnanosecond rise time pulses across a potential difference of 100 kV with the low insertion loss of -2 dB. The measured time constant was about 17 ns which corresponded to calculated values. The validity of the analytical method is also discussed. (C) 1999 American Institute of Physics. [S0034-6748(99)03801-0].