Design of an ultra‐wideband picosecond pulse generator based on step recovery diodes with an improved SPICE model

Abstract

SummaryThis article proposed an ultra‐wideband ultra‐short picosecond pulse generator based on step recovery diodes (SRDs). The equivalent circuit model of SRD is analyzed, and an improved nonlinear simulation program with integrated circuit emphasis (SPICE) model is presented for appropriate circuit simulation in Advanced Design System (ADS) software. An external direct current (DC) voltage source is added to bias the SRD. In this article, a conventional shunt SRD topology configuration is developed to generate the Gaussian pulse. According to the measured data, the Gaussian pulse duration for the shunt SRD pulse generator is 210 ps, with the full width at half‐maximum (FWHM) of 110 ps, and the ringing level is −7.8 dB. Moreover, to further improve the tail ringing level, an SRD's mixed topology configuration is introduced and fabricated. The experimental results indicate that the two SRD mixed pulse generator has a pulse duration of 220 ps with FWHM of 120 ps, validating the reasonability of the improved SRD nonlinear SPICE model in ADS. Additionally, there is a considerable improvement in the ringing level of −11.4 dB.