An avalanche transistor-based nanosecond pulse generator with 25 MHz repetition rate

TL;DR

This paper presents a high-repetition-rate nanosecond pulse generator based on avalanche transistors, suitable for synchronized low-light imaging applications, with improved power handling and pulse characteristics.

Contribution

The authors introduce a novel avalanche transistor circuit that achieves high repetition rates and overcomes power dissipation limits for imaging applications.

Findings

Produces flat-top pulses with 2 ns rise time and 10 ns FWHM.

Operates at tens of MHz repetition rate.

Enables synchronized imaging at low light levels.

Abstract

We have developed an avalanche transistor-based pulse generator for driving the photocathode of an image intensifier, which comprises a mainly capacitive load on the order of 100 pF. The circuit produces flat-top pulses with rise time of 2 ns, FWHM of 10 ns and amplitude of tens of V at a high repetition rate in the range of tens of MHz. The generator is built of identical avalanche transistor sections connected in parallel and triggered in a sequence, synchronized to a reference rf signal. The described circuit and mode of operation overcome the power dissipation limit of avalanche transistor generators and enable a significant increase of pulse repetition rates. Our approach is naturally suited for synchronized imaging applications at low light levels.