Subnanosecond-pulse generator with variable pulsewidth using avalanche transistors

The letter describes a pulse generator with epitaxial silicon planar transistors working in the avalanche-breakdown mode. The risetime is 150 ps and the fall time 200 ps. The pulse-width can be varied continuously between 0.3 and 120 ns, without changing the maximum amplitude of about 15 V. Simple rules for the exact design of the circuitry are given.