A millimicrosecond pulse-generator tube

This paper describes the theory and testing of a 100- Mc repetition-rate millimicrosecond pulse-generator tube utilizing klystron bunching. The optimum operation of the generator was obtained with a drift-tube transit angle Θ0of approximately 150°; depth of modulation\alpha = V_{1}/V_{0} = 1; and the reduced plasma-angle\Phi_{q}was less than 20°. Observations and data were determined with an Edgerton, Germeshausen and Grier traveling-wave oscilloscope and a comparison measurement technique. The generator has a measured pulse rise time of 130 µµsec (0-100 per cent), and a pulse duration of 300 µµsec at the half-voltage point. A pulse height of 20 volts on a 50-ohm coaxial line is possible. The analysis applied in predicting the shape of the pulse was based on large signal ballistic bunching theory and a quantized collector gap theory. A comparison between analysis and measurement indicates an error of about 20 per cent. Theory predicts that little improvement can be made in the pulse duration, but the pulse rise time may be improved with increased circuit complexity.