Accession Number : ADD011108

Title :   Universal Control Grid Modulator.

Descriptive Note : Patent,


Personal Author(s) : Miller,D G

Report Date : 12 Jun 1984

Pagination or Media Count : 9

Abstract : High voltage FET's (Field Effect Transistors) are used to modulate a traveling wave tube, which makes it possible to achieve fast rise, fall and delay characteristics, and very long pulsewidths to CW because of their low drive requirements to maintain the on condition. The low and high voltage portions of the modulator are coupled via special transformers having only one or two turns for each winding on torroidal cores. Since such transformers are not adequate for long pulse widths, the gate to source capacitance of a high voltage FET is charged with a short pulse from one transformer and held there by a blocking diode until it is removed by the off drive. To obtain pulse widths all the way out to CW, a regeneration circuit is incorporated in the low voltage circuitry so that if the commanded on time goes beyond a maximum time, successive pulses are generated to maintain the voltage between gate and source of the on FET. (Author).

Descriptors :   *Patents, *Modulators, *Field effect transistors, *Traveling wave tubes, Pulse duration modulation, High voltage, Continuous waves, Low voltage, Pulse rate, Drives, Short range(Distance), Regeneration(Engineering), Gates(Circuits), Requirements, Winding, Delay, Transformers, Global, Sources, Capacitance, Diodes, Blocking

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE