Hiroshi Honda

Author:

Hiroshi Honda

ISBN #:

4589029480

Author:

Hiroshi Honda

ISBN #:

0791800253

Author:

Hiroshi Honda

ISBN #:

0791801527

Author:

Hiroshi Honda

ISBN #:

0791819019

Author:

Hiroshi Honda

ISBN #:

0791836304

US Patent:

47976268, Jan 10, 1989

Filed:

Aug 29, 1986

Appl. No.:

6/902270

Inventors:

Hiroshi Honda - Garden Grove CA
Eduardo D. Szyszlican - Lanus O., AR

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

H03K 302
H01J 1982

US Classification:

328225

Abstract:

An offset voltage correction circuit for a gridded power tube, such as a gridded traveling wave tube (GTWT), provides from a pulsed, floating, negatively offset voltage signal representing the pulsed current output of the tube, a corrected pulsed, zero voltage offset signal. Such corrected signal is used in a feedback loop to control the voltage signal provided to the tube grid in a manner causing the pulsed output current of the tube to have a preestablished amplitude. The signal correcting circuit includes a. pi. -shaped network formed of a capacitor and first and second transistors. The two transistors are connected in electrical parallel so that between pulses of the offset voltage signal the first one of the transistors is held off and keeps the second transistor turned on so that the capacitor charges to the negative offset voltage of the offset voltage signal. During the pulses of the offset voltage signal, the first transistor is turned on and thereby turns the second transistor off, causing the capacitor output side to provide a zero offset voltage pulse having an amplitude equal to the sum of the negative offset and positive voltages (the total peak-to-peak voltage) of the voltage offset signal. The zero offset signal is used by a control loop circuit and a grid pulse modulator to provide a control voltage signal to the grid of the tube which maintains the pulsed output current of the tube at a preselected level in spite of tube aging and thermal effects which tend to cause the output current to change.