Title :
Development of a focus electrode modlator for a TWTA test station
Author :
Kim, S.C. ; Nam, S.H.
Author_Institution :
Pohang Accelerator Lab., Pohang Univ. of Sci. & Technol., Kyungbuk
Abstract :
To drive a traveling wave tube amplifier (TWTA) with a focus electrode (FE), a high voltage (HV) FE modulator is needed. The modulator has to be floated from the TWT cathode high voltage that typically varies from 0 to 5 kV. A FE modulator is developed to function in a TWTA test station. The modulator should have multifunctions such as continuously adjustable bias voltage from 0 to 1.5 kV, selectable pulse repetition frequency from CW to 1 kHz, and adjustable pulse width from 10 mus to 500 mus. Rise and fall times of the modulator output pulse are designed to be less than 150 ns. The insulation of the FE modulator is tested with voltage higher than 6.5 kV. In order to fulfil the required fast turn on and off switching times, we use series connected FET modules. We fabricated and fully tested the FE modulator. In this paper, we will discuss design protocols and test results of the FE modulator
Keywords :
cathodes; electrodes; field effect transistors; insulation testing; modulators; travelling wave amplifiers; travelling wave tubes; 0 to 1.5 kV; 0 to 5 kV; FET modules; TWT cathode; TWTA test station; design protocols; field effect transistors; high voltage focus electrode modulator; modulator insulation; pulse repetition frequency; traveling wave tube amplifier; Cathodes; Electrodes; Frequency; Insulation; Iron; Pulse modulation; Pulse width modulation; Space vector pulse width modulation; Testing; Voltage;
Conference_Titel :
Power Modulator Symposium, 2004 and 2004 High-Voltage Workshop. Conference Record of the Twenty-Sixth International
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-8586-1
DOI :
10.1109/MODSYM.2004.1433567
