Author: Baumgartner, R.
Paper Title Page
MOPC129 Compact Solid State RF-Modules for Direct Drive RF-linacs 382
 
  • R. Irsigler, M. Back, R. Baumgartner, O. Heid, T.J.S. Hughes, M. Kaspar, T. Kluge, J. Sirtl, K. Weidner, M. Zerb
    Siemens AG, München, Germany
 
  We pre­sent a mod­u­lar RF power source con­cept based on solid state RF-mod­ules with novel SiC tran­sis­tors. The con­cept of­fers lower cost, bet­ter re­li­a­bil­i­ty and re­duced main­te­nance com­pared to tra­di­tion­al RF-source tech­nol­o­gy. No cir­cu­la­tors are re­quired, which makes the RF-mod­ule very com­pact and re­li­able. The SiC power tran­sis­tor has a very low input ca­pac­i­tance and was op­ti­mized for low gate re­sis­tance to en­able fast switch­ing in the VHF range. It de­liv­ers a max­i­mum pulsed drain sat­u­ra­tion cur­rent of 65 A. The tran­sis­tor pro­vides at 350 V sup­ply volt­age and 150 MHz an out­put power of 5,6 kW at a gain of 15,8 dB. It is es­sen­tial to avoid high par­a­sitic source in­duc­tances at RF and good ther­mal con­duc­tiv­i­ty is re­quired for op­er­a­tion at high duty cycle. We have built very com­pact 75 x 90 mm ce­ram­ic am­pli­fi­er mod­ules using a pla­nar in­ter­con­nect tech­nol­o­gy (SIPLIT) to con­nect the bare die tran­sis­tors to the DCB sub­strate. The mod­ules have a fully sym­met­ric push-pull topol­o­gy (cir­clotron) with four tran­sis­tors in par­al­lel in each leg. The RF-mod­ules de­liv­ered at 150 MHz an im­pres­sive RF out­put power in the range of 40 kW. Fur­ther tests at 324 MHz are planned and will be pre­sent­ed.