GENERAL DESCRIPTION
NEC LD7249 series of PPM-focused traveling wave tube are designed for use as final amplifiers in the earth-tosatellite communications transmitter.
Two models of the LD7249 series are capable of delivering an output power of 350 W and 400 W over the range of 13.75 to 14.5 GHz and provide a high power gain of more than 47 dB at the rated output power level. Furthermore, this is of rugged and reliable design offering long-life service.

FEATURES
™ High Power Gain
   The power gain is typically 54 dB at the rated output power level.
™ Simple Cooling System
   The tube is conduction-cooled so that the cooling system is greatly simplified.
™ PPM Focusing
   The tube is PPM (Periodic Permanent Magnet) -focused, eliminating entirely the focusing power supplies and interlock circuits.
™ Rugged Construction
   The tube is designed to be rugged, therefore it is suitable for transportable systems.
™ Long Life and High Stability
   The tube employs an advanced impregnated cathode with a low operating temperature for long life.
™ Microdischarge Free
   The tube is carefully designed to be free from microdischarge in the electron gun for long term operation, therefore it is suitable for digital communication service.