Space qualified 140 watt linearized L-band helix TWTA

L-3 Communications Electron Technologies, Inc. (L-3 ETI) is producing flight qualified L-band linearized traveling-wave tube amplifiers (LTWTAs) for space communication and navigation systems with demonstrated efficiencies to 65%. Thermal test data for a flight set of LTWTAs generating 140 watts of output power at 1540 MHz for a narrow-band (8 MHz) application is presented. Average DC conversion efficiency (η) >; 64%, 2-tone intermodulation distortion (C3IM) below 13 dB (SAT), and phase stability better than 5°, all when tested over a nominal 100 deg C temperature range were achieved. Group delay stability of ~30 pspp over this temperature range is also demonstrated, making these amplifiers ideal for satellite navigation.