Bit-error-rate testing of high-power 30-GHz traveling-wave tubes for ground-terminal applications

Tests were conducted at NASA Lewis to measure the bit-error-rate performance of two 30-GHz 200-W coupled-cavity traveling-wave tubes (TWT´s). The transmission effects of each TWT on a band-limited 220-Mbit/s SMSK signal were investigated. The tests relied on the use of a recently developed digital simulation and evaluation system constructed at Lewis as part ot the 30/20-GHz technology development program. This paper describes the approach taken to test the 30-GHz tubes and discusses the test data. A description of the bit-error-rate measurement system and the adaptations needed to facilitate TWT testing are also presented. A more comprehensive discussion of this topic appears in NASA publication TP-2635 [1].