Traveling-Wave Tube Amplifier Characteristics Study for Stochastic Beam Cooling Experiments

The characteristics of continuous-wave wideband traveling-wave tube amplifiers have been experimentally investigated over a frequency range of 1.5 to 4.5 GHz. We present measurements of characteristics important for stochastic beam cooling systems that are generally not available from manufacturers´ data sheets. The amplifiers measured include models 1177 H01 and 1277 H01 having output power capabilities of 10 to 20 W, respectively, at frequencies of 2 to 4 GHz. The power transfer characteristics, the phase-shift characteristics as functions of frequency and the input power level, the voltage standing-wave ratio, harmonics and intermodulation products content were accurately measured and are discussed. Also several approaches are discussed for the reduction of harmonics and intermodulation products.