Traveling-Wave Amplification in a Circuit With Nonuniform Grating

The results of both numerical simulations and experimental study of the traveling-wave amplification in the
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-band circuit with the nonuniform grating are presented and discussed. The circuit supports a wide sheet electron beam that is promising for a signal gain increase in terahertz (THz) amplifiers. The small-signal gain up to 30 dB is predicted by the simulations of the two-section amplifier in the frequency range from 94 to 99 GHz. The experimental tests of the 14.3-mm input section, powered by a 3.8 kV, 100-mA sheet electron beam, revealed the linear gain of 12 dB and instantaneous bandwidth of 2 GHz. The full bandwidth of 5 GHz has been experimentally observed by adjusting the beam voltage from 3.6 to 4.1 kV.