Numerical Simulations of an X-Band Antenna-Amplifier: Investigations of Gain, Bandwidth, and Drive Frequency Harmonics Generation

Summary form only given. An antenna-amplifier, Cherenkov maser with a rod slow-wave structure operating in the non-axisymmetric HE₁₁ mode (fundamental mode of a dielectric rod antenna), can be a compact, controllable, high-power microwave source. The first antenna-amplifier simulation results obtained using the 3-D version of the MAGIC particle-in-cell code were presented in our earlier work. In this work, the results of MAGIC simulations have been obtained for the real geometry and parameters of electron diode and interaction space to be used in the experiments planned to prove the antenna-amplifier concept. Two characteristic sets of parameters have been studied. For one set providing the dominance of the operating HE₁₁ mode, the achievable gain, bandwidth, and device efficiency have been found. At the peak gain frequency of ~9.3 GHz, it reaches ~17 dB with the interaction space length of ~25 cm. The amplification band is asymmetric with respect to the peak gain frequency, and the efficiency reaches ~10% at ~20 MW output power. For another set of parameters, the effect of the drive frequency harmonics generation is significant, and the possibilities to control harmonics content in the output signal spectrum have been demonstrated