Changsheng Shen

Integrated Microstrip Meander Line Traveling Wave Tube Based on Metamaterial Absorber

An integrated microstrip meander line (MML) slow-wave structure (SWS) comprised of an MML SWS and compact wideband metamaterial absorber (MMA) is proposed and demonstrated theoretically and experimentally in this paper. The MMA consists of metallic rectangular resonators with a metallic ground plane and a separating dielectric layer. Simulation results show that the MMA has multidistinctive absorption peaks; the bandwidth at 56-GHz peak frequency is reach up to 30 GHz. The integrated MML SWS can provide flatter gain response of output power than that made by the MML SWS with a traditional resistive coating attenuator. Experimental results are in close agreement with simulation results. A traveling wave tube (TWT) is simulated based on this integrated MML SWS. The output power of this TWT is 48.21 W at 33 GHz corresponding to a maximum gain of 30.3 dB; the output power gain is greater than 25 dB across the entire working frequency range.

Study for noise performance parameter estimation of TWT electron gun

Noise performance parameters are important parameters for TWTs used in many scenarios. We proposed in the paper an electron gun noise parameter estimation method for electron guns with non-ideal electron-beams. And noise parameters for several electron guns were simulated and analyzed. The results can be used for reference of low-noise electron gun design.

An improved wavelet signal denoising method for TWT

An improved wavelet method is presented for TWT signal denoising, in which linear-hard and nonlinear-soft threshold regions are defined and given. In MATLAB simulation, Doppler signal affected by 7 dB of additive-white Gaussian noise is analyzed and denoised. The results show that signal to noise ratio is 24.2362 and root mean square error is 0.4356, and the improved method is better than the conventional methods.