Qianzhong Xue

Learn More
Double Fano resonant characteristics are investigated in planar plasmonic structure by embedding a metallic nanorod in symmetric U-shaped split ring resonators, which are caused by a strong interplay between a broad bright mode and narrow dark modes. The bright mode is resulted from the nanorod electric dipole resonance while the dark modes originate from(More)
A novel planar plasmonic metamaterial for electromagnetically induced transparency and slow light characteristic is presented in this paper, which consists of nanoring and nanorod compound structures. Two bright modes in the metamaterial are induced by the electric dipole resonance inside nanoring and nanorod, respectively. The coupling between two bright(More)
A broad-band perfect absorber composing a two-dimensional periodic metal-dielectric-metal sandwiches array on dielectric/metal substrate is designed and numerically investigated. It is shown that the nearly-perfect absorption with a bandwidth of about 50 nm in visible region can be achieved by overlapping of two plasmon resonances: one originating from the(More)
A design study for plane-distributed three-beam electron gun using theoretical method combined with 3D simulation software is described in this paper, which will be used in wideband W-band TWT. The gun is characteristic with the beam voltage of 22kV, beam current of 0.15×3 A, and the radius of beam tunnel of 0.18mm. The simulation results conform(More)
In this paper, a multimode steady-state theory is established to analyze the beam–wave interaction of gyro-traveling wave tube (Gyro-TWT) based on a distributed loss-loaded waveguide. The analysis for improving stability with uniform dielectric-loaded and periodic dielectric-loaded waveguides was studied. Using the proposed theory, the realization(More)
In this paper, an input coupler for Ka band gyrotron TWT (Traveling Wave Tube) has been designed. This input coupler can convert a TE10 rectangular waveguide mode into a TE01 cylindrical waveguide mode. The measured results agree well with the simulated results. With the measured -3dB bandwidth of more than 5GHz, the input coupler can be well used in the(More)
In this paper, an input coupler for W band gyrotron TWT (Traveling Wave Tube) has been designed. This input coupler has the ability of efficiently converts a TE10 rectangular waveguide mode into a TE01 cylindrical waveguide mode. The measured results agree well with the simulated results. With the measured -2dB bandwidth of more than 4GHz, the input coupler(More)
An approximate Pierce method is proposed which gives a convenient and theoretical analysis way for a one-dimensional compressed narrow sheet beam electron gun design by translating concentric spheres to fit coaxial cylinders. Using the theoretical calculation and the parameters analysis, the comparative Pierce gun for axially symmetric beam and narrow sheet(More)
The design and experiment of a ka-band second harmonic gyroklytron amplifier are reported. The three-cavity 35-GHz second harmonic gyroklystron operates in the TE<sub>021</sub> circular electric mode. Based on the numerical simulation, a three-cavity, second harmonic gyroklystron amplifier prototype has been fabricated. Experiments show a peak output power(More)