Yunlin Liu

Application of the hybrid algorithm combining ant colony optimization algorithm with microgenetic algorithm to the optimization of multilayered radar absorbing coating

A new optimization technique based on the hybrid algorithm combining ant colony optimization algorithm with microgenetic algorithm is presented for the design of multilayered radar absorbing materials. During the optimization procedure the optimization constrained conditions are different in order to meet the practical requirements in the different frequency bands between 2 GHz and 18 GHz, and the multilayered radar absorbing materials is also designed for a given maximum total thickness. The effects of the thickness and the number of layers on the optimization results are discussed in detail. The numerical results show that this new hybrid algorithm can obtain a better solution than that of the genetic algorithm.

Numerical analysis and simulation of high power microwave pulses propagation in the atmosphere using FDTD method

An appropriate numerical scheme based on the finite-difference time-domain (FDTD) method is firstly presented for high power microwave (HPM) pulses propagating through the atmosphere, which solves numerically Maxwells equations and Boltzmanns equation self-consistently. The derived difference scheme can be solved by time stepping. Especially, a novel method is presented that the variables coupled each other in the difference equations are solved by the binary linear equations before the time stepping. The propagation problems of HPM pulses in air breakdown environment are investigated and analyzed, and the feasibility and validity of the new numerical scheme is demonstrated.

Research on rectangular patch antenna with magnetic substrate

Theoretical analysis and experimental results of the bandwidth of one rectangular patch antenna with macromolecule magnetic substrate are presented in this paper. And the results showed that magnetic property results in wide impedance bandwidth. Experimental study on a new kind of compact stacked quarter wavelength patch antenna is presented also in this paper. The results showed the impedance bandwidth of this kind of patch antenna is double than the one of the common quarter wavelength patch antenna.

Application of TD-MEI method in FEMTD

The measured equation of invariance method in time domain (TD-MEI) is first applied to truncate the computation domain in the finite element method in time domain (FEMTD) to solve the radiation problem of a line source, the numerical results is presented and the validity and the accuracy are discussed.

On study of a new patch antenna with macromolecule magnetic substrate

A new patch antenna with macromolecule magnetic substrate is presented in this paper. Both theoretical analysis and experimental results showed that this kind of patch antenna has extremely wide frequency bandwidth for the impedance character.

A cylindrical spiral patch array

A simplified approach to the analysis of the patterns of a cylindrical spiral patch array is presented. Some numerical results and experimental data are given. The validity of the calculation is demonstrated by comparison with measured data.

The application of aggressive space mapping algorithm in microstrip patch antennna design

To meet different design requirements and improve the efficiency of antenna design, aggressive space mapping (ASM) algorithm combined with finite element method (FEM) is used to design a microstrip antenna for the first time. We exploit a coarse-mesh and a fine-mesh of FEM as the coarse model and the fine model respectively. The optimization results show the effectiveness of the method. It needs less calculation time and increases the design efficiency comparing with only optimizing the fine model.

Localized surface plasmon resonance sensing based on nanoparticles arrays

The performance of square silver nanoprisms arrays for molecular sensing applications is studied by the Finite Difference Time Domain (FDTD) method. The result shows that the electromagnetic coupling between the nanoparticles can be optimized to increase the sensitivity. Especially, arrays with the highest extinction and the sharpest resonance bandwidth are found to be more than 100 nm/RIU refractive index of sensitivity compared with the single particle. The result of study can offer some valuable guidance to the properties of localized surface plasmon resonance sensor with nanoparticles arrays how to be improved. This nanoparticle array with high sensitivity holds a great potential in the applications as biochemical sensor based localized surface plasmon rensonance.

Application of MEI-ABC in edge-based finite element method in time domain

The measured equation of invariance method in time domain (TD-MEI) worked as an absorbing boundary condition (ABC) was employed to truncate the computation domain of edge-based finite element method in time domain (TDFEM), the MEI coefficients were obtained by the self-metron method, and the radiation problem of a line source was solved by this scheme, the numerical results has shown its validity and accuracy.

A miniature broadband multilayer microstrip antenna

A novel compact broadband multilayer microstrip antenna is presented in this paper. The VSWR, gain and radiation pattern of this antenna are simulated. The measured VSWR of it is also shown in the paper. The results are discussed in detail.