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In recent years, Metamaterials is widely applied in the field of microwave, include in the field of antenna studies, but little of them come down to half wave antenna and antenna array. So a half wave dipole antenna and antenna array are simulated as a benchmark, antennas loading reflector, metal reflective plate and Metamaterials reflective plate are simulated respectively. The simulation results...
In this work, an ultra-wideband FSS is designed with a hexagonal ring unit cell and a dual-FSS array structure to widen its bandwidth. The 3dB bandwidth is from 17.83 to 45.66 GHz, covering the entire K and KA band and the unit periodicity is about λ0/5.75 for the lowest passband. The designed FSS features low profile, flat passband, and stable performance regarding incident angle and polarization,...
In order to explore the influence of loadingreactance on antenna's performances, a model of end-fire structure with loading lumped reactance was established. Based on the simulation results and statistical data, the current distribution of the end-fire structure was influenced by loading reactance on parasitic dipole, especially the current phase of parasiticdipole. Directivity and 3dB bandwidth were...
Time domain planar near field scattering measurements can obtain wideband scattering data in one measurement. Time domain measuring method is based on plane wave spectrum formulas. This paper concerns simulation of time domain planar near field scattering measurements in time domain. The near-field scattering measurement data are transformed to far-field scattering data such as Radar Cross Section...
A semi sphere loaded reversed conical antenna is designed, which is designed as dielectric embedded antenna and sleeve antenna. The bandwidth of first antenna is 770MHz while the VSWR is less than 1.5. Then the sleeve antenna is designed in order to extend the bandwidth. At last, the simulation result shows the bandwidth could be 2.925GHz while the VSWR is less than 1.5, which means the relative bandwidth...
Hardware acceleration of Finite-Difference Time-Domain (FDTD) algorithm has always been an important part of FDTD research. In this essay, we discussed the advantage and feasibility of accelerate FDTD algorithm using Graphics Processing Unit (GPU). With the implement of lattice-threads mapping and other techniques, we proposed a GPU FDTD programming model that is both efficient and accurate. Then...
Antenna measurement data are collected over a surface as a function of relative position to the antenna. The coordinate system directly affects how data are plotted to the surface. This paper introduces two useful plotting systems used to map array antennas' far-field pattern in planar near-field scanning. Then the paper proposes a method to obtain the main lobes (horizontal main lobe and vertical...
The paper firstly introduced four kinds of spark signal models which used widely in EMI analysis, compared their characteristics, then put forward a new mixed model to simulate the spark signal, which not only accords with IEC 61000–4–2, but is stochastic as well, owns randomicity and superposition so as to be more close to the reality. At last, we used CST software to analyze the spark signal coupling...
Various FDTD approaches has been applied in the analysis of periodic structures, among which Spectral FDTD is a straight-forward and robust one. This essay proposed an improved Spectral FDTD algorithm that improves the simulation speed of off-normal incident case without jeopardizing accuracy. Together with GPU accelerating, as is proven by the example, the proposed acceleration scheme offers a speedup...
This paper puts forward a design of MIMO antenna and simulates the antenna's characteristics. By adjusting the dimensions of the upper patch, an wide bandwidth omni-directional micro-strip antenna has been achieved, whose center frequency is 5GHz and its bandwidth reaches 2.2GHz with the VSWR below 1.4. Based on it, two types of array also have been analyzed, the one is planar antenna array include...
In this paper, the parallel FDTD algorithm is employed in simulating the electromagnetic field distribution under UWB pulse excitation. Several computing examples were given and the numerical results proved the feasibility and high efficiency of this method. This method provides a solve-scheme for analyzing the ultra-wideband impulse EM responses from the electrically large-scale and complex-shape...
This paper proposes an efficient approach for object classification. This method bases on bag-of-features classification framework and extends the limits of it. It applies modified spatial PACT as local feature descriptor, which can efficiently catch image patch's characteristic. In order to address the speed bottleneck of codebook creation, extremely randomized clustering forest is used to create...
A basic mathematical model of the plasma antenna is developed and using the boundary conditions, characteristic parameters and current distribution of the plasma antenna are obtained. Finally, the radiation pattern of dipole is shown
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