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124 results on '"Xia, Mingyao"'

4. Simulation of Crack Initiation and Propagation Using the Improved DDA

Author

Xia, Mingyao, Chen, Guangqi, di Prisco, Marco, Series Editor, Chen, Sheng-Hong, Series Editor, Vayas, Ioannis, Series Editor, Kumar Shukla, Sanjay, Series Editor, Sharma, Anuj, Series Editor, Kumar, Nagesh, Series Editor, Wang, Chien Ming, Series Editor, Hazarika, Hemanta, editor, Madabhushi, Gopal Santana Phani, editor, Yasuhara, Kazuya, editor, and Bergado, Dennes T., editor

Published
2021
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19. Full-Metal Dual-Polarized Phased Array Antenna With Large Element Spacing

Author

Zhou, Wen-Liang, Qu, Shi-Wei, and Xia, Mingyao

Abstract

In this letter, a full-metal ultrawideband (UWB) phased array antenna with large element spacing is proposed. Two metal blocks are loaded to increase the capacitively coupling, which can broaden the low-frequency bandwidth. Additionally, an equivalent rectangular resonator model is introduced to describe the resonance that affects the high-frequency bandwidth. Subsequently, the high-frequency resonance is shifted from 10.9 to 11.6 GHz by loading a perturbational metal column block on the ground. As a result, the element spacing of the antenna can be broadened as 0.533 × 0.533λ10.65GHz2. Consequently, the designed antenna has a reduction of at least 6.6% in the number of required expensive transmit/receive (T/R) modules compared with other antennas. Thus, the cost can be noticeably reduced. Finally, the proposed UWB array aperture demonstrates operation from 2 to 10.65 GHz, with active voltage standing wave ratios below 3 for ±60° scans in the E and H planes without scan blindness. To validate the design, a prototype of 10 × 9 array is manufactured through precision-machining and measured. Simulations and measurements show good agreement.

Published
2024
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32. Analysis of electromagnetic scattering from objects coated with arbitrarily magnetized lossy ferrite materials

Author

Wang, Pai, Zhou, Lezhu, Xia, Mingyao, and Tan, Yunhua

Subjects
Ferrites (Magnetic materials) -- Electric properties, Finite element method -- Usage, Electromagnetic waves -- Scattering, Electromagnetic waves -- Analysis, Business, Electronics, Electronics and electrical industries
Abstract

In this paper, analysis and discussion of electromagnetic scattering from objects coated with arbitrarily magnetized lossy ferrite materials are carried out by using the hybrid vector finite element method and multilevel fast multipole algorithm. For a coated cube as an example, the impact of anisotropy properties controlled by magnetized ferrite materials on the scattered field characteristics is considered. Numerical results show that the strength and direction of the biased magnetic field strongly affect the backscattered field. Index Terms--Electromagnetic scattering, ferrite materials, finite element method (FEM), method of moments (MoM).

Published
2006

47. Frequency property of buried non-symmetrical dipole

Author

Chen Zhiyu and Xia Mingyao

Subjects
Physics, Frequency response, Property (programming), business.industry, Electromagnetic radiation, Physics::Geophysics, Computational physics, Electric dipole moment, Dipole, Optics, Electric field, Equivalent circuit, Measurement while drilling, Electrical and Electronic Engineering, business
Abstract

The dependence of the electric field on frequency is studied in detail both theoretically and experimentally for the buried non-symmetrical dipole. This research aims at the ‘measurement while drilling’ with EM waves. It is interesting that there are many common features in different wells that may have greatly different depths. The theoretical results are confirmed by several experiments both in the laboratory and in geological wells. Based on these works, some simple formulae for practical design are given.

Published
1993

49. Vertical antenna embedded in earth with conductive coating

Author

Xia Mingyao and Feng Kongyu

Subjects
Materials science, Acoustics, Electric field, Drilling, Electrical and Electronic Engineering, Antenna (radio), Electric-field integral equation, Current (fluid), Real-time operating system, Integral equation, Earth (classical element), Physics::Geophysics
Abstract

A vertical antenna embedded in earth with conductive coating has been investigated by employing the method of integral equation. This topic is available to EM-MWD (Electromagnetic Measurement-While-Drilling) system, which is a new real time system for drilling measurement. Under the condition that the wave number of the earth is much larger than that of the air, a current integral equation has been derived. After the current distribution having been determined, the electric field strength on the earth surface has been predicted and its dependences on the operating frequency and the depth of the well have been discussed as well.

Published
1991

50. Macro element methods in FEM for 3-D electromagnetic radiation problems

Author

Nian Feng, Xia Mingyao, Zhou Lezhu, and Dong Shuo

Subjects
Diffuse element method, Finite element limit analysis, Mathematical analysis, Electronic engineering, Smoothed finite element method, Mixed finite element method, Boundary knot method, Finite element method, Discrete element method, Mathematics, Extended finite element method
Abstract

For the first time, macro-element technology is introduced into the vector finite element method with the perfect matching layer for analyzing 3-D electromagnetic radiation problems. By defining a macro element domain and non-macro element domain inside the finite element domain and transferring the information from the non-macro element domain onto the surface of the macro element domain, the number of unknowns in the matrix equation of the original problem and calculation time can be greatly reduced in cases where there is repetitive structural variation or when optimizing the parameters inside the macro element part. The correctness and efficiency of the proposed method are demonstrated through the numerical experiments of several typical antennas.

Published
2006

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