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A large quantity of disorders that occur in the gastrointestinal tract have always been challenging to be diagnosed in a complex environment inside the human body, but with the invention and development of wireless capsule endoscope. Many patients that experienced traditional treatment will perceive stupendous convenience. Such wireless capsule endoscope requires a highly accurate localization system...
The conventional FDTD method is extensively applied in dealing with microwave imaging, however, because of the constraint of Courant-Friedrich-Levy (CFL) stability condition, the time-step size required should be smaller enough as well as the fine cells selected is smaller, which brings an increase computational effort. The ADI-FDTD method, on the other hand, utilizing alternating-direction implicit...
A Huygens' surface that efficiently refracts normally incident electromagnetic waves at 12 GHz is reported. The phase gradient along the interface is modulated by four isotropic, non-resonant, spatial phase shifters with dimensions of 0.5λ0 × 0.5λ0, where λ0 is the free-space wavelength at 12 GHz. The electric and magnetic responses of the unit cells are controlled by metallic patterns etched on multilayer...
Analysis of fuel consumption on orbit satellite is presented. The fuel consumption model is nonlinear based on the orbit thruster and attitude control thrusters' misalignment, and is assumed to have unknown dynamics. The issue regarding as the fuel consumption of orbit optimization can be converted to multi-variable optimization with constraint. A modification of the Analytic Hierarchy Process (AHP)...
Frequency selective surfaces (FSSs) are planar structures composed of a periodic array of unit cells that filter electromagnetic (EM) waves impinging on the surfaces. They have been widely used in stealth technology, electromagnetic countermeasure, and communication systems [1, 2]. Typical FSSs are composed of metallic grids or dipole arrays, which exploit the strong interactions between EM waves...
This paper proposed the design of dual-band wearable crossed cylinders metal antenna which consists of outer ring with crack and inner orthographically placed metal cylinder. The operation frequency bands are 2.4–2.485GHz and 5.735–5.84GHz respectively, when VSWR is less than 2. The High Frequency Structure Simulator (HFSS) has been used to simulate performance such as VSWR, radiation patterns and...
We develop a three-dimensional (3-D) microwave imaging technique, which is extended from the forward-backward time-stepping (FBTS) algorithm and the Tikhonov's regularization approach, to determine the sizes and positions of tumors within breast. The effectiveness of reconstructing quantitatively of breast composition using the presented technique is demonstrated by a numerical example based on a...
In this paper, we will propose a novel approach to the radio propagation channels in complex indoor environments firstly. This technique is called the deterministic splitting method of ray tubes(DSMRT). The DSMRT is optimized for predicting indoor radio channel which can overcome the drawback of the ADRTT. At the same time, the DSMRT has the merits of less CPU time and higher computing efficiency,...
In this paper, an outdoor quasi-three dimensional ellipse MIMO channel model based on geometric scattering distribution is presented. The proposed model takes into account the polarization patterns of the transmit antennas and receive antennas and the impact of scattering patch model to the polarization properties of electromagnetic wave. The validation of dual-polarized MIMO channels is compared...
In this paper, we first derive a lower bound for the capacity of MIMO system employing dual-polarization diversity. An upper bound is also derived in the high SNR regime. In a second part, the tightness and validity of the bounds are analyzed by a definition named pseudo condition number. We conclude that the correlation matrices of antenna array have a great impact on the tightness of bounds. The...
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