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An universal approach to calculate the transfer efficiency between arbitrary transmitting and receiving elements has been proposed so for. The approach makes using of either S-parameter or Z-parameter. In this paper, firstly, the efficiency calculation method will be reviewed briefly, and then the functions of the developed calculator will be introduced.
One of the challenging aspects in directional electromagnetic measurements is to accurately estimate the formation bedding orientation angle, which is critical to help maintain drilling the wellbore in the sweetest spots of the reservoir. Various existing methods can be both noisy and susceptible to phase wrapping issues. Here we present a new approach for accurately computing the bedding orientation...
A planar microstrip-fed wideband circularly polarized antenna has been designed and investigated in this paper. First, a wideband linearly polarized antenna consisting of a rectangular ground plane and a rectangular radiating patch has been designed. To improve the impedance matching across a wide frequency range, the feeding line is formed of a 50Ω microstrip line and a tapered impedance transformer...
A planar microstrip-fed two-arm spiral antenna has been designed for achieving wideband circularly polarized bandwidth in this paper. Compared with conventional spiral antennas, a simple feeding line is employed to feed the antenna. The planar structure can be printed using a single layer substrate without an external balun. In addition, the arc-shaped cut is embedded in the ground plane and a tapered...
A broadband right-handed circularly polarized (RHCP) global navigation satellite system (GNSS) antenna is proposed to cover global positioning system (GPS), GLONASS, Galileo and Compass applications. The −10 dB reflection coefficient bandwidth is fully covered all of the GNSS bands. The 3-dB axial ratio (AR) bandwidth is 475 MHz from 1.175 to 1.65 GHz. The gain is above 0 dBi from 1.22 to 1.65 GHz...
A approach using the adaptive genetic algorithm (AGA) is proposed for array failure correction in digital beam forming of arbitrary arrays. In this article we use adaptive genetic algorithm (AGA) change the excitation of elements to improve the performance of array with failed elements. Numerical examples are presented to show the effectiveness of the approach.
Electromagnetic scattering from two-layered rough soil surfaces with object buried between the two rough interfaces is investigated utilizing method of moments (MoM). Theoretical formulas of the scattering model considered in this paper are presented and the surface electric current and surface magnetic current are numerically calculated by employing MoM with point matching and pulse basis functions...
An efficient hybrid method of SJMCFIE combined single integral equation with the electric/magnetic current combined field integral equation is used for analysing scattering from composite conductor and multiple dielectric objects, in which, SIE can reduce one half unknowns in dielectric regions. SJMCFIE can greatly reduce the storage requirement. Moreover, Multilevel Fast Multipole Algorithm is employed...
This paper analyzed the precision loss problem in calculation of EM wave propagating in extreme plasma environment. To overcome the problem, a numerical calculation with arbitrary precision is proposed. The simulation results show the effect of computational precision loss on EM wave propagation and also illustrate the validity of the arbitrary-precision calculation method.
An IR-UWB indoor positioning is proposed in the paper that combines the algorithm of Time-of-Arrival (TOA) and band-gap modulations. The positioning is referenced by three UWB locators that have different band-gap and deployed in a right triangle. An object can determine its position by identifying pulse backscattered on locators and each locator's signatures through recognizing the exact segment...
In this paper, a reconfigurable frequency selective surface (FSS) using varactor diodes is presented for low RCS radome application. The FSS is composed of three-layered metallic structures. The varactors are biased with a middle layer bias wire connected to via holes and wire grids on front layer. The back layer is a wideband bandstop structure for out-of-band RCS reduction. The FSS radome without...
In this paper, we present a multifunctional active frequency selective surface (MAFSS), which consists of two metallic layers and a substrate layer. Three electromagnetic functions of switching, polarization selection and frequency tuning, are integrated into a single board. The bias networks are embedded in each layer and comprise the MAFSS elements themselves, which eliminates the need of extra...
In this paper, a statistical research is carried on the radar cross section reduction (RCSR) performance of diffuse metasurface composed of two-layer stacked-patch elements. The research focuses on the broadband RCSR behavior of the metasurface in specular direction. An advanced uniform random distribution of reflection phase is proposed for the diffuse metasurface to improve the broadband RCSR performance...
In this paper, a Volterra series nonlinear equalization (NLE) scheme is proposed to compensate the nonlinear distortions in vector mm-wave system over fiber link. The principle of NLE scheme is presented. The performance of NLE scheme is investigated through a 5Gbaud 16QAM over 40GHz RF carrier simulation system. The proposed NLE scheme is proved to be feasible in nonlinearity mitigation in vector...
Transient voltage suppressor (TVS) device is the chief way by which the susceptibility to Electromagnetic pulse (EMP) of equipment can be decrease. Prior to each application, the TVS device has to be tested in order to evaluate its performances. In this paper, a new EMP protection performance testing system is designed and the Suppressing characteristics of four kinds of TVS device during EMP stressing,...
According to the insufficient research on the complex electromagnetic environment adaptability for the electronic equipment, two kinds of prediction model for dual-frequency in-band electromagnetic radiation effects is established. The decision method of choosing prediction model for electronic equipment is put forward. The ultra-short wave communication stations are selected as equipment under test...
In this paper, we propose a new design of a dual-polarization near-field focused reflective metasurface for wireless power transfer. The reflective metasurface is composed of printed cross-dipole elements with different arm lengths, which is aimed to independently generate focused point with dual-polarization. Numerical simulations demonstrate that the proposed reflective metasurface can focus the...
We analyze the influences of non-Kolmogorov turbulence and source parameters on beam wander of Bessel-Gaussian (BG) beams in the atmosphere. BG vortex beams with larger topological charge and beam parameter η can better mitigate the turbulence effects on beam wander than BG non-vortex beams. Both inner- and outer-scale effects on beam wander should be considered when BG beam goes through atmosphere...
The nonlinear response of silver nanoparticles filled epoxy resin composites under increasing applied voltage is investigated. The influence factors of applied high voltage on the conductivity of composites are measured by the collection of the electric current passing through the sample. With the increase of applied voltage, the composite has a nonlinear conductive characteristic. The contributing...
This paper presents analytical expressions and equivalent circuits for calculation of EMP responses (voltages or currents) on transmission lines. The analytical expressions are based on BLT equations, and equivalent circuits are based on telegraph equations and the controlled sources. Both methods are testified by experiments, and comparison of the two methods is discussed.
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