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The main problem in calculating the uniform geometrical theory of diffraction (UTD) surface diffracted fields on surfaces lies in the difficulty in determining the geodesic paths which the creeping rays propagate along. In this paper, a novel adaptation normal-section tracing algorithm (ANST) is presented for creeping ray tracing on the arbitrarily shaped surfaces modeled by triangular surfaces. The...
In this paper, based on electromagnetic theory and multi-conductor transmission lines(MTL) theory, proposes a quick measurement method of the terminal equivalent impedance for multiple parallel cable-bundles. According to the method, the multiple cable-bundles are treated as equivalent of MTL firstly. After that, using vector network analyzer(VNA) and current probe measures broadband voltage reflection...
This paper proposes an analytical method based on two ports network to analyze the conducted electromagnetic emission interference of typical airborne full bridge AC/DC Switch Mode Power Supply (SMPS) in tow modes, which are common mode and differential mode respectively. According to the analysis results, the SPICE circuit model of the SMPS is established. The model is simulated and obtained the...
This paper presents a novel broadband UHF band airborne antenna. The antenna is in the inverted L-shaped antenna to improve from, based on the increased portion of the distributed capacitance and frequency adjustment branch. In about three octave range with a good vertical linear polarization characteristics and Omni directional radiation characteristics at the horizontal plane. For DME applications,...
In this paper, a novel 4 elements GPS antenna array with UC-EBG structure is proposed for GPS navigation application. In order to achieve higher gain and lower backward radiation, the UC-EBG structure is added into the 4 elements antenna array. The effects of the UC-EBG structure on reflection coefficient and radiation performance are investigated. It is found that the gain and backward radiation...
Transmission Line Model (TLM) are well used as a partially or fully analyse method for antennas, including Microstrip Antennas (MSA). The recent appearance of EBG structures focus the interest to improve the electromagnetic characteristics of MSA, therefore the analyses has become more complex even for CAD tools consuming computer resources and time process. TLM had been proving to be a useful tool...
During equipment level electromagnetic interference (EMI) experiment, there always exist some frequency spectrum that excess the emission limit, among which harmonic spectrum is the major component. This paper puts forward a method to specially analyze the EMI harmonic spectrum, using model of grey system theory to construct grey-period model for the EMI harmonic spectrum, and the model turns out...
In this paper, we mainly discuss an evaluation method based on the Analytical Hierarchy Process (AHP) model and BP neural network. An indicator evaluation method then is proposed by combining these two models, and is applied to analyze the EMC of vehicular equipment systems. Experiment results show that this AHP and BP neural network based evaluation method is available and feasible.1
An automated testing system based on a new method is presented in this paper, which is designed to implement the radiation safety margins test. System theory and composition are described, and key points of the test method design are discussed, including the correction of the results, selection of the testing frequencies, adjustment of the generator, and frequency return during test procedure. The...
Electromagnetic pulses radiated in the explosion of mild linear shaped charges are measured and analyzed. Signals are captured by a monopole rod and two dipoles, and recorded by a real time analyzer and an oscilloscope. After corrected by the antenna factor and applied the Hilbert transform, waveforms of the pulses are reconstructed. It is shown by the measurements that abundant of electromagnetic...
System vulnerability is a theory that intends to explain, analyze chain fault. This paper analyzes the electromagnetic compatibility (EMC) vulnerability by the equipment topology. First, this paper delimits the concept of the EMC vulnerability system, the vulnerability source, the degree of vulnerability and so on. Second, this paper located the source of vulnerability equipment in some aircraft systems...
The mathematical model of LEMP is analyzed. And we also analyze the communication system's own characteristics, such as omni-directional reception, high sensitivity and so on. The result shows that the communication devices easily suffer interferences and damages of electromagnetic pulse. Using software CST, coupling characteristics of electromagnetic pulse in the port of airborne ultra shortwave...
The idea of this paper roots in the electromagnetic compatibility design of the whole aircraft system, in which out of band characteristics of airborne antennas are of equal importance as their characteristics in band. The definition of antenna characteristics for out of band is interpreted. Pyramidal horn antennas are the main research objects in this paper and focus on analyzing and investigating...
This paper deeply researches extraction method of nonlinear model and optimization technique of CAD resign for MMIC LNA. We use three-stage circuits of topology structure. Matching circuit, bias circuit and topology structure are all designed. It achieves low noise and high gain as small-scale as possible, and ensures minimize of gate dimension and as high-linearity as possible.
This paper deeply researches the design method of microwave circuits based on high performance computing simulation, relying on our existing high-performance multi-processor platform. Take X band MMIC LNA and K band down converter as example, by EDA software, microwave circuits are simulated. With high-performance computing technology has greatly enhanced the accuracy and efficiency of electromagnetic...
The proposed novel electromagnetic radiated emission source identification method is based on Independent Component Analysis (ICA). The identification is conducted by processing a suitable number of radiated spectrum data which is obtained by measurements at different points around equipment under test (EUT). Using specific kurtosis-based ICA algorithm, we can not only distinguish EUT's radiated emission...
This article presents a method that uses physical optics (PO) techniques to compute the monostatic radar cross section (RCS) of electrically large conducting objects modeled by non-uniform rational B-spline (NURBS) surfaces. At the beginning, a new algorithm to convert recursive B-spline basis function into piecewise polynomials in power form is presented. Then, algorithm computes the polynomial representation...
Signal cables and ground plane structure have many applications in electronic systems. The existence of parasitical parameters, such as the coupling inductances and coupling capacitances, make the impedance observing at the port resonant at certain frequency and far from the normal value. Adding decoupling capacitances can improve the situation. Partial element equivalent circuit (PEEC) method is...
In this article, A novel 64-element high-gain circularly polarized patch antenna array in the a-band is presented. Sequential rotation technique is employed here and the patches are excited by a new series-parallel feed power distribution network with microstrip transmission lines to improve the antenna performance. The results achieved show that the microstip antenna array provides a minimum peak...
In order to solve difficulties to build complex nonlinear EMC systems model and give an EMC design plan accurately, this paper present a nonlinear EMC simulation method based on grey system theory. Broadband components and harmonic components of subsystems were separated, and the grey nonlinear model of subsystem was designed. Then the grey model of the whole system was actualized. This method may...
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