ABSTRACT This letter proposes a novel model for inverse synthetic aperture radar (ISAR) imaging of low‐angle targets in the troposphere using echoes simulated by ray tracing method (RTM). The proposed approach integrates electromagnetic (EM) wave propagation with techniques to account influence environmental factors, such as atmospheric refraction and ground multipath, on ISAR imaging. First, spherical multipath calculation based RTM is acquire path parameters. Subsequently, an transfer...

In this paper, an extended matrix pencil method (EMPM) is proposed to achieve the equivalent analysis of a multiport system. First, Hankel constructed by sampling data from multiple ports integrated into matrix. Then, operations, including singular value decomposition, order reduction, and solution pencil, are carried out for calculate common poles. Further, residue system solved least square method. Furthermore, multiconductor transmission line (MTL) containing frequency-dependent network...

This letter proposes a 3-D parabolic equation-method of moments (PE-MoM) hybrid method to predict radar target scattering with surface ducting in large-scale environments. The divides the complex multiscale problem into two subproblems: electromagnetic (EM) wave propagation and scattering. bidirectional equation is used consider influence environmental factors, such as irregular terrain atmospheric duct on EM propagation, whereas (MoM) calculate from key target. By introducing phase...

The far-field radiation of the transmission line (TL) operating as a transmitter and induced voltage current at terminals TL regarded receiver can be correlated via electromagnetic (EM) reciprocity theorem. For above an orthogonal ground plane, formulas in testing state (where is deemed transmitter) electric field expressions around receiving considered receiver) are derived this study. Besides, expression for terminal obtained each equivalence between two proved through EM theorem method...

The field-to-line coupling problem of the transmission line (TL) excited by external fields can be analyzed adopting electromagnetic (EM) reciprocity theorem. In this article, according to frequency-domain expression test current along in case TL is terminated mismatched loads, time-domain formula, consisting original excitation, and multiple reflected waves caused derived. Furthermore, analytical induced voltage obtained based on EM-reciprocity correctness proposed method verified numerical...

Abstract This letter explores the possibility of long‐distance transmission an orbital angular momentum (OAM) beam through rectangular tunnels. Theoretical analysis reveals that OAM propagating in tunnel with square cross section fulfills conditions for axial propagation and exhibits azimuth symmetry. In comparison free‐space generation, we draw conclusion beams is achievable tunnels section. The validity our further substantiated numerical experiments. Simulation results demonstrate...

The formula for analyzing the response characteristics of induced current on a transmission line (TL) excited by high-frequency electromagnetic (EM) waves is mixed integral-differential equation. integral part Fredholm equation first kind with serious ill-posedness, which causes difficulty in solving it stably. regularization technique useful method analysis ill-posed problems. Therefore, this paper, based Tikhonov proposed to analyze finite length TL illuminated external EM waves. operator...

Following the test work is difficult and complex in modern radar maintenance support, automatic testing of board necessary for man. A system based on virtual instrument technology discussed. The used PXI bus Labview program language. design given, its hardware solution software designed. And finally reliability expansibility discussed at last.

Dating back to late 1960s, ITS has achieved a rapid development, in which US, Japan, Canada, Germany, France and other countries throughout the world invested lots of founds human resources. After long time study, these tended use high-tech transform existing road traffic management system, greatly improved quality network capacity service. The implementation programs instead relying mainly on construction more roads meet growing demand already aroused general concern. ITS, as new attempt...

Abstract In this letter, in process of using matrix pencil method (MPM) to perform the equivalent multiport frequency‐dependent system, a modified MPM is proposed realize solutions common poles and residue time domain. technique, frequency domain data all ports are transformed into vectors by IFFT. Then, superimposed single vector, which analyzed generate set poles. The obtained least square solve equation consisting vectors. fast evaluation system can be thus completed matrix. Finally,...

Following the test work is difficult and complex in modern radar maintenance support, automatic testing of necessary for man. Radar transmitter device designed to state performance parameter off-line or on-line, means while it has expert default diagnosis system analyze key signals locate typical faults. The accordingly seen as a good middle support. design given, its hardware solution software explained. And finally reliability expansibility discussed at last.

This article describes an encoding method for the orbital angular momentum(OAM) mode used in communication. Based on mutual orthogonal characteristics between different OAM beams and principle of electric field superposition, modes are superimposed. The number corresponds to a binary sequence same length, each represents data bit, thereby achieving encoding. designs 8-element uniform circular array(UCA) that can generate -3 +3 modes, 6-bit sequence. coaxial transmission seven representative...

Abstract This paper extends previous work on electromagnetic (EM) reciprocity theorem analysis from the single‐conductor to more general multiconductor transmission line (MTL) case. The focus is EM coupling problem of an ideal MTL above a perfectly electrically conducting ground when excited by plane wave. proposed methodology addresses mutual effects and mismatched loads in MTL. expression for current along test (radiation) state derived, considering these factors. A novel calculation...

Orbital angular momentum(OAM) communication requires the alignment of transmitting and receiving antennas, which limits application scenarios OAM communication. In this letter, we propose an mode modulation-based wireless backhaul scheme for downlink in a broadcast network. According to principle superposition electric fields, generates multiple modes simultaneously through uniform circular array(UCA) information modulation radiates signals outside periodic cyclic excitation manner. This...

Abstract In the tests of electromagnetic scattering characteristics electrically large objects, due to object size and installation height, physical system is large, strong. low-frequency bands, cancellation by filtering cannot be achieved, which affects test accuracy. This study proposes a radar cross section (RCS) reduction design for target supporter based on low-scattering structure, models with flat shape were formed in an array, reduced horizontally polarized within ±45° at low...

In this paper, the occlusion propagation characteristics of orbital angular momentum (OAM) beams are studied based on parabolic equation (PE) method. Two construction methods OAM aperture field in PE proposed, namely direct generation method and beam modulation The results show that uniformity amplitude generated by uniform circular array is better than rectangular array. mode helical spectrum expands when propagating blocked. forms discussed here. both cases, as range increases, energy main...

The solution of the lightning electromagnetic fields (LEMF) involves a complex and time-consuming integration process, which is very unfavorable for further analysis such as research field-to-line coupling problem. Therefore, rapid computation LEMF important ongoing In this paper, fast calculation achieved by proposed method combining matrix pencil (MPM) segmented sampling technique. First, carried out frequency spectrum pulse, values at corresponding are calculated. Then, all frequencies...

In this paper, an effective method of combining the matrix pencil (MPM) and piecewise linear recursive convolution (PLRC) is proposed to perform transient response analysis transmission line (TL) containing frequency-dependent network (FDN). Firstly, admittances FDN at sampling frequencies are obtained by calculation or measurement. Then, corresponding poles residues generated using MPM process sampled admittance data introduced into current expression in PLRC. Further, substituting formula...