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This paper discusses a modal method to enhance axial-ratio (AR) bandwidth of a circularly-polarized (CP) antenna. Particularly, a crossed dipole antenna with AR bandwidth enhanced is proposed for revealing the technical details. It is found that two new modes can be introduced by adding two parasitic dipoles. Then the AR bandwidth and the CP performance within the AR bandwidth could be improved through adjusting resonant frequency (ResF) and polarization of one of the new modes. This conclusion is validated by simulated results and parametric study.

We develop a modal method for radially inhomogeneous waveguides. The formulation is derived with the two transverse components of the magnetic field. The algebraic eigensystem is solved by using Tchebycheff polynomials and a tau method.

True monomode operation and polarization control capability of elliptical nanowires leads to the need of efficient solvers for open elliptical nanophotonic structures. In this contribution, a full-wave vectorial modal method for open boundary elliptical geometries is presented for designing quantum-dot elliptical nanowire structures. The method exploits symmetry properties, provides insight into the physical behavior of the system giving direct access to propagation constants and mode profiles, which will be used in the efficiency calculations of the single-photon sources.

The vibration fatigue life assessment of vehicle radar is carried out according to the random load of transportation faced by vehicle radar in service. The refined finite element model of vehicle-mounted radar in transportation state is established to investigate its inherent characteristics. Based on modal method, Frequency response analysis and random vibration analysis was carried out. Based on S-N curve and cumulative damage theory, fatigue life prediction was carried out. The results show that the fatigue damage of dangerous parts is very big. So it is suggested to improve the structure to reduce the stress concentration, use different materials in different parts, improve the processing technology to improve the strength, etc.

When the tunnel wall is curved, the existing electromagnetic field prediction methods will encounter serious difficulties in solving the problem, such as the difficulty in obtaining closed-form expressions, and the obvious increase in computational complexity and computational burden. A simplified method is presented in this paper. And the possibility of the field prediction for bending roadways by modal approach in straight roadways is discussed. Firstly, the propagation law in a curved roadway is analyzed. On this basis, the geometrical structure of the curved roadway is simplified. It is equivalent to a splicing of several straight roadways with different inclination angles. Then the channel model is accomplished by using the modal method for the propagation in the straight roadway. Compared with other approaches, the feasibility of the proposed method is verified.

A fast and accurate modal method for analysing waveguide extracted poles of microwave filters is presented. Basing on a previously presented analysis of a six-port junction in rectangular waveguide [1], by properly shorting the unused ports and reducing the upward directed port the required slot coupling is achieved. Additionally, the case of two contiguous extracted poles is also considered. A parallel FEM analysis of the structures confirms the accuracy of the proposed analysis method.

In this paper, we propose a new model for predicting around-corner coupling loss associated with radio signals propagating from a primary tunnel to cross junctions. The proposed model is based on the classic modal method that has been widely used for predicting power distribution in straight tunnels. The uniform theory of diffraction (UTD) is applied to calculate mode coupling coefficients. Simulation results based on the proposed model are compared to measurement results taken in a concrete tunnel and show good agreement.

For the complexity of integrated stabilization system coupled analysis, the vibration theory equation modal method is introduced into integrated stabilization system. The equations of integrated stabilization system are transformed into model space equation and the solution vector of the equation a set of base is found by using the state space method. Then, the equation has solutions which realize the decoupling of the integrated stabilization system so that the analysis of model frequency response function can be executed. In the meanwhile, we use the least square method and eliminate the polynomial trend method to optimize the input signal. This approach not only improves the signal-to-noise ratio, but also reduces the roll angel of the ship under the same input condition. The effectiveness of this method can be verified by simulation.

In order to solve the problems of complex calculation and uncontrolled accuracy in dynamic model of flexible manipulator, a new method of building dynamic model is proposed based on a new model with springs and rigid bodies. According to this method, manipulator is simplified as some rigid bodies connected by springs. So new dynamic model is built by Lagrange equation with added elastic energy which replaces elastic energy induced by manipulator deformation. Based on new dynamic model, computer simulation result of the trajectory of end point of manipulator is showed and compared to the one on basis of second order assumed modal method. Considering the comparison, it is proved that new model is available and easy to calculate. Moreover, further research shows that new model can adapt to any single flexible manipulator through adjusting parameters of manipulator and stiffness of springs. Meanwhile, the accuracy of simulation result can be controlled easily depending on changing stiffness of springs.

B-spline basis expansion is for the first time successfully employed in a modal method aimed at rigorously modeling the electromagnetic response of crossed surface-relief gratings.

In this paper, a fast technique based on modal method of moments is presented that takes into account the perforated wall thickness in the calculation of the shielding effectiveness (SE) of a rectangular enclosure. Utilizing this method, the SE of an enclosure with single and multiple rectangular apertures with various wall thicknesses is examined and very good agreement among the produced results and experimental ones is observed. It is shown that neglecting the wall thickness may decrease the accuracy of the predicted SE, and hence, the wall thickness should be taken into account in SE evaluation specifically at high frequencies.

An efficient modal method for the analysis and design of an array of probe-fed, cavity-backed patches with parasitic elements is presented. The probe feed can either be straight, stepped or L-shaped. The method described is very accurate resulting in a reliable design that works to the desired specifications the first time without any need for tuning, modification or successive iterations.

The paper presents the detailed finite element model of certain car body, which is reasonably simplified according to actual loading conditions. First, frequency response is analyzed by means of modal method with software MSC. Nastran, secondly, the correlation of spectrum loading is analyzed, by the treatment of practical loading; then the fatigue life analysis of correlated and uncorrelated loading of car body is obtained based on the theory of Palmgren-Miner cumulative fatigue damage, in MSC. Fatigue software environment; finally, the impact of correlation of loading on the fatigue life of car body is represented. The theoretical results are in agreement with the experimental ones. Some ameliorated measures are proposed to the unsubstantial regions.

Summary form only given. An approach for finite zero set compensation for multivariate systems with equal number of inputs and outputs is discussed in case of control system design by modal method where state feedback is used.

It is well known that either the electric field integral equations or the magnetic field integral equations have been widely employed to analyze electromagnetic scattering of conducting bodies. At some discrete resonance frequencies, however, when E-field integral equations or H-field integral equations are applied to attack this problem, the solution to method-of-moments matrix will be nonunique or unstable. A new effective modal method, termed Inagaki mode method, is presented here to solve this problem. At the interior resonances, this modal method, based on electric field integral equations, is used to filter out resonance modes and therefore obtain the right scattering property. The modal method doesn't need any operation of matrix inversion and possesses the merits of clarity in concept and simplicity in computation. A good agreement is achieved between the calculated results and the results published in some literatures as given in an analytical analysis

The influence of the lattice geometry to the band spacings and crosspolarisation of single layer tripole arrays is investigated. A modal method of analysing cascaded FSS with arbitrary element and lattice geometries has been developed and the performance of double 1ayer arrays is described.