The mushroom-like electromagnetic band-gap (EBG) structure combined with a choke is applied to improve the transmit-receive (T/R) isolation of two X-band large antenna arrays. basic idea presented suppress surface wave propagation between T/R arrays by utilizing EBG walls formed through vertical configuration cells, so as isolation. level and metal measured compared other methods applied. experimental results show that using this structure, can be improved at least 30 dB in radar's operation...

In this letter, a low-sidelobe, high-efficiency, series-fed 2 × 24 slot array antenna at 93 GHz is proposed. The can be divided into three separated layers and there no need of electric contact between according to gap waveguide (GW) theory. To control the magnitude coupling energy achieve −30 dB sidelobe quasi-Taylor weighing in radiation slots, transverse slots middle layer are placed certain distance relative bottom center. Measure results agree well with simulation result, which...

An improved approach is proposed for solving the axial line problem (|ρ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">→</sup> -ρ | = 0) of mixed potential Green's functions (MPGFs) in spatial domain cylindrically stratified media. Different from previous work, to alleviate convergence summation cylindrical eigenmodes spectral domain, two asymptotic terms with respect <i xmlns:xlink="http://www.w3.org/1999/xlink">n</i> are extracted...

Closed-form Green's functions for cylindrically stratified media are derived in terms of spherical waves and surface-wave contributions. The methodology is based on a two-level approximation the spectral-domain functions. In first step, large argument behavior zeroth-order Hankel used extraction quasistatic images from with use Sommerfeld identity. second remaining part approximated pole-residue expressions via rational function fitting method. This robust, efficient, fully numerical...

In satellite-borne platforms where the reduction of size, weight and power are very critical design factors. To pursuing to this goal, we present a for ultrawideband tightly coupled antenna array (TCDA) with wide angle scanning low cross polarization. Although TCDAs possess merit wideband, wide-scanning performance, they need balanced feeding structure which introduces several practical challenges. paper, demonstrate low-cost wideband integrated balun incorporate increase overall bandwidth....

Coupled volume-surface integral equation (CVSIE) and non-coupled (NCVSIE) are compared in this paper. For scattering problems, results with similar accuracy given. the radiation different impedance behaviors arrived using two approaches, by comparing numerical to from measurement or reference papers. The CVSIE approach has better performances input calculation.

In this paper, an improved CBFM/p-FFT algorithm is presented, which can be applied to solve electromagnetic scattering problems of large-scale periodic composite metallic/dielectric arrays, even when the array has electrically small periodicity or separating distance.Using characteristic basis function method (CBFM), characteristics any inhomogeneous targets represented by special responses derived from a set incident plane waves (PWs).In order reserve dominant and remove redundancy overfull...

The X-band wide band aperture-coupled stacked mi- crostrip antenna is studied and manufactured. Based on the finite- difference time-domain method, a parametric study of input impedance presented, effects some pa- rameters which are not easy to control in manufacture illustrated. structure screw-plane-support used for this kind antenna. And several notes considered based parameter analysis. measured bandwidth VSWR ≤ 2 greater than 50%. results basically accordant numerical simulated re-...

The relationship between the immittance inverter co- e-cients and coupling coe-cients is obtained under non- resonating condition. With deter- minant properties of transformation matrix, matrix could be decomposed to many sub-matrixes for fllter designs. physical signiflcance decomposition discussed. Using this idea, a can number sub-fllters, which connected by sections transmission lines with same characteris- tics kept.

Closed-form mixed potential Green's functions (MPGFs) for cylindrically stratified media are derived in terms of quasistaticwave and surface-wave contributions.In order to avoid possible overflow/underflow problems the numerical calculations special cylindrical such as Bessel Hankel functions, a novel form spectral-domain MPGFs is developed.Then, twolevel methodology used approximation spectraldomain MPGFs.In first step, qusistatic components extracted from MPGFs, then transformed into space...

Abstract The problem of the analyzing mutual coupling for conformal array in practice is addressed. Experiment designed sectoral cylinder composed 12 cavity‐backed stacked microstrip antennas. Based on measurement element complex patterns, phase pattern calibration technique and least squares method are adopted to calculate matrix (MCM) array. It shown that actual modified by MCM agrees well with ideal desired pattern, which confirms validity accuracy calculation MCM. © 2011 Wiley...

Based on the fabricated 12-element cavity-backed microstrip sector cylinder array, a novel hybrid alternate projection algorithm (HAPA), which combines analytical method with numerical techniques effectively, is proposed for synthesizing pattern of practical conformal array. The applies variable direction aperture mutual coupling correction to provide good initial excitations elements enhanced (EAPA). In order do further optimization, improves convergent speed significantly. Finally, HAPA...

A wideband phased array antenna consisted of all-metal Vivaldi is designed in this paper. It a line with 8 elements, at the ends there are two additional elements added as virtual to constitute environment. The comprised slot structure and SMA connector, so that it convenient process, size 150mm×35mm. simulated measured results show VSWR (voltage standing wave ratio) 6 ~ 12 GHz band less than 2.5, phase scanning 45-degree angle can be realized band.

This paper proposes a feeding method for four-arm sinuous antenna, which is realized by using microstrip printed board welded on metal pyramid. It an effective way to solve the problem of input impedance transformation and broadband balun. Then antennas working at 0.4GHz 2GHz given, measured results VSWR radiation pattern show that feed form reliable effective, antenna has excellent performance in operating bandwidth.

A preconditioned alternate projections method is proposed for pattern synthesis in a conformal array. The algorithm applies the aperture projection with null points adjusting technique to initialise problem, which enhances ability of solution greatly; moreover, improved project operator accelerates convergency speed iteration. Using this algorithm, low sidelobe scan beam 12-element sectoral cylinder microstrip array obtained mutual coupling considered.

In this paper, we present a wideband planar e-shape textile antenna and study its performance numerically experimentally. The material the radiation patch shape provide wide working band (2.25ghz-2.75ghz). A digital human model is established to analyze affect of body on antenna. Experiments are carried out body, simulated measured results in free space chest show good agreement with each other. suitable for body-centric wireless communications high quality.

In this paper, a macrocell radio propagation model for mobile communication is established based on three-dimensional parabolic equation (3DPE). The loss characteristics of around buildings are calculated by using 3DPE when distributing differently flat ground or irregular terrain. results compared with the physical optics (PO) method and Ray tracing method. compare shows accurate valid. So it provides an excellent prediction communication.

This paper focuses on the RFI signal in impulse UWB system with equivalent time sampling. signals sampling cannot be completely recovered. To reveal properties of aliased signals, we setup a simple mode time-varying phase and analyze effect classical average operation. Simulations about random periodic schemes are performed compared, indicate that suppression has more relationship factor other than scheme.

A printed log-periodic dipole antenna (PLDPA) with balanced feed structure is proposed. The traditional feeding using a single coaxial cable and lines equal width will lead to an unbalanced current distribution, thus, the radiation pattern performances frequency dependent deflection status. In this paper, we have modified of two compensate effect soldered external shield cable, i.e., obtain equivalent electroconductibility on both sides lines. On one side substrate, feeder narrower line...

A dual-polarized microstrip antenna with low cross polarization level is designed, then a full-polarization conformal phased array twelve elements on cylinder simulated. Based the embedded patterns of each element, convex optimization method utilized to synthesis array's radiation pattern. It has been proved that, differential-fed performs 20dB better in inhabitation cross-polarization than that dual feeds.

Millimeter-wave microstrip antenna has the advantages of low profile, easy processing and light weight. It is widely used in military civilian fields. A millimeter-wave array working 35Ghz presented this paper. new compact waveguide-slot-patch coupling structure antenna, which three functions coupling, power division radiation, effectively suppressing stray radiation slots, reducing loss transmission lines, then improving antennas. Based on structure, an 2×2 sub designed optimized by...

Different kinds of a priori information used to enhance microwave tomography are introduced and classified into two main categories. The first category is about features target, these can introduce some the target algorithm. This type lead better initial guess an appropriate regularization as well. second imaging system, though loading system configuration information, such boundary condition, background so on. changes field which inquires thus it system's ability acquiring target. Both...

In this paper, we introduce an efficient algorithm to analyze metamaterials (MTM), which can be finite periodic structures with tight coupling between nearby cells.Firstly, the algorithm, based on method of moments (MoM), uses hybrid volume-surface integral equation (VSIE) composite dielectric-conductor objects, then, characteristic basis function (CBFM) and precorrected-fast Fourier transform (p-FFT) are combined accelerate calculation equations, which, composed connected cells analyzed...