Thin Planar Antenna Research Articles

Approximating the pareto fronts for synthesis of planar antenna array using binary cat swarm optimization algorithm

Various performance indices like peak sidelobe level (PSLL), first null beamwidth (FNBW) and count of elements contrast to each other while designing an antenna array. A swarm-based intelligence mechanism has been discussed here for optimizing these performance indices. In particular, a pareto front is approximated for bringing out the best compromised array performance having low PSLL with narrow FNBW while maintaining a smaller number of antenna elements. A thinned planar antenna array of 20×10 was synthesized using multi-objective modified binary cat swarm optimization (MO-BCSO) algorithm to obtain the optimal positions of the array elements. The indicated technique is most appropriate for the synthesis of large antenna arrays.

Equilateral Triangular Dielectric Resonator and Metal Patch Hybrid Antenna for UWB Application

This paper postulates a novel omnidirectional low-profile ultra-wideband (UWB) antenna, which is structured by discrete embedded dielectric resonator antenna with features of both low-profile dielectric resonator (DR) and thin planar monopole antenna, where the laminated equilateral triangular DR and the rectangular metal patch monopole are stacked up. This new design can lower the profile of the antenna. Furthermore, the symmetric DR and the monopole structure are able to make the surface currents in some operating modes opposite in phase, together with the characteristics of the coplanar waveguide (CPW) feed structure and the DR, the cross-polarization is reduced effectively. The mode analysis has been done to show how the antenna achieves the UWB. The CPW which can integrate with integrated circuits easily is used to provide the excitation source. The antenna provides consistent omnidirectivity, consistent gain, low cross-polarization, and high-radiation efficiency within the entire operation band. A prototype (dimensions are 17.6 mm $\times33.6$ mm and 1.524 mm thickness) is fabricated and measured. The measurements are well correlated with the simulations.

Metamaterial-Based Thin Planar Lens Antenna for Spatial Beamforming and Multibeam Massive MIMO

A metamaterial (MTM)-based thin planar lens antenna is proposed for spatial beamforming and multibeam massive multiple-input multiple-output systems. The antenna consists of a planar lens and a linear array of receive/transmit elements. To lower the insertion and reflection loss, the lens is formed by the two-layered ultrathin MTM-based surface separated with air and fed by substrate integrated waveguide-fed stacked-patch antennas. The effects of the focal-to-diameter ( f/D) on the power distribution of the lens are investigated to work out a design method. A planar lens antenna fed with seven elements is, for example, designed to operate at 28-GHz bands. The measured results show that the proposed antenna can achieve a scanning coverage of ±27° with a gain tolerance of 3.7 dB and a maximum gain of 24.2 dBi with an aperture efficiency of 24.5% over the operating bandwidth of 26.6-29 GHz. The lens antenna also features the advantages of compact size, low cost, lightweight, simple feeding network, and easy integration with other circuits for the next generation mobile communication and radar systems.

The pulsed EM plane-wave response of a thin planar antenna

Electromagnetic coupling of an impulsive plane wave to a thin planar antenna is described analytically using the reciprocity theorem of the time-convolution type. It is shown that the pulsed voltage response induced within a thin planar antenna can be expressed through a simple rim integration of either the “testing” voltage distribution or the generalized-ray representation of the time-domain Green’s function. Numerical experiments demonstrate the validity and high computational efficiency of the proposed closed-form coupling model.

Synthesis of Thinned Planar Antenna Array Using Multiobjective Normal Mutated Binary Cat Swarm Optimization

The process of thinned antenna array synthesis involves the optimization of a number of mutually conflicting parameters, such as peak sidelobe level, first null beam width, and number of active elements. This necessitates the development of a multiobjective optimization approach which will provide the best compromised solution based on the application at hand. In this paper, a novel multiobjective normal mutated binary cat swarm optimization (MO-NMBCSO) is developed and proposed for the synthesis of thinned planar antenna arrays. Through this method, a high degree of flexibility is introduced to the realm of thinned array design. A Pareto-optimal front containing all the probable designs is obtained in this process. Targeted solutions may be chosen from the Pareto front to satisfy the different requirements demonstrating the superiority of the proposed approach over multiobjective binary particle swarm optimization method (MO-BPSO). A comparative study is carried out to quantify the performance of the two algorithms using two performance metrics.

Pulsed EM Field Radiation, Mutual Coupling, and Reciprocity of Thin Planar Antennas

The reciprocity theorem of the time-convolution type is used to construct a purely time-domain methodology that makes possible to readily evaluate the pulsed electromagnetic field radiation characteristics of arbitrarily shaped thin planar antennas and their time-domain mutual coupling. The developed computational model provides an insightful description of thin planar antennas that reveals the principal aspects of their pulsed-radiation behavior. The derived self-reciprocity (time-derivative) relation provides a useful means for determining planar antenna's radiation characteristics from its response on a plane wave in the receiving state. Moreover, it is demonstrated that this relation may find its applications in consistency checks of general-purpose computational tools. The proposed coupling model indicates the huge savings of computational resources with respect to the traditional approaches such as the finite difference time-domain technique. It is shown that all the obtained results agree well with the (full-wave) finite integration technique.

薄板構造への超高速衝突により発生するプラズマの伝播特性

Light-weight thin plate structure is expected to play an important role in space development in the near future. Thin film solar array, solar sail, planar antenna, and inflatable structure are the typical examples. We have carried out hyper-velocity impact experiments on thin plate targets using a light gas gun, to study propagation of the impact plasma associated with an interference with electrical parts on the planar plate. Propagation of the luminous cloud and generated plasma were observed by a high-speed video camera and an array of plasma probes, respectively. It was found there existed a high-dense plasma propagating along the surface of the plate at a high-speed more than the projectile velocity. The characteristic behaviors of the plasma propagation were explained by the half-range Maxwellian plasma uniformly ejected from the collision area.

SYNTHESIS OF THINNED LINEAR AND PLANAR ANTENNA ARRAYS USING BINARY PSO ALGORITHM

Traditional optimization methods are not well suitable for thinning large arrays to obtain a low sidelobe level (SLL). The chaotic binary particle swarm optimization (CBPSO) algorithm is presented as a useful alternative for the synthesis of thinned arrays. The proposed algorithm can be improved by nonlinear inertia weight with chaotic mutation to increase the diversity of particles. Two examples have been presented and solved. Simulation results are proposed to compare with published results to verify the efiectiveness of the proposed method for both linear and planar arrays.

UWB Dielectric Resonator Antenna Having Consistent Omnidirectional Pattern and Low Cross-Polarization Characteristics

A new simple compact monopole type dielectric resonator antenna (DRA) for ultrawideband (UWB, 3.1-10.6 GHz) applications is presented. The design combines the advantages of small size DRA and thin planar monopole antennas. The design provides high-radiation efficiency, consistent omnidirectional characteristics, and low cross polarization within the entire band. The antenna size is 15 × 33 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> with 5.08 mm thickness. The dielectric resonator (DR) is shaped to house the excitation feed and the dielectric substrate is cut to house the DR. The coplanar waveguide is used to feed the antenna.

Development of a One-Sided Directional Thin Planar Antenna for 5GHz Application

Development of a One-Sided Directional Thin Planar Antenna for 5GHz Application

Thin internal planar antenna for GSM/DCS/PCS/UMTS operation in a PDA phone

A novel thin internal planar antenna for GSM/DCS/PCS/UMTS quad-band operation in a PDA (personal digital assistant) phone is presented. The proposed internal antenna has a small thickness of only 3 mm, yet it is capable of providing two wide operating bands at about 0.9 and 2 GHz so as to meet the bandwidth requirements of the GSM/DCS/PCS/UMTS systems. Details of the design considerations of the proposed antenna are described, and the experimental results of the constructed prototype are presented. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 423–426, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21190

Antenna Miniaturization and Bandwidth Enhancement Using a Reactive Impedance Substrate

The concept of a novel reactive impedance surface (RIS) as a substrate for planar antennas, that can miniaturize the size and significantly enhance both the bandwidth and the radiation characteristics of an antenna is introduced. Using the exact image formulation for the fields of elementary sources above impedance surfaces, it is shown that a purely reactive impedance plane with a specific surface reactance can minimize the interaction between the elementary source and its image in the RIS substrate. An RIS can be tuned anywhere between perfectly electric and magnetic conductor (PEC and PMC) surfaces offering a property to achieve the optimal bandwidth and miniaturization factor. It is demonstrated that RIS can provide performance superior to PMC when used as substrate for antennas. The RIS substrate is designed utilizing two-dimensional periodic printed metallic patches on a metal-backed high dielectric material. A simplified circuit model describing the physical phenomenon of the periodic surface is developed for simple analysis and design of the RIS substrate. Also a finite-difference time-domain (FDTD) full-wave analysis in conjunction with periodic boundary conditions and perfectly matched layer walls is applied to provide comprehensive study and analysis of complex antennas on such substrates. Examples of different planar antennas including dipole and patch antennas on RIS are considered, and their characteristics are compared with those obtained from the same antennas over PEC and PMC. The simulations compare very well with measured results obtained from a prototype /spl lambda//10 miniaturized patch antenna fabricated on an RIS substrate. This antenna shows measured relative bandwidth, gain, and radiation efficiency of BW=6.7, G=4.5 dBi, and e/sub r/=90, respectively, which constitutes the highest bandwidth, gain, and efficiency for such a small size thin planar antenna.

Estimation of the radiation loss from microstrip antenna feed transitions

The concept of creating thin planar microwave antennas from microstrip substrates is rapidly establishing itself as an important new antenna design technique, but the extraneous radiation that is emitted from the antenna/feed transition region is now recognized as a severe constraint on the achievable side‐lobe level performance of these antennas. Consideration is now given to the determination of the extent of this limitation and to how the extraneous radiation loss can be reduced. Two types of microwave feeds, the coax/microstrip and the triplate/microstrip, are analyzed using a variational method, and approximate field representations are introduced to obtain estimates of the radiation associated with these feeds. The computed results for polyguide and alumina substrates are examined in the light of the limited amount of independent experimental evidence available and the usefulness of the estimations endorsed.