We present a modified quasi-Yagi antenna for use in WLAN access points. The antenna uses a new microstrip-to-coplanar strip (CPS) transition, consisting of a tapered microstrip input, T-junction, conventional 50-ohm microstrip line, and three artificial transmission line (ATL) sections. The design concept, mode conversion scheme, and simulated and experimental S-parameters of the transition are discussed first. It features a compact size, and a 3dB-insertion loss bandwidth of 78.6%. Based on the transition, a modified quasi-Yagi antenna is demonstrated. In addition to the new transition, the antenna consists of a CPS feed line, a meandered dipole, and a parasitic element. The meandered dipole can substantially increase to the front-to-back ratio of the antenna without sacrificing the operating bandwidth. The parasitic element is placed in close proximity to the driven element to improve impedance bandwidth and radiation characteristics. The antenna exhibits excellent end-fire radiation with a front-to-back ratio of greater than 15 dB. It features a moderate gain around 4 dBi, and a fractional bandwidth of 38.3%. We carefully investigate the concept, methodology, and experimental results of the proposed antenna.

A Modified Quasi-Yagi Antenna With a New Compact Microstrip-to-Coplanar Strip Transition Using Artificial Transmission Lines

A systematic approach is presented for the design of profiled dielectric rod antennas that satisfy specified radiation pattern objectives. The approach uses a body of revolution method of moments technique to rapidly analyze arbitrarily profiled dielectric rods while a genetic algorithm is used to achieve the design objectives. As examples we present dielectric rod designs optimized for maximum gain and low sidelobes. These designs are compared with a conventional linear profile design. Measured results are presented and these are shown to agree well with the calculated radiation patterns. We show that improved gain and sidelobe performance is achieved using a non-linear rod profile compared to a standard linear profile. The generality of the approach is demonstrated with a shaped beam antenna design that has a cosecant-squared pattern.

Evolved-Profile Dielectric Rod Antennas

Fabry-Perot cavity two-dimensional leaky-wave antennas with polarization-reconfigurable omnidirectional conical beam are proposed. The antenna cavity is bounded by an annular, locally periodic metal partially reflective surface, and is loaded by a dielectric or a wire-medium slab in order to suppress undesired radiation from the fundamental quasi-TEM mode. A suitable design of the partially reflective surface and of the loading slab, based on a dispersion analysis of the linearized structure, allows for equalizing the phase and attenuation constants of the first higher order TM
 1
 and TE
 1
 leaky modes around a given frequency. Omnidirectional beams with full polarization reconfigurability are then achieved through independent excitation of such modes with a pair of azimuthally independent sources. Preliminary designs, aimed at producing a conical beam with circular polarization, are presented and optimized with state-of-art simulation software.

Omnidirectional 2-D Leaky-Wave Antennas With Reconfigurable Polarization

Analytical and numerical approaches are presented for modeling the interaction of azimuthally symmetric fields with omnidirectional metasurfaces, based on the use of locally homogenized equivalent sheet impedances. Radially uniform metasurfaces on layered dielectric media are described in terms of a spectral impedance dyadic, thus allowing for the derivation of the field excited by omnidirectional sources through a simple transmission-line model. In a first approximation, the effect of circular edges in laterally truncated structures is taken into account through an efficient physical- optics method. Then, truncated and radially non-uniform homogenized layered structures are treated numerically with the method of moments, by suitably extending a recently developed spectral-domain formulation. Numerical results are presented for planar radiating structures based on omnidirectional metasurfaces, comparing the radiation patterns obtained through the proposed homogenized models with those calculated by means of full-wave simulations. The discussion emphasizes the validity of the proposed approaches and their usefulness in the analysis of two-dimensional leaky-wave antennas based on printed omnidirectional metasurfaces.

/pdf/omnidirectional-radiation-in-the-presence-of-homogenized-40a0f802yh.pdf

Omnidirectional radiation in the presence of homogenized metasurfaces

An efficient method-of-moments formulation is proposed for the analysis of planar structures in the presence of azimuthally symmetric fields. Boundary integral equations are derived for TM and TE polarizations, assuming as a reference structure a metal plate with a finite number of concentric annular slots placed above a stratified medium. The equations are discretized with a Galerkin testing scheme in the Fourier-Bessel domain, adopting suitable sub-domain basis functions that ensure a very rapid convergence of the involved spectral integrals. Numerical validation is provided by comparison with state-of-art simulation software, considering planar antennas with omnidirectional radiation patterns, in order to show the accuracy of the proposed formulation.

Spectral Method of Moments for Planar Structures With Azimuthal Symmetry

The design of a number of new antennas that radiate linearly polarized toroidal beams is described. The developed procedures are based on the use of a method of moments commercial software tool. Several numerical examples, working at WLAN communication frequencies, are derived and analyzed. Two experimental prototypes validate the numerical results

New Toroidal Beam Antennas for WLAN Communications

This paper is a postprint of a paper submitted to and accepted for publication in journal Electronics Letters and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at IET Digital Library"

Synthesis of multi-radial line antenna for HIPERLAN

Some new antennas that radiate linearly polarized toroidal beams are presented. Two prototypes have been constructed. Their design procedure is based on the use of a method of moments commercial software tool. Very accurate toroidal beams are obtained with large operating relative bandwidths - up to almost 24% in one of the models. Fairly good agreement between calculations and measurements were obtained.

New toroidal beam antennas for WLAN communications: Validation of two prototypes

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

A.G. Roederer

Author Tools

Chat about Author

Papers

New Toroidal Beam Antennas for WLAN Communications

Synthesis of multi-radial line antenna for HIPERLAN

New toroidal beam antennas for WLAN communications: Validation of two prototypes