Topic
Helical antenna
About: Helical antenna is a research topic. Over the lifetime, 5650 publications have been published within this topic receiving 71572 citations.
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TL;DR: In this article, a planar circular disc monopole has been demonstrated to provide an ultra wide 10 dB return loss bandwidth with satisfactory radiation properties, and the parameters which affect the performance of the antenna in terms of its frequency domain characteristics are investigated.
Abstract: This paper presents a study of a novel monopole antenna for ultrawide-band (UWB) applications. Printed on a dielectric substrate and fed by a 50 /spl Omega/ microstrip line, a planar circular disc monopole has been demonstrated to provide an ultra wide 10 dB return loss bandwidth with satisfactory radiation properties. The parameters which affect the performance of the antenna in terms of its frequency domain characteristics are investigated. A good agreement is achieved between the simulation and the experiment. In addition, the time domain performance of the proposed antenna is also evaluated in simulations.
948 citations
TL;DR: In this article, a simple formula is proposed to predict the frequency corresponding to the lower edge of the bandwidth for each of these configurations, including square, rectangular, and hexagonal disc monopole antennas.
Abstract: The circular disc monopole (CDM) antenna has been reported to yield wide-impedance bandwidth. Experiments have been carried out on a CDM that has twice the diameter of the reported disc with similar results. New configurations are proposed such as elliptical (with different ellipticity ratios), square, rectangular, and hexagonal disc monopole antennas. A simple formula is proposed to predict the frequency corresponding to the lower edge of the bandwidth for each of these configurations. The elliptical disc monopole (EDM) with ellipticity ratio of 1.1 yields the maximum bandwidth from 1.21 GHz to more than 13 GHz for voltage standing wave ratio (VSWR)<2.
866 citations
TL;DR: In this article, three types of single-feed circularly polarized microstrip antennas, namely, a diagonal fed nearly square, a truncated-corners square and a square with a diagonal slot, are presented.
Abstract: Analysis and optimized designs are presented of three types of single feed circularly polarized microstrip antennas, namely, a diagonal fed nearly square, a truncated-corners square and a square with a diagonal slot. The Green's function approach and the desegmentation methods are used. The resonant frequencies are calculated for two orthogonal modes which together yield circular polarization. Optimum feed locations are determined for the best impedance match to a 50 \Omega coaxial feed line. Axial-ratio bandwidths, voltage standing-wave ratio (VSWR) bandwidths and radiation patterns are evaluated and verified experimentally.
602 citations
TL;DR: In this article, a planar monopole antenna with a staircase shape and small volume (25times26times1 mm3) was proposed for ultrawideband (UWB) systems.
Abstract: A planar monopole antenna with a staircase shape and small volume (25times26times1 mm3) is proposed in this paper. With the use of a half-bowtie radiating element, the staircase-shape, and a modified ground plane structure, the proposed antenna has a very wide impedance bandwidth measured at about 11.6 GHz (2.9-14.5 GHz, bandwidth ratio about 1:5) below VSWR 2 including the WLAN band notched in the vicinity of 5 GHz. An omnidirectional radiation pattern is obtained. The group delay which is an indication of linearity between two proposed antennas is less than 1 ns. The electrical characteristics in terms of frequency and time domains and physical ones of the proposed antenna make it attractive for use in ultrawideband (UWB) systems
433 citations
TL;DR: In this article, an antenna consisting of a resonant dielectric hemisphere on top of a ground plane is investigated, with emphasis on the lowest-order mode that results in efficient radiation in the direction perpendicular to the ground plane.
Abstract: An antenna consisting of a resonant dielectric hemisphere on top of a ground plane is investigated. Calculations of the internal and external fields are made with emphasis on the lowest-order mode that results in efficient radiation in the direction perpendicular to the ground plane. Measured input impedance data are also presented for a practical radiator.
389 citations