Patch antenna directivity analysis using an equi-area method

The widespread exploitation of mobile cellular phones and use of wireless devices such as PDAs, in-vehicle Global Positioning System (GPS) receivers, and the future deployment of mobile satellite digital audio and video has developed a re-energized interest in efficient and accurate measurement techniques for antennas. This paper demonstrates directivity analysis of a patch antenna using a new fast, rotation-invariant spherical near-field antenna measurement technique. The method is based on an equi-area surface partitioning algorithm. The paper evaluates the sampling technique’s performance when compared with a normal spherical near-field measurement technique using equal angle sampling

Design and parametric analysis of a dual band frequency reconfigurable planar dipole using a dual band artificial ground plane

This paper presents the design of dual-band frequency reconfigurable fork shape planar dipole in the industrial, scientific and medical (ISM) band (2.4 and 5.2 GHz). The proposed antenna can be used for wireless local area network (WLAN) applications. Antenna operates in dual-band as well as single-band mode depending on switching combination. The proposed antenna gives bandwidth of 12.5% and 6.7% for 2.4 GHz and 5.2 GHz, respectively, in dual-band mode while 15.5% for 2.4 GHz in single-band mode. The performance of the antenna is analysed with a ground-free substrate and traditional perfect electric conductor (PEC) ground plane. The same antenna is mounted on a dual-band slotted mushroom-type electromagnetic bandgap (EBG) surface which improves the return loss of the antenna in both bands by 25 dB w. r. t. the PEC-based dipole antenna. The proposed antenna can be used in WLAN applications. The simulations were carried out in SEMCAD and CST MWS

Design and analysis of a novel tri-band flower-shaped planar antenna for GPS and WiMAX applications

This paper presents the design of a tri-band flower-shaped planar monopole antenna operating at three frequencies i.e. 1.576 GHz (GPS), 2.668 GHz and 3.636 GHz (Mobile WiMAX). The radiating element of the antenna is backed by a 1.6 mm thicker FR-4 substrate having a dielectric constant of 4.3. The substrate is backed by a truncated ground plane. The antenna is fed through a 50 Ω microstrip line. The flower shape of the radiating element is derived from the basic circular shape by introducing in it rounded slots of various radii. The upper part of the antenna is flower-shaped while the lower part comprises a microstrip feed line and two branches, each having two ‘leaves’ at the end. The leaves and branches contribute in the impedance matching of the lower (1.576 GHz) and middle (2.668 GHz) frequency bands. The antenna gives an acceptable simulated efficiency >70% in the three frequency bands. Suitable gains of 1.63, 2.59 and 3.23dB are obtained at 1.576 GHz, 2.668 GHz and 3.636 GHz, respectively. The antenna matched with a VSWR<1.2 in the three frequency bands. The prototype of the antenna is fabricated and tested in the laboratory, and good agreement in simulated and measured results is achieved. The proposed design is a visually appealing and may find uses as an external antenna in GPS and WiMAX applications

Design and SAR analysis of wearable antenna on various parts of human body, using conventional and artificial ground planes

This paper presents design and specific absorption rate analysis of a 2.4 GHz wearable patch antenna on a conventional and electromagnetic bandgap (EBG) ground planes, under normal and bent conditions. Wearable materials are used in the design of the antenna and EBG surfaces. A woven fabric (Zelt) is used as a conductive material and a 3 mm thicker Wash Cotton is used as a substrate. The dielectric constant and tangent loss of the substrate are 1.51 and 0.02 respectively. The volume of the proposed antenna is 113×96.4×3 mm3. The metamaterial surface is used as a high impedance surface which shields the body from the hazards of electromagnetic radiations to reduce the Specific Absorption Rate (SAR). For on-body analysis a three layer model (containing skin, fats and muscles) of human arm is used. Antenna employing the EBG ground plane gives safe value of SAR (i.e. 1.77W/kg2W/kg). The efficiency of the EBG based antenna is improved from 52 to 74%, relative to the conventional counterpart. The proposed antenna can be used in wearable electronics and smart clothing

Design and measurement of metamaterials based antennas

Design and measurement of metamaterials based antenna

Patch antenna directivity analysis using an equi-area method

The widespread exploitation of mobile cellular phones and use of wireless devices such as PDAs, in-vehicle Global Positioning System (GPS) receivers, and the future deployment of mobile satellite digital audio and video has developed a re-energized interest in efficient and accurate measurement techniques for antennas. This paper demonstrates directivity analysis of a patch antenna using a new fast, rotation-invariant spherical near-field antenna measurement technique. The method is based on an equi-area surface partitioning algorithm. The paper evaluates the sampling technique’s performance when compared with a normal spherical near-field measurement technique using equal angle sampling

A novel FSS for gain enhancement of printed antennas in UWB frequency spectrum

This paper presents a novel compact unilayer frequency selective surface (FSS) for ultra-wideband (UWB) applications particularly for gain enhancement of printed antennas. The proposed FSS unit cell consists of simple metallic patterns printed on both sides of 14 mm × 14 mm FR4 substrate. The proposed FSS has very low transmission co-efficient and linearly decreasing reflection phase over the bandwidth of 9 GHz in 3–12 GHz range, which makes it suitable candidate to provide in-phase reflection for UWB antennas. For the validation of gain-enhancement capability, the FSS is paired with a general monopole UWB antenna demonstrating an average gain improvement of 4 dB. The antenna composite has a maximum gain of 8.9 dBi