Wideband and UWB antennas for wireless applications. A comprehensive review

A comprehensive review concerning the geometry, the manufacturing technologies, the materials, and the numerical techniques, adopted for the analysis and design of wideband and ultrawideband (UWB) antennas for wireless applications, is presented. Planar, printed, dielectric, and wearable antennas, achievable on laminate (rigid and flexible), and textile dielectric substrates are taken into account. The performances of small, low-profile, and dielectric resonator antennas are illustrated paying particular attention to the application areas concerning portable devices (mobile phones, tablets, glasses, laptops, wearable computers, etc.) and radio base stations. This information provides a guidance to the selection of the different antenna geometries in terms of bandwidth, gain, field polarization, time-domain response, dimensions, and materials useful for their realization and integration in modern communication systems

DUAL WIDEBAND AND HIGH GAIN MICROSTRIP ANTENNA FOR WIRELESS SYSTEM

In this paper dual wideband high gain circular shaped microstrip antenna with modified ground plane is presented for wireless communication systems. The overall dimension of the proposed antenna is 50 x 40 x 1.6 mm3. The radiating element consists of circular shaped patch which is excited by microstrip feed-line printed on FR4 epoxy substrate. The ground plane is on the other side of the substrate having a rectangular ring shape to enhance the peak gain of the antenna. The proposed antenna exhibits two wide fractional bandwidths (based on ≤ -10 dB) of 61.1% (ranging from 2.0 to 3.8 GHz, centred at 2.88 GHz) and 53.37% (ranging from 5.48 to 9.6 GHz, centred at 7.44 GHz). The measured peak gain achieved is 8.25 dBi at 8.76 GHz. The measured impedance bandwidth and gain suffice all the commercial bands of wireless systems such as 4G LTE band-40, Bluetooth, Wi-Fi, WLAN, WiMAX, C-band, and X-band. The measured results are experimentally tested and verified with simulated results. A reasonable agreement is found between them

Planar Antennas

This article reviews the state of the art in broadband antennas for emerging UWB applications and addresses the important issues of the broadband antenna design for UWB applications. First, a variety of planar monopoles with finite ground planes are reviewed. Next, the roll antennas with enhanced radiation performance are outlined. After that, the planar antennas printed on PCBs are described. A directional antipodal Vivaldi antenna is also presented for UWB applications. Last, a UWB antenna for wearable applications is exemplifie

Wideband Reconfigurable Rolled Planar Monopole Antenna

A novel technique to reconfigure the frequency range of a planar monopole antenna is presented. By adjusting the degree of spiral tightness, a shift of the well-matched operating frequency range is achieved. The proposed antenna is capable of covering the frequencies in the range from 2.9 to 15 GHz, depending on the degree of spiral tightness. The antenna yields a high-efficiency across the full operating bandwidth. Radiation patterns show good omni-directional features in all primary cuts and remain relatively stable with the change of antenna configuration, so that it is a remarkable candidate for indoor or mobile applications where a large frequency range and omnidirectional radiation are required

A Compact Shorted Printed Monopole Antenna for TV White Space Trials

This paper presents a compact shorted printed monopole antenna for machine-to-machine, remote sensing and rural wireless applications in the TV whitespace band from 470 MHz to 862 MHz. The antennas performance in this operating band is demonstrated

A Printed Triangular Monopole with Wideband Circular Polarization

A printed triangular monopole antenna with wideband circular polarization is presented. The wideband circular polarization is achieved by asymmetrical excitation of a triangular ground plane and planar triangular monopole. The combined radiation provides a wide axial-ratio bandwidth spanning from 1.42 to 2.7 GHz (62%). A parametric study of key geometric parameters is given for clear understanding of the radiation mechanism

Design Method for Wideband Circularly Polarized Slot Antennas

A compact ultrawideband (UWB) circularly polarized (CP) slot antenna is proposed with a methodology for automated reoptimization for packaging with proprietary devices. The slot structure employs a dual-feed with an integrated compact UWB phase shifter. The design process involves an advanced optimization algorithm and demonstrates the use of spline curves for generation of CP signals. These allow easy optimization, while preserving phase coherency across a wideband. The prototyped antennahas a CP bandwidth of 54% (from 3.2 to 6.1 GHz)

State-of-the-Art of Metamaterials: Characterization, Realization and Applications

Metamaterials is a large family of microwave structures that produces interesting ε and μ conditions with huge implications for numerous electromagnetic applications. Following a description of modern techniques to realize epsilon-negative, mu-negative and double-negative metamaterials, this paper explores recent literature on the use of metamaterials in hot research areas such as metamaterial-inspired microwave components, antenna applications and imaging. This contribution is meant to provide an updated overview of complex microwave engineering for the generation of different types of metamaterials and their application in topical electromagnetic scenarios

Dual Band LTE Planar Inverted-F Antenna for M2M Applications

A Planar Inverted-F Antenna for M2M applications is presented. The antenna is located on a rectangular ground plane and operates across both LTE frequency bands (690-960 MHz) and (1710-2690 MHz). The low cost antenna has omni-directional characteristics. The efficiency is better than 86% in both bands and the gain is more than 1.38 dBi across the whole frequency range. A parametric study of key geometrical parameters is reported