Printed Slot Antenna Research Articles

A Novel Design of Small Square Slot Antenna with Circular Polarization Characteristics for X-Band Applications

This article proposes a novel printed slot antenna with circular polarization characteristics for X-band applications. By using a modified L-shaped ring radiating stub, and also by inserting a U-shaped strip with an open stub inside it protruded on the ground plane, additional resonances are excited and, hence, much wider impedance bandwidth can be produced, especially at the higher band. By using these structures, very good axial-ratio bandwidth is obtained. The operating frequencies of 8.213 to over 11.87 GHz with circular polarization characteristics 8.32–10.79 GHz. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behavior within the X-band frequency range. The designed antenna has a small size of 20 × 20 mm2.

Novel F-Shaped Quad-Band Printed Slot Antenna for WLAN and WiMAX MIMO Systems

A novel F-shaped microstrip slot antenna for WLAN and WiMAX multiple-input-multiple-output (MIMO) systems is presented. The proposed antenna structure consists of both open-ended and short-ended slots connected by a metal “via” to a microstrip line. The open-ended slot is exploited to obtain resonant mode at 2.4 GHz, and three short-ended slots are aimed to obtain resonant modes at 3.5, 5.2, and 5.8 GHz, whose center frequencies can be adjust by the slot lengths. The parametric studies show that the center frequencies are independent of each other. A four-element array configuration of the proposed antenna for MIMO applications is also studied. The simulation and measurement results of reflection coefficient, mutual coupling, and radiation pattern are presented, which attest to the applicability of antenna.

Microstrip-Fed Printed Slot Antennas Based on Hilbert-Type Space-Filling Curves for Wireless Communication Systems

In this paper, two microstrip-fed printed slot antennas have been introduced to be used in modern communication systems, as alternatives for conventional Hilbert slot antenna. The slot structures of the proposed antennas are in the form of the 3rd iteration of two variants of the conventional Hilbert space-filling curves. These antennas are fed with 50 Ω microstrip line printed on the reverse side of the slot structure. The proposed antennas have been modelled and analyzed using the method of moments (MoM) based commercially available software, IE3D from Zeland Software Inc,. Simulation results show that all these antennas possess a multi-resonant behavior with a miniature size of about half the guided wavelength. It has been found that the fundamental resonance depends on the external side length of the slot structure, while higher mode resonances are attributed by the smaller self-similar structures the slot pattern contains. Furthermore, amongst the proposed antennas, the antenna with slot structure based on Moore’s space-filling curve, which is a closed version of Hilbert curve, has been found to offer a multiband behavior with enhanced bandwidths around the multiple resonances as compared with the other two antennas based on other Hilbert space-filling variants.

A DESIGN OF MINIATURIZED ULTRA–WIDEBAND PRINTED SLOT ANTENNA WITH 3.5/5.5 GHZ DUAL BAND–NOTCHED CHARACTERISTICS: ANALYSIS AND IMPLEMENTATION

A design and analysis of a novel proximity-fed printed slot antenna with 3.5/5.5GHz dual band-notched characteristics are presented. To obtain an ultra-wideband (UWB) response, a circular patch with a rectangular conjunction arm is etched concentrically inside a ground plane aperture. The antenna is proximity-fed by a microstrip line with an open shunt stub on the other side of the substrate. The designed antenna satisfles a i10dB return loss requirement in the frequency band from 2.7 to 17GHz. In order to obtain dual band-notched properties at 3.5 and 5.5GHz, an open ring slot is etched ofi the circular patch and a …-shaped slot is etched ofi the microstrip feeding line, respectively. A curve fltting formulation is obtained to describe the in∞uences of the notched resonators on the corresponding notched frequencies. The proposed antenna is designed, simulated and fabricated. The measured data show a good agreement with the simulated results and the equivalent circuit results through the use of a modifled Vector Fitting technique for a rational function approximation. The proposed antenna provides almost omnidirectional radiation patterns, relatively ∞at gain and high radiation e-ciency over the entire UWB frequency excluding the two rejected bands.

ACS fed Koch fractal antenna for wide-band applications

A compact Asymmetric Coplanar Strip (ACS) feed modified Koch fractal shape printed slot antenna is presented in this paper. It is suitable for Wireless, WiMax, WiBro and other important frequencies. Here, the operating frequencies of the triangular slot antenna are lowered by the Koch iterations technique resulting in compact antenna. The proposed antenna exhibits wideband frequency response. The simulated -10 dB bandwidth for this resonant frequency is 97.7% in the range of 2.7-7.88 GHz. The antenna exhibit omnidirectional radiation pattern with ≤3 dBi gain for entire band. Parametric study of different antenna is presented and discussed in this paper.

DESIGN OF TEMPLE SHAPE SLOT ANTENNA FOR ULTRA WIDEBAND APPLICATIONS

A novel design of a temple shaped printed slot antenna for circular polarization applications is presented in this paper. The slot, half trapezoidal and half semi-circular in shape, is excited by a 50› CPW feed terminated with a tuning stub. Modiflcations of the initial design for improving return loss and circular polarization characteristics are proposed and discussed. The antenna is very compact (40mm £ 35mm) in size and simple to design. The flnal version of the antenna ofiers an experimentally measured impedance bandwidth of 108%, i.e., from 2.75GHz to 9.25GHz. The 3-dB axial ratio bandwidth achieved is 51.6%, i.e., from 4.6GHz to 7.8GHz. The antenna is further characterized by a peak gain of about 5dB and a relatively stable radiation pattern in the useful band.

AN OPTIMAL DESIGN OF CPW-FED UWB APERTURE ANTENNAS WITH WIMAX/WLAN NOTCHED BAND CHARACTERISTICS

In this paper, a printed slot antenna fed by a co-planar waveguide for ultra wide bandwidth (UWB) with dual notch bands has been presented and discussed. The band notches are realized by etching one C-slot resonator inside a plaque shape exciting stub as well as symmetrically adding a pair of open-circuit stubs at the edge of the slot resulting in dual stop band flltering properties for WiMAX, WLAN application. Surface current distributions are used to analyze the efiects of the slot and open circuit stub. The proposed antenna is fabricated and experimental results show that it has an impedance bandwidth of 2.6{14.34GHz for VSWR • 2, except dual frequency stop-bands of 3.3{3.7, 5.04{6.0GHz. From the simulation results, it is observed that the radiation patterns are omnidirectional in the H- plane and dipole like nature in the E-plane. The gain varies from 3.7dB to 5.7dB over the whole UWB region excluding at notch bands.

Dual band‐notch slot antenna by using a pair of Γ‐shaped slits and Ω–shaped parasitic structure for UWB applications

AbstractIn this article, we present a novel design of dual band‐notch printed slot antenna for ultrawideband (UWB) applications. The antenna consists of a square radiating stub and a ground plane structure with two Γ‐shaped slits and Ω‐shaped parasitic structure, which provides a wide usable fractional bandwidth of more than 145% (3.04–17.13 GHz). To increase the impedance bandwidth of the ordinary slot antenna, we use two L‐shaped parasitic structure in the ground plane that with this structure UWB frequency range can be achieved. Additionally, using two Γ‐shaped slits, a single frequency band‐stop performance can be achieved, also to create the second notch frequency, we combine an inverted U‐shaped strip with two L‐shaped parasitic structure, that using this additional inverted U‐shaped strip, Ω‐shaped parasitic structure can be created. Simulated and measured results obtained for this antenna show that the proposed slot antenna offers two notched bands, around 3.67–4.13 GHz and 5.09–5.97 GHz, covering all the 5.2/5.8 GHz WLAN, 3.5/5.5 GHz WiMAX and 4‐GHz C‐band range. The antenna has a small dimension of 20 × 20 mm2. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:102–105, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27223

A Design of Dual-Frequency Dual-Sense Circularly-Polarized Slot Antenna

A single-feed dual-frequency dual-sense circularly-polarized (CP) printed slot antenna etched on a single substrate is proposed. This antenna is composed of an annular slot and a cross slot, which produce two different frequency bands. The lower band and the upper band are controlled by the annular slot and the cross slot respectively. By introducing asymmetry on both annular slot and cross slot, CP radiation at the two frequencies can be obtained. The method of impedance matching has been discussed in detail. The key parameters of the design are investigated to show how to obtain dual-frequency and dual circular polarization. Two antenna prototypes are fabricated and measured, experimental results show that good CP radiation performances are obtained at both frequencies.

Printed slot antenna for seven-band GSM/UMTS/LTE operation in the internal mobile phone

In this paper, a promising internal printed slot antenna for seven-band operation applied to the mobile phone has been proposed, covering all the five WWAN (namely, Wireless Wide Area Network) bands of GSM850/900/DCS1800/PCS1900/UMTS2100 and two LTE (namely, Long Term Evolution) bands of LTE2300/2500. With the use of slot elements, the presented antenna can be easily printed on an inexpensive FR4 substrate and shows a planar structure for low-profile mobile handsets. The antenna comprises an inverted L-shaped slot and three open-ended monopole slots, and these slot elements are integrated into a compact configuration to occupy a small area of 15 mm 40 mm in the back side of the system circuit board. A 50- microstrip feed line is employed to excite the designed antenna, which is printed on the top side of the PCB (Printed Circuit Board). Details of the antenna design, simulated and measured results on the return loss and radiation characteristics of the proposed antenna are presented and discussed.

Printed Slot and Wire Antennas: A Review

The first part of this paper focuses on printed slot antennas. Starting with discussions of a narrow modified slot and a wide slot fed by a microstrip line, we proceed to a topic of generation of a circularly polarized beam. In addition, a rectangular slot antenna fed by a coplanar waveguide is described. The modification of a rectangular slot into an elliptical slot for enhancing the bandwidth is also presented. The second part of this paper covers wire antennas, first presenting the theoretical treatment and then the radiation characteristics of various configurations. It is described that a multiloop antenna exhibits multiband characteristics; a spiral antenna has wideband characteristics with the help of resistive material; and a helical element, having only the region, radiates a circularly polarized wave. An inverted F-antenna (IFA) backed by an electromagnetic band gap (EBG) reflector and a composite helical and spiral (CHES) antenna are then presented, both radiating a tilted beam. Next, a curl antenna array that has an unrivaled aperture efficiency of more than 90% is introduced.

Band‐notched small square slot antenna for ultra‐wideband applications

AbstractIn this article, a novel printed slot antenna for ultra wideband applications with variable frequency band‐notch characteristic is presented.The proposed antenna consists of a modified radiating stub with a pair of L‐shaped slits and a ground plane with two T‐shaped parasitic structures, which provides a wide usable fractional bandwidth of more than 135% (2.81–5.1 GHz) while showing the band rejection performance in the frequency band of 5 to 6 GHz. By cutting a pair of L‐shaped slits with variable dimensions on the radiating stub frequency band‐stop performance is generated and we can control its characteristics such as band‐notch frequency and its bandwidth. The designed antenna has a small size of 20 × 20 mm2. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behavior within the UWB frequency range. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1138–1143, 2012

High-band UWB通信用単方向性平面スロットアンテナの開発

High-band UWB通信用単方向性平面スロットアンテナの開発

CPW-Fed Cavity-Backed Slot Radiator Loaded With an AMC Reflector

A low profile coplanar waveguide (CPW) fed printed slot antenna is presented with uni-directional radiation properties. The slot antenna radiates above a closely spaced artificial magnetic conducting (AMC) reflector consisting of an array of rectangular patches, a substrate and an electric ground plane. The electromagnetic bandgap (EBG) performance of the cavity structure between the upper conducting surface in which the slot is etched, and the ground plane at the bottom of the reflector, is investigated using an equivalent waveguide feed in the place of a half-wavelength section of the slot antenna. From the reflection coefficient of the equivalent waveguide feed one can determine the frequency band where minimum energy will be lost due to unwanted radiation from the cavity sides. The dimensions of the cavity were found to be very important for minimum energy loss. Experimental results for the final antenna design (with a size of 1.02λ0×0.82λ0×0.063λ0), mounted on a 1.5λ0×1.5λ0 back plate, exhibit a 5% impedance bandwidth, maximum gain in excess of 10 dBi, low cross-polarization, and a front-to-back ratio of approximately 25 dB. This low-profile antenna with relatively high gain could be a good candidate for a 2.4 GHz WLAN application.

Compact UWB Printed Slot Antenna With Extra Bluetooth, GSM, and GPS Bands

A novel compact ultrawideband (UWB) printed slot antenna with three extra bands for various wireless applications is presented. The low-profile antenna consists of an octagonal-shaped slot fed by a beveled and stepped rectangular patch for covering the UWB band (3.1–10.6 GHz). By attaching three inverted U-shaped strips at the upper part of the slot in the ground, additional triple linear polarized bands can be realized covering GPS (1520–1590 MHz), part of GSM (1770–1840 MHz), and Bluetooth (2385–2490 MHz). Simulated and measured results are presented and compared, which shows that the antenna has a stable radiation pattern both at the triple and the whole of the UWB bands.

A DECISION-MAKING MODEL FOR SELECTING THE GSM MOBILE PHONE ANTENNA IN THE DESIGN PHASE TO INCREASE OVER ALL PERFORMANCE

The wireless link between a mobile phone and its surrounding crucially depends on the quality and properties of the mobile phone antenna. The process of antenna selection is a multi-criteria decision-making problem with con∞icting and diverse objectives. In this work, a model was built to select the best GSM mobile phone antenna in the design phase to increase the overall performance in the band. The model includes building an analytic hierarchy structure with a tree of hierarchical criteria and alternatives to ease the decision-making. The antenna options considered were limited to retractable whip antenna, loop chip antenna, monopole antenna, planar inverted F-antenna (PIFA), microstrip patch antenna, and printed slot antenna. An Analytical Hierarchy Process (AHP) was used to assist in building the model and help draw decisions. As a result of the decision making process, the monopole antenna was found to be the best choice for the GSM mobile phone antenna. Expert Choice TM software was used to conduct the experimental assessments. The judgments were found to be consistent, precise and justiflable with narrow marginal inconsistency values. The paper also presents a thorough sensitivity analysis to demonstrate the confldence in the drawn conclusions.

Bandwidth Enhancement of a Printed Slot Antenna With a Pair of Parasitic Patches

A printed microstrip-line-fed slot antenna with a pair of parasitic patches for bandwidth enhancement is proposed in this letter. By using the parasitic patches along the microstrip feed line, an additional resonance is excited, and a good performance of bandwidth enhancement can be obtained. The proposed antenna is designed and manufactured successfully. The measurement shows a good agreement with the simulation. From the measured results, the enhanced impedance bandwidth, defined by voltage standing wave ratio (VSWR) less than 2, is about 136% ranging from 2.1 to 11.1 GHz. In addition, stable and nearly omnidirectional far-field radiation patterns are observed over the entire operating band.

WWAN/LTE printed slot antenna for tablet computer application

AbstractA printed slot antenna comprising two quarter‐wavelength slots of different lengths and a half‐wavelength slot for eight‐band wireless wide area network/long term evolution operation in the tablet computer is presented. The two quarter‐wavelength slots are open slots or monopole slots, and the half‐wavelength slot is aligned in‐between the two quarter‐wavelength slots. The three slots are excited using a two‐strip feedline which is printed on the opposite surface of the printed slots. The proposed three‐slot configuration can lead to two wide operating bands, with the lower one covering the 704–960 MHz band and the upper one covering the 1710–2690 MHz band. Good radiation efficiency for frequencies over the operating bands is obtained. The simulated body specific absorption rate values of the antenna in the bottom face, landscape and portrait orientations to the flat phantom in the body specific absorption rate testing model also meet the limit of 1.6 W/kg for 1‐g tissue. Details of the results are presented. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:44–49, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26509

UWB Printed Slot Antenna With Bluetooth and Dual Notch Bands

A novel technique to add an extra Bluetooth band and dual notch bands simultaneously to a compact ultrawideband (UWB) printed slot antenna is proposed. The UWB slot antenna, covering 3.1-11 GHz, is in the shape of an octagon and is fed by a rectangular patch with a beveled bottom edge. To create an extra band outside the UWB frequency range, centered at the 2.4-GHz Bluetooth band, a quarter-wavelength stub is attached to the high concentrated current area in the ground plane. Two notch bands, centered at 3.5-GHz WiMAX and 5.8-GHz WLAN, are also created by placing two stubs similar to that of the extra band. The proposed antenna has a compact size (23 × 28 mm 2), almost stable radiation pattern, and reflection coefficient of lower than -10 dB across the entire passband. A prototype of the proposed antenna is fabricated, and the measured results are shown to be in good agreement with the simulated results.

A Miniaturized Printed Slot Antenna for Six-Band Operation of Mobile Handsets

A novel miniaturized multiband antenna formed by three folded slots of different lengths cut at the ground plane of the mobile handsets is presented. The proposed antenna can generate six wireless communication bands to cover GSM900/DCS1800/PCS1900/UMTS/2.4-GHz-based WLAN and Satellite DMB bands. Moreover, the antenna has a simple planar structure of small area of only 18×38 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . It is also promising to bend the antenna into an L shape or meander line to reduce its volume occupied inside the mobile handsets. Good radiation characteristics, gain, and radiation efficiency are obtained over these six operating bands.