Compact Ultra-wideband Antenna Research Articles

CPW-fed compact thin-film UWB antenna with dual band-notched characteristics

This paper presents a new compact thin-film ultrawideband (UWB) antenna with dual band-notched characteristics. The antenna contains a rectangular slot with a fork-like tuning stub. To achieve the dual band-notched characteristics, narrow and U-shaped slots are inserted on the radiator. This antenna is printed on a Mylar film substrate of 0.3 mm thickness with a dielectric constant of 3.2. The antenna has compact dimensions of 34.5 × 27.3 mm2. It operates in the frequency range 2.9–11.3 GHz with impedance matching covering the entire bandwidth and reasonable radiation properties. It also exhibits dual band-notched characteristics. One of the notched frequencies is in the range 3.3–3.7 GHz (WiMAX band) and the other in the range 5.1–5.8 GHz (WLAN band). The antenna is designed and simulated by using the commercial IE3D software, which is based on the method of moments. The antenna was fabricated and measured using Agilent E363B PNA network analyzers. The characteristics of the fabricated antenna show high correlation with those obtained from the simulation. The results confirm that the proposed antenna can achieve notch performance for WLAN and WiMAX communication systems and is also suitable for various portable UWB applications. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

A Compact Triple Band-Notched UWB Antenna Using Sinusoidal EBG

In this paper, a compact (17.7 mm 12 mm) triple band-notched UWB antenna is presented. For inserting desirable notches, three concentric ring resonators have been placed on the back side of antenna in a manner that the first resonance frequency of each resonator coincides with one of the desired notches. Considering that the second resonance frequency of outer ring resonator places in UWB frequency band, an EBG using sinusoidal variation of the characteristic impedance of outer resonator is used to reject the spurious notch. CST simulation results verify good performance of the antenna and show acceptable frequency and time domain characteristics such as wide frequency band width (3 GHz - 10.3 GHz) with good return loss( greater than 17 dB in most parts of band), fairly deep notches, approximately omnidirectional patterns and low group delay variations. Keywords: Band-notched UWB antenna, electromagnetic band gap (EBG), group delay variation, ultra wide band (UWB).

A Compact UWB and Bluetooth Slot Antenna for MIMO/Diversity Applications

A novel compact pattern diversity slot antenna for ultra-wideband (UWB) and Bluetooth applications is presented. This antenna consists of two modified coplanar waveguides that feed staircase-shaped radiating elements, wherein two different fork-like stubs are placed at the 45° axis. The measured results show that this proposed antenna operates from 2.3 GHz to 12.5 GHz, covering Bluetooth, WLAN, WiMAX, and UWB. The performance of radiation patterns and the corresponding envelope correlation coefficient prove this antenna is suitable for MIMO/diversity systems. Also, the antenna's compact size makes it a good candidate for portable devices.

Compact slot antenna for ultra‐wide band applications

A novel compact ultra-wide band antenna with L-shaped slot is presented. The printed antenna is fed by a microstrip feed line to achieve impedance matching for the SMA connector. The proposed antenna offers 118% bandwidth when printed on a substrate of dielectric constant 4.4 and has an overall dimension of 23.7 × 23.7 × 0.8 mm3. The simulated and measured reflection characteristics of the antenna with the variation of key-parameters along with radiation patterns of the final antenna are presented and discussed. In addition, by decreasing the dimension of radiating patch, band-notched properties in the lower wireless local area network (WLAN) (5.15–5.35 GHz) or higher WLAN (5.725–5.825 GHz) bands are achieved. With the compact size and broadband, this antenna is very suitable for using in a trade-off which has to be taken account for a design of miniaturisation.

Three‐dimensional folded antenna with ultra‐wideband performance, directional radiation and compact size

A compact ultra-wideband (UWB) antenna with directional radiation is presented. The antenna has a low profile and does not need a large ground for its performance. The antenna is based on using a three-dimensional folded structure that is modified using semi-circular slots on bowtie-shaped elements. The antenna's mechanism, its design guidelines and its optimisation are described thoroughly. A prototype of the antenna is fabricated andmeasured for performance verification. The prototype shows 77% fractional bandwidth (centred at 2 GHz) based on 10 dB return loss reference. The equivalent overall size of the prototype is (λeff/3) × (λeff/4) × 0.07λeff (λeff = effective wavelength at the lowest resonant frequency), which proves the compactness of the antenna. The antenna shows unidirectional radiation pattern with around 15 dB front-to-back ratio, -20 dB cross-polarisation in the two principle planes and around 5 dBi gain. The antenna is prescribed for compact UWB applications that use the low 1-3 GHz frequency band.

A compact circular slot UWB antenna with multimode reconfigurable band‐notched characteristics using resonator and switch techniques

AbstractIn this article, we propose a circular slot ultrawideband (UWB) antenna with multimode reconfigurable dual band‐notched characteristics. By using a two‐stage T‐shaped stepped impedance resonator (TS‐TSIR) and a parallel stubs loaded resonator (PSLR), dual band‐notched function is achieved to reject worldwide interoperability for microwave access, WLAN, and X‐band signals. The multimode reconfigurable band‐notched characteristic is realized by integrating four switches onto the TS‐TSIR and the PSLR. Simulated and measured results show that this antenna, with multimode reconfigurable characteristics and dual band‐notched function, can operate from 2.7 to 12 GHz (VSWR<2), which includes the entire UWB band. This antenna maintains omnidirectional radiation patterns that is suitable for UWB applications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:570–574, 2014

Design of a Compact UWB Antenna with Triple Band-Notched Characteristics

A new compact ultra-wideband (UWB) antenna with triband-notched characteristics is presented. The structure of the proposed antenna is simple and symmetric. A modified ground is introduced to obtain a wide impedance bandwidth of 2.9–13.4 GHz withS11<-10 dB. By inserting two arc-shaped slots in the radiation patch, two sharp bands of 3.3–3.7 GHz and 5.15–5.35 GHz are notched. The notch band of 7.25–7.75 GHz is achieved by etching a U-shaped slot in the ground plane. The notched bands can be controlled, respectively, while the characteristics of the proposed UWB antenna almost keep completely unchanged at the unnotched frequencies. Equivalent circuit models, surface current distributions, and input impedance are applied to analyze the principle of the proposed UWB antenna. Parametric studies are given. Simulated and measured results show that the proposed antenna has good impedance matching, stable radiation patterns, and constant gain.

ANALYSIS OF CPW-FED UWB ANTENNA FOR WIMAX AND WLAN BAND REJECTION

A compact ultra wide band (UWB) antenna with dual band notch characteristics is proposed. The antenna consists of a coplanar waveguide (CPW) fed bevelled rectangular patch and a modifled rectangular ground plane. A Z-shaped meander line parasitic element and a pair of symmetrical L-shaped quarter-wavelength stubs are employed to realise band-notched functions at WiMAX and WLAN bands respectively. By optimizing the dimensions and positions of these notch structures, the desired notch-bands of WLAN and WiMAX are achieved. Unlike other dual band-notched antennas reported in literature this antenna has a merit of regulating the centre frequency as well as the bandwidth of both the notched bands easily and independently. The measured i10dB S11 covers the bandwidth from 2.5 to 11.5GHz, with two notched bands from 3.3 to 3.6GHz and 5.2 to 5.75GHz. The proposed antenna exhibits nearly omni-directional radiation patterns with moderate gain and small group delay variations less than 0.5ns over the entire operating bandwidth except at the notched bands. Moreover, by using antenna transfer function, the time domain characteristic of the antenna is also studied to conflrm its suitability for UWB pulse communication.

Wideband Monopole Antenna With Three Band-Notched Characteristics

A configuration of multiband and compact ultrawideband (UWB) antenna is present. The antenna is printed on a dielectric substrate and fed by microstrip line. The dimensions of square slots etched into the microstrip feedline can be used to tune the antennas' band-notch and bandwidth characteristics. This antenna is designed to cover the bandwidth for UWB applications (3.1-10.6 GHz) with a VSWR lower than 2 and provide sufficient rejection band notches for WiMAX (3.3-3.88 GHz), WLAN (4.96-6.23 GHz), and ITU (7.9-8.7 GHz). A better gain pattern is realized by inserting slots in the microstrip feedline, compared to the defected structure. Furthermore, by the analysis of the current distribution on the antenna surface, we can deduce the equivalent circuit of the antenna.

A Compact Planar UWB Antenna with Triple Controllable Band-Notched Characteristics

A modified compact planar ultrawideband (UWB) monopole antenna with triple controllable band-notched characteristics is presented in this paper. The proposed antenna consists of a modified stair cased V-shaped radiating element and partial ground plane. The triple band-notched characteristics are achieved by embedding two different vertical up C-shaped slots with a vertical down C-shaped slot in the radiating patch and in the ground plane, respectively. Besides, the bandwidth of each rejected band can be independently controlled by adjusting the dimensions of the corresponding band notched structure. The proposed antenna with rejected bands characteristics is successfully simulated, prototyped, and measured. The measured results show that the antenna operates until upper 11 GHz for voltage standing wave ratio (VSWR) is less than 2, and exhibits bands rejection of 1.6–2.66 GHz (49.76%), 3-4 GHz (28.57%), and 5.13–6.03 GHz (16.12%). Moreover, the proposed antenna shows a near omnidirectional radiation patterns, stable peak gain, and with small group delay and transfer function variation on the whole UWB frequency range except in the notched frequency bands, which makes it suitable for being used in the future UWB applications.

Compact Microstrip Antenna Structures with Multiband, Broadband, and Band-Notched Properties, for Portable Devices

It is difficult to list all the current applications for microstrip antennas; it could be said that they are the transducers that control modern life. Yet, every year, new applications are required which challenge the performance limits of current designs. Some of those challenges are associated with controlling the spectrum performance and continuing to seek techniques to tailor the shape to the applications. This special issue brings some of the latest thinking in compact microstrip antenna design. However, the variety of approaches presented in the papers shows the possibilities that exist for future developments: this special issue is as much about setting out possibilities as it is about presenting new thinking. The papers in this special issue are as follows. An approach to design microstrip antennas is presented in “Design of arbitrarily shaped planar microstrip antenna arrays with improved efficiency” which considers improved radiation efficiency. Focusing on the application areas of Bluetooth and WLAN, a dual-band planar inverted-E antenna (PIEA) is presented in “Compact dual-band planar inverted-eshaped antenna using defected ground structure” with a novel ground. A mesh grid structure planar wideband zero index metamaterial (ZIM) antenna is presented in “Zero index metamaterial for designing high-gain patch antenna” that provides a bandwidth of 9.9GHz to 11.4 GHz.An arc H-shaped slot on the radiating patch provides dual bandnotched characteristics which is discussed in “Design and analysis of a novel dual band-notched UWB antenna.” The paper entitled “Printed modified bow-tie dipole antenna for DVB/WLAN applications” presents a printed modified bow-tie dipole antenna which consists of asymmetric feed and inserted slots. A frequency range of 3.1– 10.6GHz is achieved by an antenna of only 30mm × 36mm and is discussed in “A compact UWB diversity antenna.” Amodified compact planar ultrawideband (UWB) monopole antenna with triple controllable band-notched characteristics is presented in “A compact planar UWB antenna with triple controllable band-notched characteristics,” which consists of a modified staircased V-shaped radiating element and partial ground plane. The radiation pattern is controlled using elliptical and rectangular patches, which is discussed in “A compact size 4–19.1 GHz heart shape UWB antenna with triangular patches.”

A Compact Vivaldi Shaped Partially Dielectric Loaded TEM Horn Antenna for UWB Communication

Ultrawideband (UWB) antennas are of huge demand and Vivaldi antennas as well as the TEM horn antennas are good candidates for UWB applications as they both have relatively simple geometry and high gain over a wide bandwidth. The aim of this study is to design a compact antenna that achieves maximum gain over a bandwidth between 1.5 and 10.6 GHz while minimizing its size. The idea is to make use of combined respective advantages of Vivaldi and TEM horn antennas to achieve the desired goals by shaping the TEM horn antenna to look like a Vivaldi antenna. The antenna structure is modified by a dielectric load in the center to increase the gain bandwidth. It is placed in a surrounding box made of PEC material to reduce the undesired side lobes and to obtain more directive radiation pattern. The simulations are performed by using the CST STUDIO SUITE electromagnetic (EM) simulation software and they are later verified by the actual measurements. The Vivaldi shaped partially dielectric loaded (VS-PDL) TEM horn antenna is proposed as a compact UWB antenna for systems using the newly established UWB band and also for the communication systems of popular bands like ISM, Wi-Fi, and GSM.

Ultra-wideband microwave robust Capon beamforming imaging system for early breast cancer detection

An ultra-wideband (UWB) microwave robust Capon beamforming imaging system is presented based on a self-designed compact UWB antenna for early breast cancer detection. Simulation results show that the proposed detection system is sensitive to tumor response. Simulated tumor detection experiments are carried out in both simple planar breast model and magnetic resonance imagining (MRI)-derived model using the antenna array. Robust Capon beamforming algorithm is employed to reconstruct the breast image. Successful detection of 3-mm-diameter tumor is achieved in the planar model and the same detection result of 4-mm-diameter tumor is achieved in the MRI-derived model. The right information of the tumor can be obtained from the imaging results, which demonstrates the feasibility of the proposed system in early breast cancer detection.

Improved band‐notch techniques for miniature UWB CPW‐fed slot antenna

ABSTRACTThis article describes a compact ultrawideband (UWB) antenna that exhibits desirable band‐notch and gain characteristics. The antenna consists of a rectangular aperture etched on a printed circuit board's ground plane that is excited by a rectangular‐shaped patch. It uses a novel technique comprising of open‐end stubs at the periphery of the ground in the vicinity of the feed‐line to improve its voltage standing wave ratio (VSWR) performance across the UWB. The proposed antenna uses three techniques to provide band‐notch function necessary to eliminate the wireless local‐area network interfering signals between 5 and 6 GHz. The frequency of the band‐notch characteristic can be tuned by varying the parameters defining the notch structure. The antenna was fabricated and its performance measured to validate its feasibility including the band‐notch techniques. A compact 19 × 19 mm2 antenna with aperture area of 9 × 18 mm2 was realized that exhibits an excellent VSWR performance and stable radiation patterns across the UWB spectrum. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:408–415, 2014

Compact UWB Antenna Design for MIMO Applications

In this study, a compact printed Multiple-Input-Multiple-Output (MIMO) antenna with a dimension of 32×70 mm² has been proposed for Ultra-Wideband (UWB) systems applications. The design constitutes of two identical UWB antenna elements, which is etched onto a Taconic TLC-30 printed circuit board. The proposed antenna has been designed and simulated using computer simulation software. For validation purposes, antenna prototype is fabricated and tested. The UWB-MIMO antenna yields an impedance bandwidth of 2.9 to 12 GHz with a return loss of less than-10 dB. Furthermore, the isolation characteristic between the two antenna elements is more than 15 dB within the operating frequency range. The designed structure is found to provide good MIMO/diversity characteristic across the UWB band.

A Compact Ultra-Wideband Monopole Antenna with Dual Bandstop Characteristics

A compact and simple ultra-wideband microstrip-fed planar antenna with double bandstop characteristic is presented. The antenna consists of a rectangular monopole and two W-shaped slots inserted into the radiating patch and the truncated ground plane. By using a W-shaped slot defected ground structure (DGS) in the feedline, a stopband of 800 MHz (from 5.1 to 5.9 GHz) for band rejection of wireless local area network (WLAN) is achieved. To obtain the other stopband (from 3.7-4.4 GHz), a same shaped slot is etched into the monopole. Moreover, the two stopbands can be controlled by adjusting the length of the slot respectively. The simulation results show that the designed antenna, with a compact size of 38.5 mm×42.5 mm, has an impedance bandwidth of 2.811 GHz for voltage standing wave ratio (VSWR) less than 2, besides two frequency stopbands of 3.74.4 GHz and 5.15.9 GHz. Moreover, the main features including omnidirectional H-plane radiation patterns and the appropriate impedance characteristic are achieved by beveling the radiating patch and the microstrip-fed line of the proposed antenna.

Design, Investigation and Measurement of A Compact Ultra Wideband Antenna for Portable Applications

The design of a printed compact planar antenna of asymmetrical structure with ultra wide bandwidth is described and investigated in this paper. The antenna provides more than 114% impedance bandwidth below VSWR 2 (from 3.3 to more than 12 GHz) with a center frequency of 7.65 GHz; thus it covers the bandwidth requirement for portable UWB wireless device applications. The structure of the asymmetric proposed antenna is very simple and composed of a small hexagonal shaped patch with two asymmetrical coplanar ground planes. It occupies an area of only 20 × 24.5 mm2 when printed on one side of an FR4 substrate with a thickness of 1.6 mm.

Compact UWB printed slot antenna with extra UMTS and Bluetooth bands

In this article, a novel compact ultra-wideband (UWB) antenna with two lower pass bands for wireless applications is presented and investigated. The low-profile antenna comprises of a pentagonal shaped patch for covering the UWB band (3.1–10.6 GHz). Two lower pass bands, 2.1 GHz The Universal Mobile Telecommunications System band and 2.4 GHz Bluetooth band, can be realized by etching two meander slots on the both sides of the ground bilaterally and adding a pair of inverted U-shaped stubs attached to the UWB antenna, respectively. The proposed antenna is designed and built on a FR-4 substrate, with a overall size of 26 mm × 37 mm. The simulated and measured results are presented and shown that the proposed compact antenna has a stable and good radiation patterns across all the relevant bands.

A compact ultra wideband antenna with WiMax band rejection for energy scavenging

Radio Frequency (RF) energy harvesting has been rapidly advancing as a promising alternative to existing energy scavenging system. A well designed broadband antenna such as ultra-wideband (UWB) antenna can be used as one of the major components in an RF energy scavenging system. This paper presents a compact UWB antenna showing good impedance matching over a bandwidth of 2.8 to 11 GHz, suiTable for broadband RF energy scavenging. Nevertheless, the antenna usage in wireless communication has a limitation due to the problem of interference between UWB system and other narrowband systems. Thus, the proposed antenna is successfully designed with a single band-notched at the targeted WiMAX operating band of 3.3 to 3.6 GHz.

Compact Ultra-Wideband Antenna for Portable Devices

This article presents a compact ultra-wideband (UWB) antenna for wireless dongle devices. The printed monopole antenna, with the size of 15 mm × 30 mm, has an impedance bandwidth ranges from 2.9 to 13 GHz. The proposed structure comprises of a hexagonal radiator fed by a microstrip line with a modified ground plane. Such a design can be easily integrated with wireless universal serial bus (USB) devices. Having stable radiation patterns and constant gain within the UWB spectrum are significant characteristics of this antenna. The time domain studies on the designed antenna indicate reduced ringing effect for impulse excitation across the band of interest.