HIPERLAN Band Research Articles

Compact Ultra-­Wideband Planar Inverted F Antenna on Laminated Paper­-Based Substrate with Reduced Specific Absorption Rate

This paper presents a laminated paper-based Planar Inverted F Antenna (PIFA) for wireless body area network (WBAN) applications. The major challenges like providing adequate thickness, uniformity of surface, and water wet ability associated with paper substrate have been transcended in this antenna design by laminating the substrate with a transparent sheet. The simulated and measured reflection coefficients of the fabricated antenna in free space and on human arm are remarkably good, validating the prototype’s utility. It can operate effectively in GSM, WMTS, GPS, DCS, ISM, WiMAX, HIPERLAN, WLAN, and UWB frequency bands with S11 less than -10 dB and the gain ranging from 0.94 to 9.53 dB (free space) and 1.03 to 6.07 dB (on-body). The electrical size of the proposed antenna is 0.16 λg x 0.12 λg at 0.7 GHz with a group delay below 2.3 ns over the desired frequency bands. The performance characteristics are also investigated on-body and it encompasses most of the desired frequency bands for the body area network. This paper also analyses the specific absorption rate (SAR) of the designed antenna by placing it on a tissue-layered human arm model, which is 0.64 Watt/kg, complying with the SAR safety guidelines.

A Switchable Polarization Slotted WLAN Antenna with DGS for IOT and Medical Applications

This work a 20 X 35 X 0.8 mm3 rectangular polarization reconfigurable antenna with four slots made at the corners of the patch. These four slots give the appropriate extra modes for circular polarization. Switching between LP and CP can be achieved using a PIN diode which is inserted across an L-shaped slit in the plane of the ground. The designed antenna is optimized and analyzed through simulations. The axial ratio (< 3 dB) bandwidth and impedance bandwidth (< -10 dB) are overlapped from 5.15 to 6.25 GHz (19.3%). The prototype antenna is tested for both states of the diode (forward and reverse bias). The working band covers the wireless local area network (IEEE 802.11a) band (5150 – 5350 MHz, 5725 – 5825 MHz) and HIPERLAN band (5450 – 5725 MHz) and a favorable compromise between simulated and tested outcomes. The omnidirectional radiation diagrams of the antenna are suitable for wireless portable medical devices.

Design of a Dual Band On and Off-Body Antenna for Medical Applications

Design of a dual-band Planar Inverted-F Antenna (PIFA) for on-body and off-body communications implementable in medical applications is presented in this paper. Both free-space and on-body performance parameters of this antenna are shown and examined through the simulation process using CST software. This planer inverted F antenna works at ISM band (2.45 GHz, on-body) and HiperLAN band (5.2 GHz, off-body) simultaneously. This proposed PIFA radiates at the ISM frequency band, dual-band is achieved due to the double F slits and radiates at the HiperLAN frequency band as well. Performance parameters such as return loss, bandwidth, radiation pattern, and efficiency on free space of this antenna are examined first. Then the on-body performance parameters of this dual-band PIFA have also been tested on some close proximities such as 4mm, 8mm, and 16mm distance from a modified 3-layers human body model. Comparison and analysis between free space results and on-body results are also shown in this paper. As the proposed antenna reveals significant on-body performances at both ISM and HiperLAN bands, it can be said that this antenna will be suitable to be used in different medical applications.

Microwave characteristics and microstructure of Zn2(Sn1−xTix)O4 for use as a Yagi antenna

The microwave characteristics of Zn2(Sn1−xTix)O4 are studied to determine the feasibility of their use in Yagi antenna. The microwave characteristics of Zn2(Sn1−xTix)O4 are determined using X-ray diffraction (XRD) patterns, Rietveld refinement patterns, and Raman spectra. The relative permittivity (er) of Zn2(Sn0.97Ti0.03)O4 that is sintered at 1250 °C for 4 h is 9.8, the unloaded quality factor (Qu × f) is 47,200 GHz, and it has a temperature coefficient at the resonance frequency (TCF) of − 93 ppm/°C. The proposed Yagi antenna covered the HIPERLAN and UNII bands. A 33.48% bandwidth (return loss < 10 dB) of 5.791 GHz was successfully achieved.

V-Shaped Monopole Antenna with Chichena Itzia Inspired Defected Ground Structure for UWB Applications

Due to rapid growth in wireless communication technology, higher bandwidth requirement for advance telecommunication systems, capable of operating on two or higher bands with higher channel capacities and minimum distortion losses is desired. In this paper, a compact Ultra-Wideband (UWB) V-shaped monopole antenna is presented. UWB response is achieved by modifying the ground plane with Chichen Itzia inspired rectangular staircase shape. The proposed V-shaped is designed by incorporating a rectangle, and an inverted isosceles triangle using FR4 substrate. The size of the antenna is 25 mm×26 mm×1.6 mm. The proposed V-shaped monopole antenna produces bandwidth response of 3 GHz Industrial, Scientific, and Medical (ISM), Worldwide Interoperability for Microwave Access (WiMAX), (IEEE 802.11/HIPERLAN band, 5G sub 6 GHz) which with an additional square cut amplified the bandwidth response up to 8 GHz ranging from 3.1 GHz to 10.6 GHz attaining UWB defined by Federal Communications Commission (FCC) with a maximum gain of 3.83 dB. The antenna is designed in Ansys HFSS. Results for key performance parameters of the antenna are presented. The measured results are in good agreement with the simulated results. Due to flat gain, uniform group delay, omni directional radiation pattern characteristics and well-matched impedance, the proposed antenna is suitable for WiMAX, ISM and heterogeneous wireless systems.

Printed Monopole Diversity Antenna for USB Dongle Applications

A compact printed multiple-input multiple-output antenna is presented for USB dongle application which covers the WLAN (2.4---2.48 GHz), WiMAX (3.4---3.8 GHz), and HiperLAN (4.7---5.83 GHz) bands. The two monopoles are closely spaced on the PCB at distance of about $$ 0.094\,\lambda_{0} $$0.094?0 at lowest resonant frequency. To reduce the mutual coupling between the ports as well as to get the desired operating bands, combination of Ω-shaped neutralization line and L-shaped slots [defected ground structure (DGS)] are used. Due to which aimed frequency bands as well as better than ?14 dB isolation are achieved. The mechanism of neutralization line and DGS are analysed based on the S-parameters and surface current distributions. An equivalent circuit model is also used to understand the mechanism of the neutralization line alone. The envelope correlation coefficient and ratio of mean effective gain are calculated which are found to be well below 0.4 and close to unity, respectively.

Design and performance investigation of a low profile MIMO/Diversity antenna for WLAN/WiMAX/HIPERLAN applications with high isolation

A low profile triband compact multiple input multiple output (MIMO) antenna operating at WLAN, WiMAX, and HIPERLAN bands is presented. The proposed MIMO antenna consists of two planar inverted-F antenna elements located at the top two corners of printed circuit board (PCB). Dimensions of each antenna elements are reduced substantially by employing a meandered line and folded patch structure so that it occupies a small volume of 9 × 8.8 × 5.4 mm3. The proposed antenna consists of three arms namely, Main arm, Side arm 1, and Side arm 2. Each individual arm resonates corresponding to the λ/4 electrical length. Characterization of the antenna is carried out in the mobile environment as well as in user proximity. In the presence of mobile environment which includes liquid crystal display (LCD), Battery, RF components, and plastic housing, the isolation as well as reflection coefficient parameters deteriorated. To avoid the aggravation of S-parameters, two nonradiating folded shorting strips are connected between each antenna element and ground plane of PCB. This folded shorting strip not only improves the isolation between ports but also prevent the deterioration of reflection coefficient parameter. The total efficiency, envelope correlation coefficient, and multiplexing efficiency are studied in the user proximity. The optimized structure is fabricated and measured. The measured S-parameters cover WLAN (2.46–2.6 GHz), WiMAX (3.37–3.75 GHz), and HIPERLAN (5.2–5.87 GHz) based on −10 dB reflection coefficient and −24 dB isolation is achieved between antenna ports. Good agreement is obtained between the simulated and measured results. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:510–521, 2015.

Inverted-F/Slot Integrated Dual-Band Four-Antenna System for WLAN Access Points

A four-antenna system applicable to compact access points of wireless local area network is proposed. The antenna topology integrates an inverted-F antenna and a folded slot antenna in the same space to reduce sizes to 15.5 mm × 7.5 mm. The inverted-F antenna operates in the 5 GHz HiperLAN band and the slot functions in the 2.4 GHz ISM band. Antenna tuning can be done without difficulty because the two are of different antenna types. Four antenna assemblies are placed at corners of a 50 mm × 50 mm board to meet the multi-input multi-output operation needs. Since the element antenna exhibits moderate directivity and the four antennas are arranged in a rotational symmetry, decent isolations are achieved in both operation bands without additional decoupling measures. The antenna structure is fully planar and can be integrated within the printed circuit board, which makes it an attractive candidate for compact access point uses.

A low profile tri‐band diversity antenna for WLAN/WiMAX/HIPERLAN applications with high isolation

ABSTRACTA low profile tri‐band compact multiple input multiple output (MIMO) antenna operating at 2.4 GHz band (2.4−2.485 GHz), 3.4 GHz band (3.25−3.5 GHz), and 5.5 GHz band (5.15−5.85 GHz) for WLAN, WiMAX, and HIPERLAN band is presented, respectively. The proposed MIMO antenna consists of two planar inverted‐F antenna elements located at the top two corners of PCB. Each element dimension is reduced substantially by using a meandered line and folded patch structure with two vertical parasitic strips so that it takes a small volume of 9 × 8.8 × 5.4 mm3. Two nonradiating folded shorting strips are connected between each antenna element and ground plane of PCB to enhance the port isolation. The S‐parameters, mean effective gain, envelope correlation coefficient, effective diversity gain, total efficiency, and peak realized gain are studied. The optimized structure is fabricated and measured. Good agreement is obtained between the simulated and measured results. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:452–457, 2015

Modeling and Simulation of Sierpinski Pentagon Fractal Antennas

Measurements of fractal shaped antennas are not enough to understand their physical behavior and there are antenna characteristics that can not be obtained by present day measurement techniques. Therefore, in the present work, the Ansoft HFSS finite element electromagnetic computer package was used to model, simulate and analyze the Sierpinski pentagon monopole microstrip patch fractal antenna and its complementary. The simulation results for both antennas show good matching with their feeds in the frequency range (2 GHz–12 GHz) and indicate that they can operate in the UMTS (2000 MHz–2200 MHz), Bluetooth (2400 MHz–2480 MHz), WLAN (2.4 GHz) and HIPERLAN (5.2 GHz) bands. Also, the computed results show, in general, good agreement with measured data for the S-parameter and radiation patterns.

Dual-Band Suspended-Plate Wearable Textile Antenna

A novel, dual-band wearable textile antenna fabricated using conductive textiles for operation in both ISM and HiperLAN applications is presented. Its concept is based on the suspended-plate antenna. It features a 60 $\,\times\,$ 45 mm $^2$ rectangular radiating element suspended over a 80 $\,\times\,$ 60 mm $^{2}$ ground plane using a 5-mm foam substrate. The proposed rectangular radiator is modified using slots, slits, and shorting posts to enable dual-band resonance and broad bandwidths in both frequency bands: 277 MHz (2.22–2.48 GHz) in the ISM and 850 MHz (4.95–5.80 GHz) in the HiperLAN band. The antenna radiates unidirectionally, and the ground plane avoids coupling to the users' body. The SP-WTA shows a total efficiency between 67% and 89% and a peak gain of 8.33 dB.

Compact CPW-fed uniplanar antenna for multiband wireless applications

A compact coplanar waveguide (CPW) fed uniplanar antenna for Quad-band applications is presented. The Quad-band operation is realized by imposing various current paths in a modified T-shaped radiating element. The antenna covers GSM 900, DCS 1800, IEEE802.11.a, IEEE802.11.b and HiperLAN-2 bands and exhibits good radiation characteristics. This low profile antenna has a dimension of 32mm×31mm when printed on a substrate of dielectric constant 4.4 and height 1.6mm. Details of design with experimental and simulated results are presented.

A Technique of Bandwidth Enhancement for the Slot Antenna

A new technique is proposed to increase the bandwidth (BW) of a Z-like slot antenna for operation at 2.4 GHz and 5 GHz, over the industrial-scientific-medical (ISM) bands and the Hiperlan2 bands. By splitting two side slots of the Z-like slot antenna into two or three fingers, several additional resonances can be created. After careful optimization of the geometrical parameters of the antenna, the resonances are merged and thus a wide impedance bandwidth is obtained.

STUDIES ON DUAL-BAND MULTI-SLOT ANTENNAS

Abstract—A new technique is proposed to increase the bandwidth (BW) of slot antenna operated at 2.4 GHz and 5 GHz, over the industrial-scientific-medical (ISM) bands and the Hiperlan2 bands. By splitting two side slots of the Z-like slot antenna into two or three fingers, several additional resonances can be created. By properly arranging the geometry of the feeding structure in the multi-slot region, the double-slot and triple-slot antennas have respectively 2.0 and 3.2 times wider bandwidth than the single Z-slot antenna. According to the results, the proposed triple-slot antenna can provide two separated impedance bandwidths of 672 Hz (about 28.3% centered at 2.4 GHz band) and 2752 MHz (about 53.5% centered at 5.2 GHz band), making it easily cover the required bandwidths for WLAN operation in the 2.4 GHz band and 5.2/5.8 GHz bands.

Small Planar Monopole Antenna With a Shorted Parasitic Inverted-L Wire for Wireless Communications in the 2.4-, 5.2-, and 5.8-GHz Bands

A low-profile planar monopole antenna with a shorted parasitic inverted-L wire fed using a microstrip feedline for wireless communications in the wireless local-area network (WLAN) bands is studied. The driven monopole element and shorted parasitic wire can separately control the operating frequencies of two excited resonant modes, which cover the 2.4-, 5.2-, and 5.8-GHz WLAN bands. This antenna design is not only suitable as a monopole antenna but also as a diversity antenna for 2.4-, 5.2-, and 5.8-GHz band operations. The lower mode of the proposed antenna has an impedance bandwidth (2:1 VSWR) of about 188 MHz (2313-2501 MHz), which covers the required bandwidth for 2.4 GHz WLAN band (2400-2484 MHz); on the other band, the upper mode has a bandwidth of about 2843 MHz (3930-6773 MHz) covering the HIPERLAN band (5150-5350 MHz) and 5.8-GHz WLAN band (5725-5852 MHz). For frequencies across the three operating bands, the proposed antenna shows similar monopole-like radiation patterns, and good antenna gain across the operating bands is obtained. Details of the design considerations for the proposed antenna are described, and the experimental results of the antenna performances obtained are presented and discussed.

Design of multiple U‐shaped slot microstrip patch antenna in Hiper‐LAN band

AbstractIn this paper, a multiple U‐shaped slot antenna is described, designed, fabricated, and measured for Hiper‐LAN. The design is based on a U‐shaped slot and two inverted U‐shaped slots. To obtain sufficient bandwidth, a foam layer is inserted between the ground plane and substrate. A measured impedance bandwidth approximately 400 MHz or about 7.6% (VSWR ≤ 1.5) referenced to the center frequency is obtained. The gain is measured at 5.43–4.45 dBi. The experimental far‐field patterns are shown to be broad across the pass band, with the 3‐dB beam width in azimuth and elevation at 58.17° and 66.57°, respectively. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 368–370, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11384

A low‐cost surface‐mount monopole antenna for 2.4/5.2/5.8‐GHz band operation

AbstractA low‐cost surface‐mount monopole antenna obtained by folding a metallic strip onto a low‐profile square‐disk foam base is presented. With a compact size of 10 × 10 × 2 mm3, the antenna can generate two separate wide resonant modes, with the lower mode covering the 2.4‐GHz WLAN band (2400–2484 MHz), and the upper mode covering both of the 5.2‐GHz HIPERLAN band (5150–5350 MHz) and the 5.8‐GHz ISM band (5725–5875 MHz). Good measured antenna gain for operating frequencies across the 2.4/5.2/5.8‐GHz bands is also obtained. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 487–489, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10798

Beamforming strategies for compact arrays in mobile terminals using the exact active element pattern method

AbstractSome beamforming strategies are presented for compact arrays in wireless systems. To rigorously account for mutual coupling, we rely on the exact active element pattern method. By considering a compact and low‐cost array operating in the HiperLAN band, it is shown that the proposed method allows null steering and beam steering. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 201–203, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10557

Low-cost planar rectangular ring antenna for operation in HiperLAN band

A field simulator optimised rectangular-ring microstrip antenna covering the HiperLAN band is described. The proposed design has the advantage of operating with a single feed while avoiding linear polarisation. Measured data from an indoor environment confirm the method of moments (MoM) predictions both with respect to efficiency and with respect to polarisation.