Search

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. [ABSTRACT FROM AUTHOR]

A novel frequency reconfigurable multiple-input multiple-output (MIMO) antenna, operating in triple and dual band, is presented for wireless local area networks (WLAN). The proposed antenna comprises of two planar inverted F antenna (PIFA) elements integrated with two PIN diodes. When diodes are ON, the proposed antenna operates at 2.4, 5.2 and 5.8 GHz with a maximum frequency ratio of 2.41. When diodes are OFF, it operates at 5.2 GHz, 5.8 GHz with a frequency ratio of 1.11. Meander line resonator and T slot achieve good isolation amid PIFA elements. The simulated and experimental characteristics are in good agreement. [ABSTRACT FROM AUTHOR]

In this paper, a dual band planar inverted F antenna (PIFA) has been investigated for cooperative on- and off-body communications. Free space and on-body performance parameters like return loss, bandwidth, radiation pattern and efficiency of this antenna are shown and investigated. The on- and off-body radio propagation channel performance at 2.45 GHz and 1.9 GHz have been investigated, respectively. Experimental investigations are performed both in the anechoic chamber and in an indoor environment. The path loss exponent has been extracted for both on- and off-body radio propagation scenarios. For on-body propagation, the path loss exponent is 2.48 and 2.22 in the anechoic chamber and indoor environment, respectively. The path loss exponent is 1.27 for off-body radio propagation situation. For on-body case, the path loss has been characterized for ten different locations on the body at 2.45 GHz, whereas for off-body case radio channel studies are performed for five different locations at 1.9 GHz. The proposed antenna shows a good on- and off-body radio channel performance.

The purpose of this paper is to calculate the reduction of specific absorption rate (SAR) with a new design of square metamaterials (SMMs). The finite-difference time-domain (FDTD) method with lossy-Drude model is adopted in this analysis. The method of SAR reduction is discussed and the effects of location, distance, and size of metamaterials are analyzed. SMMs have achieved a 53.06% reduction of the initial SAR value for the case of 10 gm SAR. These results put forward a guideline to select various types of metamaterials with the maximum SAR reducing effect for a cellular phone.

ABSTRACT To meet antenna design specifications under realistic conditions, electromagnetic coupling effects between the antenna and its environment must be considered. In this work, an efficient antenna design optimization methodology that considers the influence of the human head and main mobile handset components on the antenna performance is presented. The computational optimization time is dramatically reduced by exploiting a Broyden-based input space mapping (SM) algorithm. Both coarse and fine models required for the SM algorithm are based on the finite-element method and are implemented in the same simulator; simplifying the modeling process. However, our coarse model does not consider any object of the actual operational environment. In spite of that and other simplifications applied to the coarse model, the proposed optimization scheme is able to find a solution that meets the specifications in a realistic environment by performing an extremely small number of expensive fine model simulations. Our practical illustration opens up the feasibility of using this CAD methodology to optimize other RF devices that operate in close proximity to objects that affect its desired response, as it is the case for many wearable devices. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:121-128, 2016. [ABSTRACT FROM AUTHOR]

A simple internal antenna that combines a planar inverted F antenna (PIFA) and a loop antenna to achieve wideband (BW ∼ 48%) operation in ultra‐high frequency (UHF: 470–771 MHz) band for digital television (DTV) applications is presented. The design allows the installation of an antenna within a TV model, thereby addressing the limitations of space. The 49‐inch DTV is used for the practical implementation experiment. The TV bezel (made of polycarbonate‐acrylonitrile butadiene styrene (PC‐ABS): εr = 3.5; tan δ = 0.005) is used as the substrate for the antenna design. The antenna is placed on the top edge of the TV model. With the combination of the PIFA mode and loop mode operations, the operating bandwidth of the proposed PIFA‐loop antenna is significantly broadened. The measured results show that the proposed antenna has wide bandwidth of about 410 MHz (460–870 MHz) and suitable radiation performance with higher than 2.2 dBi of peak gain and 47% of efficiency within the operating bandwidth. [ABSTRACT FROM AUTHOR]

In this paper, a dual band planar inverted F antenna (PIFA) has been investigated for cooperative on- and off-body communications. Free space and on-body performance parameters like return loss, bandwidth, radiation pattern and efficiency of this antenna are shown and investigated. The on- and off-body radio propagation channel performance at 2.45 GHz and 1.9 GHz have been investigated, respectively. Experimental investigations are performed both in the anechoic chamber and in an indoor environment. The path loss exponent has been extracted for both on- and off-body radio propagation scenarios. For on-body propagation, the path loss exponent is 2.48 and 2.22 in the anechoic chamber and indoor environment, respectively. The path loss exponent is 1.27 for off-body radio propagation situation. For on-body case, the path loss has been characterized for ten different locations on the body at 2.45 GHz, whereas for off-body case radio channel studies are performed for five different locations at 1.9 GHz. The proposed antenna shows a good on- and off-body radio channel performance. [ABSTRACT FROM AUTHOR]

ABSTRACT A wideband dual polarized planar inverted F antenna-based 16 × 20 multi-input multi-output (MIMO) antenna cube with radome is designed and developed with an aim to achieve high data rate (>1 Gbps) wireless link in an urban street grid scenario. Developed antenna is mechanically stable and has a volume of 1.8λo3. All the elements have a wide impedance bandwidth from 2.4 to 2.8 GHz (VSWR < 1.6), low mutual coupling (<−15 dB) with almost hemispherical coverage (120° beam width) and peak gain of 3 dBi. MATLAB codes were generated to calculate mean effective gain (MEG), envelop correlation and channel capacity using simulated and measured values of antenna parameter. For urban street grid line of sight case, expected channel capacity of our 16 × 20 MIMO cube antenna is 80 b/s/Hz at 30-dB SNR, with MEG (0 dB) and envelop correlation coefficient less than 0.7. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:685-690, 2015 [ABSTRACT FROM AUTHOR]

ABSTRACT In this article, multiband fractal planar inverted F antenna with two folded edges is designed and fabricated. The proposed antenna resonates at two different bands of frequencies with lower band at frequency 2.25-2.863 GHz and upper band at frequency 4.81-6.21 GHz. The proposed design offers broad bandwidth of (613-MHz impedance bandwidth) 25% at lower band and (impedance bandwidth 1400 MHz) 26.4% bandwidth at upper band of frequency. The gain of antenna at lower frequency band (centered at 2.45 GHz) is 3.8 dBi and the gain at upper frequency band (centered at 5.3 GHz) is 7.2 dBi. The overall dimensions of the proposed antenna are 19.8 × 19.8 mm2. The antenna patch is folded under itself to achieve compactness in design and also to configure frequency of resonance for antenna. The designed antenna is best candidate for the WiFi, LTE, WiMAX, and WLAN applications in mobile phones. The antenna is fabricated and results are compared with simulation results. The measured and simulated results shows good agreement for proposed design proves validity of design for practical usage. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2836-2841, 2014 [ABSTRACT FROM AUTHOR]

ABSTRACT Two enhancements, size reduction and impedance bandwidth improvement, for a multiband antenna for mobile handsets are presented. The size of the designed antenna can be significantly reduced by inserting chip inductors, whereas the impedance bandwidth can be enhanced with a chip capacitor. Measurements demonstrate that the proposed antenna possesses frequencies of 130 MHz (2.39-2.52 GHz) and 1.3 GHz (5.06-6.36 GHz) with a voltage standing wave ratio of 2. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2841-2844, 2013 [ABSTRACT FROM AUTHOR]

ABSTRACT Low specific absorption rate (SAR) compact hexaband planar inverted-F antenna (PIFA) with independent resonant frequency control has been studied in this letter. Two trapezoidal-shaped slots are etched on the coplanar waveguide-fed PIFA-radiating plate to create two independent resonant frequencies as well as the fundamental PIFA itself. Three coupled slots are added within the ground plane to create an additional three independent resonant frequencies with slight effect on the other resonant frequencies. Multiband capabilities with bandwidth enhancement and acceptable SAR values are realized for different wireless communication applications. The SAR in the presence of human head is investigated by using CST 2012 Microwave Studio Hugo Voxil Model. The proposed antennas are fabricated, and there is a good agreement between measured and simulated results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1802-1810, 2013 [ABSTRACT FROM AUTHOR]

In this work, genetic algorithm is used to optimize the ground plane shape of planar inverted F antenna on FR-4 substrate designed for broadband applications. Novel optimized antennas were presented. A relative bandwidth about 88% was obtained with the optimized antenna. With this procedure the total bandwidth increased more than 2.5 times relatively the total bandwidth of the not optimized antenna. However, the dimensions and the cost did not increase. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2842-2845, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27174 [ABSTRACT FROM AUTHOR]

A planar inverted F antenna (PIFA) is integrated with a software-defined match control (SDMC) circuit in order to create an impedance match for a diverse set of frequency standards. The individual PIFA achieves better than -10 dB reflection coefficient for a 13.6% bandwidth at 2.45 GHz. The SDMC is a microstrip circuit with tuning diodes that are adjusted to tune the input impedance of the antenna and to select a targeted frequency range of operation. It is both an antenna impedance tuner and tunable filter. This paper discusses the design approach for the system and presents simulated and measured results. The results show that the combined antenna and SDMC can be tuned to operate at many worldwide frequency ranges even when the individual PIFA is not specifically matched to the frequencies. [ABSTRACT FROM AUTHOR]

In this letter, a novel method that can achieve critical coupling in a planar inverted F-antenna of high height is proposed. Theproposed antenna can achieve critical coupling by attachment of a ferrite sheet without changing the size of the antenna or ground plane. A ferrite sheet is used to increase shunt inductance of the shorting pin loop. The proposed antenna is modeled by an equivalent circuit based on transmission line modeling. It has a very wide bandwidth of 16% for a voltage standing wave ratios <2. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 400–403, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24950 [ABSTRACT FROM AUTHOR]

The antennas must work in several bands in multi-band systems, and the size must be compact enough. Based on it, a new compact triple-band (GSM/DCS/ISM) planar inverted-F antenna (PIFA) was presented and a prototype was constructed and studied. The S11 parameters were measured, and the bandwidths are 3.4%, 10.3%, and 2.1% for corresponding band, respectively. For real use, the presence of the plastic case and the hand were considered, and the resulting data of the influence were measured and discussed. The radiation patterns and gains in free space were also measured, which show that this type of PIYA is suitable for multi-band mobile communication applications. [ABSTRACT FROM AUTHOR]